NEWS revision 1.13
1 This file contains information about GCC releases which has been generated 2 automatically from the online release notes. It covers releases of GCC 3 (and the former EGCS project) since EGCS 1.0, on the line of development 4 that led to GCC 3. For information on GCC 2.8.1 and older releases of GCC 2, 5 see ONEWS. 6 7 ====================================================================== 8 http://gcc.gnu.org/gcc-9/index.html 9 GCC 9 Release Series 10 11 Mar 12, 2020 12 13 The [1]GNU project and the GCC developers are pleased to announce the 14 release of GCC 9.3. 15 16 This release is a bug-fix release, containing fixes for regressions in 17 GCC 9.2 relative to previous releases of GCC. 18 19 Release History 20 21 GCC 9.3 22 Mar 12, 2020 ([2]changes, [3]documentation) 23 24 GCC 9.2 25 Aug 12, 2019 ([4]changes, [5]documentation) 26 27 GCC 9.1 28 May 3, 2019 ([6]changes, [7]documentation) 29 30 References and Acknowledgements 31 32 GCC used to stand for the GNU C Compiler, but since the compiler 33 supports several other languages aside from C, it now stands for the 34 GNU Compiler Collection. 35 36 A list of [8]successful builds is updated as new information becomes 37 available. 38 39 The GCC developers would like to thank the numerous people that have 40 contributed new features, improvements, bug fixes, and other changes as 41 well as test results to GCC. This [9]amazing group of volunteers is 42 what makes GCC successful. 43 44 For additional information about GCC please refer to the [10]GCC 45 project web site or contact the [11]GCC development mailing list. 46 47 To obtain GCC please use [12]our mirror sites or [13]our version 48 control system. 49 50 51 For questions related to the use of GCC, please consult these web 52 pages and the [14]GCC manuals. If that fails, the 53 [15]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 54 web pages and the development of GCC are welcome on our developer 55 list at [16]gcc (a] gcc.gnu.org. All of [17]our lists have public 56 archives. 57 58 Copyright (C) [18]Free Software Foundation, Inc. Verbatim copying and 59 distribution of this entire article is permitted in any medium, 60 provided this notice is preserved. 61 62 These pages are [19]maintained by the GCC team. Last modified 63 2020-03-12[20]. 64 65 References 66 67 1. http://www.gnu.org/ 68 2. http://gcc.gnu.org/gcc-9/changes.html 69 3. http://gcc.gnu.org/onlinedocs/9.3.0/ 70 4. http://gcc.gnu.org/gcc-9/changes.html 71 5. http://gcc.gnu.org/onlinedocs/9.2.0/ 72 6. http://gcc.gnu.org/gcc-9/changes.html 73 7. http://gcc.gnu.org/onlinedocs/9.1.0/ 74 8. http://gcc.gnu.org/gcc-9/buildstat.html 75 9. http://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Contributors.html 76 10. http://gcc.gnu.org/index.html 77 11. mailto:gcc (a] gcc.gnu.org 78 12. http://gcc.gnu.org/mirrors.html 79 13. http://gcc.gnu.org/git.html 80 14. https://gcc.gnu.org/onlinedocs/ 81 15. mailto:gcc-help (a] gcc.gnu.org 82 16. mailto:gcc (a] gcc.gnu.org 83 17. https://gcc.gnu.org/lists.html 84 18. https://www.fsf.org/ 85 19. https://gcc.gnu.org/about.html 86 20. http://validator.w3.org/check/referer 87 ====================================================================== 88 http://gcc.gnu.org/gcc-9/changes.html 89 GCC 9 Release Series 90 Changes, New Features, and Fixes 91 92 This page is a "brief" summary of some of the huge number of 93 improvements in GCC 9. You may also want to check out our [1]Porting to 94 GCC 9 page and the [2]full GCC documentation. 95 96 Caveats 97 98 * On Arm targets (arm*-*-*), [3]a bug in the implementation of the 99 procedure call standard (AAPCS) in the GCC 6, 7 and 8 releases has 100 been fixed: a structure containing a bit-field based on a 64-bit 101 integral type and where no other element in a structure required 102 64-bit alignment could be passed incorrectly to functions. This is 103 an ABI change. If the option -Wpsabi is enabled (on by default) the 104 compiler will emit a diagnostic note for code that might be 105 affected. 106 * Support for a number of older systems and recently unmaintained or 107 untested target ports of GCC has been declared obsolete in GCC 9. 108 Unless there is activity to revive them, the next release of GCC 109 will have their sources permanently removed. 110 The following ports for individual systems on particular 111 architectures have been obsoleted: 112 + Solaris 10 (*-*-solaris2.10). Details can be found in the 113 [4]announcement. 114 + Cell Broadband Engine SPU (spu*-*-*). Details can be found in 115 the [5]announcement. 116 * A change to the C++ std::rotate algorithm in GCC 9.1.0 can cause 117 ABI incompatibilities with object files compiled with other 118 versions of GCC. If the std::rotate algorithm is called with an 119 empty range then it might cause a divide-by-zero error (as a SIGFPE 120 signal) and crash. The change has been reverted for GCC 9.2.0 and 121 future releases. For more details see [6]Bug 90920. The problem can 122 be avoided by recompiling any objects that might call std::rotate 123 with an empty range, so that the GCC 9.1.0 definition of 124 std::rotate is not used. 125 * The automatic template instantiation at link time ([7]-frepo) has 126 been deprecated and will be removed in a future release. 127 * The --with-default-libstdcxx-abi=gcc4-compatible configure option 128 is broken in the 9.1 and 9.2 releases, producing a shared library 129 with missing symbols (see [8]Bug 90361). As a workaround, configure 130 without that option and build GCC as normal, then edit the 131 installed <bits/c++config.h> headers to define the 132 _GLIBCXX_USE_CXX11_ABI macro to 0. 133 134 General Improvements 135 136 The following GCC command line options have been introduced or 137 improved. 138 * All command line options that take a byte-size argument accept 139 64-bit integers as well as standard SI and IEC suffixes such as kb 140 and KiB, MB and MiB, or GB and GiB denoting the corresponding 141 multiples of bytes. See [9]Invoking GCC for more. 142 * A new option, 143 [10]-flive-patching=[inline-only-static|inline-clone], has been 144 introduced to provide a safe compilation for live-patching. At the 145 same time, provides multiple-level control on the enabled IPA 146 optimizations. See the user guide for more details about the 147 option. 148 * A new option, --completion, has been added to provide more fine 149 option completion in a shell. It is intended to be used by 150 Bash-completion. 151 * GCC's diagnostics now print source code with a left margin showing 152 line numbers, configurable with 153 [11]-fno-diagnostics-show-line-numbers. 154 GCC's diagnostics can also now label regions of the source code to 155 show pertinent information, such as the types within an expression. 156 $ g++ t.cc 157 t.cc: In function 'int test(const shape&, const shape&)': 158 t.cc:15:4: error: no match for 'operator+' (operand types are 'boxed_value<doubl 159 e>' and 'boxed_value<double>') 160 14 | return (width(s1) * height(s1) 161 | ~~~~~~~~~~~~~~~~~~~~~~ 162 | | 163 | boxed_value<[...]> 164 15 | + width(s2) * height(s2)); 165 | ^ ~~~~~~~~~~~~~~~~~~~~~~ 166 | | 167 | boxed_value<[...]> 168 169 These labels can be disabled via [12]-fno-diagnostics-show-labels. 170 * A new option [13]-fdiagnostics-format=json has been introduced for 171 emitting diagnostics in a machine-readable format. 172 * The alignment-related options [14]-falign-functions, 173 [15]-falign-labels, [16]-falign-loops, and [17]-falign-jumps 174 received support for a secondary alignment (e.g. 175 -falign-loops=n:m:n2:m2). 176 * New pair of profiling options ([18]-fprofile-filter-files and 177 [19]-fprofile-exclude-files) has been added. The options help to 178 filter which source files are instrumented. 179 * AddressSanitizer generates more compact redzones for automatic 180 variables. That helps to reduce memory footprint of a sanitized 181 binary. 182 * Numerous improvements have been made to the output of 183 [20]-fopt-info. 184 Messages are now prefixed with optimized, missed, or note, rather 185 than the old behavior of all being prefixed with note. 186 The output from -fopt-info can now contain information on inlining 187 decisions: 188 $ g++ -c inline.cc -O2 -fopt-info-inline-all 189 inline.cc:24:11: note: Considering inline candidate void foreach(T, T, void (*)( 190 E)) [with T = char**; E = char*]/2. 191 inline.cc:24:11: optimized: Inlining void foreach(T, T, void (*)(E)) [with T = 192 char**; E = char*]/2 into int main(int, char**)/1. 193 inline.cc:19:12: missed: not inlinable: void inline_me(char*)/0 -> int std::pu 194 ts(const char*)/3, function body not available 195 inline.cc:13:8: optimized: Inlined void inline_me(char*)/4 into int main(int, c 196 har**)/1 which now has time 127.363637 and size 11, net change of +0. 197 Unit growth for small function inlining: 16->16 (0%) 198 199 Inlined 2 calls, eliminated 1 functions 200 201 202 The output from the vectorizer has been rationalized so that failed 203 attempts to vectorize a loop are displayed in the form 204 [LOOP-LOCATION]: couldn't vectorize this loop 205 [PROBLEM-LOCATION]: because of [REASON] 206 207 rather than an exhaustive log of all decisions made by the 208 vectorizer. For example: 209 $ gcc -c v.c -O3 -fopt-info-all-vec 210 v.c:7:3: missed: couldn't vectorize loop 211 v.c:10:7: missed: statement clobbers memory: __asm__ __volatile__("" : : : "me 212 mory"); 213 v.c:3:6: note: vectorized 0 loops in function. 214 v.c:10:7: missed: statement clobbers memory: __asm__ __volatile__("" : : : "me 215 mory"); 216 217 The old behavior can be obtained via a new -internals suboption of 218 -fopt-info. 219 * A new option, [21]-fsave-optimization-record has been added, which 220 writes a SRCFILE.opt-record.json.gz file describing the 221 optimization decisions made by GCC. This is similar to the output 222 of -fopt-info, but with additional metadata such as the inlining 223 chain, and profile information (if available). 224 * Inter-procedural propagation of stack alignment can now be 225 controlled by [22]-fipa-stack-alignment. 226 * Propagation of addressability, readonly and writeonly flags on 227 static variables can now be controlled by 228 [23]-fipa-reference-addressable. 229 230 The following built-in functions have been introduced. 231 * [24]__builtin_expect_with_probability to provide branch prediction 232 probability hints to the optimizer. 233 * [25]__builtin_has_attribute determines whether a function, type, or 234 variable has been declared with some attribute. 235 * [26]__builtin_speculation_safe_value can be used to help mitigate 236 against unsafe speculative execution. 237 238 The following attributes have been introduced. 239 * The [27]copy function attribute has been added. The attribute can 240 also be applied to type definitions and to variable declarations. 241 242 A large number of improvements to code generation have been made, 243 including but not limited to the following. 244 * Switch expansion has been improved by using a different strategy 245 (jump table, bit test, decision tree) for a subset of switch cases. 246 * A linear function expression defined as a switch statement can be 247 transformed by [28]-ftree-switch-conversion. For example: 248 249 int 250 foo (int how) 251 { 252 switch (how) { 253 case 2: how = 205; break; 254 case 3: how = 305; break; 255 case 4: how = 405; break; 256 case 5: how = 505; break; 257 case 6: how = 605; break; 258 } 259 return how; 260 } 261 262 can be transformed into 100 * how + 5 (for values defined in the 263 switch statement). 264 * Inter-procedural optimization improvements: 265 + Inliner defaults was tuned to better suits modern C++ 266 codebases especially when built with link time optimizations. 267 New parameters max-inline-insns-small, max-inline-insns-size, 268 uninlined-function-insns, uninlined-function-time, 269 uninlined-thunk-insns, and uninlined-thunk-time were added. 270 + Hot/cold partitioning is now more precise and aggressive. 271 + Improved scalability for very large translation units 272 (especially when link-time optimizing large programs). 273 * Profile driven optimization improvements: 274 + [29]-fprofile-use now enables [30]-fversion-loops-for-strides, 275 [31]-floop-interchange, [32]-floop-unroll-and-jam, 276 [33]-ftree-loop-distribution. 277 + Streaming of counter histograms was removed. This reduces the 278 size of profile files. Histogram is computed on the fly with 279 link-time optimization. Parameter hot-bb-count-ws-permille was 280 reduced from 999 to 990 to account for more precise 281 histograms. 282 * Link-time optimization improvements: 283 + Types are now simplified prior streaming resulting in 284 significant reductions of the LTO object files, link-time 285 memory use, and improvements of link-time parallelism. 286 + Default number of partitions (--param lto-partitions) was 287 increased from 32 to 128 enabling effective use of CPUs with 288 more than 32 hyperthreads. --param 289 lto-max-streaming-parallelism can now be used to control 290 number of streaming processes. 291 + Warnings on C++ One Decl Rule violations (-Wodr) are now more 292 informative and produce fewer redundant results. 293 Overall compile time of Firefox 66 and LibreOffice 6.2.3 on an 294 8-core machine was reduced by about 5% compared to GCC 8.3, and the 295 size of LTO object files by 7%. LTO link-time improves by 11% on an 296 8-core machine and scales significantly better for more parallel 297 build environments. The serial stage of the link-time optimization 298 is 28% faster consuming 20% less memory. The parallel stage now 299 scales to up to 128 partitions rather than 32 and reduces memory 300 use for every worker by 30%. 301 302 The following improvements to the gcov command-line utility have been 303 made. 304 * The gcov tool received a new option [34]--use-hotness-colors (-q) 305 that can provide perf-like coloring of hot functions. 306 * The gcov tool has changed its intermediate format to a new JSON 307 format. 308 309 New Languages and Language specific improvements 310 311 [35]OpenACC support in C, C++, and Fortran continues to be maintained 312 and improved. Most of the OpenACC 2.5 specification is implemented. See 313 the [36]implementation status section on the OpenACC wiki page for 314 further information. 315 316 C family 317 318 * Version 5.0 of the [37]OpenMP specification is now partially 319 supported in the C and C++ compilers. For details which features of 320 OpenMP 5.0 are and which are not supported in the GCC 9 release see 321 [38]this mail. 322 * New extensions: 323 + [39]__builtin_convertvector built-in for vector conversions 324 has been added. 325 * New warnings: 326 + [40]-Waddress-of-packed-member, enabled by default, warns 327 about an unaligned pointer value from the address of a packed 328 member of a struct or union. 329 * Enhancements to existing warnings: 330 + [41]-Warray-bounds detects more instances of out-of-bounds 331 indices. 332 + [42]-Wattribute-alias also detects attribute mismatches 333 between alias declarations and their targets, in addition to 334 mismatches between their types. 335 + [43]-Wformat-overflow and [44]-Wformat-truncation have been 336 extended to all formatted input/output functions (where 337 applicable) and enhanced to detect a subset of instances of 338 reading past the end of unterminated constant character arrays 339 in %s directives. 340 + [45]-Wmissing-attributes detects instances of missing function 341 attributes on declarations of aliases and weak references. 342 + [46]-Wstringop-truncation also detects a subset of instances 343 of reading past the end of unterminated constant character 344 arrays, 345 * If a macro is used with the wrong argument count, the C and C++ 346 front ends now show the definition of that macro via a note. 347 * The spelling corrector now considers transposed letters, and the 348 threshold for similarity has been tightened, to avoid nonsensical 349 suggestions. 350 351 C 352 353 * There is now experimental support for -std=c2x, to select support 354 for the upcoming C2X revision of the ISO C standard. This standard 355 is in the early stages of development and the only feature 356 supported in GCC 9 is _Static_assert with a single argument 357 (support for _Static_assert with two arguments was added in C11 and 358 GCC 4.6). There are also new options -std=gnu2x, for C2X with GNU 359 extensions, and -Wc11-c2x-compat, to warn for uses of features 360 added in C2X (such warnings are also enabled by use of -Wpedantic 361 if not using -std=c2x or -std=gnu2x). 362 * New warnings: 363 + [47]-Wabsolute-value warns for calls to standard functions 364 that compute the absolute value of an argument when a more 365 appropriate standard function is available. For example, 366 calling abs(3.14) triggers the warning because the appropriate 367 function to call to compute the absolute value of a double 368 argument is fabs. The option also triggers warnings when the 369 argument in a call to such a function has an unsigned type. 370 This warning can be suppressed with an explicit type cast and 371 it is also enabled by -Wextra. 372 373 C++ 374 375 * New warnings: 376 + [48]-Wdeprecated-copy, implied by -Wextra, warns about the 377 C++11 deprecation of implicitly declared copy constructor and 378 assignment operator if one of them is user-provided. 379 -Wdeprecated-copy-dtor also warns if the destructor is 380 user-provided, as specified in C++11. 381 + [49]-Winit-list-lifetime, on by default, warns about uses of 382 std::initializer_list that are likely to result in a dangling 383 pointer, such as returning or assigning from a temporary list. 384 + [50]-Wredundant-move, implied by -Wextra, warns about 385 redundant calls to std::move. 386 + [51]-Wpessimizing-move, implied by -Wall, warns when a call to 387 std::move prevents copy elision. 388 + [52]-Wclass-conversion, on by default, warns when a conversion 389 function will never be called due to the type it converts to. 390 * The C++ front end has experimental support for some of the upcoming 391 C++2a draft features with the -std=c++2a or -std=gnu++2a flags, 392 including range-based for statements with initializer, default 393 constructible and assignable stateless lambdas, lambdas in 394 unevaluated contexts, language support for empty data members, 395 allowing pack expansion in lambda init-capture, likely and unlikely 396 attributes, class types in non-type template parameters, allowing 397 virtual function calls in constant expressions, explicit(bool), 398 std::is_constant_evaluated, nested inline namespaces, etc. For a 399 full list of new features, see [53]the C++ status page. 400 * The C++ front end now preserves source locations for literals, 401 id-expression, and mem-initializer for longer. For example it is 402 now able to pin-point the pertinent locations for bad 403 initializations such as these 404 $ g++ -c bad-inits.cc 405 bad-inits.cc:10:14: error: cannot convert 'json' to 'int' in initialization 406 10 | { 3, json::object }, 407 | ~~~~~~^~~~~~ 408 | | 409 | json 410 bad-inits.cc:14:31: error: initializer-string for array of chars is too long [-f 411 permissive] 412 14 | char buffers[3][5] = { "red", "green", "blue" }; 413 | ^~~~~~~ 414 bad-inits.cc: In constructor 'X::X()': 415 bad-inits.cc:17:13: error: invalid conversion from 'int' to 'void*' [-fpermissiv 416 e] 417 17 | X() : one(42), two(42), three(42) 418 | ^~ 419 | | 420 | int 421 422 rather than emitting the error at the final closing parenthesis or 423 brace. 424 * Error-reporting of overload resolution has been special-cased to 425 make the case of a single failed candidate easier to read. For 426 example: 427 $ g++ param-type-mismatch.cc 428 param-type-mismatch.cc: In function 'int test(int, const char*, float)': 429 param-type-mismatch.cc:8:32: error: cannot convert 'const char*' to 'const char* 430 *' 431 8 | return foo::member_1 (first, second, third); 432 | ^~~~~~ 433 | | 434 | const char* 435 param-type-mismatch.cc:3:46: note: initializing argument 2 of 'static int foo: 436 :member_1(int, const char**, float)' 437 3 | static int member_1 (int one, const char **two, float three); 438 | ~~~~~~~~~~~~~^~~ 439 440 highlights both the problematic argument, and the parameter that it 441 can't be converted to. 442 * Diagnostics involving binary operators now use color to distinguish 443 the two operands, and label them separately (as per the example of 444 source labelling above). 445 * Diagnostics involving function calls now highlight the pertinent 446 parameter of the declaration in more places. 447 $ g++ bad-conversion.cc 448 bad-conversion.cc: In function 'void caller()': 449 bad-conversion.cc:9:14: error: cannot convert 'bool' to 'void*' 450 9 | callee (0, false, 2); 451 | ^~~~~ 452 | | 453 | bool 454 bad-conversion.cc:3:19: note: initializing argument 2 of 'void callee(int, voi 455 d*, int)' 456 3 | void callee (int, void *, int) 457 | ^~~~~~ 458 459 * The C++ front end's implementation of [54]-Wformat now shows 460 precise locations within string literals, and underlines the 461 pertinent arguments at bogus call sites (the C front end has been 462 doing this since GCC 7). For example: 463 $ g++ -c bad-printf.cc -Wall 464 bad-printf.cc: In function 'void print_field(const char*, float, long int, long 465 int)': 466 bad-printf.cc:6:17: warning: field width specifier '*' expects argument of type 467 'int', but argument 3 has type 'long int' [-Wformat=] 468 6 | printf ("%s: %*ld ", fieldname, column - width, value); 469 | ~^~~ ~~~~~~~~~~~~~~ 470 | | | 471 | int long int 472 bad-printf.cc:6:19: warning: format '%ld' expects argument of type 'long int', b 473 ut argument 4 has type 'double' [-Wformat=] 474 6 | printf ("%s: %*ld ", fieldname, column - width, value); 475 | ~~~^ ~~~~~ 476 | | | 477 | long int double 478 | %*f 479 480 * The C++ front end has gained new fix-it hints for forgetting the 481 return *this; needed by various C++ operators: 482 $ g++ -c operator.cc 483 operator.cc: In member function 'boxed_ptr& boxed_ptr::operator=(const boxed_ptr 484 &)': 485 operator.cc:7:3: warning: no return statement in function returning non-void [-W 486 return-type] 487 6 | m_ptr = other.m_ptr; 488 +++ |+ return *this; 489 7 | } 490 | ^ 491 492 for when the compiler needs a typename: 493 $ g++ -c template.cc 494 template.cc:3:3: error: need 'typename' before 'Traits::type' because 'Traits' i 495 s a dependent scope 496 3 | Traits::type type; 497 | ^~~~~~ 498 | typename 499 500 when trying to use an accessor member as if it were a data member: 501 $ g++ -c fncall.cc 502 fncall.cc: In function 'void hangman(const mystring&)': 503 fncall.cc:12:11: error: invalid use of member function 'int mystring::get_length 504 () const' (did you forget the '()' ?) 505 12 | if (str.get_length > 0) 506 | ~~~~^~~~~~~~~~ 507 | () 508 509 for C++11's scoped enums: 510 $ g++ -c enums.cc 511 enums.cc: In function 'void json::test(const json::value&)': 512 enums.cc:12:26: error: 'STRING' was not declared in this scope; did you mean 'js 513 on::kind::STRING'? 514 12 | if (v.get_kind () == STRING) 515 | ^~~~~~ 516 | json::kind::STRING 517 enums.cc:3:44: note: 'json::kind::STRING' declared here 518 3 | enum class kind { OBJECT, ARRAY, NUMBER, STRING, TRUE, FALSE, NULL_ }; 519 | ^~~~~~ 520 521 and a tweak to integrate the suggestions about misspelled members 522 with that for accessors: 523 $ g++ -c accessor-fixit.cc 524 accessor-fixit.cc: In function 'int test(t*)': 525 accessor-fixit.cc:17:15: error: 'class t' has no member named 'ratio'; did you m 526 ean 'int t::m_ratio'? (accessible via 'int t::get_ratio() const') 527 17 | return ptr->ratio; 528 | ^~~~~ 529 | get_ratio() 530 531 In addition, various diagnostics in the C++ front-end have been 532 streamlined by consolidating the suggestion into the initial error, 533 rather than emitting a follow-up note: 534 $ g++ typo.cc 535 typo.cc:5:13: error: 'BUFSIZE' was not declared in this scope; did you mean 'BUF 536 _SIZE'? 537 5 | uint8_t buf[BUFSIZE]; 538 | ^~~~~~~ 539 | BUF_SIZE 540 541 Runtime Library (libstdc++) 542 543 * Improved support for C++17, including: 544 + The C++17 implementation is no longer experimental. 545 + Parallel algorithms and <execution> (requires [55]Thread 546 Building Blocks 2018 or newer). 547 + <memory_resource>. 548 + Using the types and functions in <filesystem> does not require 549 linking with -lstdc++fs now. 550 * Improved experimental support for C++2a, including: 551 + Type traits std::remove_cvref, std::unwrap_reference, 552 std::unwrap_decay_ref, std::is_nothrow_convertible, and 553 std::type_identity. 554 + Headers <bit> and <version>. 555 + Uniform container erasure (std::erase_if). 556 + contains member of maps and sets. 557 + String prefix and suffix checking (starts_with, ends_with). 558 + Functions std::midpoint and std::lerp for interpolation. 559 + std::bind_front. 560 + std::visit<R>. 561 + std::assume_aligned. 562 + Uses-allocator construction utilities. 563 + std::pmr::polymorphic_allocator<std::byte>. 564 + Library support for char8_t type. 565 + Destroying delete. 566 + std::is_constant_evaluated() function. 567 * Support for opening file streams with wide character paths on 568 Windows 569 * Incomplete support for the C++17 Filesystem library and the 570 Filesystem TS on Windows. 571 * Incomplete, experimental support for the Networking TS. 572 573 D 574 575 * Support for the D programming language has been added to GCC, 576 implementing version 2.076 of the language and run-time library. 577 578 Fortran 579 580 * Asynchronous I/O is now fully supported. The program needs to be 581 linked against the pthreads library to use it, otherwise the I/O is 582 done synchronously. For systems which do not support POSIX 583 condition variables, such as AIX, all I/O is still done 584 synchronously. 585 * The BACK argument for MINLOC and MAXLOC has been implemented. 586 * The FINDLOC intrinsic function has been implemented. 587 * The IS_CONTIGUOUS intrinsic function has been implemented. 588 * Direct access to the real and imaginary parts of a complex variable 589 via c%re and c%im has been implemented. 590 * Type parameter inquiry via str%len and a%kind has been implemented. 591 * C descriptors and the ISO_Fortran_binding.h source file have been 592 implemented. 593 * The MAX and MIN intrinsics are no longer guaranteed to return any 594 particular value in case one of the arguments is a NaN. Note that 595 this conforms to the Fortran standard and to what other Fortran 596 compilers do. If there is a need to handle that case in some 597 specific way, one needs to explicitly check for NaN's before 598 calling MAX or MIN, e.g. by using the IEEE_IS_NAN function from the 599 intrinsic module IEEE_ARITHMETIC. 600 * A new command-line option [56]-fdec-include, set also by the 601 [57]-fdec option, has been added to increase compatibility with 602 legacy code. With this option, an INCLUDE directive is also parsed 603 as a statement, which allows the directive to be spread across 604 multiple source lines with line continuations. 605 * A new [58]BUILTIN directive, has been added. The purpose of the 606 directive is to provide an API between the GCC compiler and the GNU 607 C Library which would define vector implementations of math 608 routines. 609 610 Go 611 612 * GCC 9 provides a complete implementation of the Go 1.12.2 user 613 packages. 614 615 libgccjit 616 617 * The libgccjit API gained a new entry point: 618 [59]gcc_jit_context_add_driver_option. 619 620 New Targets and Target Specific Improvements 621 622 AArch64 & Arm 623 624 * Support has been added for the following processors (GCC 625 identifiers in parentheses): 626 + Arm Cortex-A76 (cortex-a76). 627 + Arm Cortex-A55/Cortex-A76 DynamIQ big.LITTLE 628 (cortex-a76.cortex-a55). 629 + Arm Neoverse N1 (neoverse-n1). 630 The GCC identifiers can be used as arguments to the -mcpu or -mtune 631 options, for example: -mcpu=cortex-a76 or 632 -mtune=cortex-a76.cortex-a55 or as arguments to the equivalent 633 target attributes and pragmas. 634 * The Armv8.3-A complex number instructions are now supported via 635 intrinsics when the option -march=armv8.3-a or equivalent is 636 specified. For the half-precision floating-point variants of these 637 instructions use the architecture extension flag +fp16, e.g. 638 -march=armv8.3-a+fp16. 639 The intrinsics are defined by the ACLE specification. 640 * The Armv8.5-A architecture is now supported through the 641 -march=armv8.5-a option. 642 * The Armv8.5-A architecture also adds some security features that 643 are optional to all older architecture versions. These are now 644 supported and only affect the assembler. 645 + Speculation Barrier instruction through the -march=armv8-a+sb 646 option. 647 + Execution and Data Prediction Restriction instructions through 648 the -march=armv8-a+predres option. 649 + Speculative Store Bypass Safe instruction through the 650 -march=armv8-a+ssbs option. This does not require a compiler 651 option for Arm and thus -march=armv8-a+ssbs is an 652 AArch64-specific option. 653 654 AArch64 specific 655 656 * Support has been added for the Arm Neoverse E1 processor 657 (-mcpu=neoverse-e1). 658 * The AArch64 port now has support for stack clash protection using 659 the [60]-fstack-clash-protection option. The probing interval/guard 660 size can be set by using --param 661 stack-clash-protection-guard-size=12|16. The value of this 662 parameter must be in bytes represented as a power of two. The two 663 supported values for this parameter are 12 (for a 4KiB size, 2^12) 664 and 16 (for a 64KiB size, 2^16). The default value is 16 (64Kb) and 665 can be changed at configure time using the flag 666 --with-stack-clash-protection-guard-size=12|16. 667 * The option -msign-return-address= has been deprecated. This has 668 been replaced by the new -mbranch-protection= option. This new 669 option can now be used to enable the return address signing as well 670 as the new Branch Target Identification feature of Armv8.5-A 671 architecture. For more information on the arguments accepted by 672 this option, please refer to [61]AArch64-Options. 673 * The following optional extensions to Armv8.5-A architecture are now 674 supported and only affect the assembler. 675 + Random Number Generation instructions through the 676 -march=armv8.5-a+rng option. 677 + Memory Tagging Extension through the -march=armv8.5-a+memtag 678 option. 679 680 Arm specific 681 682 * Support for the deprecated Armv2 and Armv3 architectures and their 683 variants has been removed. Their corresponding -march values and 684 the -mcpu options that used these architectures have been removed. 685 * Support for the Armv5 and Armv5E architectures (which have no known 686 implementations) has been removed. Note that Armv5T, Armv5TE and 687 Armv5TEJ architectures remain supported. 688 * Corrected FPU configurations for Cortex-R7 and Cortex-R8 when using 689 their respective -mcpu options. 690 691 AMD GCN 692 693 * A new back end targeting AMD GCN GPUs has been contributed to GCC. 694 The implementation is currently limited to compiling 695 single-threaded, stand-alone programs. Future versions will add 696 support for offloading multi-threaded kernels via OpenMP and 697 OpenACC. The following devices are supported (GCC identifiers in 698 parentheses): 699 + Fiji (fiji). 700 + Vega 10 (gfx900). 701 702 ARC 703 704 * LRA is now on by default for the ARC target. This can be controlled 705 by -mlra. 706 * Add support for frame code-density and branch-and-index 707 instructions. 708 709 C-SKY 710 711 * A new back end targeting C-SKY V2 processors has been contributed 712 to GCC. 713 714 IA-32/x86-64 715 716 * Support of Intel MPX (Memory Protection Extensions) has been 717 removed. 718 * New ISA extension support for Intel PTWRITE was added to GCC. 719 PTWRITE intrinsics are available via the -mptwrite compiler switch. 720 * GCC now supports the Intel CPU named Cascade Lake with AVX512 721 extensions through -march=cascadelake. The switch enables the 722 following ISA extensions: AVX512F, AVX512VL, AVX512CD, AVX512BW, 723 AVX512DQ, AVX512VNNI. 724 725 OpenRISC 726 727 * A new back end targeting OpenRISC processors has been contributed 728 to GCC. 729 730 S/390, System z, IBM z Systems 731 732 * Support for the arch13 architecture has been added. When using the 733 -march=arch13 option, the compiler will generate code making use of 734 the new instructions introduced with the vector enhancement 735 facility 2 and the miscellaneous instruction extension facility 2. 736 The -mtune=arch13 option enables arch13 specific instruction 737 scheduling without making use of new instructions. 738 * Builtins for the new vector instructions have been added and can be 739 enabled using the -mzvector option. 740 * Support for ESA architecture machines g5 and g6 is deprecated since 741 GCC 6.1.0 and has been removed now. 742 * When compiling with -march=z14 or higher GCC emits alignments hints 743 on the vector load/store instructions (8 or 16 byte). 744 * Functions now have a default alignment of 16 bytes. This helps with 745 branch prediction effects. 746 * -mfentry is now supported. As well as the mcount mechanism the 747 __fentry__ is called before the function prologue. However, since 748 just a single instruction is required to call __fentry__ the call 749 sequence imposes a smaller overhead than mcount (4 instructions). 750 The produced code is compatible only with newer glibc versions, 751 which provide the __fentry__ symbol and do not clobber r0 when 752 resolving lazily bound functions. -mfentry is only supported when 753 generating 64 bit code and does not work with nested C functions. 754 * The -mnop-mcount option can be used to emit NOP instructions 755 instead of an mcount or fentry call stub. 756 * With the -mrecord-mcount option a __mcount_loc section is generated 757 containing pointers to each profiling call stub. This is useful for 758 automatically patching in and out calls. 759 760 Operating Systems 761 762 Solaris 763 764 * g++ now unconditionally enables large file support when compiling 765 32-bit code. 766 * Support for the AddressSanitizer and UndefinedBehaviorSanitizer has 767 been merged from LLVM. For the moment, this only works for 32-bit 768 code on both SPARC and x86. 769 * An initial port of the D runtime library has been completed on 770 Solaris 11/x86. It requires the use of GNU as. Solaris 11/SPARC 771 support is still work-in-progress. 772 773 Windows 774 775 * A C++ Microsoft ABI bitfield layout bug, [62]PR87137 has been 776 fixed. A non-field declaration could cause the current bitfield 777 allocation unit to be completed, incorrectly placing a following 778 bitfield into a new allocation unit. The Microsoft ABI is selected 779 for: 780 + Mingw targets 781 + PowerPC, IA-32 or x86-64 targets when the -mms-bitfields 782 option is specified, or __attribute__((ms_struct)) is used 783 + SuperH targets when the -mhitachi option is specified, or 784 __attribute__((renesas)) is used 785 786 Improvements for plugin authors 787 788 * GCC's diagnostic subsystem now has a way to logically group 789 together related diagnostics, auto_diagnostic_group. Such 790 diagnostics will be nested by the output of 791 [63]-fdiagnostics-format=json. 792 * GCC now has a set of [64]user experience guidelines for GCC, with 793 information and advice on implementing new diagnostics. 794 795 Other significant improvements 796 797 * GCC's internal "selftest" suite now runs for C++ as well as C (in 798 debug builds of the compiler). 799 800 GCC 9.1 801 802 This is the [65]list of problem reports (PRs) from GCC's bug tracking 803 system that are known to be fixed in the 9.1 release. This list might 804 not be complete (that is, it is possible that some PRs that have been 805 fixed are not listed here). 806 807 GCC 9.2 808 809 This is the [66]list of problem reports (PRs) from GCC's bug tracking 810 system that are known to be fixed in the 9.2 release. This list might 811 not be complete (that is, it is possible that some PRs that have been 812 fixed are not listed here). 813 814 GCC 9.3 815 816 This is the [67]list of problem reports (PRs) from GCC's bug tracking 817 system that are known to be fixed in the 9.3 release. This list might 818 not be complete (that is, it is possible that some PRs that have been 819 fixed are not listed here). 820 821 822 For questions related to the use of GCC, please consult these web 823 pages and the [68]GCC manuals. If that fails, the 824 [69]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 825 web pages and the development of GCC are welcome on our developer 826 list at [70]gcc (a] gcc.gnu.org. All of [71]our lists have public 827 archives. 828 829 Copyright (C) [72]Free Software Foundation, Inc. Verbatim copying and 830 distribution of this entire article is permitted in any medium, 831 provided this notice is preserved. 832 833 These pages are [73]maintained by the GCC team. 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https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Optimize-Options.html#index-fipa-stack-alignment 860 23. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Optimize-Options.html#index-fipa-reference-addressable 861 24. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Other-Builtins.html#index-_005f_005fbuiltin_005fexpect_005fwith_005fprobability 862 25. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Other-Builtins.html#index-_005f_005fbuiltin_005fhas_005fattribute-1 863 26. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Other-Builtins.html#index-_005f_005fbuiltin_005fspeculation_005fsafe_005fvalue-1 864 27. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Common-Function-Attributes.html#index-copy-function-attribute 865 28. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Optimize-Options.html#index-ftree-switch-conversion 866 29. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Optimize-Options.html#index-fprofile-use 867 30. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Optimize-Options.html#index-fversion-loops-for-strides 868 31. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Optimize-Options.html#index-floop-interchange 869 32. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Optimize-Options.html#index-floop-unroll-and-jam 870 33. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Optimize-Options.html#index-ftree-loop-distribution 871 34. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Invoking-Gcov.html#Invoking-Gcov 872 35. https://www.openacc.org/ 873 36. https://gcc.gnu.org/wiki/OpenACC#status-9 874 37. https://www.openmp.org/specifications/ 875 38. https://gcc.gnu.org/ml/gcc-patches/2018-11/msg00628.html 876 39. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Vector-Extensions.html#index-_005f_005fbuiltin_005fconvertvector 877 40. https://gcc.gnu.org/onlinedocs/gcc-9.1.0/gcc/Warning-Options.html#index-Waddress-of-packed-member 878 41. 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911 74. http://validator.w3.org/check/referer 912 ====================================================================== 913 http://gcc.gnu.org/gcc-8/index.html 914 GCC 8 Release Series 915 916 Mar 4, 2020 917 918 The [1]GNU project and the GCC developers are pleased to announce the 919 release of GCC 8.4. 920 921 This release is a bug-fix release, containing fixes for regressions in 922 GCC 8.3 relative to previous releases of GCC. 923 924 Release History 925 926 GCC 8.4 927 Mar 4, 2020 ([2]changes, [3]documentation) 928 929 GCC 8.3 930 Feb 22, 2019 ([4]changes, [5]documentation) 931 932 GCC 8.2 933 Jul 26, 2018 ([6]changes, [7]documentation) 934 935 GCC 8.1 936 May 2, 2018 ([8]changes, [9]documentation) 937 938 References and Acknowledgements 939 940 GCC used to stand for the GNU C Compiler, but since the compiler 941 supports several other languages aside from C, it now stands for the 942 GNU Compiler Collection. 943 944 A list of [10]successful builds is updated as new information becomes 945 available. 946 947 The GCC developers would like to thank the numerous people that have 948 contributed new features, improvements, bug fixes, and other changes as 949 well as test results to GCC. This [11]amazing group of volunteers is 950 what makes GCC successful. 951 952 For additional information about GCC please refer to the [12]GCC 953 project web site or contact the [13]GCC development mailing list. 954 955 To obtain GCC please use [14]our mirror sites or [15]our version 956 control system. 957 958 959 For questions related to the use of GCC, please consult these web 960 pages and the [16]GCC manuals. If that fails, the 961 [17]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 962 web pages and the development of GCC are welcome on our developer 963 list at [18]gcc (a] gcc.gnu.org. All of [19]our lists have public 964 archives. 965 966 Copyright (C) [20]Free Software Foundation, Inc. Verbatim copying and 967 distribution of this entire article is permitted in any medium, 968 provided this notice is preserved. 969 970 These pages are [21]maintained by the GCC team. Last modified 971 2020-03-04[22]. 972 973 References 974 975 1. http://www.gnu.org/ 976 2. http://gcc.gnu.org/gcc-8/changes.html 977 3. http://gcc.gnu.org/onlinedocs/8.4.0/ 978 4. http://gcc.gnu.org/gcc-8/changes.html 979 5. http://gcc.gnu.org/onlinedocs/8.3.0/ 980 6. http://gcc.gnu.org/gcc-8/changes.html 981 7. http://gcc.gnu.org/onlinedocs/8.2.0/ 982 8. http://gcc.gnu.org/gcc-8/changes.html 983 9. http://gcc.gnu.org/onlinedocs/8.1.0/ 984 10. http://gcc.gnu.org/gcc-8/buildstat.html 985 11. http://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/Contributors.html 986 12. http://gcc.gnu.org/index.html 987 13. mailto:gcc (a] gcc.gnu.org 988 14. http://gcc.gnu.org/mirrors.html 989 15. http://gcc.gnu.org/git.html 990 16. https://gcc.gnu.org/onlinedocs/ 991 17. mailto:gcc-help (a] gcc.gnu.org 992 18. mailto:gcc (a] gcc.gnu.org 993 19. https://gcc.gnu.org/lists.html 994 20. https://www.fsf.org/ 995 21. https://gcc.gnu.org/about.html 996 22. http://validator.w3.org/check/referer 997 ====================================================================== 998 http://gcc.gnu.org/gcc-8/changes.html 999 GCC 8 Release Series 1000 Changes, New Features, and Fixes 1001 1002 This page is a "brief" summary of some of the huge number of 1003 improvements in GCC 8. You may also want to check out our [1]Porting to 1004 GCC 8 page and the [2]full GCC documentation. 1005 1006 Caveats 1007 1008 * Support for the obsolete SDB/coff debug info format has been 1009 removed. The option -gcoff no longer does anything. 1010 * The Cilk+ extensions to the C and C++ languages have been removed. 1011 * The MPX extensions to the C and C++ languages have been deprecated 1012 and will be removed in a future release. 1013 * The extension allowing arithmetic on std::atomic<void*> and types 1014 like std::atomic<R(*)()> has been deprecated. 1015 * The non-standard C++0x std::copy_exception function was removed. 1016 std::make_exception_ptr should be used instead. 1017 * Support for the powerpc*-*-*spe* target ports which have been 1018 recently unmaintained and untested in GCC has been declared 1019 obsolete in GCC 8 as [3]announced. Unless there is activity to 1020 revive them, the next release of GCC will have their sources 1021 permanently removed. 1022 1023 General Improvements 1024 1025 * Inter-procedural optimization improvements: 1026 + Reworked run-time estimation metrics leading to more realistic 1027 guesses driving inliner and cloning heuristics. 1028 + The ipa-pure-const pass is extended to propagate the malloc 1029 attribute, and the corresponding warning option 1030 -Wsuggest-attribute=malloc emits a diagnostic for functions 1031 which can be annotated with the malloc attribute. 1032 * Profile driven optimization improvements: 1033 + New infrastructure for representing profiles (both statically 1034 guessed and profile feedback) which allows propagation of 1035 additional information about the reliability of the profile. 1036 + A number of improvements in the profile updating code solving 1037 problems found by new verification code. 1038 + Static detection of code which is not executed in a valid run 1039 of the program. This includes paths which trigger undefined 1040 behavior as well as calls to functions declared with the cold 1041 attribute. Newly the noreturn attribute does not imply all 1042 effects of cold to differentiate between exit (which is 1043 noreturn) and abort (which is in addition not executed in 1044 valid runs). 1045 + -freorder-blocks-and-partition, a pass splitting function 1046 bodies into hot and cold regions, is now enabled by default at 1047 -O2 and higher for x86 and x86-64. 1048 * Link-time optimization improvements: 1049 + We have significantly improved debug information on ELF 1050 targets using DWARF by properly preserving language-specific 1051 information. This allows for example the libstdc++ 1052 pretty-printers to work with LTO optimized executables. 1053 * A new option -fcf-protection=[full|branch|return|none] is 1054 introduced to perform code instrumentation to increase program 1055 security by checking that target addresses of control-flow transfer 1056 instructions (such as indirect function call, function return, 1057 indirect jump) are valid. Currently the instrumentation is 1058 supported on x86 GNU/Linux targets only. See the user guide for 1059 further information about the option syntax and section "New 1060 Targets and Target Specific Improvements" for IA-32/x86-64 for more 1061 details. 1062 * The -gcolumn-info option is now enabled by default. It includes 1063 column information in addition to just filenames and line numbers 1064 in DWARF debugging information. 1065 * The polyhedral-based loop nest optimization pass 1066 -floop-nest-optimize has been overhauled. It's still considered 1067 experimental and may not result in any runtime improvements. 1068 * Two new classical loop nest optimization passes have been added. 1069 -floop-unroll-and-jam performs outer loop unrolling and fusing of 1070 the inner loop copies. -floop-interchange exchanges loops in a loop 1071 nest to improve data locality. Both passes are enabled by default 1072 at -O3 and above. 1073 * The classic loop nest optimization pass -ftree-loop-distribution 1074 has been improved and enabled by default at -O3 and above. It 1075 supports loop nest distribution in some restricted scenarios; it 1076 also supports cancellable innermost loop distribution with loop 1077 versioning under run-time alias checks. 1078 * The new option -fstack-clash-protection causes the compiler to 1079 insert probes whenever stack space is allocated statically or 1080 dynamically to reliably detect stack overflows and thus mitigate 1081 the attack vector that relies on jumping over a stack guard page as 1082 provided by the operating system. 1083 * A new pragma GCC unroll has been implemented in the C family of 1084 languages, as well as Fortran and Ada, so as to make it possible 1085 for the user to have a finer-grained control over the loop 1086 unrolling optimization. 1087 * GCC has been enhanced to detect more instances of meaningless or 1088 mutually exclusive attribute specifications and handle such 1089 conflicts more consistently. Mutually exclusive attribute 1090 specifications are ignored with a warning regardless of whether 1091 they appear on the same declaration or on distinct declarations of 1092 the same entity. For example, because the noreturn attribute on the 1093 second declaration below is mutually exclusive with the malloc 1094 attribute on the first, it is ignored and a warning is issued. 1095 > 1096 void* __attribute__ ((malloc)) f (unsigned); 1097 void* __attribute__ ((noreturn)) f (unsigned); 1098 1099 warning: ignoring attribute 'noreturn' because it conflicts with attribute 1100 'malloc' [-Wattributes] 1101 * The gcov tool can distinguish functions that begin on a same line 1102 in a source file. This can be a different template instantiation or 1103 a class constructor: 1104 1105 File 'ins.C' 1106 Lines executed:100.00% of 8 1107 Creating 'ins.C.gcov' 1108 1109 -: 0:Source:ins.C 1110 -: 0:Graph:ins.gcno 1111 -: 0:Data:ins.gcda 1112 -: 0:Runs:1 1113 -: 0:Programs:1 1114 -: 1:template<class T> 1115 -: 2:class Foo 1116 -: 3:{ 1117 -: 4: public: 1118 2: 5: Foo(): b (1000) {} 1119 ------------------ 1120 Foo<char>::Foo(): 1121 1: 5: Foo(): b (1000) {} 1122 ------------------ 1123 Foo<int>::Foo(): 1124 1: 5: Foo(): b (1000) {} 1125 ------------------ 1126 2: 6: void inc () { b++; } 1127 ------------------ 1128 Foo<char>::inc(): 1129 1: 6: void inc () { b++; } 1130 ------------------ 1131 Foo<int>::inc(): 1132 1: 6: void inc () { b++; } 1133 ------------------ 1134 -: 7: 1135 -: 8: private: 1136 -: 9: int b; 1137 -: 10:}; 1138 -: 11: 1139 1: 12:int main(int argc, char **argv) 1140 -: 13:{ 1141 1: 14: Foo<int> a; 1142 1: 15: Foo<char> b; 1143 -: 16: 1144 1: 17: a.inc (); 1145 1: 18: b.inc (); 1146 1: 19:} 1147 1148 * The gcov tool has more accurate numbers for execution of lines in a 1149 source file. 1150 * The gcov tool can use TERM colors to provide more readable output. 1151 * AddressSanitizer gained a new pair of sanitization options, 1152 -fsanitize=pointer-compare and -fsanitize=pointer-subtract, which 1153 warn about subtraction (or comparison) of pointers that point to a 1154 different memory object: 1155 1156 int 1157 main () 1158 { 1159 /* Heap allocated memory. */ 1160 char *heap1 = (char *)__builtin_malloc (42); 1161 char *heap2 = (char *)__builtin_malloc (42); 1162 if (heap1 > heap2) 1163 return 1; 1164 1165 return 0; 1166 } 1167 1168 ==17465==ERROR: AddressSanitizer: invalid-pointer-pair: 0x604000000010 0x6040000 1169 00050 1170 #0 0x40070f in main /tmp/pointer-compare.c:7 1171 #1 0x7ffff6a72a86 in __libc_start_main (/lib64/libc.so.6+0x21a86) 1172 #2 0x400629 in _start (/tmp/a.out+0x400629) 1173 1174 0x604000000010 is located 0 bytes inside of 42-byte region [0x604000000010,0x604 1175 00000003a) 1176 allocated by thread T0 here: 1177 #0 0x7ffff6efb390 in __interceptor_malloc ../../../../libsanitizer/asan/asan 1178 _malloc_linux.cc:86 1179 #1 0x4006ea in main /tmp/pointer-compare.c:5 1180 #2 0x7ffff6a72a86 in __libc_start_main (/lib64/libc.so.6+0x21a86) 1181 1182 0x604000000050 is located 0 bytes inside of 42-byte region [0x604000000050,0x604 1183 00000007a) 1184 allocated by thread T0 here: 1185 #0 0x7ffff6efb390 in __interceptor_malloc ../../../../libsanitizer/asan/asan 1186 _malloc_linux.cc:86 1187 #1 0x4006f8 in main /tmp/pointer-compare.c:6 1188 #2 0x7ffff6a72a86 in __libc_start_main (/lib64/libc.so.6+0x21a86) 1189 1190 SUMMARY: AddressSanitizer: invalid-pointer-pair /tmp/pointer-compare.c:7 in main 1191 1192 * The store merging pass has been enhanced to handle bit-fields and 1193 not just constant stores, but also data copying from adjacent 1194 memory locations into other adjacent memory locations, including 1195 bitwise logical operations on the data. The pass can also handle 1196 byte swapping into memory locations. 1197 * The undefined behavior sanitizer gained two new options included in 1198 -fsanitize=undefined: -fsanitize=builtin which diagnoses at run 1199 time invalid arguments to __builtin_clz or __builtin_ctz prefixed 1200 builtins, and -fsanitize=pointer-overflow which performs cheap run 1201 time tests for pointer wrapping. 1202 * A new attribute no_sanitize can be applied to functions to instruct 1203 the compiler not to do sanitization of the options provided as 1204 arguments to the attribute. Acceptable values for no_sanitize match 1205 those acceptable by the -fsanitize command-line option. 1206 1207 void __attribute__ ((no_sanitize ("alignment", "object-size"))) 1208 f () { /* Do something. */; } 1209 1210 New Languages and Language specific improvements 1211 1212 Ada 1213 1214 * For its internal exception handling used on the host for error 1215 recovery in the front-end, the compiler now relies on the native 1216 exception handling mechanism of the host platform, which should be 1217 more efficient than the former mechanism. 1218 1219 BRIG (HSAIL) 1220 1221 In this release cycle, the focus for the BRIGFE was on stabilization 1222 and performance improvements. Also a couple of completely new features 1223 were added. 1224 * Improved support for function and module scope group segment 1225 variables. PRM specs define function and module scope group segment 1226 variables as an experimental feature. However, PRM test suite uses 1227 them. Now group segment is handled by separate book keeping of 1228 module scope and function (kernel) offsets. Each function has a 1229 "frame" in the group segment offset to which is given as an 1230 argument, similar to traditional call stack frame handling. 1231 * Reduce the number of type conversions due to the untyped HSAIL 1232 registers. Instead of always representing the HSAIL's untyped 1233 registers as unsigned int, the gccbrig now pre-analyzes the BRIG 1234 code and builds the register variables as a type used the most when 1235 storing or reading data to/from each register. This reduces the 1236 number of total casts which cannot be always optimized away. 1237 * Support for BRIG_KIND_NONE directives. 1238 * Made -O3 the default optimization level for BRIGFE. 1239 * Fixed illegal addresses generated from address expressions which 1240 refer only to offset 0. 1241 * Fixed a bug with reg+offset addressing on 32b segments. In 'large' 1242 mode, the offset is treated as 32bits unless it's in global, 1243 read-only or kernarg address space. 1244 * Fixed a crash caused sometimes by calls with more than 4 arguments. 1245 * Fixed a mis-execution issue with kernels that have both unexpanded 1246 ID functions and calls to subfunctions. 1247 * Treat HSAIL barrier builtins as setjmp/longjump style functions to 1248 avoid illegal optimizations. 1249 * Ensure per WI copies of private variables are aligned correctly. 1250 * libhsail-rt: Assume the host runtime allocates the work group 1251 memory. 1252 1253 C family 1254 1255 * New command-line options have been added for the C and C++ 1256 compilers: 1257 + [4]-Wmultistatement-macros warns about unsafe macros expanding 1258 to multiple statements used as a body of a statement such as 1259 if, else, while, switch, or for. 1260 + [5]-Wstringop-truncation warns for calls to bounded string 1261 manipulation functions such as strncat, strncpy, and stpncpy 1262 that might either truncate the copied string or leave the 1263 destination unchanged. For example, the following call to 1264 strncat is diagnosed because it appends just three of the four 1265 characters from the source string. 1266 void append (char *buf, size_t bufsize) 1267 { 1268 strncat (buf, ".txt", 3); 1269 } 1270 warning: 'strncat' output truncated copying 3 bytes from a string of length 4 [- 1271 Wstringop-truncation] 1272 Similarly, in the following example, the call to strncpy 1273 specifies the size of the destination buffer as the bound. If 1274 the length of the source string is equal to or greater than 1275 this size the result of the copy will not be NUL-terminated. 1276 Therefore, the call is also diagnosed. To avoid the warning, 1277 specify sizeof buf - 1 as the bound and set the last element 1278 of the buffer to NUL. 1279 void copy (const char *s) 1280 { 1281 char buf[80]; 1282 strncpy (buf, s, sizeof buf); 1283 1284 } 1285 warning: 'strncpy' specified bound 80 equals destination size [-Wstringop-trunca 1286 tion] 1287 The -Wstringop-truncation option is included in -Wall. 1288 Note that due to GCC bug [6]82944, defining strncat, strncpy, 1289 or stpncpy as a macro in a system header as some 1290 implementations do, suppresses the warning. 1291 + [7]-Wif-not-aligned controls warnings issued in response to 1292 invalid uses of objects declared with attribute 1293 [8]warn_if_not_aligned. 1294 The -Wif-not-aligned option is included in -Wall. 1295 + [9]-Wmissing-attributes warns when a declaration of a function 1296 is missing one or more attributes that a related function is 1297 declared with and whose absence may adversely affect the 1298 correctness or efficiency of generated code. For example, in 1299 C++, the warning is issued when an explicit specialization of 1300 a primary template declared with attribute alloc_align, 1301 alloc_size, assume_aligned, format, format_arg, malloc, or 1302 nonnull is declared without it. Attributes deprecated, error, 1303 and warning suppress the warning. 1304 The -Wmissing-attributes option is included in -Wall. 1305 + [10]-Wpacked-not-aligned warns when a struct or union declared 1306 with attribute packed defines a member with an explicitly 1307 specified alignment greater than 1. Such a member will wind up 1308 under-aligned. For example, a warning will be issued for the 1309 definition of struct A in the following: 1310 struct __attribute__ ((aligned (8))) 1311 S8 { char a[8]; }; 1312 1313 struct __attribute__ ((packed)) A 1314 { 1315 struct S8 s8; 1316 }; 1317 warning: alignment 1 of 'struct S' is less than 8 [-Wpacked-not-aligned] 1318 The -Wpacked-not-aligned option is included in -Wall. 1319 + -Wcast-function-type warns when a function pointer is cast to 1320 an incompatible function pointer. This warning is enabled by 1321 -Wextra. 1322 + -Wsizeof-pointer-div warns for suspicious divisions of the 1323 size of a pointer by the size of the elements it points to, 1324 which looks like the usual way to compute the array size but 1325 won't work out correctly with pointers. This warning is 1326 enabled by -Wall. 1327 + -Wcast-align=strict warns whenever a pointer is cast such that 1328 the required alignment of the target is increased. For 1329 example, warn if a char * is cast to an int * regardless of 1330 the target machine. 1331 + -fprofile-abs-path creates absolute path names in the .gcno 1332 files. This allows gcov to find the correct sources in 1333 projects where compilations occur with different working 1334 directories. 1335 * -fno-strict-overflow is now mapped to -fwrapv -fwrapv-pointer and 1336 signed integer overflow is now undefined by default at all 1337 optimization levels. Using -fsanitize=signed-integer-overflow is 1338 now the preferred way to audit code, -Wstrict-overflow is 1339 deprecated. 1340 * The [11]-Warray-bounds option has been improved to detect more 1341 instances of out-of-bounds array indices and pointer offsets. For 1342 example, negative or excessive indices into flexible array members 1343 and string literals are detected. 1344 * The [12]-Wrestrict option introduced in GCC 7 has been enhanced to 1345 detect many more instances of overlapping accesses to objects via 1346 restrict-qualified arguments to standard memory and string 1347 manipulation functions such as memcpy and strcpy. For example, the 1348 strcpy call in the function below attempts to truncate the string 1349 by replacing its initial characters with the last four. However, 1350 because the function writes the terminating NUL into a[4], the 1351 copies overlap and the call is diagnosed. 1352 void f (void) 1353 { 1354 char a[] = "abcd1234"; 1355 strcpy (a, a + 4); 1356 1357 } 1358 warning: 'strcpy' accessing 5 bytes at offsets 0 and 4 overlaps 1 byte at offset 1359 4 [-Wrestrict] 1360 The -Wrestrict option is included in -Wall. 1361 * Several optimizer enhancements have enabled improvements to the 1362 [13]-Wformat-overflow and [14]-Wformat-truncation options. The 1363 warnings detect more instances of buffer overflow and truncation 1364 than in GCC 7 and are better at avoiding certain kinds of false 1365 positives. 1366 * When reporting mismatching argument types at a function call, the C 1367 and C++ compilers now underline both the argument and the pertinent 1368 parameter in the declaration. 1369 $ gcc arg-type-mismatch.cc 1370 arg-type-mismatch.cc: In function 'int caller(int, int, float)': 1371 arg-type-mismatch.cc:5:24: error: invalid conversion from 'int' to 'const char*' 1372 [-fpermissive] 1373 return callee(first, second, third); 1374 ^~~~~~ 1375 arg-type-mismatch.cc:1:40: note: initializing argument 2 of 'int callee(int, c 1376 onst char*, float)' 1377 extern int callee(int one, const char *two, float three); 1378 ~~~~~~~~~~~~^~~ 1379 1380 * When reporting on unrecognized identifiers, the C and C++ compilers 1381 will now emit fix-it hints suggesting #include directives for 1382 various headers in the C and C++ standard libraries. 1383 $ gcc incomplete.c 1384 incomplete.c: In function 'test': 1385 incomplete.c:3:10: error: 'NULL' undeclared (first use in this function) 1386 return NULL; 1387 ^~~~ 1388 incomplete.c:3:10: note: 'NULL' is defined in header '<stddef.h>'; did you forge 1389 t to '#include <stddef.h>'? 1390 incomplete.c:1:1: 1391 +#include <stddef.h> 1392 const char *test(void) 1393 incomplete.c:3:10: 1394 return NULL; 1395 ^~~~ 1396 incomplete.c:3:10: note: each undeclared identifier is reported only once for ea 1397 ch function it appears in 1398 1399 $ gcc incomplete.cc 1400 incomplete.cc:1:6: error: 'string' in namespace 'std' does not name a type 1401 std::string s("hello world"); 1402 ^~~~~~ 1403 incomplete.cc:1:1: note: 'std::string' is defined in header '<string>'; did you 1404 forget to '#include <string>'? 1405 +#include <string> 1406 std::string s("hello world"); 1407 ^~~ 1408 1409 * The C and C++ compilers now use more intuitive locations when 1410 reporting on missing semicolons, and offer fix-it hints: 1411 $ gcc t.c 1412 t.c: In function 'test': 1413 t.c:3:12: error: expected ';' before '}' token 1414 return 42 1415 ^ 1416 ; 1417 } 1418 ~ 1419 1420 * When reporting on missing '}' and ')' tokens, the C and C++ 1421 compilers will now highlight the corresponding '{' and '(' token, 1422 issuing a 'note' if it's on a separate line: 1423 $ gcc unclosed.c 1424 unclosed.c: In function 'log_when_out_of_range': 1425 unclosed.c:12:50: error: expected ')' before '{' token 1426 && (temperature < MIN || temperature > MAX) { 1427 ^~ 1428 ) 1429 unclosed.c:11:6: note: to match this '(' 1430 if (logging_enabled && check_range () 1431 ^ 1432 1433 or highlighting it directly if it's on the same line: 1434 $ gcc unclosed-2.c 1435 unclosed-2.c: In function 'test': 1436 unclosed-2.c:8:45: error: expected ')' before '{' token 1437 if (temperature < MIN || temperature > MAX { 1438 ~ ^~ 1439 ) 1440 1441 They will also emit fix-it hints. 1442 1443 C++ 1444 1445 * GCC 8 (-fabi-version=12) has a couple of corrections to the calling 1446 convention, which changes the ABI for some uncommon code: 1447 + Passing an empty class as an argument now takes up no space on 1448 x86_64, as required by the psABI. 1449 + Passing or returning a class with only deleted copy and move 1450 constructors now uses the same calling convention as a class 1451 with a non-trivial copy or move constructor. This only affects 1452 C++17 mode, as in earlier standards passing or returning such 1453 a class was impossible. 1454 + WARNING: In GCC 8.1 the second change mistakenly also affects 1455 classes with a deleted copy constructor and defaulted trivial 1456 move constructor (bug [15]c++/86094). This issue is fixed in 1457 GCC 8.2 (-fabi-version=13). 1458 You can test whether these changes affect your code with -Wabi=11 1459 (or -Wabi=12 in GCC 8.2 for the third issue); if these changes are 1460 problematic for your project, the GCC 7 ABI can be selected with 1461 -fabi-version=11. 1462 * The value of the C++11 alignof operator has been corrected to match 1463 C _Alignof (minimum alignment) rather than GNU __alignof__ 1464 (preferred alignment); on ia32 targets this means that 1465 alignof(double) is now 4 rather than 8. Code that wants the 1466 preferred alignment should use __alignof__ instead. 1467 * New command-line options have been added for the C++ compiler to 1468 control warnings: 1469 + [16]-Wclass-memaccess warns when objects of non-trivial class 1470 types are manipulated in potentially unsafe ways by raw memory 1471 functions such as memcpy, or realloc. The warning helps detect 1472 calls that bypass user-defined constructors or copy-assignment 1473 operators, corrupt virtual table pointers, data members of 1474 const-qualified types or references, or member pointers. The 1475 warning also detects calls that would bypass access controls 1476 to data members. For example, a call such as: 1477 memcpy (&std::cout, &std::cerr, sizeof std::cout); 1478 results in 1479 warning: 'void* memcpy(void*, const void*, long unsigned int)' writing t 1480 o an object of type 'std::ostream' {aka 'class std::basic_ostream<char>'} with n 1481 o trivial copy-assignment [-Wclass-memaccess] 1482 The -Wclass-memaccess option is included in -Wall. 1483 * The C++ front end has experimental support for some of the upcoming 1484 C++2a draft features with the -std=c++2a or -std=gnu++2a flags, 1485 including designated initializers, default member initializers for 1486 bit-fields, __VA_OPT__ (except that #__VA_OPT__ is unsupported), 1487 lambda [=, this] captures, etc. For a full list of new features, 1488 see [17]the C++ status page. 1489 * When reporting on attempts to access private fields of a class or 1490 struct, the C++ compiler will now offer fix-it hints showing how to 1491 use an accessor function to get at the field in question, if one 1492 exists. 1493 $ gcc accessor.cc 1494 accessor.cc: In function 'void test(foo*)': 1495 accessor.cc:12:12: error: 'double foo::m_ratio' is private within this context 1496 if (ptr->m_ratio >= 0.5) 1497 ^~~~~~~ 1498 accessor.cc:7:10: note: declared private here 1499 double m_ratio; 1500 ^~~~~~~ 1501 accessor.cc:12:12: note: field 'double foo::m_ratio' can be accessed via 'double 1502 foo::get_ratio() const' 1503 if (ptr->m_ratio >= 0.5) 1504 ^~~~~~~ 1505 get_ratio() 1506 1507 * The C++ compiler can now give you a hint if you use a macro before 1508 it was defined (e.g. if you mess up the order of your #include 1509 directives): 1510 $ gcc ordering.cc 1511 ordering.cc:2:24: error: expected ';' at end of member declaration 1512 virtual void clone() const OVERRIDE { } 1513 ^~~~~ 1514 ; 1515 ordering.cc:2:30: error: 'OVERRIDE' does not name a type 1516 virtual void clone() const OVERRIDE { } 1517 ^~~~~~~~ 1518 ordering.cc:2:30: note: the macro 'OVERRIDE' had not yet been defined 1519 In file included from ordering.cc:5: 1520 c++11-compat.h:2: note: it was later defined here 1521 #define OVERRIDE override 1522 1523 1524 * The -Wold-style-cast diagnostic can now emit fix-it hints telling 1525 you when you can use a static_cast, const_cast, or 1526 reinterpret_cast. 1527 $ gcc -c old-style-cast-fixits.cc -Wold-style-cast 1528 old-style-cast-fixits.cc: In function 'void test(void*)': 1529 old-style-cast-fixits.cc:5:19: warning: use of old-style cast to 'struct foo*' [ 1530 -Wold-style-cast] 1531 foo *f = (foo *)ptr; 1532 ^~~ 1533 ---------- 1534 static_cast<foo *> (ptr) 1535 1536 * When reporting on problems within extern "C" linkage 1537 specifications, the C++ compiler will now display the location of 1538 the start of the extern "C". 1539 $ gcc -c extern-c.cc 1540 extern-c.cc:3:1: error: template with C linkage 1541 template <typename T> void test (void); 1542 ^~~~~~~~ 1543 In file included from extern-c.cc:1: 1544 unclosed.h:1:1: note: 'extern "C"' linkage started here 1545 extern "C" { 1546 ^~~~~~~~~~ 1547 extern-c.cc:3:39: error: expected '}' at end of input 1548 template <typename T> void test (void); 1549 ^ 1550 In file included from extern-c.cc:1: 1551 unclosed.h:1:12: note: to match this '{' 1552 extern "C" { 1553 ^ 1554 1555 * When reporting on mismatching template types, the C++ compiler will 1556 now use color to highlight the mismatching parts of the template, 1557 and will elide the parameters that are common between two 1558 mismatching templates, printing [...] instead: 1559 $ gcc templates.cc 1560 templates.cc: In function 'void test()': 1561 templates.cc:9:8: error: could not convert 'vector<double>()' from 'vector<doubl 1562 e>' to 'vector<int>' 1563 fn_1(vector<double> ()); 1564 ^~~~~~~~~~~~~~~~~ 1565 templates.cc:10:8: error: could not convert 'map<int, double>()' from 'map<[...] 1566 ,double>' to 'map<[...],int>' 1567 fn_2(map<int, double>()); 1568 ^~~~~~~~~~~~~~~~~~ 1569 1570 Those [...] elided parameters can be seen using -fno-elide-type: 1571 $ gcc templates.cc -fno-elide-type 1572 templates.cc: In function 'void test()': 1573 templates.cc:9:8: error: could not convert 'vector<double>()' from 'vector<doubl 1574 e>' to 'vector<int>' 1575 fn_1(vector<double> ()); 1576 ^~~~~~~~~~~~~~~~~ 1577 templates.cc:10:8: error: could not convert 'map<int, double>()' from 'map<int,d 1578 ouble>' to 'map<int,int>' 1579 fn_2(map<int, double>()); 1580 ^~~~~~~~~~~~~~~~~~ 1581 1582 The C++ compiler has also gained an option 1583 -fdiagnostics-show-template-tree which visualizes such mismatching 1584 templates in a hierarchical form: 1585 $ gcc templates-2.cc -fdiagnostics-show-template-tree 1586 templates-2.cc: In function 'void test()': 1587 templates-2.cc:9:8: error: could not convert 'vector<double>()' from 'vector<dou 1588 ble>' to 'vector<int>' 1589 vector< 1590 [double != int]> 1591 fn_1(vector<double> ()); 1592 ^~~~~~~~~~~~~~~~~ 1593 templates-2.cc:10:8: error: could not convert 'map<map<int, vector<double> >, ve 1594 ctor<double> >()' from 'map<map<[...],vector<double>>,vector<double>>' to 'map<m 1595 ap<[...],vector<float>>,vector<float>>' 1596 map< 1597 map< 1598 [...], 1599 vector< 1600 [double != float]>>, 1601 vector< 1602 [double != float]>> 1603 fn_2(map<map<int, vector<double>>, vector<double>> ()); 1604 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1605 1606 which again works with -fno-elide-type: 1607 $ gcc templates-2.cc -fdiagnostics-show-template-tree -fno-elide-type 1608 templates-2.cc: In function 'void test()': 1609 templates-2.cc:9:8: error: could not convert 'vector<double>()' from 'vector<dou 1610 ble>' to 'vector<int>' 1611 vector< 1612 [double != int]> 1613 fn_1(vector<double> ()); 1614 ^~~~~~~~~~~~~~~~~ 1615 templates-2.cc:10:8: error: could not convert 'map<map<int, vector<double> >, ve 1616 ctor<double> >()' from 'map<map<int,vector<double>>,vector<double>>' to 'map<map 1617 <int,vector<float>>,vector<float>>' 1618 map< 1619 map< 1620 int, 1621 vector< 1622 [double != float]>>, 1623 vector< 1624 [double != float]>> 1625 fn_2(map<map<int, vector<double>>, vector<double>> ()); 1626 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1627 1628 * Flowing off the end of a non-void function is considered 1629 unreachable and may be subject to optimization on that basis. As a 1630 result of this change, -Wreturn-type warnings are enabled by 1631 default for C++. 1632 1633 Runtime Library (libstdc++) 1634 1635 * Improved experimental support for C++17, including the following 1636 features: 1637 + Deduction guides to support class template argument deduction. 1638 + std::filesystem implementation. 1639 + std::char_traits<char> and std::char_traits<wchar_t> are 1640 usable in constant expressions. 1641 + std::to_chars and std::from_chars (for integers only, not for 1642 floating point types). 1643 * Experimental support for C++2a: std::to_address (thanks to Glen 1644 Fernandes) and std::endian. 1645 * On GNU/Linux, std::random_device::entropy() accesses the kernel's 1646 entropy count for the random device, if known (thanks to Xi 1647 Ruoyao). 1648 * Support for std::experimental::source_location. 1649 * AddressSanitizer integration for std::vector, detecting 1650 out-of-range accesses to the unused capacity of a vector. 1651 * Extensions __gnu_cxx::airy_ai and __gnu_cxx::airy_bi added to the 1652 Mathematical Special Functions. 1653 1654 Fortran 1655 1656 * The main version of libfortran has been changed to 5. 1657 * Parameterized derived types, a major feature of Fortran 2003, have 1658 been implemented. 1659 * Partial support is provided for Fortran 2018 teams, which are 1660 hierarchical subsets of images that execute independently of other 1661 image subsets. 1662 * The maximum rank for arrays has been increased to 15, conforming to 1663 the Fortran 2008 standard. 1664 * Transformational intrinsics are now fully supported in 1665 initialization expressions. 1666 * New flag -fc-prototypes to write C prototypes for BIND(C) 1667 procedures and variables. 1668 * If -fmax-stack-var-size is honored if given together with -Ofast, 1669 -fstack-arrays is no longer set in that case. 1670 * New options -fdefault-real-16 and -fdefault-real-10 to control the 1671 default kind of REAL variables. 1672 * A warning is now issued if an array subscript inside a DO loop 1673 could lead to an out-of-bounds-access. The new option 1674 -Wdo-subscript, enabled by -Wextra, warns about this even if the 1675 compiler can not prove that the code will be executed. 1676 * The Fortran front end now attempts to interchange loops if it is 1677 deemed profitable. So far, this is restricted to FORALL and DO 1678 CONCURRENT statements with multiple indices. This behavior be 1679 controlled with the new flag -ffrontend-loop-interchange, which is 1680 enabled with optimization by default. The 1681 -Wfrontend-loop-interchange option warns about such occurrences. 1682 * When an actual argument contains too few elements for a dummy 1683 argument, an error is now issued. The -std=legacy option can be 1684 used to still compile such code. 1685 * The RECL= argument to OPEN and INQUIRE statements now allows 64-bit 1686 integers, making records larger than 2GiB possible. 1687 * The GFORTRAN_DEFAULT_RECL environment variable no longer has any 1688 effect. The record length for preconnected units is now larger than 1689 any practical limit, same as for sequential access units opened 1690 without an explicit RECL= specifier. 1691 * Character variables longer than HUGE(0) elements are now possible 1692 on 64-bit targets. Note that this changes the procedure call ABI 1693 for all procedures with character arguments on 64-bit targets, as 1694 the type of the hidden character length argument has changed. The 1695 hidden character length argument is now of type INTEGER(C_SIZE_T). 1696 * Partial support is provided for Fortran 2018 teams, which are 1697 hierarchical subsets of images that execute independently of other 1698 image subsets. 1699 1700 Go 1701 1702 * GCC 8 provides a complete implementation of the Go 1.10.1 user 1703 packages. 1704 * The garbage collector is now fully concurrent. As before, values 1705 stored on the stack are scanned conservatively, but value stored in 1706 the heap are scanned precisely. 1707 * Escape analysis is fully implemented and enabled by default in the 1708 Go frontend. This significantly reduces the number of heap 1709 allocations by allocating values on the stack instead. 1710 1711 libgccjit 1712 1713 The libgccjit API gained four new entry points: 1714 * [18]gcc_jit_type_get_vector and 1715 * [19]gcc_jit_context_new_rvalue_from_vector for working with 1716 vectors, 1717 * [20]gcc_jit_type_get_aligned 1718 * [21]gcc_jit_function_get_address 1719 1720 The C code generated by [22]gcc_jit_context_dump_reproducer_to_file is 1721 now easier-to-read. 1722 1723 New Targets and Target Specific Improvements 1724 1725 AArch64 1726 1727 * The Armv8.4-A architecture is now supported. It can be used by 1728 specifying the -march=armv8.4-a option. 1729 * The Dot Product instructions are now supported as an optional 1730 extension to the Armv8.2-A architecture and newer and are mandatory 1731 on Armv8.4-A. The extension can be used by specifying the +dotprod 1732 architecture extension. E.g. -march=armv8.2-a+dotprod. 1733 * The Armv8-A +crypto extension has now been split into two 1734 extensions for finer grained control: 1735 + +aes which contains the Armv8-A AES crytographic instructions. 1736 + +sha2 which contains the Armv8-A SHA2 and SHA1 cryptographic 1737 instructions. 1738 Using +crypto will now enable these two extensions. 1739 * New Armv8.4-A FP16 Floating Point Multiplication Variant 1740 instructions have been added. These instructions are mandatory in 1741 Armv8.4-A but available as an optional extension to Armv8.2-A and 1742 Armv8.3-A. The new extension can be used by specifying the +fp16fml 1743 architectural extension on Armv8.2-A and Armv8.3-A. On Armv8.4-A 1744 the instructions can be enabled by specifying +fp16. 1745 * New cryptographic instructions have been added as optional 1746 extensions to Armv8.2-A and newer. These instructions can be 1747 enabled with: 1748 + +sha3 New SHA3 and SHA2 instructions from Armv8.4-A. This 1749 implies +sha2. 1750 + +sm4 New SM3 and SM4 instructions from Armv8.4-A. 1751 * The Scalable Vector Extension (SVE) is now supported as an optional 1752 extension to the Armv8.2-A architecture and newer. This support 1753 includes automatic vectorization with SVE instructions, but it does 1754 not yet include the SVE Arm C Language Extensions (ACLE). It can be 1755 enabled by specifying the +sve architecture extension (for example, 1756 -march=armv8.2-a+sve). By default, the generated code works with 1757 all vector lengths, but it can be made specific to N-bit vectors 1758 using -msve-vector-bits=N. 1759 * Support has been added for the following processors (GCC 1760 identifiers in parentheses): 1761 + Arm Cortex-A75 (cortex-a75). 1762 + Arm Cortex-A55 (cortex-a55). 1763 + Arm Cortex-A55/Cortex-A75 DynamIQ big.LITTLE 1764 (cortex-a75.cortex-a55). 1765 The GCC identifiers can be used as arguments to the -mcpu or -mtune 1766 options, for example: -mcpu=cortex-a75 or -mtune=cortex-a75 or as 1767 arguments to the equivalent target attributes and pragmas. 1768 1769 ARC 1770 1771 * Added support for: 1772 + Fast interrupts. 1773 + Naked functions. 1774 + aux variable attributes. 1775 + uncached type qualifier. 1776 + Secure functions via sjli instruction. 1777 * New exception handling implementation. 1778 * Revamped trampoline implementation. 1779 * Refactored small data feature implementation, controlled via -G 1780 command line option. 1781 * New support for reduced register set ARC architecture 1782 configurations, controlled via -mrf16 command line option. 1783 * Refurbished and improved support for zero overhead loops. 1784 Introduced -mlpc-width command line option to control the width of 1785 lp_count register. 1786 1787 ARM 1788 1789 * The -mfpu option now takes a new option setting of -mfpu=auto. When 1790 set to this the floating-point and SIMD settings are derived from 1791 the settings of the -mcpu or -march options. The internal CPU 1792 configurations have been updated with information about the 1793 permitted floating-point configurations supported. See the user 1794 guide for further information about the extended option syntax for 1795 controlling architectural extensions via the -march option. 1796 -mfpu=auto is now the default setting unless the compiler has been 1797 configured with an explicit --with-fpu option. 1798 * The -march and -mcpu options now accept optional extensions to the 1799 architecture or CPU option, allowing the user to enable or disable 1800 any such extensions supported by that architecture or CPU such as 1801 (but not limited to) floating-point and AdvancedSIMD. For example: 1802 the option -mcpu=cortex-a53+nofp will generate code for the 1803 Cortex-A53 processor with no floating-point support. This, in 1804 combination with the new -mfpu=auto option, provides a 1805 straightforward way of specifying a valid build target through a 1806 single -mcpu or -march option. The -mtune option accepts the same 1807 arguments as -mcpu but only the CPU name has an effect on tuning. 1808 The architecture extensions do not have any effect. For details of 1809 what extensions a particular architecture or CPU option supports 1810 please refer to the [23]documentation. 1811 * The -mstructure-size-boundary option has been deprecated and will 1812 be removed in a future release. 1813 * The default link behavior for Armv6 and Armv7-R targets has been 1814 changed to produce BE8 format when generating big-endian images. A 1815 new flag -mbe32 can be used to force the linker to produce legacy 1816 BE32 format images. There is no change of behavior for Armv6-M and 1817 other Armv7 or later targets: these already defaulted to BE8 1818 format. This change brings GCC into alignment with other compilers 1819 for the ARM architecture. 1820 * The Armv8-R architecture is now supported. It can be used by 1821 specifying the -march=armv8-r option. 1822 * The Armv8.3-A architecture is now supported. It can be used by 1823 specifying the -march=armv8.3-a option. 1824 * The Armv8.4-A architecture is now supported. It can be used by 1825 specifying the -march=armv8.4-a option. 1826 * The Dot Product instructions are now supported as an optional 1827 extension to the Armv8.2-A architecture and newer and are mandatory 1828 on Armv8.4-A. The extension can be used by specifying the +dotprod 1829 architecture extension. E.g. -march=armv8.2-a+dotprod. 1830 * Support for setting extensions and architectures using the GCC 1831 target pragma and attribute has been added. It can be used by 1832 specifying #pragma GCC target ("arch=..."), #pragma GCC target 1833 ("+extension"), __attribute__((target("arch=..."))) or 1834 __attribute__((target("+extension"))). 1835 * New Armv8.4-A FP16 Floating Point Multiplication Variant 1836 instructions have been added. These instructions are mandatory in 1837 Armv8.4-A but available as an optional extension to Armv8.2-A and 1838 Armv8.3-A. The new extension can be used by specifying the +fp16fml 1839 architectural extension on Armv8.2-A and Armv8.3-A. On Armv8.4-A 1840 the instructions can be enabled by specifying +fp16. 1841 * Support has been added for the following processors (GCC 1842 identifiers in parentheses): 1843 + Arm Cortex-A75 (cortex-a75). 1844 + Arm Cortex-A55 (cortex-a55). 1845 + Arm Cortex-A55/Cortex-A75 DynamIQ big.LITTLE 1846 (cortex-a75.cortex-a55). 1847 + Arm Cortex-R52 for Armv8-R (cortex-r52). 1848 The GCC identifiers can be used as arguments to the -mcpu or -mtune 1849 options, for example: -mcpu=cortex-a75 or -mtune=cortex-r52 or as 1850 arguments to the equivalent target attributes and pragmas. 1851 1852 AVR 1853 1854 * The AVR port now supports the following XMEGA-like devices: 1855 1856 ATtiny212, ATtiny214, ATtiny412, ATtiny414, ATtiny416, ATtiny417, 1857 ATtiny814, ATtiny816, ATtiny817, ATtiny1614, ATtiny1616, ATtiny1617, 1858 ATtiny3214, ATtiny3216, ATtiny3217 1859 The new devices are listed under [24]-mmcu=avrxmega3. 1860 + These devices see flash memory in the RAM address space, so 1861 that features like PROGMEM and __flash are not needed any more 1862 (as opposed to other AVR families for which read-only data 1863 will be located in RAM except special, non-standard features 1864 are used to locate and access such data). This requires that 1865 the compiler is used with Binutils 2.29 or newer so that 1866 [25]read-only data will be located in flash memory. 1867 + A new command-line option -mshort-calls is supported. This 1868 option is used internally for multilib selection of the 1869 avrxmega3 variants. It is not an optimization option. Do not 1870 set it by hand. 1871 * The compiler now generates [26]efficient interrupt service routine 1872 (ISR) prologues and epilogues. This is achieved by using the new 1873 [27]AVR pseudo instruction __gcc_isr which is supported and 1874 resolved by the GNU assembler. 1875 + As the __gcc_isr pseudo-instruction will be resolved by the 1876 assembler, inline assembly is transparent to the process. This 1877 means that when inline assembly uses an instruction like INC 1878 that clobbers the condition code, then the assembler will 1879 detect this and generate an appropriate ISR prologue / 1880 epilogue chunk to save / restore SREG as needed. 1881 + A new command-line option -mno-gas-isr-prologues disables the 1882 generation of the __gcc_isr pseudo instruction. Any non-naked 1883 ISR will save and restore SREG, tmp_reg and zero_reg, no 1884 matter whether the respective register is clobbered or used. 1885 + The feature is turned on per default for all optimization 1886 levels except for -O0 and -Og. It is explicitly enabled by 1887 means of option -mgas-isr-prologues. 1888 + Support has been added for a new [28]AVR function attribute 1889 no_gccisr. It can be used to disable __gcc_isr pseudo 1890 instruction generation for individual ISRs. 1891 + This optimization is only available if GCC is configured with 1892 GNU Binutils 2.29 or newer; or at least with a version of 1893 Binutils that implements feature [29]PR21683. 1894 * The compiler no more saves / restores registers in main; the effect 1895 is the same as if attribute OS_task was specified for main. This 1896 optimization can be switched off by the new command-line option 1897 -mno-main-is-OS_task. 1898 1899 IA-32/x86-64 1900 1901 * The x86 port now supports the naked function attribute. 1902 * Better tuning for znver1 and Intel Core based CPUs. 1903 * Vectorization cost metrics has been reworked leading to significant 1904 improvements on some benchmarks. 1905 * GCC now supports the Intel CPU named Cannonlake through 1906 -march=cannonlake. The switch enables the AVX512VBMI, AVX512IFMA 1907 and SHA ISA extensions. 1908 * GCC now supports the Intel CPU named Icelake through 1909 -march=icelake. The switch enables the AVX512VNNI, GFNI, VAES, 1910 AVX512VBMI2, VPCLMULQDQ, AVX512BITALG, RDPID and AVX512VPOPCNTDQ 1911 ISA extensions. 1912 * GCC now supports the Intel Control-flow Enforcement Technology 1913 (CET) extension through -fcf-protection option. 1914 1915 NDS32 1916 1917 * New command-line options -mext-perf, -mext-perf2, and -mext-string 1918 have been added for performance extension instructions. 1919 1920 Nios II 1921 1922 * The Nios II back end has been improved to generate better-optimized 1923 code. Changes include switching to LRA, more accurate cost models, 1924 and more compact code for addressing static variables. 1925 * New command-line options -mgprel-sec= and -mr0rel-sec= have been 1926 added. 1927 * The stack-smashing protection options are now enabled on Nios II. 1928 1929 PA-RISC 1930 1931 * The default call ABI on 32-bit linux has been changed from callee 1932 copies to caller copies. This affects objects larger than eight 1933 bytes passed by value. The goal is to improve compatibility with 1934 x86 and resolve issues with OpenMP. 1935 * Other PA-RISC targets are unchanged. 1936 1937 PowerPC / PowerPC64 / RS6000 1938 1939 * The PowerPC SPE support is split off to a separate powerpcspe port. 1940 The separate port is deprecated and might be removed in a future 1941 release. 1942 * The Paired Single support (as used on some PPC750 CPUs, -mpaired, 1943 powerpc*-*-linux*paired*) is deprecated and will be removed in a 1944 future release. 1945 * The Xilinx floating point support (-mxilinx-fpu, 1946 powerpc-xilinx-eabi*) is deprecated and will be removed in a future 1947 release. 1948 * Support for using big-endian AltiVec intrinsics on a little-endian 1949 target (-maltivec=be) is deprecated and will be removed in a future 1950 release. 1951 1952 Tile 1953 1954 * The TILE-Gx port is deprecated and will be removed in a future 1955 release. 1956 1957 Operating Systems 1958 1959 Windows 1960 1961 * GCC on Microsoft Windows can now be configured via 1962 --enable-mingw-wildcard or --disable-mingw-wildcard to force a 1963 specific behavior for GCC itself with regards to supporting the 1964 wildcard character. Prior versions of GCC would follow the 1965 configuration of the MinGW runtime. This behavior can still be 1966 obtained by not using the above options or by using 1967 --enable-mingw-wildcard=platform. 1968 1969 Improvements for plugin authors 1970 1971 * Plugins can now register a callback hook for when comments are 1972 encountered by the C and C++ compilers, e.g. allowing for plugins 1973 to handle documentation markup in code comments. 1974 * The gdbinit support script for debugging GCC now has a 1975 break-on-diagnostic command, providing an easy way to trigger a 1976 breakpoint whenever a diagnostic is emitted. 1977 * The API for creating fix-it hints now supports newlines, and for 1978 emitting mutually incompatible fix-it hints for one diagnostic. 1979 1980 GCC 8.1 1981 1982 This is the [30]list of problem reports (PRs) from GCC's bug tracking 1983 system that are known to be fixed in the 8.1 release. This list might 1984 not be complete (that is, it is possible that some PRs that have been 1985 fixed are not listed here). 1986 1987 GCC 8.2 1988 1989 This is the [31]list of problem reports (PRs) from GCC's bug tracking 1990 system that are known to be fixed in the 8.2 release. This list might 1991 not be complete (that is, it is possible that some PRs that have been 1992 fixed are not listed here). 1993 1994 General Improvements 1995 1996 * Fixed LTO link-time performance problems caused by an overflow in 1997 the partitioning algorithm while building large binaries. 1998 1999 Language Specific Changes 2000 2001 C++ 2002 2003 GCC 8.2 fixed a bug introduced in GCC 8.1 affecting passing or 2004 returning of classes with a deleted copy constructor and defaulted 2005 trivial move constructor (bug [32]c++/86094). GCC 8.2 introduces 2006 -fabi-version=13 and makes it the default, ABI incompatibilities 2007 between GCC 8.1 and 8.2 can be reported with -Wabi=12. See [33]C++ 2008 changes for more details. 2009 2010 Target Specific Changes 2011 2012 IA-32/x86-64 2013 2014 * -mtune=native performance regression [34]PR84413 on Intel Skylake 2015 processors has been fixed. 2016 2017 GCC 8.3 2018 2019 This is the [35]list of problem reports (PRs) from GCC's bug tracking 2020 system that are known to be fixed in the 8.3 release. This list might 2021 not be complete (that is, it is possible that some PRs that have been 2022 fixed are not listed here). 2023 2024 Windows 2025 2026 * A C++ Microsoft ABI bitfield layout bug, [36]PR87137 has been 2027 fixed. A non-field declaration could cause the current bitfield 2028 allocation unit to be completed, incorrectly placing a following 2029 bitfield into a new allocation unit. The Microsoft ABI is selected 2030 for: 2031 + Mingw targets 2032 + PowerPC, IA-32 or x86-64 targets when the -mms-bitfields 2033 option is specified, or __attribute__((ms_struct)) is used 2034 + SuperH targets when the -mhitachi option is specified, or 2035 __attribute__((renesas)) is used 2036 GCC 8 introduced additional cases of this defect, but rather than 2037 resolve only those regressions, we decided to resolve all the cases 2038 of this defect in single change. 2039 2040 GCC 8.4 2041 2042 This is the [37]list of problem reports (PRs) from GCC's bug tracking 2043 system that are known to be fixed in the 8.4 release. This list might 2044 not be complete (that is, it is possible that some PRs that have been 2045 fixed are not listed here). 2046 2047 2048 For questions related to the use of GCC, please consult these web 2049 pages and the [38]GCC manuals. If that fails, the 2050 [39]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 2051 web pages and the development of GCC are welcome on our developer 2052 list at [40]gcc (a] gcc.gnu.org. All of [41]our lists have public 2053 archives. 2054 2055 Copyright (C) [42]Free Software Foundation, Inc. Verbatim copying and 2056 distribution of this entire article is permitted in any medium, 2057 provided this notice is preserved. 2058 2059 These pages are [43]maintained by the GCC team. Last modified 2060 2020-03-04[44]. 2061 2062 References 2063 2064 1. http://gcc.gnu.org/gcc-8/porting_to.html 2065 2. http://gcc.gnu.org/onlinedocs/index.html#current 2066 3. https://gcc.gnu.org/ml/gcc/2018-04/msg00102.html 2067 4. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/Warning-Options.html#index-Wmultistatement-macros 2068 5. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/Warning-Options.html#index-Wstringop-truncation 2069 6. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82944 2070 7. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/Warning-Options.html#index-Wif-not-aligned 2071 8. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/Common-Variable-Attributes.html#index-warn_005fif_005fnot_005faligned-variable-attribute 2072 9. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/Warning-Options.html#index-Wmissing-attributes 2073 10. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/Warning-Options.html#index-Wpacked-not-aligned 2074 11. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/Warning-Options.html#index-Warray-bounds 2075 12. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/Warning-Options.html#index-Wrestrict 2076 13. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/Warning-Options.html#index-Wformat-overflow 2077 14. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/Warning-Options.html#index-Wformat-truncation 2078 15. https://gcc.gnu.org/PR86094 2079 16. https://gcc.gnu.org/onlinedocs/gcc/C_002b_002b-Dialect-Options.html#index-Wclass-memaccess 2080 17. http://gcc.gnu.org/projects/cxx-status.html#cxx2a 2081 18. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/jit/topics/types.html#gcc_jit_type_get_vector 2082 19. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/jit/topics/expressions.html#gcc_jit_context_new_rvalue_from_vector 2083 20. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/jit/topics/types.html#gcc_jit_type_get_aligned 2084 21. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/jit/topics/function-pointers.html#gcc_jit_function_get_address 2085 22. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/jit/topics/contexts.html#gcc_jit_context_dump_reproducer_to_file 2086 23. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/ARM-Options.html#ARM-Options 2087 24. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/AVR-Options.html 2088 25. https://sourceware.org/PR21472 2089 26. https://gcc.gnu.org/PR20296 2090 27. https://sourceware.org/binutils/docs-2.29/as/AVR-Pseudo-Instructions.html 2091 28. https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/AVR-Function-Attributes.html 2092 29. https://sourceware.org/PR21683 2093 30. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=8.0 2094 31. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=8.2 2095 32. https://gcc.gnu.org/PR86094 2096 33. http://gcc.gnu.org/gcc-8/changes.html#cxx 2097 34. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84413 2098 35. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=8.3 2099 36. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87137 2100 37. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=8.4 2101 38. https://gcc.gnu.org/onlinedocs/ 2102 39. mailto:gcc-help (a] gcc.gnu.org 2103 40. mailto:gcc (a] gcc.gnu.org 2104 41. https://gcc.gnu.org/lists.html 2105 42. https://www.fsf.org/ 2106 43. https://gcc.gnu.org/about.html 2107 44. http://validator.w3.org/check/referer 2108 ====================================================================== 2109 http://gcc.gnu.org/gcc-7/index.html 2110 GCC 7 Release Series 2111 2112 Nov 14, 2019 2113 2114 The [1]GNU project and the GCC developers are pleased to announce the 2115 release of GCC 7.5. 2116 2117 This release is a bug-fix release, containing fixes for regressions in 2118 GCC 7.4 relative to previous releases of GCC. 2119 2120 Release History 2121 2122 GCC 7.5 2123 Nov 14, 2019 ([2]changes, [3]documentation) 2124 2125 GCC 7.4 2126 Dec 6, 2018 ([4]changes, [5]documentation) 2127 2128 GCC 7.3 2129 Jan 25, 2018 ([6]changes, [7]documentation) 2130 2131 GCC 7.2 2132 Aug 14, 2017 ([8]changes, [9]documentation) 2133 2134 GCC 7.1 2135 May 2, 2017 ([10]changes, [11]documentation) 2136 2137 References and Acknowledgements 2138 2139 GCC used to stand for the GNU C Compiler, but since the compiler 2140 supports several other languages aside from C, it now stands for the 2141 GNU Compiler Collection. 2142 2143 A list of [12]successful builds is updated as new information becomes 2144 available. 2145 2146 The GCC developers would like to thank the numerous people that have 2147 contributed new features, improvements, bug fixes, and other changes as 2148 well as test results to GCC. This [13]amazing group of volunteers is 2149 what makes GCC successful. 2150 2151 For additional information about GCC please refer to the [14]GCC 2152 project web site or contact the [15]GCC development mailing list. 2153 2154 To obtain GCC please use [16]our mirror sites or [17]our version 2155 control system. 2156 2157 2158 For questions related to the use of GCC, please consult these web 2159 pages and the [18]GCC manuals. If that fails, the 2160 [19]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 2161 web pages and the development of GCC are welcome on our developer 2162 list at [20]gcc (a] gcc.gnu.org. All of [21]our lists have public 2163 archives. 2164 2165 Copyright (C) [22]Free Software Foundation, Inc. Verbatim copying and 2166 distribution of this entire article is permitted in any medium, 2167 provided this notice is preserved. 2168 2169 These pages are [23]maintained by the GCC team. Last modified 2170 2020-01-14[24]. 2171 2172 References 2173 2174 1. http://www.gnu.org/ 2175 2. http://gcc.gnu.org/gcc-7/changes.html 2176 3. http://gcc.gnu.org/onlinedocs/7.5.0/ 2177 4. http://gcc.gnu.org/gcc-7/changes.html 2178 5. http://gcc.gnu.org/onlinedocs/7.4.0/ 2179 6. http://gcc.gnu.org/gcc-7/changes.html 2180 7. http://gcc.gnu.org/onlinedocs/7.3.0/ 2181 8. http://gcc.gnu.org/gcc-7/changes.html 2182 9. http://gcc.gnu.org/onlinedocs/7.2.0/ 2183 10. http://gcc.gnu.org/gcc-7/changes.html 2184 11. http://gcc.gnu.org/onlinedocs/7.1.0/ 2185 12. http://gcc.gnu.org/gcc-7/buildstat.html 2186 13. http://gcc.gnu.org/onlinedocs/gcc/Contributors.html 2187 14. http://gcc.gnu.org/index.html 2188 15. mailto:gcc (a] gcc.gnu.org 2189 16. http://gcc.gnu.org/mirrors.html 2190 17. http://gcc.gnu.org/git.html 2191 18. https://gcc.gnu.org/onlinedocs/ 2192 19. mailto:gcc-help (a] gcc.gnu.org 2193 20. mailto:gcc (a] gcc.gnu.org 2194 21. https://gcc.gnu.org/lists.html 2195 22. https://www.fsf.org/ 2196 23. https://gcc.gnu.org/about.html 2197 24. http://validator.w3.org/check/referer 2198 ====================================================================== 2199 http://gcc.gnu.org/gcc-7/changes.html 2200 GCC 7 Release Series 2201 Changes, New Features, and Fixes 2202 2203 This page is a brief summary of some of the huge number of improvements 2204 in GCC 7. For more information, see the [1]Porting to GCC 7 page and 2205 the [2]full GCC documentation. 2206 2207 Caveats 2208 2209 * GCC now uses [3]LRA (a new local register allocator) by default for 2210 new targets. 2211 * The non-standard C++0x type traits has_trivial_default_constructor, 2212 has_trivial_copy_constructor and has_trivial_copy_assign have been 2213 removed. 2214 * The libstdc++ [4]Profile Mode has been deprecated and will be 2215 removed in a future version. 2216 * The Cilk+ extensions to the C and C++ languages have been 2217 deprecated. 2218 * On ARM targets (arm*-*-*), [5]a bug introduced in GCC 5 that 2219 affects conformance to the procedure call standard (AAPCS) has been 2220 fixed. The bug affects some C++ code where class objects are passed 2221 by value to functions and could result in incorrect or inconsistent 2222 code being generated. This is an ABI change. If the option -Wpsabi 2223 is enabled (on by default) the compiler will emit a diagnostic note 2224 for code that might be affected. 2225 2226 General Optimizer Improvements 2227 2228 * GCC 7 can determine the return value or range of return values of 2229 some calls to the sprintf family of functions and make it available 2230 to other optimization passes. Some calls to the snprintf function 2231 with a zero size argument can be folded into constants. This 2232 optimization is included in -O1 and can be selectively controlled 2233 by the -fprintf-return-value option. 2234 * A new store merging pass has been added. It merges constant stores 2235 to adjacent memory locations into fewer, wider, stores. It is 2236 enabled by the -fstore-merging option and at the -O2 optimization 2237 level or higher (and -Os). 2238 * A new code hoisting optimization has been added to the partial 2239 redundancy elimination pass. It attempts to move evaluation of 2240 expressions executed on all paths to the function exit as early as 2241 possible. This primarily helps improve code size, but can improve 2242 the speed of the generated code as well. It is enabled by the 2243 -fcode-hoisting option and at the -O2 optimization level or higher 2244 (and -Os). 2245 * A new interprocedural bitwise constant propagation optimization has 2246 been added, which propagates knowledge about which bits of 2247 variables are known to be zero (including pointer alignment 2248 information) across the call graph. It is enabled by the 2249 -fipa-bit-cp option if -fipa-cp is enabled as well, and is enabled 2250 at the -O2 optimization level and higher (and -Os). This 2251 optimization supersedes interprocedural alignment propagation of 2252 GCC 6, and therefore the option -fipa-cp-alignment is now 2253 deprecated and ignored. 2254 * A new interprocedural value range propagation optimization has been 2255 added, which propagates integral range information across the call 2256 graph when variable values can be proven to be within those ranges. 2257 It is enabled by the -fipa-vrp option and at the -O2 optimization 2258 level and higher (and -Os). 2259 * A new loop splitting optimization pass has been added. Certain 2260 loops which contain a condition that is always true on one side of 2261 the iteration space and always false on the other are split into 2262 two loops, such that each of the two new loops iterates on just one 2263 side of the iteration space and the condition does not need to be 2264 checked inside of the loop. It is enabled by the -fsplit-loops 2265 option and at the -O3 optimization level or higher. 2266 * The shrink-wrapping optimization can now separate portions of 2267 prologues and epilogues to improve performance if some of the work 2268 done traditionally by prologues and epilogues is not needed on 2269 certain paths. This is controlled by the -fshrink-wrap-separate 2270 option, enabled by default. It requires target support, which is 2271 currently only implemented in the PowerPC and AArch64 ports. 2272 * AddressSanitizer gained a new sanitization option, 2273 -fsanitize-address-use-after-scope, which enables sanitization of 2274 variables whose address is taken and used after a scope where the 2275 variable is defined: 2276 2277 int 2278 main (int argc, char **argv) 2279 { 2280 char *ptr; 2281 { 2282 char my_char; 2283 ptr = &my_char; 2284 } 2285 2286 *ptr = 123; 2287 return *ptr; 2288 } 2289 2290 ==28882==ERROR: AddressSanitizer: stack-use-after-scope on address 0x7fffb8dba99 2291 0 at pc 0x0000004006d5 bp 0x7fffb8dba960 sp 0x7fffb8dba958 2292 WRITE of size 1 at 0x7fffb8dba990 thread T0 2293 #0 0x4006d4 in main /tmp/use-after-scope-1.c:10 2294 #1 0x7f9c71943290 in __libc_start_main (/lib64/libc.so.6+0x20290) 2295 #2 0x400739 in _start (/tmp/a.out+0x400739) 2296 2297 Address 0x7fffb8dba990 is located in stack of thread T0 at offset 32 in frame 2298 #0 0x40067f in main /tmp/use-after-scope-1.c:3 2299 2300 This frame has 1 object(s): 2301 [32, 33) 'my_char' <== Memory access at offset 32 is inside this variable 2302 2303 The option is enabled by default with -fsanitize=address and 2304 disabled by default with -fsanitize=kernel-address. Compared to the 2305 LLVM compiler, where the option already exists, the implementation 2306 in the GCC compiler has some improvements and advantages: 2307 + Complex uses of gotos and case labels are properly handled and 2308 should not report any false positive or false negatives. 2309 + C++ temporaries are sanitized. 2310 + Sanitization can handle invalid memory stores that are 2311 optimized out by the LLVM compiler when optimization is 2312 enabled. 2313 * The -fsanitize=signed-integer-overflow suboption of the 2314 UndefinedBehavior Sanitizer now diagnoses arithmetic overflows even 2315 on arithmetic operations with generic vectors. 2316 * Version 5 of the [6]DWARF debugging information standard is 2317 supported through the -gdwarf-5 option. The DWARF version 4 2318 debugging information remains the default until consumers of 2319 debugging information are adjusted. 2320 2321 New Languages and Language specific improvements 2322 2323 OpenACC support in C, C++, and Fortran continues to be maintained and 2324 improved. See the [7]OpenACC and [8]Offloading wiki pages for further 2325 information. 2326 2327 Ada 2328 2329 * On mainstream native platforms, Ada programs no longer require the 2330 stack to be made executable in order to run properly. 2331 2332 BRIG (HSAIL) 2333 2334 Support for processing BRIG 1.0 files was added in this release. BRIG 2335 is a binary format for HSAIL (Heterogeneous System Architecture 2336 Intermediate Language). The BRIG front end can be used for implementing 2337 HSAIL "finalizers" (compilation of HSAIL to a native ISA) for 2338 GCC-supported targets. An implementation of an HSAIL runtime library, 2339 libhsail-rt is also included. 2340 2341 C family 2342 2343 * New command-line options have been added for the C and C++ 2344 compilers: 2345 + -Wimplicit-fallthrough warns when a switch case falls through. 2346 This warning has five different levels. The compiler is able 2347 to parse a wide range of fallthrough comments, depending on 2348 the level. It also handles control-flow statements, such as 2349 ifs. It's possible to suppress the warning by either adding a 2350 fallthrough comment, or by using a null statement: 2351 __attribute__ ((fallthrough)); (C, C++), or [[fallthrough]]; 2352 (C++17), or [[gnu::fallthrough]]; (C++11/C++14). This warning 2353 is enabled by -Wextra. 2354 + -Wpointer-compare warns when a pointer is compared with a zero 2355 character constant. Such code is now invalid in C++11 and GCC 2356 rejects it. This warning is enabled by default. 2357 + -Wduplicated-branches warns when an if-else has identical 2358 branches. 2359 + -Wrestrict warns when an argument passed to a 2360 restrict-qualified parameter aliases with another argument. 2361 + -Wmemset-elt-size warns for memset calls, when the first 2362 argument references an array, and the third argument is a 2363 number equal to the number of elements of the array, but not 2364 the size of the array. This warning is enabled by -Wall. 2365 + -Wint-in-bool-context warns about suspicious uses of integer 2366 values where boolean values are expected. This warning is 2367 enabled by -Wall. 2368 + -Wswitch-unreachable warns when a switch statement has 2369 statements between the controlling expression and the first 2370 case label which will never be executed. This warning is 2371 enabled by default. 2372 + -Wexpansion-to-defined warns when defined is used outside #if. 2373 This warning is enabled by -Wextra or -Wpedantic. 2374 + -Wregister warns about uses of the register storage specifier. 2375 In C++17 this keyword has been removed and for C++17 this is a 2376 pedantic warning enabled by default. The warning is not 2377 emitted for the GNU Explicit Register Variables extension. 2378 + -Wvla-larger-than=N warns about unbounded uses of 2379 variable-length arrays, and about bounded uses of 2380 variable-length arrays whose bound can be larger than N bytes. 2381 + -Wduplicate-decl-specifier warns when a declaration has 2382 duplicate const, volatile, restrict or _Atomic specifier. This 2383 warning is enabled by -Wall. 2384 * GCC 6's C and C++ front ends were able to offer suggestions for 2385 misspelled field names: 2386 2387 spellcheck-fields.cc:52:13: error: 'struct s' has no member named 'colour'; did 2388 you mean 'color'? 2389 return ptr->colour; 2390 ^~~~~~ 2391 2392 GCC 7 greatly expands the scope of these suggestions. Firstly, it 2393 adds fix-it hints to such suggestions: 2394 2395 spellcheck-fields.cc:52:13: error: 'struct s' has no member named 'colour'; did 2396 you mean 'color'? 2397 return ptr->colour; 2398 ^~~~~~ 2399 color 2400 2401 The suggestions now cover many other things, such as misspelled 2402 function names: 2403 2404 spellcheck-identifiers.c:11:3: warning: implicit declaration of function 'gtk_wi 2405 dget_showall'; did you mean 'gtk_widget_show_all'? [-Wimplicit-function-declarat 2406 ion] 2407 gtk_widget_showall (w); 2408 ^~~~~~~~~~~~~~~~~~ 2409 gtk_widget_show_all 2410 2411 misspelled macro names and enum values: 2412 2413 spellcheck-identifiers.cc:85:11: error: 'MAX_ITEM' undeclared here (not in a fun 2414 ction); did you mean 'MAX_ITEMS'? 2415 int array[MAX_ITEM]; 2416 ^~~~~~~~ 2417 MAX_ITEMS 2418 2419 misspelled type names: 2420 2421 spellcheck-typenames.c:7:14: error: unknown type name 'singed'; did you mean 'si 2422 gned'? 2423 void test (singed char e); 2424 ^~~~~~ 2425 signed 2426 2427 and, in the C front end, named initializers: 2428 2429 test.c:7:20: error: 'struct s' has no member named 'colour'; did you mean 'color 2430 '? 2431 struct s test = { .colour = 3 }; 2432 ^~~~~~ 2433 color 2434 2435 * The preprocessor can now offer suggestions for misspelled 2436 directives, e.g.: 2437 2438 test.c:5:2: error:invalid preprocessing directive #endfi; did you mean #endif? 2439 #endfi 2440 ^~~~~ 2441 endif 2442 2443 * Warnings about format strings now underline the pertinent part of 2444 the string, and can offer suggested fixes. In some cases, the 2445 pertinent argument is underlined. 2446 2447 test.c:51:29: warning: format '%s' expects argument of type 'char *', but argume 2448 nt 3 has type 'int' [-Wformat=] 2449 printf ("foo: %d bar: %s baz: %d", 100, i + j, 102); 2450 ~^ ~~~~~ 2451 %d 2452 2453 * The new -Wdangling-else command-line option has been split out of 2454 -Wparentheses and warns about dangling else. 2455 * The -Wshadow warning has been split into three variants. 2456 -Wshadow=global warns for any shadowing. This is the default when 2457 using -Wshadow without any argument. -Wshadow=local only warns for 2458 a local variable shadowing another local variable or parameter. 2459 -Wshadow=compatible-local only warns for a local variable shadowing 2460 another local variable or parameter whose type is compatible (in 2461 C++ compatible means that the type of the shadowing variable can be 2462 converted to that of the shadowed variable). 2463 The following example shows the different kinds of shadow warnings: 2464 2465 enum operation { add, count }; 2466 struct container { int nr; }; 2467 2468 int 2469 container_count (struct container c, int count) 2470 { 2471 int r = 0; 2472 for (int count = 0; count > 0; count--) 2473 { 2474 struct container count = c; 2475 r += count.nr; 2476 } 2477 return r; 2478 } 2479 2480 -Wshadow=compatible-local will warn for the parameter being 2481 shadowed with the same type: 2482 2483 warn-test.c:8:12: warning: declaration of 'count' shadows a parameter [-Wshadow= 2484 compatible-local] 2485 for (int count = 0; count > 0; count--) 2486 ^~~~~ 2487 warn-test.c:5:42: note: shadowed declaration is here 2488 container_count (struct container c, int count) 2489 ^~~~~ 2490 2491 -Wshadow=local will warn for the above and for the shadowed 2492 declaration with incompatible type: 2493 2494 warn-test.c:10:24: warning: declaration of 'count' shadows a previous local [-Ws 2495 hadow=local] 2496 struct container count = c; 2497 ^~~~~ 2498 warn-test.c:8:12: note: shadowed declaration is here 2499 for (int count = 0; count > 0; count--) 2500 ^~~~~ 2501 2502 -Wshadow=global will warn for all of the above and the shadowing of 2503 the global declaration: 2504 2505 warn-test.c:5:42: warning: declaration of 'count' shadows a global declaration [ 2506 -Wshadow] 2507 container_count (struct container c, int count) 2508 ^~~~~ 2509 warn-test.c:1:23: note: shadowed declaration is here 2510 enum operation { add, count }; 2511 ^~~~~ 2512 2513 * GCC 7 contains a number of enhancements that help detect buffer 2514 overflow and other forms of invalid memory accesses. 2515 + The -Walloc-size-larger-than=size option detects calls to 2516 standard and user-defined memory allocation functions 2517 decorated with attribute alloc_size whose argument exceeds the 2518 specified size (PTRDIFF_MAX by default). The option also 2519 detects arithmetic overflow in the computation of the size in 2520 two-argument allocation functions like calloc where the total 2521 size is the product of the two arguments. Since calls with an 2522 excessive size cannot succeed they are typically the result of 2523 programming errors. Such bugs have been known to be the source 2524 of security vulnerabilities and a target of exploits. 2525 -Walloc-size-larger-than=PTRDIFF_MAX is included in -Wall. 2526 For example, the following call to malloc incorrectly tries to 2527 avoid passing a negative argument to the function and instead 2528 ends up unconditionally invoking it with an argument less than 2529 or equal to zero. Since after conversion to the type of the 2530 argument of the function (size_t) a negative argument results 2531 in a value in excess of the maximum PTRDIFF_MAX the call is 2532 diagnosed. 2533 2534 void* f (int n) 2535 { 2536 return malloc (n > 0 ? 0 : n); 2537 } 2538 2539 warning: argument 1 range [2147483648, 4294967295] exceeds maximum object size 2 2540 147483647 [-Walloc-size-larger-than=] 2541 2542 + The -Walloc-zero option detects calls to standard and 2543 user-defined memory allocation functions decorated with 2544 attribute alloc_size with a zero argument. -Walloc-zero is not 2545 included in either -Wall or -Wextra and must be explicitly 2546 enabled. 2547 + The -Walloca option detects all calls to the alloca function 2548 in the program. -Walloca is not included in either -Wall or 2549 -Wextra and must be explicitly enabled. 2550 + The -Walloca-larger-than=size option detects calls to the 2551 alloca function whose argument either may exceed the specified 2552 size, or that is not known to be sufficiently constrained to 2553 avoid exceeding it. -Walloca-larger-than is not included in 2554 either -Wall or -Wextra and must be explicitly enabled. 2555 For example, compiling the following snippet with 2556 -Walloca-larger-than=1024 results in a warning because even 2557 though the code appears to call alloca only with sizes of 1kb 2558 and less, since n is signed, a negative value would result in 2559 a call to the function well in excess of the limit. 2560 2561 void f (int n) 2562 { 2563 char *d; 2564 if (n < 1025) 2565 d = alloca (n); 2566 else 2567 d = malloc (n); 2568 2569 } 2570 2571 warning: argument to 'alloca may be too large due to conversion from 'int' to 'l 2572 ong unsigned int' [-Walloca-larger-than=] 2573 2574 In contrast, a call to alloca that isn't bounded at all such 2575 as in the following function will elicit the warning below 2576 regardless of the size argument to the option. 2577 2578 void f (size_t n) 2579 { 2580 char *d = alloca (n); 2581 2582 } 2583 2584 warning: unbounded use of 'alloca' [-Walloca-larger-than=] 2585 2586 + The -Wformat-overflow=level option detects certain and likely 2587 buffer overflow in calls to the sprintf family of formatted 2588 output functions. Although the option is enabled even without 2589 optimization it works best with -O2 and higher. 2590 For example, in the following snippet the call to sprintf is 2591 diagnosed because even though its output has been constrained 2592 using the modulo operation it could result in as many as three 2593 bytes if mday were negative. The solution is to either 2594 allocate a larger buffer or make sure the argument is not 2595 negative, for example by changing mday's type to unsigned or 2596 by making the type of the second operand of the modulo 2597 expression unsigned: 100U. 2598 2599 void* f (int mday) 2600 { 2601 char *buf = malloc (3); 2602 sprintf (buf, "%02i", mday % 100); 2603 return buf; 2604 } 2605 2606 warning: 'sprintf may write a terminating nul past the end of the destination [- 2607 Wformat-overflow=] 2608 note: 'sprintf' output between 3 and 4 bytes into a destination of size 3 2609 2610 + The -Wformat-truncation=level option detects certain and 2611 likely output truncation in calls to the snprintf family of 2612 formatted output functions. -Wformat-truncation=1 is included 2613 in -Wall and enabled without optimization but works best with 2614 -O2 and higher. 2615 For example, the following function attempts to format an 2616 integer between 0 and 255 in hexadecimal, including the 0x 2617 prefix, into a buffer of four characters. But since the 2618 function must always terminate output by the null character 2619 ('\0') such a buffer is only big enough to fit just one digit 2620 plus the prefix. Therefore the snprintf call is diagnosed. To 2621 avoid the warning either use a bigger buffer or handle the 2622 function's return value which indicates whether or not its 2623 output has been truncated. 2624 2625 void f (unsigned x) 2626 { 2627 char d[4]; 2628 snprintf (d, sizeof d, "%#02x", x & 0xff); 2629 2630 } 2631 2632 warning: 'snprintf' output may be truncated before the last format character [-W 2633 format-truncation=] 2634 note: 'snprintf' output between 3 and 5 bytes into a destination of size 4 2635 2636 + The -Wnonnull option has been enhanced to detect a broader set 2637 of cases of passing null pointers to functions that expect a 2638 non-null argument (those decorated with attribute nonnull). By 2639 taking advantage of optimizations the option can detect many 2640 more cases of the problem than in prior GCC versions. 2641 + The -Wstringop-overflow=type option detects buffer overflow in 2642 calls to string handling functions like memcpy and strcpy. The 2643 option relies on [9]Object Size Checking and has an effect 2644 similar to defining the _FORTIFY_SOURCE macro. 2645 -Wstringop-overflow=2 is enabled by default. 2646 For example, in the following snippet, because the call to 2647 strncat specifies a maximum that allows the function to write 2648 past the end of the destination, it is diagnosed. To correct 2649 the problem and avoid the overflow the function should be 2650 called with a size of at most sizeof d - strlen(d) - 1. 2651 2652 void f (const char *fname) 2653 { 2654 char d[8]; 2655 strncpy (d, "/tmp/", sizeof d); 2656 strncat (d, fname, sizeof d); 2657 2658 } 2659 2660 warning: specified bound 8 equals the size of the destination [-Wstringop-overfl 2661 ow=] 2662 2663 * The <limits.h> header provided by GCC defines macros such as 2664 INT_WIDTH for the width in bits of integer types, if 2665 __STDC_WANT_IEC_60559_BFP_EXT__ is defined before the header is 2666 included. The <stdint.h> header defines such macros as SIZE_WIDTH 2667 and INTMAX_WIDTH for the width of some standard typedef names for 2668 integer types, again if __STDC_WANT_IEC_60559_BFP_EXT__ is defined 2669 before the header is included; note that GCC's implementation of 2670 this header is only used for freestanding compilations, not hosted 2671 compilations, on most systems. These macros come from ISO/IEC TS 2672 18661-1:2014. 2673 * The <float.h> header provided by GCC defines the macro 2674 CR_DECIMAL_DIG, from ISO/IEC TS 18661-1:2014, if 2675 __STDC_WANT_IEC_60559_BFP_EXT__ is defined before the header is 2676 included. This represents the number of decimal digits for which 2677 conversions between decimal character strings and binary formats, 2678 in both directions, are correctly rounded, and currently has the 2679 value of UINTMAX_MAX on all systems, reflecting that GCC's 2680 compile-time conversions are correctly rounded for any number of 2681 digits. 2682 * New __builtin_add_overflow_p, __builtin_sub_overflow_p, 2683 __builtin_mul_overflow_p built-in functions have been added. These 2684 work similarly to their siblings without the _p suffix, but do not 2685 actually store the result of the arithmetics anywhere, just return 2686 whether the operation would overflow. Calls to these built-ins with 2687 integer constant arguments evaluate to integer constants 2688 expressions. 2689 For example, in the following, c is assigned the result of a * b 2690 only if the multiplication does not overflow, otherwise it is 2691 assigned the value zero. The multiplication is performed at 2692 compile-time and without triggering a -Woverflow warning. 2693 2694 enum { 2695 a = 12345678, 2696 b = 87654321, 2697 c = __builtin_mul_overflow_p (a, b, a) ? 0 : a * b 2698 }; 2699 2700 C 2701 2702 * The C front end now supports type names _FloatN for floating-point 2703 types with IEEE interchange formats and _FloatNx for floating-point 2704 types with IEEE extended formats. These type names come from 2705 ISO/IEC TS 18661-3:2015. 2706 The set of types supported depends on the target for which GCC is 2707 configured. Most targets support _Float32, _Float32x and _Float64. 2708 _Float128 is supported on targets where IEEE binary128 encoding was 2709 already supported as long double or __float128. _Float64x is 2710 supported on targets where a type with either binary128 or Intel 2711 extended precision format is available. 2712 Constants with these types are supported using suffixes fN, FN, fNx 2713 and FNx (e.g., 1.2f128 or 2.3F64x). Macros such as FLT128_MAX are 2714 defined in <float.h> if __STDC_WANT_IEC_60559_TYPES_EXT__ is 2715 defined before it is included. 2716 These new types are always distinct from each other and from float, 2717 double and long double, even if they have the same encoding. 2718 Complex types such as _Complex _Float128 are also supported. 2719 Type-generic built-in functions such as __builtin_isinf support the 2720 new types, and the following type-specific built-in functions have 2721 versions (suffixed fN or fNx) for the new types: 2722 __builtin_copysign, __builtin_fabs, __builtin_huge_val, 2723 __builtin_inf, __builtin_nan, __builtin_nans. 2724 * Compilation with -fopenmp is now compatible with the C11 _Atomic 2725 keyword. 2726 2727 C++ 2728 2729 * The C++ front end has experimental support for all of the current 2730 C++17 draft with the -std=c++1z or -std=gnu++1z flags, including if 2731 constexpr, class template argument deduction, auto template 2732 parameters, and structured bindings. For a full list of new 2733 features, see [10]the C++ status page. 2734 * C++17 support for new of over-aligned types can be enabled in other 2735 modes with the -faligned-new flag. 2736 * The C++17 evaluation order requirements can be selected in other 2737 modes with the -fstrong-eval-order flag, or disabled in C++17 mode 2738 with -fno-strong-eval-order. 2739 * The default semantics of inherited constructors has changed in all 2740 modes, following [11]P0136. Essentially, overload resolution 2741 happens as if calling the inherited constructor directly, and the 2742 compiler fills in construction of the other bases and members as 2743 needed. Most uses should not need any changes. The old behavior can 2744 be restored with -fno-new-inheriting-ctors, or -fabi-version less 2745 than 11. 2746 * The resolution of DR 150 on matching of template template 2747 parameters, allowing default template arguments to make a template 2748 match a parameter, is currently enabled by default in C++17 mode 2749 only. The default can be overridden with -f{no-,}new-ttp-matching. 2750 * The C++ front end will now provide fix-it hints for some missing 2751 semicolons, allowing for automatic fixes by IDEs: 2752 2753 test.cc:4:11: error: expected ';' after class definition 2754 class a {} 2755 ^ 2756 ; 2757 2758 * -Waligned-new has been added to the C++ front end. It warns about 2759 new of type with extended alignment without -faligned-new. 2760 2761 Runtime Library (libstdc++) 2762 2763 * The type of exception thrown by iostreams, std::ios_base::failure, 2764 now uses the [12]cxx11 ABI. 2765 * Experimental support for C++17, including the following new 2766 features: 2767 + std::string_view; 2768 + std::any, std::optional, and std::variant; 2769 + std::invoke, std::is_invocable, std::is_nothrow_invocable, and 2770 invoke_result; 2771 + std::is_swappable, and std::is_nothrow_swappable; 2772 + std::apply, and std::make_from_tuple; 2773 + std::void_t, std::bool_constant, std::conjunction, 2774 std::disjunction, and std::negation; 2775 + Variable templates for type traits; 2776 + Mathematical Special Functions; 2777 + std::chrono::floor, std::chrono::ceil, std::chrono::round, and 2778 std::chrono::abs; 2779 + std::clamp, std::gcd, std::lcm, 3-dimensional std::hypot; 2780 + std::scoped_lock, std::shared_mutex, 2781 std::atomic<T>::is_always_lock_free; 2782 + std::sample, std::default_searcher, std::boyer_moore_searcher 2783 and std::boyer_moore_horspool_searcher; 2784 + Extraction and re-insertion of map and set nodes, try_emplace 2785 members for maps, and functions for accessing containers 2786 std::size, std::empty, and std::data; 2787 + std::shared_ptr support for arrays, 2788 std::shared_ptr<T>::weak_type, 2789 std::enable_shared_from_this<T>::weak_from_this(), and 2790 std::owner_less<void>; 2791 + std::byte; 2792 + std::as_const, std::not_fn, 2793 std::has_unique_object_representations, constexpr 2794 std::addressof. 2795 Thanks to Daniel Krgler, Tim Shen, Edward Smith-Rowland, and Ville 2796 Voutilainen for work on the C++17 support. 2797 * A new power-of-two rehashing policy for use with the _Hashtable 2798 internals, thanks to Franois Dumont. 2799 2800 Fortran 2801 2802 * Support for a number of extensions for compatibility with legacy 2803 code with new flags: 2804 + -fdec-structure Support for DEC STRUCTURE and UNION 2805 + -fdec-intrinsic-ints Support for new integer intrinsics with 2806 B/I/J/K prefixes such as BABS, JIAND... 2807 + -fdec-math Support for additional math intrinsics, including 2808 COTAN and degree-valued trigonometric functions such as TAND, 2809 ASIND... 2810 + -fdec Enable the -fdec-* family of extensions. 2811 * New flag -finit-derived to allow default initialization of 2812 derived-type variables. 2813 * Improved DO loops with step equal to 1 or -1, generates faster code 2814 without a loop preheader. A new warning, -Wundefined-do-loop, warns 2815 when a loop iterates either to HUGE(i) (with step equal to 1), or 2816 to -HUGE(i) (with step equal to -1). Invalid behavior can be caught 2817 at run time with -fcheck=do enabled: 2818 2819 program test 2820 implicit none 2821 integer(1) :: i 2822 do i = -HUGE(i)+10, -HUGE(i)-1, -1 2823 print *, i 2824 end do 2825 end program test 2826 2827 At line 8 of file do_check_12.f90 2828 Fortran runtime error: Loop iterates infinitely 2829 2830 * Version 4.5 of the [13]OpenMP specification is now partially 2831 supported in the Fortran compiler; the largest missing item is 2832 structure element mapping. 2833 * User-defined derived-type input/output (UDTIO) is added. 2834 * Derived type coarrays with allocatable and pointer components are 2835 partially supported. 2836 * Non-constant stop codes and error stop codes (Fortran 2015 2837 feature). 2838 * Derived types with allocatable components of recursive type. 2839 * Intrinsic assignment to polymorphic variables. 2840 * Improved submodule support. 2841 * Improved diagnostics (polymorphic results in pure functions). 2842 * Coarray: Support for failed images (Fortan 2015 feature). 2843 2844 Go 2845 2846 * GCC 7 provides a complete implementation of the Go 1.8.1 user 2847 packages. 2848 * Compared to the Go 1.8.1 toolchain, the garbage collector is more 2849 conservative and less concurrent. 2850 * Escape analysis is available for experimental use via the 2851 -fgo-optimize-allocs option. The -fgo-debug-escape prints 2852 information useful for debugging escape analysis choices. 2853 2854 Java (GCJ) 2855 2856 The GCC Java front end and associated libjava runtime library have been 2857 removed from GCC. 2858 2859 libgccjit 2860 2861 The libgccjit API gained support for marking calls as requiring 2862 tail-call optimization via a new entry point: 2863 [14]gcc_jit_rvalue_set_bool_require_tail_call. 2864 2865 libgccjit performs numerous checks at the API boundary, but if these 2866 succeed, it previously ignored errors and other diagnostics emitted 2867 within the core of GCC, and treated the compile of a gcc_jit_context as 2868 having succeeded. As of GCC 7 it now ensures that if any diagnostics 2869 are emitted, they are visible from the libgccjit API, and that the the 2870 context is flagged as having failed. 2871 2872 New Targets and Target Specific Improvements 2873 2874 AArch64 2875 2876 * GCC has been updated to the latest revision of the procedure call 2877 standard (AAPCS64) to provide support for parameter passing when 2878 data types have been over-aligned. 2879 * The ARMv8.3-A architecture is now supported. It can be used by 2880 specifying the -march=armv8.3-a option. 2881 * The option -msign-return-address= is supported to enable return 2882 address protection using ARMv8.3-A Pointer Authentication 2883 Extensions. For more information on the arguments accepted by this 2884 option, please refer to [15]AArch64-Options. 2885 * The ARMv8.2-A architecture and the ARMv8.2-A 16-bit Floating-Point 2886 Extensions are now supported. They can be used by specifying the 2887 -march=armv8.2-a or -march=armv8.2-a+fp16 options. The 16-bit 2888 Floating-Point Extensions introduce new half-precision data 2889 processing floating-point instructions. 2890 * Support has been added for the following processors (GCC 2891 identifiers in parentheses): ARM Cortex-A73 (cortex-a73), Broadcom 2892 Vulcan (vulcan), Cavium ThunderX CN81xx (thunderxt81), Cavium 2893 ThunderX CN83xx (thunderxt83), Cavium ThunderX CN88xx 2894 (thunderxt88), Cavium ThunderX CN88xx pass 1.x (thunderxt88p1), 2895 Cavium ThunderX 2 CN99xx (thunderx2t99), Qualcomm Falkor (falkor). 2896 The GCC identifiers can be used as arguments to the -mcpu or -mtune 2897 options, for example: -mcpu=cortex-a73 or -mtune=vulcan or as 2898 arguments to the equivalent target attributes and pragmas. 2899 2900 ARC 2901 2902 * Added support for ARC HS and ARC EM processors. 2903 * Added support for ARC EM variation found in Intel QuarkSE SoCs. 2904 * Added support for NPS400 ARC700 based CPUs. 2905 * Thread Local Storage is now supported by ARC CPUs. 2906 * Fixed errors for ARC600 when using 32x16 multiplier option. 2907 * Fixed PIE for ARC CPUs. 2908 * New CPU templates are supported via multilib. 2909 2910 ARM 2911 2912 * Support for the ARMv5 and ARMv5E architectures has been deprecated 2913 (which have no known implementations) and will be removed in a 2914 future GCC release. Note that ARMv5T, ARMv5TE and ARMv5TEJ 2915 architectures remain supported. The values armv5 and armv5e of 2916 -march are thus deprecated. 2917 * The ARMv8.2-A architecture and the ARMv8.2-A 16-bit Floating-Point 2918 Extensions are now supported. They can be used by specifying the 2919 -march=armv8.2-a or -march=armv8.2-a+fp16 options. The 16-bit 2920 Floating-Point Extensions introduce new half-precision data 2921 processing floating-point instructions. 2922 * The ARMv8-M architecture is now supported in its two architecture 2923 profiles: ARMv8-M Baseline and ARMv8-M Mainline with its DSP and 2924 Floating-Point Extensions. They can be used by specifying the 2925 -march=armv8-m.base, armv8-m.main or armv8-m.main+dsp options. 2926 * Support has been added for the following processors (GCC 2927 identifiers in parentheses): ARM Cortex-A73 (cortex-a73), ARM 2928 Cortex-M23 (cortex-m23) and ARM Cortex-M33 (cortex-m33). The GCC 2929 identifiers can be used as arguments to the -mcpu or -mtune 2930 options, for example: -mcpu=cortex-a73 or -mtune=cortex-m33. 2931 * A new command-line option -mpure-code has been added. It does not 2932 allow constant data to be placed in code sections. This option is 2933 only available when generating non-PIC code for ARMv7-M targets. 2934 * Support for the ACLE Coprocessor Intrinsics has been added. This 2935 enables the generation of coprocessor instructions through the use 2936 of intrinsics such as cdp, ldc, and others. 2937 * The configure option --with-multilib-list now accepts the value 2938 rmprofile to build multilib libraries for a range of embedded 2939 targets. See our [16]installation instructions for details. 2940 2941 AVR 2942 2943 * On the reduced Tiny cores, the progmem [17]variable attribute is 2944 now properly supported. Respective read-only variables are located 2945 in flash memory in section .progmem.data. No special code is needed 2946 to access such variables; the compiler automatically adds an offset 2947 of 0x4000 to all addresses, which is needed to access variables in 2948 flash memory. As opposed to ordinary cores where it is sufficient 2949 to specify the progmem attribute with definitions, on the reduced 2950 Tiny cores the attribute also has to be specified with (external) 2951 declarations: 2952 2953 extern const int array[] __attribute__((__progmem__)); 2954 2955 int get_value2 (void) 2956 { 2957 /* Access via addresses array + 0x4004 and array + 0x4005. */ 2958 return array[2]; 2959 } 2960 2961 const int* get_address (unsigned idx) 2962 { 2963 /* Returns array + 0x4000 + 2 * idx. */ 2964 return &array[idx]; 2965 } 2966 2967 * A new command-line option -Wmisspelled-isr has been added. It turns 2968 off or turns into errors warnings that are reported for 2969 interrupt service routines (ISRs) which don't follow AVR-LibC's 2970 naming convention of prefixing ISR names with __vector. 2971 * __builtin_avr_nops(n) is a new [18]built-in function that inserts n 2972 NOP instructions into the instruction stream. n must be a value 2973 known at compile time. 2974 2975 IA-32/x86-64 2976 2977 * Support for the AVX-512 Fused Multiply Accumulation Packed Single 2978 precision (4FMAPS), AVX-512 Vector Neural Network Instructions Word 2979 variable precision (4VNNIW), AVX-512 Vector Population Count 2980 (VPOPCNTDQ) and Software Guard Extensions (SGX) ISA extensions has 2981 been added. 2982 2983 NVPTX 2984 2985 * OpenMP target regions can now be offloaded to NVidia PTX GPGPUs. 2986 See the [19]Offloading Wiki on how to configure it. 2987 2988 PowerPC / PowerPC64 / RS6000 2989 2990 * The PowerPC port now uses LRA by default. 2991 * GCC now diagnoses inline assembly that clobbers register r2. This 2992 has always been invalid code, and is no longer quietly tolerated. 2993 * The PowerPC port's support for ISA 3.0 (-mcpu=power9) has been 2994 enhanced to generate more of the new instructions by default, and 2995 to provide more built-in functions to generate code for other new 2996 instructions. 2997 * The configuration option --enable-gnu-indirect-function is now 2998 enabled by default on PowerPC GNU/Linux builds. 2999 * The PowerPC port will now allow 64-bit and 32-bit integer types to 3000 be allocated to the VSX vector registers (ISA 2.06 and above). In 3001 addition, on ISA 3.0, 16-bit and 8-bit integer types can be 3002 allocated in the vector registers. Previously, only 64-bit integer 3003 types were allowed in the traditional floating point registers. 3004 * New options -mstack-protector-guard=global, 3005 -mstack-protector-guard=tls, -mstack-protector-guard-reg=, and 3006 -mstack-protector-guard-offset= change how the stack protector gets 3007 the value to use as canary. 3008 3009 S/390, System z, IBM z Systems, IBM Z 3010 3011 * Support for the IBM z14 processor has been added. When using the 3012 -march=z14 option, the compiler will generate code making use of 3013 the new instructions introduced with the vector enhancement 3014 facility and the miscellaneous instruction extension facility 2. 3015 The -mtune=z14 option enables z14 specific instruction scheduling 3016 without making use of new instructions. 3017 * Builtins for the new vector instructions have been added and can be 3018 enabled using the -mzvector option. 3019 3020 RISC-V 3021 3022 * Support for the RISC-V instruction set has been added. 3023 3024 RX 3025 3026 Basic support for atomic built-in function has been added. It is 3027 currently implemented by flipping interrupts off and on as needed. 3028 3029 SH 3030 3031 * Support for SH5/SH64 has been removed. 3032 * Improved utilization of delay slots on SH2A. 3033 * Improved utilization of zero-displacement conditional branches. 3034 * The following deprecated options have been removed 3035 + -mcbranchdi 3036 + -mcmpeqdi 3037 + -minvalid-symbols 3038 + -msoft-atomic 3039 + -mspace 3040 + -madjust-unroll 3041 * Support for the following SH2A instructions has been added 3042 + mov.b @-Rm,R0 3043 + mov.w @-Rm,R0 3044 + mov.l @-Rm,R0 3045 + mov.b R0,@Rn+ 3046 + mov.w R0,@Rn+ 3047 + mov.l R0,@Rn+ 3048 3049 SPARC 3050 3051 * The SPARC port now uses LRA by default. 3052 * Support for the new Subtract-Extended-with-Carry instruction 3053 available in SPARC M7 (Niagara 7) has been added. 3054 3055 Operating Systems 3056 3057 AIX 3058 3059 * Visibility support has been enabled for AIX 7.1 and above. 3060 3061 Fuchsia 3062 3063 * Support has been added for the [20]Fuchsia OS. 3064 3065 RTEMS 3066 3067 * The ABI changes on ARM so that no short enums are used by default. 3068 3069 Other significant improvements 3070 3071 * -fverbose-asm previously emitted information on the meanings of 3072 assembly expressions. This has been extended so that it now also 3073 prints comments showing the source lines that correspond to the 3074 assembly, making it easier to read the generated assembly 3075 (especially with larger functions). For example, given this C 3076 source file: 3077 3078 int test (int n) 3079 { 3080 int i; 3081 int total = 0; 3082 3083 for (i = 0; i < n; i++) 3084 total += i * i; 3085 return total; 3086 } 3087 3088 -fverbose-asm now gives output similar to this for the function 3089 body (when compiling for x86_64, with -Os): 3090 3091 .text 3092 .globl test 3093 .type test, @@function 3094 test: 3095 .LFB0: 3096 .cfi_startproc 3097 # example.c:4: int total = 0; 3098 xorl %eax, %eax # <retval> 3099 # example.c:6: for (i = 0; i < n; i++) 3100 xorl %edx, %edx # i 3101 .L2: 3102 # example.c:6: for (i = 0; i < n; i++) 3103 cmpl %edi, %edx # n, i 3104 jge .L5 #, 3105 # example.c:7: total += i * i; 3106 movl %edx, %ecx # i, tmp92 3107 imull %edx, %ecx # i, tmp92 3108 # example.c:6: for (i = 0; i < n; i++) 3109 incl %edx # i 3110 # example.c:7: total += i * i; 3111 addl %ecx, %eax # tmp92, <retval> 3112 jmp .L2 # 3113 .L5: 3114 # example.c:10: } 3115 ret 3116 .cfi_endproc 3117 3118 * Two new options have been added for printing fix-it hints: 3119 + -fdiagnostics-parseable-fixits allows for fix-it hints to be 3120 emitted in a machine-readable form, suitable for consumption 3121 by IDEs. For example, given: 3122 3123 spellcheck-fields.cc:52:13: error: 'struct s' has no member named 'colour'; did 3124 you mean 'color'? 3125 return ptr->colour; 3126 ^~~~~~ 3127 color 3128 3129 it will emit: 3130 3131 fix-it:"spellcheck-fields.cc":{52:13-52:19}:"color" 3132 3133 + -fdiagnostics-generate-patch will print a patch in "unified" 3134 format after any diagnostics are printed, showing the result 3135 of applying all fix-it hints. For the above example it would 3136 emit: 3137 3138 --- spellcheck-fields.cc 3139 +++ spellcheck-fields.cc 3140 @@ -49,5 +49,5 @@ 3141 3142 color get_color(struct s *ptr) 3143 { 3144 - return ptr->colour; 3145 + return ptr->color; 3146 } 3147 3148 * The gcc and g++ driver programs will now provide suggestions for 3149 misspelled arguments to command-line options. 3150 3151 $ gcc -c test.c -ftls-model=global-dinamic 3152 gcc: error: unknown TLS model 'global-dinamic' 3153 gcc: note: valid arguments to '-ftls-model=' are: global-dynamic initial-exec lo 3154 cal-dynamic local-exec; did you mean 'global-dynamic'? 3155 3156 * The compiler will now provide suggestions for misspelled 3157 parameters. 3158 3159 $ gcc -c test.c --param max-early-inliner-iteration=3 3160 cc1: error: invalid --param name 'max-early-inliner-iteration'; did you mean 'ma 3161 x-early-inliner-iterations'? 3162 3163 * Profile-guided optimization (PGO) instrumentation, as well as test 3164 coverage (GCOV), can newly instrument constructors (functions marks 3165 with __attribute__((constructor))), destructors and C++ 3166 constructors (and destructors) of classes that are used as the type 3167 of a global variable. 3168 * A new option -fprofile-update=atomic prevents creation of corrupted 3169 profiles created during an instrumentation run (-fprofile=generate) 3170 of an application. The downside of the option is a speed penalty. 3171 Providing -pthread on the command line selects atomic profile 3172 updating (when supported by the target). 3173 * GCC's already extensive testsuite has gained some new capabilities, 3174 to further improve the reliability of the compiler: 3175 + GCC now has an internal unit-testing API and a suite of tests 3176 for programmatic self-testing of subsystems. 3177 + GCC's C front end has been extended so that it can parse dumps 3178 of GCC's internal representations, allowing for DejaGnu tests 3179 that more directly exercise specific optimization passes. This 3180 covers both the [21]GIMPLE representation (for testing 3181 higher-level optimizations) and the [22]RTL representation, 3182 allowing for more direct testing of lower-level details, such 3183 as register allocation and instruction selection. 3184 3185 GCC 7.1 3186 3187 This is the [23]list of problem reports (PRs) from GCC's bug tracking 3188 system that are known to be fixed in the 7.1 release. This list might 3189 not be complete (that is, it is possible that some PRs that have been 3190 fixed are not listed here). 3191 3192 GCC 7.2 3193 3194 This is the [24]list of problem reports (PRs) from GCC's bug tracking 3195 system that are known to be fixed in the 7.2 release. This list might 3196 not be complete (that is, it is possible that some PRs that have been 3197 fixed are not listed here). 3198 3199 Target Specific Changes 3200 3201 SPARC 3202 3203 * Support for the SPARC M8 processor has been added. 3204 * The switches -mfix-ut700 and -mfix-gr712rc have been added to work 3205 around an erratum in LEON3FT processors. 3206 * Use of the Floating-point Multiply Single to Double (FsMULd) 3207 instruction can now be controlled by the -mfsmuld and -fno-fsmuld 3208 options. 3209 3210 Operating Systems 3211 3212 RTEMS 3213 3214 * The Ada run-time support uses now thread-local storage (TLS). 3215 * Support for RISC-V has been added. 3216 * Support for 64-bit PowerPC using the ELFv2 ABI with 64-bit long 3217 double has been added. 3218 3219 GCC 7.3 3220 3221 This is the [25]list of problem reports (PRs) from GCC's bug tracking 3222 system that are known to be fixed in the 7.3 release. This list might 3223 not be complete (that is, it is possible that some PRs that have been 3224 fixed are not listed here). 3225 3226 Target Specific Changes 3227 3228 SPARC 3229 3230 * Workarounds for the four [26]LEON3FT errata GRLIB-TN-0010..0013 3231 have been added. Relevant errata are activated by the target 3232 specific -mfix-ut699, -mfix-ut700 and -mfix-gr712rc switches. 3233 3234 Operating Systems 3235 3236 RTEMS 3237 3238 * Support has been added for Epiphany target. 3239 3240 GCC 7.4 3241 3242 This is the [27]list of problem reports (PRs) from GCC's bug tracking 3243 system that are known to be fixed in the 7.4 release. This list might 3244 not be complete (that is, it is possible that some PRs that have been 3245 fixed are not listed here). 3246 3247 GCC 7.5 3248 3249 This is the [28]list of problem reports (PRs) from GCC's bug tracking 3250 system that are known to be fixed in the 7.5 release. This list might 3251 not be complete (that is, it is possible that some PRs that have been 3252 fixed are not listed here). 3253 3254 3255 For questions related to the use of GCC, please consult these web 3256 pages and the [29]GCC manuals. If that fails, the 3257 [30]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 3258 web pages and the development of GCC are welcome on our developer 3259 list at [31]gcc (a] gcc.gnu.org. All of [32]our lists have public 3260 archives. 3261 3262 Copyright (C) [33]Free Software Foundation, Inc. Verbatim copying and 3263 distribution of this entire article is permitted in any medium, 3264 provided this notice is preserved. 3265 3266 These pages are [34]maintained by the GCC team. Last modified 3267 2019-11-28[35]. 3268 3269 References 3270 3271 1. http://gcc.gnu.org/gcc-7/porting_to.html 3272 2. http://gcc.gnu.org/onlinedocs/index.html#current 3273 3. https://gcc.gnu.org/wiki/LRAIsDefault 3274 4. https://gcc.gnu.org/onlinedocs/gcc-7.1.0/libstdc++/manual/manual/profile_mode.html 3275 5. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77728 3276 6. http://www.dwarfstd.org/Download.php 3277 7. https://gcc.gnu.org/wiki/OpenACC 3278 8. https://gcc.gnu.org/wiki/Offloading 3279 9. https://gcc.gnu.org/onlinedocs/gcc-7.1.0/gcc/Object-Size-Checking.html 3280 10. https://gcc.gnu.org/projects/cxx-status.html#cxx1z 3281 11. http://wg21.link/p0136 3282 12. https://gcc.gnu.org/onlinedocs/gcc-7.1.0/libstdc++/manual/using_dual_abi.html 3283 13. https://www.openmp.org/specifications/ 3284 14. https://gcc.gnu.org/onlinedocs/gcc-7.1.0/jit/topics/expressions.html#gcc_jit_rvalue_set_bool_require_tail_call 3285 15. https://gcc.gnu.org/onlinedocs/gcc-7.1.0/gcc/AArch64-Options.html#AArch64-Options 3286 16. https://gcc.gnu.org/install/configure.html 3287 17. https://gcc.gnu.org/onlinedocs/gcc-7.1.0/gcc/AVR-Variable-Attributes.html 3288 18. https://gcc.gnu.org/onlinedocs/gcc-7.1.0/gcc/AVR-Built-in-Functions.html 3289 19. https://gcc.gnu.org/wiki/Offloading 3290 20. https://fuchsia.googlesource.com/ 3291 21. https://gcc.gnu.org/onlinedocs/gcc-7.1.0/gccint/GIMPLE-Tests.html 3292 22. https://gcc.gnu.org/onlinedocs/gcc-7.1.0/gccint/RTL-Tests.html 3293 23. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=7.0 3294 24. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=7.2 3295 25. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=7.3 3296 26. https://www.gaisler.com/index.php/information/app-tech-notes 3297 27. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=7.4 3298 28. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=7.5 3299 29. https://gcc.gnu.org/onlinedocs/ 3300 30. mailto:gcc-help (a] gcc.gnu.org 3301 31. mailto:gcc (a] gcc.gnu.org 3302 32. https://gcc.gnu.org/lists.html 3303 33. https://www.fsf.org/ 3304 34. https://gcc.gnu.org/about.html 3305 35. http://validator.w3.org/check/referer 3306 ====================================================================== 3307 http://gcc.gnu.org/gcc-6/index.html 3308 GCC 6 Release Series 3309 3310 (This release series is no longer supported.) 3311 3312 October 26, 2018 3313 3314 The [1]GNU project and the GCC developers are pleased to announce the 3315 release of GCC 6.5. 3316 3317 This release is a bug-fix release, containing fixes for regressions in 3318 GCC 6.4 relative to previous releases of GCC. 3319 3320 Release History 3321 3322 GCC 6.5 3323 October 26, 2018 ([2]changes, [3]documentation) 3324 3325 GCC 6.4 3326 July 4, 2017 ([4]changes, [5]documentation) 3327 3328 GCC 6.3 3329 December 21, 2016 ([6]changes, [7]documentation) 3330 3331 GCC 6.2 3332 August 22, 2016 ([8]changes, [9]documentation) 3333 3334 GCC 6.1 3335 April 27, 2016 ([10]changes, [11]documentation) 3336 3337 References and Acknowledgements 3338 3339 GCC used to stand for the GNU C Compiler, but since the compiler 3340 supports several other languages aside from C, it now stands for the 3341 GNU Compiler Collection. 3342 3343 A list of [12]successful builds is updated as new information becomes 3344 available. 3345 3346 The GCC developers would like to thank the numerous people that have 3347 contributed new features, improvements, bug fixes, and other changes as 3348 well as test results to GCC. This [13]amazing group of volunteers is 3349 what makes GCC successful. 3350 3351 For additional information about GCC please refer to the [14]GCC 3352 project web site or contact the [15]GCC development mailing list. 3353 3354 To obtain GCC please use [16]our mirror sites or [17]our version 3355 control system. 3356 3357 3358 For questions related to the use of GCC, please consult these web 3359 pages and the [18]GCC manuals. If that fails, the 3360 [19]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 3361 web pages and the development of GCC are welcome on our developer 3362 list at [20]gcc (a] gcc.gnu.org. All of [21]our lists have public 3363 archives. 3364 3365 Copyright (C) [22]Free Software Foundation, Inc. Verbatim copying and 3366 distribution of this entire article is permitted in any medium, 3367 provided this notice is preserved. 3368 3369 These pages are [23]maintained by the GCC team. Last modified 3370 2020-01-14[24]. 3371 3372 References 3373 3374 1. http://www.gnu.org/ 3375 2. http://gcc.gnu.org/gcc-6/changes.html 3376 3. http://gcc.gnu.org/onlinedocs/6.5.0/ 3377 4. http://gcc.gnu.org/gcc-6/changes.html 3378 5. http://gcc.gnu.org/onlinedocs/6.4.0/ 3379 6. http://gcc.gnu.org/gcc-6/changes.html 3380 7. http://gcc.gnu.org/onlinedocs/6.3.0/ 3381 8. http://gcc.gnu.org/gcc-6/changes.html 3382 9. http://gcc.gnu.org/onlinedocs/6.2.0/ 3383 10. http://gcc.gnu.org/gcc-6/changes.html 3384 11. http://gcc.gnu.org/onlinedocs/6.1.0/ 3385 12. http://gcc.gnu.org/gcc-6/buildstat.html 3386 13. http://gcc.gnu.org/onlinedocs/gcc/Contributors.html 3387 14. http://gcc.gnu.org/index.html 3388 15. mailto:gcc (a] gcc.gnu.org 3389 16. http://gcc.gnu.org/mirrors.html 3390 17. http://gcc.gnu.org/git.html 3391 18. https://gcc.gnu.org/onlinedocs/ 3392 19. mailto:gcc-help (a] gcc.gnu.org 3393 20. mailto:gcc (a] gcc.gnu.org 3394 21. https://gcc.gnu.org/lists.html 3395 22. https://www.fsf.org/ 3396 23. https://gcc.gnu.org/about.html 3397 24. http://validator.w3.org/check/referer 3398 ====================================================================== 3399 http://gcc.gnu.org/gcc-6/changes.html 3400 GCC 6 Release Series 3401 Changes, New Features, and Fixes 3402 3403 This page is a brief summary of some of the huge number of improvements 3404 in GCC 6. For more information, see the [1]Porting to GCC 6 page and 3405 the [2]full GCC documentation. 3406 3407 Caveats 3408 3409 * The default mode for C++ is now -std=gnu++14 instead of 3410 -std=gnu++98. 3411 * Support for a number of older systems and recently unmaintained or 3412 untested target ports of GCC has been declared obsolete in GCC 6. 3413 Unless there is activity to revive them, the next release of GCC 3414 will have their sources permanently removed. 3415 The following ports for individual systems on particular 3416 architectures have been obsoleted: 3417 + SH5 / SH64 (sh64-*-*) as announced [3]here. 3418 * The AVR port requires binutils version 2.26.1 or later for the fix 3419 for [4]PR71151 to work. 3420 * The GCC 6.5 release has an accidental ABI incompatibility for 3421 nested std::pair objects, for more details see [5]PR 87822. The bug 3422 causes a layout change for pairs where the first member is also a 3423 pair, e.g. std::pair<std::pair<X, Y>, Z>. The GCC 6 release series 3424 is closed so the bug in GCC 6.5 will not be fixed upstream, but 3425 there is a patch in the bug report to allow it to be fixed by 3426 anybody packaging GCC 6.5 or installing it themselves. 3427 3428 General Optimizer Improvements 3429 3430 * UndefinedBehaviorSanitizer gained a new sanitization option, 3431 -fsanitize=bounds-strict, which enables strict checking of array 3432 bounds. In particular, it enables -fsanitize=bounds as well as 3433 instrumentation of flexible array member-like arrays. 3434 * Type-based alias analysis now disambiguates accesses to different 3435 pointers. This improves precision of the alias oracle by about 3436 20-30% on higher-level C++ programs. Programs doing invalid type 3437 punning of pointer types may now need -fno-strict-aliasing to work 3438 correctly. 3439 * Alias analysis now correctly supports the weakref and alias 3440 attributes. This allows accessing both a variable and its alias in 3441 one translation unit which is common with link-time optimization. 3442 * Value range propagation now assumes that the this pointer in C++ 3443 member functions is non-null. This eliminates common null pointer 3444 checks but also breaks some non-conforming code-bases (such as 3445 Qt-5, Chromium, KDevelop). As a temporary work-around 3446 -fno-delete-null-pointer-checks can be used. Wrong code can be 3447 identified by using -fsanitize=undefined. 3448 * Link-time optimization improvements: 3449 + warning and error attributes are now correctly preserved by 3450 declaration linking and thus -D_FORTIFY_SOURCE=2 is now 3451 supported with -flto. 3452 + Type merging was fixed to handle C and Fortran 3453 interoperability rules as defined by the Fortran 2008 language 3454 standard. 3455 As an exception, CHARACTER(KIND=C_CHAR) is not inter-operable 3456 with char in all cases because it is an array while char is 3457 scalar. INTEGER(KIND=C_SIGNED_CHAR) should be used instead. In 3458 general, this inter-operability cannot be implemented, for 3459 example on targets where the argument passing convention for 3460 arrays differs from scalars. 3461 + More type information is now preserved at link time, reducing 3462 the loss of accuracy of the type-based alias analysis compared 3463 to builds without link-time optimization. 3464 + Invalid type punning on global variables and declarations is 3465 now reported with -Wodr-type-mismatch. 3466 + The size of LTO object files was reduced by about 11% 3467 (measured by compiling Firefox 46.0). 3468 + Link-time parallelization (enabled using -flto=n) was 3469 significantly improved by decreasing the size of streamed data 3470 when partitioning programs. The size of streamed IL while 3471 compiling Firefox 46.0 was reduced by 66%. 3472 + The linker plugin was extended to pass information about the 3473 type of binary produced to the GCC back end. (That can also be 3474 controlled manually by -flinker-output.) This makes it 3475 possible to properly configure the code generator and support 3476 incremental linking. Incremental linking of LTO objects by gcc 3477 -r is now supported for plugin-enabled setups. 3478 There are two ways to perform incremental linking: 3479 1. Linking by ld -r will result in an object file with all 3480 sections from individual object files mechanically 3481 merged. This delays the actual link-time optimization to 3482 the final linking step and thus permits whole program 3483 optimization. Linking the final binary with such object 3484 files is however slower. 3485 2. Linking by gcc -r will lead to link-time optimization and 3486 emit the final binary into the object file. Linking such 3487 an object file is fast but avoids any benefits from whole 3488 program optimization. 3489 GCC 7 will support incremental link-time optimization with gcc 3490 -r. 3491 * Inter-procedural optimization improvements: 3492 + Basic jump threading is now performed before profile 3493 construction and inline analysis, resulting in more realistic 3494 size and time estimates that drive the heuristics of the 3495 inliner and function cloning passes. 3496 + Function cloning now more aggressively eliminates unused 3497 function parameters. 3498 3499 New Languages and Language specific improvements 3500 3501 Compared to GCC 5, the GCC 6 release series includes a much improved 3502 implementation of the [6]OpenACC 2.0a specification. Highlights are: 3503 * In addition to single-threaded host-fallback execution, offloading 3504 is supported for nvptx (Nvidia GPUs) on x86_64 and PowerPC 64-bit 3505 little-endian GNU/Linux host systems. For nvptx offloading, with 3506 the OpenACC parallel construct, the execution model allows for an 3507 arbitrary number of gangs, up to 32 workers, and 32 vectors. 3508 * Initial support for parallelized execution of OpenACC kernels 3509 constructs: 3510 + Parallelization of a kernels region is switched on by 3511 -fopenacc combined with -O2 or higher. 3512 + Code is offloaded onto multiple gangs, but executes with just 3513 one worker, and a vector length of 1. 3514 + Directives inside a kernels region are not supported. 3515 + Loops with reductions can be parallelized. 3516 + Only kernels regions with one loop nest are parallelized. 3517 + Only the outer-most loop of a loop nest can be parallelized. 3518 + Loop nests containing sibling loops are not parallelized. 3519 Typically, using the OpenACC parallel construct gives much better 3520 performance, compared to the initial support of the OpenACC kernels 3521 construct. 3522 * The device_type clause is not supported. The bind and nohost 3523 clauses are not supported. The host_data directive is not supported 3524 in Fortran. 3525 * Nested parallelism (cf. CUDA dynamic parallelism) is not supported. 3526 * Usage of OpenACC constructs inside multithreaded contexts (such as 3527 created by OpenMP, or pthread programming) is not supported. 3528 * If a call to the acc_on_device function has a compile-time constant 3529 argument, the function call evaluates to a compile-time constant 3530 value only for C and C++ but not for Fortran. 3531 3532 See the [7]OpenACC and [8]Offloading wiki pages for further 3533 information. 3534 3535 C family 3536 3537 * Version 4.5 of the [9]OpenMP specification is now supported in the 3538 C and C++ compilers. 3539 * The C and C++ compilers now support attributes on enumerators. For 3540 instance, it is now possible to mark enumerators as deprecated: 3541 3542 enum { 3543 newval, 3544 oldval __attribute__ ((deprecated ("too old"))) 3545 }; 3546 3547 * Source locations for the C and C++ compilers are now tracked as 3548 ranges, rather than just points, making it easier to identify the 3549 subexpression of interest within a complicated expression. For 3550 example: 3551 3552 test.cc: In function 'int test(int, int, foo, int, int)': 3553 test.cc:5:16: error: no match for 'operator*' (operand types are 'int' and 'foo' 3554 ) 3555 return p + q * r * s + t; 3556 ~~^~~ 3557 3558 In addition, there is now initial support for precise diagnostic 3559 locations within strings: 3560 3561 format-strings.c:3:14: warning: field width specifier '*' expects a matching 'in 3562 t' argument [-Wformat=] 3563 printf("%*d"); 3564 ^ 3565 3566 * Diagnostics can now contain "fix-it hints", which are displayed in 3567 context underneath the relevant source code. For example: 3568 3569 fixits.c: In function 'bad_deref': 3570 fixits.c:11:13: error: 'ptr' is a pointer; did you mean to use '->'? 3571 return ptr.x; 3572 ^ 3573 -> 3574 3575 * The C and C++ compilers now offer suggestions for misspelled field 3576 names: 3577 3578 spellcheck-fields.cc:52:13: error: 'struct s' has no member named 'colour'; did 3579 you mean 'color'? 3580 return ptr->colour; 3581 ^~~~~~ 3582 3583 * New command-line options have been added for the C and C++ 3584 compilers: 3585 + -Wshift-negative-value warns about left shifting a negative 3586 value. 3587 + -Wshift-overflow warns about left shift overflows. This 3588 warning is enabled by default. -Wshift-overflow=2 also warns 3589 about left-shifting 1 into the sign bit. 3590 + -Wtautological-compare warns if a self-comparison always 3591 evaluates to true or false. This warning is enabled by -Wall. 3592 + -Wnull-dereference warns if the compiler detects paths that 3593 trigger erroneous or undefined behavior due to dereferencing a 3594 null pointer. This option is only active when 3595 -fdelete-null-pointer-checks is active, which is enabled by 3596 optimizations in most targets. The precision of the warnings 3597 depends on the optimization options used. 3598 + -Wduplicated-cond warns about duplicated conditions in an 3599 if-else-if chain. 3600 + -Wmisleading-indentation warns about places where the 3601 indentation of the code gives a misleading idea of the block 3602 structure of the code to a human reader. For example, given 3603 [10]CVE-2014-1266: 3604 3605 sslKeyExchange.c: In function 'SSLVerifySignedServerKeyExchange': 3606 sslKeyExchange.c:629:3: warning: this 'if' clause does not guard... [-Wmisleadin 3607 g-indentation] 3608 if ((err = SSLHashSHA1.update(&hashCtx, &signedParams)) != 0) 3609 ^~ 3610 sslKeyExchange.c:631:5: note: ...this statement, but the latter is misleadingly 3611 indented as if it is guarded by the 'if' 3612 goto fail; 3613 ^~~~ 3614 3615 This warning is enabled by -Wall. 3616 * The C and C++ compilers now emit saner error messages if 3617 merge-conflict markers are present in a source file. 3618 3619 test.c:3:1: error: version control conflict marker in file 3620 <<<<<<< HEAD 3621 ^~~~~~~ 3622 3623 C 3624 3625 * It is possible to disable warnings when an initialized field of a 3626 structure or a union with side effects is being overridden when 3627 using designated initializers via a new warning option 3628 -Woverride-init-side-effects. 3629 * A new type attribute scalar_storage_order applying to structures 3630 and unions has been introduced. It specifies the storage order (aka 3631 endianness) in memory of scalar fields in structures or unions. 3632 3633 C++ 3634 3635 * The default mode has been changed to -std=gnu++14. 3636 * [11]C++ Concepts are now supported when compiling with -fconcepts. 3637 * -flifetime-dse is more aggressive in dead-store elimination in 3638 situations where a memory store to a location precedes a 3639 constructor to that memory location. 3640 * G++ now supports [12]C++17 fold expressions, u8 character literals, 3641 extended static_assert, and nested namespace definitions. 3642 * G++ now allows constant evaluation for all non-type template 3643 arguments. 3644 * G++ now supports C++ Transactional Memory when compiling with 3645 -fgnu-tm. 3646 3647 Runtime Library (libstdc++) 3648 3649 * Extensions to the C++ Library to support mathematical special 3650 functions (ISO/IEC 29124:2010), thanks to Edward Smith-Rowland. 3651 * Experimental support for C++17, including the following new 3652 features: 3653 + std::uncaught_exceptions function (this is also available for 3654 -std=gnu++NN modes); 3655 + new member functions try_emplace and insert_or_assign for 3656 unique_key maps; 3657 + non-member functions std::size, std::empty, and std::data for 3658 accessing containers and arrays; 3659 + std::invoke; 3660 + std::shared_mutex; 3661 + std::void_t and std::bool_constant metaprogramming utilities. 3662 Thanks to Ville Voutilainen for contributing many of the C++17 3663 features. 3664 * An experimental implementation of the File System TS. 3665 * Experimental support for most features of the second version of the 3666 Library Fundamentals TS. This includes polymorphic memory resources 3667 and array support in shared_ptr, thanks to Fan You. 3668 * Some assertions checked by Debug Mode can now also be enabled by 3669 _GLIBCXX_ASSERTIONS. The subset of checks enabled by the new macro 3670 have less run-time overhead than the full _GLIBCXX_DEBUG checks and 3671 don't affect the library ABI, so can be enabled per-translation 3672 unit. 3673 * Timed mutex types are supported on more targets, including Darwin. 3674 * Improved std::locale support for DragonFly and FreeBSD, thanks to 3675 John Marino and Andreas Tobler. 3676 3677 Fortran 3678 3679 * Fortran 2008 SUBMODULE support. 3680 * Fortran 2015 EVENT_TYPE, EVENT_POST, EVENT_WAIT, and EVENT_QUERY 3681 support. 3682 * Improved support for Fortran 2003 deferred-length character 3683 variables. 3684 * Improved support for OpenMP and OpenACC. 3685 * The MATMUL intrinsic is now inlined for straightforward cases if 3686 front-end optimization is active. The maximum size for inlining can 3687 be set to n with the -finline-matmul-limit=n option and turned off 3688 with -finline-matmul-limit=0. 3689 * The -Wconversion-extra option will warn about REAL constants which 3690 have excess precision for their kind. 3691 * The -Winteger-division option has been added, which warns about 3692 divisions of integer constants which are truncated. This option is 3693 included in -Wall by default. 3694 3695 libgccjit 3696 3697 * The driver code is now run in-process within libgccjit, providing a 3698 small speed-up of the compilation process. 3699 * The API has gained entrypoints for 3700 + [13]timing how long was spent in different parts of code, 3701 + [14]creating switch statements, 3702 + [15]allowing unreachable basic blocks in a function, and 3703 + [16]adding arbitrary command-line options to a compilation. 3704 3705 New Targets and Target Specific Improvements 3706 3707 AArch64 3708 3709 * A number of AArch64-specific options have been added. The most 3710 important ones are summarised in this section; for more detailed 3711 information please refer to the documentation. 3712 * The command-line options -march=native, -mcpu=native and 3713 -mtune=native are now available on native AArch64 GNU/Linux 3714 systems. Specifying these options causes GCC to auto-detect the 3715 host CPU and choose the optimal setting for that system. 3716 * -fpic is now supported when generating code for the small code 3717 model (-mcmodel=small). The size of the global offset table (GOT) 3718 is limited to 28KiB under the LP64 SysV ABI, and 15KiB under the 3719 ILP32 SysV ABI. 3720 * The AArch64 port now supports target attributes and pragmas. Please 3721 refer to the [17]documentation for details of available attributes 3722 and pragmas as well as usage instructions. 3723 * Link-time optimization across translation units with different 3724 target-specific options is now supported. 3725 * The option -mtls-size= is now supported. It can be used to specify 3726 the bit size of TLS offsets, allowing GCC to generate better TLS 3727 instruction sequences. 3728 * The option -fno-plt is now fully functional. 3729 * The ARMv8.1-A architecture and the Large System Extensions are now 3730 supported. They can be used by specifying the -march=armv8.1-a 3731 option. Additionally, the +lse option extension can be used in a 3732 similar fashion to other option extensions. The Large System 3733 Extensions introduce new instructions that are used in the 3734 implementation of atomic operations. 3735 * The ACLE half-precision floating-point type __fp16 is now supported 3736 in the C and C++ languages. 3737 * The ARM Cortex-A35 processor is now supported via the 3738 -mcpu=cortex-a35 and -mtune=cortex-a35 options as well as the 3739 equivalent target attributes and pragmas. 3740 * The Qualcomm QDF24xx processor is now supported via the 3741 -mcpu=qdf24xx and -mtune=qdf24xx options as well as the equivalent 3742 target attributes and pragmas. 3743 * Code generation for the ARM Cortex-A57 processor is improved. Among 3744 general code generation improvements, a better algorithm is added 3745 for allocating registers to floating-point multiply-accumulate 3746 instructions offering increased performance when compiling with 3747 -mcpu=cortex-a57 or -mtune=cortex-a57. 3748 * Code generation for the ARM Cortex-A53 processor is improved. A 3749 more accurate instruction scheduling model for the processor is now 3750 used, and a number of compiler tuning parameters have been set to 3751 offer increased performance when compiling with -mcpu=cortex-a53 or 3752 -mtune=cortex-a53. 3753 * Code generation for the Samsung Exynos M1 processor is improved. A 3754 more accurate instruction scheduling model for the processor is now 3755 used, and a number of compiler tuning parameters have been set to 3756 offer increased performance when compiling with -mcpu=exynos-m1 or 3757 -mtune=exynos-m1. 3758 * Improvements in the generation of conditional branches and literal 3759 pools allow the compiler to compile functions of a large size. 3760 Constant pools are now placed into separate rodata sections. The 3761 new option -mpc-relative-literal-loads generates per-function 3762 literal pools, limiting the maximum size of functions to 1MiB. 3763 * Several correctness issues generating Advanced SIMD instructions 3764 for big-endian targets have been fixed resulting in improved code 3765 generation for ACLE intrinsics with -mbig-endian. 3766 3767 ARM 3768 3769 * Support for revisions of the ARM architecture prior to ARMv4t has 3770 been deprecated and will be removed in a future GCC release. The 3771 -mcpu and -mtune values that are deprecated are: arm2, arm250, 3772 arm3, arm6, arm60, arm600, arm610, arm620, arm7, arm7d, arm7di, 3773 arm70, arm700, arm700i, arm710, arm720, arm710c, arm7100, arm7500, 3774 arm7500fe, arm7m, arm7dm, arm7dmi, arm8, arm810, strongarm, 3775 strongarm110, strongarm1100, strongarm1110, fa526, fa626. The value 3776 arm7tdmi is still supported. The values of -march that are 3777 deprecated are: armv2,armv2a,armv3,armv3m,armv4. 3778 * The ARM port now supports target attributes and pragmas. Please 3779 refer to the [18]documentation for details of available attributes 3780 and pragmas as well as usage instructions. 3781 * Support has been added for the following processors (GCC 3782 identifiers in parentheses): ARM Cortex-A32 (cortex-a32), ARM 3783 Cortex-A35 (cortex-a35) and ARM Cortex-R8 (cortex-r8). The GCC 3784 identifiers can be used as arguments to the -mcpu or -mtune 3785 options, for example: -mcpu=cortex-a32 or -mtune=cortex-a35. 3786 3787 Heterogeneous Systems Architecture 3788 3789 * GCC can now generate HSAIL (Heterogeneous System Architecture 3790 Intermediate Language) for simple OpenMP device constructs if 3791 configured with --enable-offload-targets=hsa. A new libgomp plugin 3792 then runs the HSA GPU kernels implementing these constructs on HSA 3793 capable GPUs via a standard HSA run time. 3794 If the HSA compilation back end determines it cannot output HSAIL 3795 for a particular input, it gives a warning by default. These 3796 warnings can be suppressed with -Wno-hsa. To give a few examples, 3797 the HSA back end does not implement compilation of code using 3798 function pointers, automatic allocation of variable sized arrays, 3799 functions with variadic arguments as well as a number of other less 3800 common programming constructs. 3801 When compilation for HSA is enabled, the compiler attempts to 3802 compile composite OpenMP constructs 3803 3804 #pragma omp target teams distribute parallel for 3805 3806 into parallel HSA GPU kernels. 3807 3808 IA-32/x86-64 3809 3810 * GCC now supports the Intel CPU named Skylake with AVX-512 3811 extensions through -march=skylake-avx512. The switch enables the 3812 following ISA extensions: AVX-512F, AVX512VL, AVX-512CD, AVX-512BW, 3813 AVX-512DQ. 3814 * Support for new AMD instructions monitorx and mwaitx has been 3815 added. This includes new intrinsic and built-in support. It is 3816 enabled through option -mmwaitx. The instructions monitorx and 3817 mwaitx implement the same functionality as the old monitor and 3818 mwait instructions. In addition mwaitx adds a configurable timer. 3819 The timer value is received as third argument and stored in 3820 register %ebx. 3821 * x86-64 targets now allow stack realignment from a word-aligned 3822 stack pointer using the command-line option -mstackrealign or 3823 __attribute__ ((force_align_arg_pointer)). This allows functions 3824 compiled with a vector-aligned stack to be invoked from objects 3825 that keep only word-alignment. 3826 * Support for address spaces __seg_fs, __seg_gs, and __seg_tls. These 3827 can be used to access data via the %fs and %gs segments without 3828 having to resort to inline assembly. Please refer to the 3829 [19]documentation for usage instructions. 3830 * Support for AMD Zen (family 17h) processors is now available 3831 through the -march=znver1 and -mtune=znver1 options. 3832 3833 MeP 3834 3835 * Support for the MeP (mep-elf) architecture has been deprecated and 3836 will be removed in a future GCC release. 3837 3838 MSP430 3839 3840 * The MSP430 compiler now has the ability to automatically distribute 3841 code and data between low memory (addresses below 64K) and high 3842 memory. This only applies to parts that actually have both memory 3843 regions and only if the linker script for the part has been 3844 specifically set up to support this feature. 3845 A new attribute of either can be applied to both functions and 3846 data, and this tells the compiler to place the object into low 3847 memory if there is room and into high memory otherwise. Two other 3848 new attributes - lower and upper - can be used to explicitly state 3849 that an object should be placed in the specified memory region. If 3850 there is not enough left in that region the compilation will fail. 3851 Two new command-line options - -mcode-region=[lower|upper|either] 3852 and -mdata-region=[lower|upper|either] - can be used to tell the 3853 compiler what to do with objects that do not have one of these new 3854 attributes. 3855 3856 PowerPC / PowerPC64 / RS6000 3857 3858 * PowerPC64 now supports IEEE 128-bit floating-point using the 3859 __float128 data type. In GCC 6, this is not enabled by default, but 3860 you can enable it with -mfloat128. The IEEE 128-bit floating-point 3861 support requires the use of the VSX instruction set. IEEE 128-bit 3862 floating-point values are passed and returned as a single vector 3863 value. The software emulator for IEEE 128-bit floating-point 3864 support is only built on PowerPC GNU/Linux systems where the 3865 default CPU is at least power7. On future ISA 3.0 systems (POWER 9 3866 and later), you will be able to use the -mfloat128-hardware option 3867 to use the ISA 3.0 instructions that support IEEE 128-bit 3868 floating-point. An additional type (__ibm128) has been added to 3869 refer to the IBM extended double type that normally implements long 3870 double. This will allow for a future transition to implementing 3871 long double with IEEE 128-bit floating-point. 3872 * Basic support has been added for POWER9 hardware that will use the 3873 recently published OpenPOWER ISA 3.0 instructions. The following 3874 new switches are available: 3875 + -mcpu=power9: Implement all of the ISA 3.0 instructions 3876 supported by the compiler. 3877 + -mtune=power9: In the future, apply tuning for POWER9 systems. 3878 Currently, POWER8 tunings are used. 3879 + -mmodulo: Generate code using the ISA 3.0 integer instructions 3880 (modulus, count trailing zeros, array index support, integer 3881 multiply/add). 3882 + -mpower9-fusion: Generate code to suitably fuse instruction 3883 sequences for a POWER9 system. 3884 + -mpower9-dform: Generate code to use the new D-form 3885 (register+offset) memory instructions for the vector 3886 registers. 3887 + -mpower9-vector: Generate code using the new ISA 3.0 vector 3888 (VSX or Altivec) instructions. 3889 + -mpower9-minmax: Reserved for future development. 3890 + -mtoc-fusion: Keep TOC entries together to provide more fusion 3891 opportunities. 3892 * New constraints have been added to support IEEE 128-bit 3893 floating-point and ISA 3.0 instructions: 3894 + wb: Altivec register if -mpower9-dform is enabled. 3895 + we: VSX register if -mpower9-vector is enabled for 64-bit code 3896 generation. 3897 + wo: VSX register if -mpower9-vector is enabled. 3898 + wp: Reserved for future use if long double is implemented with 3899 IEEE 128-bit floating-point instead of IBM extended double. 3900 + wq: VSX register if -mfloat128 is enabled. 3901 + wF: Memory operand suitable for POWER9 fusion load/store. 3902 + wG: Memory operand suitable for TOC fusion memory references. 3903 + wL: Integer constant identifying the element number mfvsrld 3904 accesses within a vector. 3905 * Support has been added for __builtin_cpu_is() and 3906 __builtin_cpu_supports(), allowing for very fast access to 3907 AT_PLATFORM, AT_HWCAP, and AT_HWCAP2 values. This requires use of 3908 glibc 2.23 or later. 3909 * All hardware transactional memory builtins now correctly behave as 3910 memory barriers. Programmers can use #ifdef __TM_FENCE__ to 3911 determine whether their "old" compiler treats the builtins as 3912 barriers. 3913 * Split-stack support has been added for gccgo on PowerPC64 for both 3914 big- and little-endian (but not for 32-bit). The gold linker from 3915 at least binutils 2.25.1 must be available in the PATH when 3916 configuring and building gccgo to enable split stack. (The 3917 requirement for binutils 2.25.1 applies to PowerPC64 only.) The 3918 split-stack feature allows a small initial stack size to be 3919 allocated for each goroutine, which increases as needed. 3920 * GCC on PowerPC now supports the standard lround function. 3921 * A new configuration option ---with-advance-toolchain=at was added 3922 for PowerPC 64-bit GNU/Linux systems to use the header files, 3923 library files, and the dynamic linker from a specific Advance 3924 Toolchain release instead of the default versions that are provided 3925 by the GNU/Linux distribution. In general, this option is intended 3926 for the developers of GCC, and it is not intended for general use. 3927 * The "q", "S", "T", and "t" asm-constraints have been removed. 3928 * The "b", "B", "m", "M", and "W" format modifiers have been removed. 3929 3930 S/390, System z, IBM z Systems 3931 3932 * Support for the IBM z13 processor has been added. When using the 3933 -march=z13 option, the compiler will generate code making use of 3934 the new instructions and registers introduced with the vector 3935 extension facility. The -mtune=z13 option enables z13 specific 3936 instruction scheduling without making use of new instructions. 3937 Compiling code with -march=z13 reduces the default alignment of 3938 vector types bigger than 8 bytes to 8. This is an ABI change and 3939 care must be taken when linking modules compiled with different 3940 arch levels which interchange variables containing vector type 3941 values. For newly compiled code the GNU linker will emit a warning. 3942 * The -mzvector option enables a C/C++ language extension. This 3943 extension provides a new keyword vector which can be used to define 3944 vector type variables. (Note: This is not available when enforcing 3945 strict standard compliance e.g. with -std=c99. Either enable GNU 3946 extensions with e.g. -std=gnu99 or use __vector instead of vector.) 3947 Additionally a set of overloaded builtins is provided which is 3948 partially compatible to the PowerPC Altivec builtins. In order to 3949 make use of these builtins the vecintrin.h header file needs to be 3950 included. 3951 * The new command-line options -march=native, and -mtune=native are 3952 now available on native IBM z Systems. Specifying these options 3953 causes GCC to auto-detect the host CPU and choose the optimal 3954 setting for that system. If GCC is unable to detect the host CPU 3955 these options have no effect. 3956 * The IBM z Systems port now supports target attributes and pragmas. 3957 Please refer to the [20]documentation for details of available 3958 attributes and pragmas as well as usage instructions. 3959 * -fsplit-stack is now supported as part of the IBM z Systems port. 3960 This feature requires a recent gold linker to be used. 3961 * Support for the g5 and g6 -march=/-mtune= CPU level switches has 3962 been deprecated and will be removed in a future GCC release. -m31 3963 from now on defaults to -march=z900 if not specified otherwise. 3964 -march=native on a g5/g6 machine will default to -march=z900. 3965 3966 SH 3967 3968 * Support for SH5 / SH64 has been declared obsolete and will be 3969 removed in future releases. 3970 * Support for the FDPIC ABI has been added. It can be enabled using 3971 the new -mfdpic target option and --enable-fdpic configure option. 3972 3973 SPARC 3974 3975 * An ABI bug has been fixed in 64-bit mode. Unfortunately, this 3976 change will break binary compatibility with earlier releases for 3977 code it affects, but this should be pretty rare in practice. The 3978 conditions are: a 16-byte structure containing a double or a 8-byte 3979 vector in the second half is passed to a subprogram in slot #15, 3980 for example as 16th parameter if the first 15 ones have at most 8 3981 bytes. The double or vector was wrongly passed in floating-point 3982 register %d32 in lieu of on the stack as per the SPARC calling 3983 conventions. 3984 3985 Operating Systems 3986 3987 AIX 3988 3989 * DWARF debugging support for AIX 7.1 has been enabled as an optional 3990 debugging format. A more recent Technology Level (TL) and GCC built 3991 with that level are required for full exploitation of DWARF 3992 debugging capabilities. 3993 3994 Linux 3995 3996 * Support for the [21]musl C library was added for the AArch64, ARM, 3997 MicroBlaze, MIPS, MIPS64, PowerPC, PowerPC64, SH, i386, x32 and 3998 x86_64 targets. It can be selected using the new -mmusl option in 3999 case musl is not the default libc. GCC defaults to musl libc if it 4000 is built with a target triplet matching the *-linux-musl* pattern. 4001 4002 RTEMS 4003 4004 * The RTEMS thread model implementation changed. Mutexes now use 4005 self-contained objects defined in Newlib <sys/lock.h> instead of 4006 Classic API semaphores. The keys for thread specific data and the 4007 once function are directly defined via <pthread.h>. Self-contained 4008 condition variables are provided via Newlib <sys/lock.h>. The RTEMS 4009 thread model also supports C++11 threads. 4010 * OpenMP support now uses self-contained objects provided by Newlib 4011 <sys/lock.h> and offers a significantly better performance compared 4012 to the POSIX configuration of libgomp. It is possible to configure 4013 thread pools for each scheduler instance via the environment 4014 variable GOMP_RTEMS_THREAD_POOLS. 4015 4016 Solaris 4017 4018 * Solaris 12 is now fully supported. Minimal support had already been 4019 present in GCC 5.3. 4020 * Solaris 12 provides a full set of startup files (crt1.o, crti.o, 4021 crtn.o), which GCC now prefers over its own ones. 4022 * Position independent executables (PIE) are now supported on Solaris 4023 12. 4024 * Constructor priority is now supported on Solaris 12 with the system 4025 linker. 4026 * libvtv has been ported to Solaris 11 and up. 4027 4028 Windows 4029 4030 * The option -mstackrealign is now automatically activated in 32-bit 4031 mode whenever the use of SSE instructions is requested. 4032 4033 Other significant improvements 4034 4035 * The gcc and g++ driver programs will now provide suggestions for 4036 misspelled command-line options. 4037 4038 $ gcc -static-libfortran test.f95 4039 gcc: error: unrecognized command line option '-static-libfortran'; did you mean 4040 '-static-libgfortran'? 4041 4042 * The --enable-default-pie configure option enables generation of PIE 4043 by default. 4044 4045 GCC 6.2 4046 4047 This is the [22]list of problem reports (PRs) from GCC's bug tracking 4048 system that are known to be fixed in the 6.2 release. This list might 4049 not be complete (that is, it is possible that some PRs that have been 4050 fixed are not listed here). 4051 4052 Target Specific Changes 4053 4054 SPARC 4055 4056 * Support for --with-cpu-32 and --with-cpu-64 configure options has 4057 been added on bi-architecture platforms. 4058 * Support for the SPARC M7 (Niagara 7) processor has been added. 4059 * Support for the VIS 4.0 instruction set has been added. 4060 4061 GCC 6.3 4062 4063 This is the [23]list of problem reports (PRs) from GCC's bug tracking 4064 system that are known to be fixed in the 6.3 release. This list might 4065 not be complete (that is, it is possible that some PRs that have been 4066 fixed are not listed here). 4067 4068 Target Specific Changes 4069 4070 IA-32/x86-64 4071 4072 * Support for the [24]deprecated pcommit instruction has been 4073 removed. 4074 4075 GCC 6.4 4076 4077 This is the [25]list of problem reports (PRs) from GCC's bug tracking 4078 system that are known to be fixed in the 6.4 release. This list might 4079 not be complete (that is, it is possible that some PRs that have been 4080 fixed are not listed here). 4081 4082 Operating Systems 4083 4084 RTEMS 4085 4086 * The ABI changes on ARM so that no short enums are used by default. 4087 4088 GCC 6.5 4089 4090 This is the [26]list of problem reports (PRs) from GCC's bug tracking 4091 system that are known to be fixed in the 6.5 release. This list might 4092 not be complete (that is, it is possible that some PRs that have been 4093 fixed are not listed here). 4094 4095 4096 For questions related to the use of GCC, please consult these web 4097 pages and the [27]GCC manuals. If that fails, the 4098 [28]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 4099 web pages and the development of GCC are welcome on our developer 4100 list at [29]gcc (a] gcc.gnu.org. All of [30]our lists have public 4101 archives. 4102 4103 Copyright (C) [31]Free Software Foundation, Inc. Verbatim copying and 4104 distribution of this entire article is permitted in any medium, 4105 provided this notice is preserved. 4106 4107 These pages are [32]maintained by the GCC team. Last modified 4108 2019-11-28[33]. 4109 4110 References 4111 4112 1. http://gcc.gnu.org/gcc-6/porting_to.html 4113 2. http://gcc.gnu.org/onlinedocs/index.html#current 4114 3. https://gcc.gnu.org/ml/gcc/2015-08/msg00101.html 4115 4. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71151 4116 5. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87822 4117 6. https://www.openacc.org/ 4118 7. https://gcc.gnu.org/wiki/OpenACC 4119 8. https://gcc.gnu.org/wiki/Offloading 4120 9. https://www.openmp.org/specifications/ 4121 10. https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-1266 4122 11. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4377.pdf 4123 12. https://gcc.gnu.org/projects/cxx-status.html#cxx1z 4124 13. https://gcc.gnu.org/onlinedocs/gcc-6.1.0/jit/topics/performance.html 4125 14. https://gcc.gnu.org/onlinedocs/gcc-6.1.0/jit/topics/functions.html#gcc_jit_block_end_with_switch 4126 15. https://gcc.gnu.org/onlinedocs/gcc-6.1.0/jit/topics/contexts.html#gcc_jit_context_set_bool_allow_unreachable_blocks 4127 16. https://gcc.gnu.org/onlinedocs/gcc-6.1.0/jit/topics/contexts.html#gcc_jit_context_add_command_line_option 4128 17. https://gcc.gnu.org/onlinedocs/gcc-6.1.0/gcc/AArch64-Function-Attributes.html#AArch64-Function-Attributes 4129 18. https://gcc.gnu.org/onlinedocs/gcc-6.1.0/gcc/ARM-Function-Attributes.html#ARM-Function-Attributes 4130 19. https://gcc.gnu.org/onlinedocs/gcc-6.1.0/gcc/Named-Address-Spaces.html#Named-Address-Spaces 4131 20. https://gcc.gnu.org/onlinedocs/gcc-6.1.0/gcc/S_002f390-Function-Attributes.html#S_002f390-Function-Attributes 4132 21. http://www.musl-libc.org/ 4133 22. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=6.2 4134 23. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=6.3 4135 24. https://software.intel.com/en-us/blogs/2016/09/12/deprecate-pcommit-instruction 4136 25. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=6.4 4137 26. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=6.5 4138 27. https://gcc.gnu.org/onlinedocs/ 4139 28. mailto:gcc-help (a] gcc.gnu.org 4140 29. mailto:gcc (a] gcc.gnu.org 4141 30. https://gcc.gnu.org/lists.html 4142 31. https://www.fsf.org/ 4143 32. https://gcc.gnu.org/about.html 4144 33. http://validator.w3.org/check/referer 4145 ====================================================================== 4146 http://gcc.gnu.org/gcc-5/index.html 4147 GCC 5 Release Series 4148 4149 (This release series is no longer supported.) 4150 4151 October 10, 2017 4152 4153 The [1]GNU project and the GCC developers are pleased to announce the 4154 release of GCC 5.5. 4155 4156 This release is a bug-fix release, containing fixes for regressions in 4157 GCC 5.4 relative to previous releases of GCC. 4158 4159 Release History 4160 4161 GCC 5.5 4162 October 10, 2017 ([2]changes, [3]documentation) 4163 4164 GCC 5.4 4165 June 3, 2016 ([4]changes, [5]documentation) 4166 4167 GCC 5.3 4168 December 4, 2015 ([6]changes, [7]documentation) 4169 4170 GCC 5.2 4171 July 16, 2015 ([8]changes, [9]documentation) 4172 4173 GCC 5.1 4174 April 22, 2015 ([10]changes, [11]documentation) 4175 4176 References and Acknowledgements 4177 4178 GCC used to stand for the GNU C Compiler, but since the compiler 4179 supports several other languages aside from C, it now stands for the 4180 GNU Compiler Collection. 4181 4182 A list of [12]successful builds is updated as new information becomes 4183 available. 4184 4185 The GCC developers would like to thank the numerous people that have 4186 contributed new features, improvements, bug fixes, and other changes as 4187 well as test results to GCC. This [13]amazing group of volunteers is 4188 what makes GCC successful. 4189 4190 For additional information about GCC please refer to the [14]GCC 4191 project web site or contact the [15]GCC development mailing list. 4192 4193 To obtain GCC please use [16]our mirror sites or [17]our version 4194 control system. 4195 4196 4197 For questions related to the use of GCC, please consult these web 4198 pages and the [18]GCC manuals. If that fails, the 4199 [19]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 4200 web pages and the development of GCC are welcome on our developer 4201 list at [20]gcc (a] gcc.gnu.org. All of [21]our lists have public 4202 archives. 4203 4204 Copyright (C) [22]Free Software Foundation, Inc. Verbatim copying and 4205 distribution of this entire article is permitted in any medium, 4206 provided this notice is preserved. 4207 4208 These pages are [23]maintained by the GCC team. Last modified 4209 2020-01-14[24]. 4210 4211 References 4212 4213 1. http://www.gnu.org/ 4214 2. http://gcc.gnu.org/gcc-5/changes.html 4215 3. http://gcc.gnu.org/onlinedocs/5.5.0/ 4216 4. http://gcc.gnu.org/gcc-5/changes.html 4217 5. http://gcc.gnu.org/onlinedocs/5.4.0/ 4218 6. http://gcc.gnu.org/gcc-5/changes.html 4219 7. http://gcc.gnu.org/onlinedocs/5.3.0/ 4220 8. http://gcc.gnu.org/gcc-5/changes.html 4221 9. http://gcc.gnu.org/onlinedocs/5.2.0/ 4222 10. http://gcc.gnu.org/gcc-5/changes.html 4223 11. http://gcc.gnu.org/onlinedocs/5.1.0/ 4224 12. http://gcc.gnu.org/gcc-5/buildstat.html 4225 13. http://gcc.gnu.org/onlinedocs/gcc/Contributors.html 4226 14. http://gcc.gnu.org/index.html 4227 15. mailto:gcc (a] gcc.gnu.org 4228 16. http://gcc.gnu.org/mirrors.html 4229 17. http://gcc.gnu.org/git.html 4230 18. https://gcc.gnu.org/onlinedocs/ 4231 19. mailto:gcc-help (a] gcc.gnu.org 4232 20. mailto:gcc (a] gcc.gnu.org 4233 21. https://gcc.gnu.org/lists.html 4234 22. https://www.fsf.org/ 4235 23. https://gcc.gnu.org/about.html 4236 24. http://validator.w3.org/check/referer 4237 ====================================================================== 4238 http://gcc.gnu.org/gcc-5/changes.html 4239 GCC 5 Release Series 4240 Changes, New Features, and Fixes 4241 4242 Caveats 4243 4244 * The default mode for C is now -std=gnu11 instead of -std=gnu89. 4245 * The C++ runtime library (libstdc++) uses a new ABI by default (see 4246 [1]below). 4247 * The Graphite framework for loop optimizations no longer requires 4248 the CLooG library, only ISL version 0.14 (recommended) or 0.12.2. 4249 The installation manual contains more information about 4250 requirements to build GCC. 4251 * The non-standard C++0x type traits has_trivial_default_constructor, 4252 has_trivial_copy_constructor and has_trivial_copy_assign have been 4253 deprecated and will be removed in a future version. The standard 4254 C++11 traits is_trivially_default_constructible, 4255 is_trivially_copy_constructible and is_trivially_copy_assignable 4256 should be used instead. 4257 * On AVR, support has been added for the devices 4258 ATtiny4/5/9/10/20/40. This requires Binutils 2.25 or newer. 4259 * The AVR port uses a new scheme to describe supported devices: For 4260 each supported device the compiler provides a device-specific 4261 [2]spec file. If the compiler is used together with AVR-LibC, this 4262 requires at least GCC 5.2 and a version of AVR-LibC which 4263 implements [3]feature #44574. 4264 4265 General Optimizer Improvements 4266 4267 * Inter-procedural optimization improvements: 4268 + An Identical Code Folding (ICF) pass (controlled via 4269 -fipa-icf) has been added. Compared to the identical code 4270 folding performed by the Gold linker this pass does not 4271 require function sections. It also performs merging before 4272 inlining, so inter-procedural optimizations are aware of the 4273 code re-use. On the other hand not all unifications performed 4274 by a linker are doable by GCC which must honor aliasing 4275 information. During link-time optimization of Firefox, this 4276 pass unifies about 31000 functions, that is 14% overall. 4277 + The devirtualization pass was significantly improved by adding 4278 better support for speculative devirtualization and dynamic 4279 type detection. About 50% of virtual calls in Firefox are now 4280 speculatively devirtualized during link-time optimization. 4281 + A new comdat localization pass allows the linker to eliminate 4282 more dead code in presence of C++ inline functions. 4283 + Virtual tables are now optimized. Local aliases are used to 4284 reduce dynamic linking time of C++ virtual tables on ELF 4285 targets and data alignment has been reduced to limit data 4286 segment bloat. 4287 + A new -fno-semantic-interposition option can be used to 4288 improve code quality of shared libraries where interposition 4289 of exported symbols is not allowed. 4290 + Write-only variables are now detected and optimized out. 4291 + With profile feedback the function inliner can now bypass 4292 --param inline-insns-auto and --param inline-insns-single 4293 limits for hot calls. 4294 + The IPA reference pass was significantly sped up making it 4295 feasible to enable -fipa-reference with -fprofile-generate. 4296 This also solves a bottleneck seen when building Chromium with 4297 link-time optimization. 4298 + The symbol table and call-graph API was reworked to C++ and 4299 simplified. 4300 + The interprocedural propagation of constants now also 4301 propagates alignments of pointer parameters. This for example 4302 means that the vectorizer often does not need to generate loop 4303 prologues and epilogues to make up for potential 4304 misalignments. 4305 * Link-time optimization improvements: 4306 + One Definition Rule based merging of C++ types has been 4307 implemented. Type merging enables better devirtualization and 4308 alias analysis. Streaming extra information needed to merge 4309 types adds about 2-6% of memory size and object size increase. 4310 This can be controlled by -flto-odr-type-merging. 4311 + Command-line optimization and target options are now streamed 4312 on a per-function basis and honored by the link-time 4313 optimizer. This change makes link-time optimization a more 4314 transparent replacement of per-file optimizations. It is now 4315 possible to build projects that require different optimization 4316 settings for different translation units (such as -ffast-math, 4317 -mavx, or -finline). Contrary to earlier GCC releases, the 4318 optimization and target options passed on the link command 4319 line are ignored. 4320 Note that this applies only to those command-line options that 4321 can be passed to optimize and target attributes. Command-line 4322 options affecting global code generation (such as -fpic), 4323 warnings (such as -Wodr), optimizations affecting the way 4324 static variables are optimized (such as -fcommon), debug 4325 output (such as -g), and --param parameters can be applied 4326 only to the whole link-time optimization unit. In these cases, 4327 it is recommended to consistently use the same options at both 4328 compile time and link time. 4329 + GCC bootstrap now uses slim LTO object files. 4330 + Memory usage and link times were improved. Tree merging was 4331 sped up, memory usage of GIMPLE declarations and types was 4332 reduced, and, support for on-demand streaming of variable 4333 constructors was added. 4334 * Feedback directed optimization improvements: 4335 + A new auto-FDO mode uses profiles collected by low overhead 4336 profiling tools (perf) instead of more expensive program 4337 instrumentation (via -fprofile-generate). SPEC2006 benchmarks 4338 on x86-64 improve by 4.7% with auto-FDO and by 7.3% with 4339 traditional feedback directed optimization. 4340 + Profile precision was improved in presence of C++ inline and 4341 extern inline functions. 4342 + The new gcov-tool utility allows manipulating profiles. 4343 + Profiles are now more tolerant to source file changes (this 4344 can be controlled by --param profile-func-internal-id). 4345 * Register allocation improvements: 4346 + A new local register allocator (LRA) sub-pass, controlled by 4347 -flra-remat, implements control-flow sensitive global register 4348 rematerialization. Instead of spilling and restoring a 4349 register value, it is recalculated if it is profitable. The 4350 sub-pass improved SPEC2000 generated code by 1% and 0.5% 4351 correspondingly on ARM and x86-64. 4352 + Reuse of the PIC hard register, instead of using a fixed 4353 register, was implemented on x86/x86-64 targets. This improves 4354 generated PIC code performance as more hard registers can be 4355 used. Shared libraries can significantly benefit from this 4356 optimization. Currently it is switched on only for x86/x86-64 4357 targets. As RA infrastructure is already implemented for PIC 4358 register reuse, other targets might follow this in the future. 4359 + A simple form of inter-procedural RA was implemented. When it 4360 is known that a called function does not use caller-saved 4361 registers, save/restore code is not generated around the call 4362 for such registers. This optimization can be controlled by 4363 -fipa-ra 4364 + LRA is now much more effective at generating spills of general 4365 registers into vector registers instead of memory on 4366 architectures (e.g., modern Intel processors) where this is 4367 profitable. 4368 * UndefinedBehaviorSanitizer gained a few new sanitization options: 4369 + -fsanitize=float-divide-by-zero: detect floating-point 4370 division by zero; 4371 + -fsanitize=float-cast-overflow: check that the result of 4372 floating-point type to integer conversions do not overflow; 4373 + -fsanitize=bounds: enable instrumentation of array bounds and 4374 detect out-of-bounds accesses; 4375 + -fsanitize=alignment: enable alignment checking, detect 4376 various misaligned objects; 4377 + -fsanitize=object-size: enable object size checking, detect 4378 various out-of-bounds accesses. 4379 + -fsanitize=vptr: enable checking of C++ member function calls, 4380 member accesses and some conversions between pointers to base 4381 and derived classes, detect if the referenced object does not 4382 have the correct dynamic type. 4383 * Pointer Bounds Checker, a bounds violation detector, has been added 4384 and can be enabled via -fcheck-pointer-bounds. Memory accesses are 4385 instrumented with run-time checks of used pointers against their 4386 bounds to detect pointer bounds violations (overflows). The Pointer 4387 Bounds Checker is available on x86/x86-64 GNU/Linux targets with a 4388 new ISA extension Intel MPX support. See the Pointer Bounds Checker 4389 [4]Wiki page for more details. 4390 4391 New Languages and Language specific improvements 4392 4393 * [5]OpenMP 4.0 specification offloading features are now supported 4394 by the C, C++, and Fortran compilers. Generic changes: 4395 + Infrastructure (suitable for any vendor). 4396 + Testsuite which covers offloading from the [6]OpenMP 4.0 4397 Examples document. 4398 Specific for upcoming Intel Xeon Phi products: 4399 + Run-time library. 4400 + Card emulator. 4401 * GCC 5 includes a preliminary implementation of the OpenACC 2.0a 4402 specification. OpenACC is intended for programming accelerator 4403 devices such as GPUs. See [7]the OpenACC wiki page for more 4404 information. 4405 4406 C family 4407 4408 * The default setting of the -fdiagnostics-color= command-line option 4409 is now [8]configurable when building GCC using configuration option 4410 --with-diagnostics-color=. The possible values are: never, always, 4411 auto and auto-if-env. The new default auto uses color only when the 4412 standard error is a terminal. The default in GCC 4.9 was 4413 auto-if-env, which is equivalent to auto if there is a non-empty 4414 GCC_COLORS environment variable, and never otherwise. As in GCC 4415 4.9, an empty GCC_COLORS variable in the environment will always 4416 disable colors, no matter what the default is or what command-line 4417 options are used. 4418 * A new command-line option -Wswitch-bool has been added for the C 4419 and C++ compilers, which warns whenever a switch statement has an 4420 index of boolean type. 4421 * A new command-line option -Wlogical-not-parentheses has been added 4422 for the C and C++ compilers, which warns about "logical not" used 4423 on the left hand side operand of a comparison. 4424 * A new command-line option -Wsizeof-array-argument has been added 4425 for the C and C++ compilers, which warns when the sizeof operator 4426 is applied to a parameter that has been declared as an array in a 4427 function definition. 4428 * A new command-line option -Wbool-compare has been added for the C 4429 and C++ compilers, which warns about boolean expressions compared 4430 with an integer value different from true/false. 4431 * Full support for [9]Cilk Plus has been added to the GCC compiler. 4432 Cilk Plus is an extension to the C and C++ languages to support 4433 data and task parallelism. 4434 * A new attribute no_reorder prevents reordering of selected symbols 4435 against other such symbols or inline assembler. This enables to 4436 link-time optimize the Linux kernel without having to resort to 4437 -fno-toplevel-reorder that disables several optimizations. 4438 * New preprocessor constructs, __has_include and __has_include_next, 4439 to test the availability of headers have been added. 4440 This demonstrates a way to include the header <optional> only if it 4441 is available: 4442 4443 #ifdef __has_include 4444 # if __has_include(<optional>) 4445 # include <optional> 4446 # define have_optional 1 4447 # elif __has_include(<experimental/optional>) 4448 # include <experimental/optional> 4449 # define have_optional 1 4450 # define experimental_optional 4451 # else 4452 # define have_optional 0 4453 # endif 4454 #endif 4455 4456 The header search paths for __has_include and __has_include_next 4457 are equivalent to those of the standard directive #include and the 4458 extension #include_next respectively. 4459 * A new built-in function-like macro to determine the existence of an 4460 attribute, __has_attribute, has been added. The equivalent built-in 4461 macro __has_cpp_attribute was added to C++ to support 4462 [10]Feature-testing recommendations for C++. The macro 4463 __has_attribute is added to all C-like languages as an extension: 4464 4465 int 4466 #ifdef __has_attribute 4467 # if __has_attribute(__noinline__) 4468 __attribute__((__noinline__)) 4469 # endif 4470 #endif 4471 foo(int x); 4472 4473 If an attribute exists, a nonzero constant integer is returned. For 4474 standardized C++ attributes a date is returned, otherwise the 4475 constant returned is 1. Both __has_attribute and 4476 __has_cpp_attribute will add underscores to an attribute name if 4477 necessary to resolve the name. For C++11 and onwards the attribute 4478 may be scoped. 4479 * A new set of built-in functions for arithmetics with overflow 4480 checking has been added: __builtin_add_overflow, 4481 __builtin_sub_overflow and __builtin_mul_overflow and for 4482 compatibility with clang also other variants. These builtins have 4483 two integral arguments (which don't need to have the same type), 4484 the arguments are extended to infinite precision signed type, +, - 4485 or * is performed on those, and the result is stored in an integer 4486 variable pointed to by the last argument. If the stored value is 4487 equal to the infinite precision result, the built-in functions 4488 return false, otherwise true. The type of the integer variable that 4489 will hold the result can be different from the types of the first 4490 two arguments. The following snippet demonstrates how this can be 4491 used in computing the size for the calloc function: 4492 4493 void * 4494 calloc (size_t x, size_t y) 4495 { 4496 size_t sz; 4497 if (__builtin_mul_overflow (x, y, &sz)) 4498 return NULL; 4499 void *ret = malloc (sz); 4500 if (ret) memset (res, 0, sz); 4501 return ret; 4502 } 4503 4504 On e.g. i?86 or x86-64 the above will result in a mul instruction 4505 followed by a jump on overflow. 4506 * The option -fextended-identifiers is now enabled by default for 4507 C++, and for C99 and later C versions. Various bugs in the 4508 implementation of extended identifiers have been fixed. 4509 4510 C 4511 4512 * The default mode has been changed to -std=gnu11. 4513 * A new command-line option -Wc90-c99-compat has been added to warn 4514 about features not present in ISO C90, but present in ISO C99. 4515 * A new command-line option -Wc99-c11-compat has been added to warn 4516 about features not present in ISO C99, but present in ISO C11. 4517 * It is possible to disable warnings about conversions between 4518 pointers that have incompatible types via a new warning option 4519 -Wno-incompatible-pointer-types; warnings about implicit 4520 incompatible integer to pointer and pointer to integer conversions 4521 via a new warning option -Wno-int-conversion; and warnings about 4522 qualifiers on pointers being discarded via a new warning option 4523 -Wno-discarded-qualifiers. 4524 * To allow proper use of const qualifiers with multidimensional 4525 arrays, GCC will not warn about incompatible pointer types anymore 4526 for conversions between pointers to arrays with and without const 4527 qualifier (except when using -pedantic). Instead, a new warning is 4528 emitted only if the const qualifier is lost. This can be controlled 4529 with a new warning option -Wno-discarded-array-qualifiers. 4530 * The C front end now generates more precise caret diagnostics. 4531 * The -pg command-line option now only affects the current file in an 4532 LTO build. 4533 4534 C++ 4535 4536 * G++ now supports [11]C++14 variable templates. 4537 * -Wnon-virtual-dtor doesn't warn anymore for final classes. 4538 * Excessive template instantiation depth is now a fatal error. This 4539 prevents excessive diagnostics that usually do not help to identify 4540 the problem. 4541 * G++ and libstdc++ now implement the feature-testing macros from 4542 [12]Feature-testing recommendations for C++. 4543 * G++ now allows typename in a template template parameter. 4544 4545 template<template<typename> typename X> struct D; // OK 4546 4547 * G++ now supports [13]C++14 aggregates with non-static data member 4548 initializers. 4549 4550 struct A { int i, j = i; }; 4551 A a = { 42 }; // a.j is also 42 4552 4553 * G++ now supports [14]C++14 extended constexpr. 4554 4555 constexpr int f (int i) 4556 { 4557 int j = 0; 4558 for (; i > 0; --i) 4559 ++j; 4560 return j; 4561 } 4562 4563 constexpr int i = f(42); // i is 42 4564 4565 * G++ now supports the [15]C++14 sized deallocation functions. 4566 4567 void operator delete (void *, std::size_t) noexcept; 4568 void operator delete[] (void *, std::size_t) noexcept; 4569 4570 * A new One Definition Rule violation warning (controlled by -Wodr) 4571 detects mismatches in type definitions and virtual table contents 4572 during link-time optimization. 4573 * New warnings -Wsuggest-final-types and -Wsuggest-final-methods help 4574 developers to annotate programs with final specifiers (or anonymous 4575 namespaces) to improve code generation. These warnings can be used 4576 at compile time, but they are more useful in combination with 4577 link-time optimization. 4578 * G++ no longer supports [16]N3639 variable length arrays, as they 4579 were removed from the C++14 working paper prior to ratification. 4580 GNU VLAs are still supported, so VLA support is now the same in 4581 C++14 mode as in C++98 and C++11 modes. 4582 * G++ now allows passing a non-trivially-copyable class via C 4583 varargs, which is conditionally-supported with 4584 implementation-defined semantics in the standard. This uses the 4585 same calling convention as a normal value parameter. 4586 * G++ now defaults to -fabi-version=9 and -fabi-compat-version=2. So 4587 various mangling bugs are fixed, but G++ will still emit aliases 4588 with the old, wrong mangling where feasible. -Wabi=2 will warn 4589 about differences between ABI version 2 and the current setting. 4590 * G++ 5.2 fixes the alignment of std::nullptr_t. Most code is likely 4591 to be unaffected, but -Wabi=8 will warn about a non-static data 4592 member with type std::nullptr_t which changes position due to this 4593 change. 4594 4595 Runtime Library (libstdc++) 4596 4597 * A [17]Dual ABI is provided by the library. A new ABI is enabled by 4598 default. The old ABI is still supported and can be used by defining 4599 the macro _GLIBCXX_USE_CXX11_ABI to 0 before including any C++ 4600 standard library headers. 4601 * A new implementation of std::string is enabled by default, using 4602 the small string optimization instead of copy-on-write reference 4603 counting. 4604 * A new implementation of std::list is enabled by default, with an 4605 O(1) size() function; 4606 * [18]Full support for C++11, including the following new features: 4607 + std::deque and std::vector<bool> meet the allocator-aware 4608 container requirements; 4609 + movable and swappable iostream classes; 4610 + support for std::align and std::aligned_union; 4611 + type traits std::is_trivially_copyable, 4612 std::is_trivially_constructible, std::is_trivially_assignable 4613 etc.; 4614 + I/O manipulators std::put_time, std::get_time, std::hexfloat 4615 and std::defaultfloat; 4616 + generic locale-aware std::isblank; 4617 + locale facets for Unicode conversion; 4618 + atomic operations for std::shared_ptr; 4619 + std::notify_all_at_thread_exit() and functions for making 4620 futures ready at thread exit. 4621 * Support for the C++11 hexfloat manipulator changes how the num_put 4622 facet formats floating point types when 4623 ios_base::fixed|ios_base::scientific is set in a stream's fmtflags. 4624 This change affects all language modes, even though the C++98 4625 standard gave no special meaning to that combination of flags. To 4626 prevent the use of hexadecimal notation for floating point types 4627 use str.unsetf(std::ios_base::floatfield) to clear the relevant 4628 bits in str.flags(). 4629 * [19]Full experimental support for C++14, including the following 4630 new features: 4631 + std::is_final type trait; 4632 + heterogeneous comparison lookup in associative containers. 4633 + global functions cbegin, cend, rbegin, rend, crbegin, and 4634 crend for range access to containers, arrays and initializer 4635 lists. 4636 * [20]Improved experimental support for the Library Fundamentals TS, 4637 including: 4638 + class std::experimental::any; 4639 + function template std::experimental::apply; 4640 + function template std::experimental::sample; 4641 + function template std::experimental::search and related 4642 searcher types; 4643 + variable templates for type traits; 4644 + function template std::experimental::not_fn. 4645 * New random number distributions logistic_distribution and 4646 uniform_on_sphere_distribution as extensions. 4647 * [21]GDB Xmethods for containers and std::unique_ptr. 4648 4649 Fortran 4650 4651 * Compatibility notice: 4652 + The version of the module files (.mod) has been incremented. 4653 + For free-form source files [22]-Werror=line-truncation is now 4654 enabled by default. Note that comments exceeding the line 4655 length are not diagnosed. (For fixed-form source code, the 4656 same warning is available but turned off by default, such that 4657 excess characters are ignored. -ffree-line-length-n and 4658 -ffixed-line-length-n can be used to modify the default line 4659 lengths of 132 and 72 columns, respectively.) 4660 + The -Wtabs option is now more sensible: with -Wtabs the 4661 compiler warns if it encounters tabs and with -Wno-tabs this 4662 warning is turned off. Before, -Wno-tabs warned and -Wtabs 4663 disabled the warning. As before, this warning is also enabled 4664 by -Wall, -pedantic and the f95, f2003, f2008 and f2008ts 4665 options of -std=. 4666 * Incomplete support for colorizing diagnostics emitted by gfortran 4667 has been added. The option [23]-fdiagnostics-color controls when 4668 color is used in diagnostics. The default value of this option can 4669 be [24]configured when building GCC. The GCC_COLORS environment 4670 variable can be used to customize the colors or disable coloring 4671 completely. Sample diagnostics output: 4672 $ gfortran -fdiagnostics-color=always -Wuse-without-only test.f90 4673 test.f90:6:1: 4674 4675 0 continue 4676 1 4677 Error: Zero is not a valid statement label at (1) 4678 test.f90:9:6: 4679 4680 USE foo 4681 1 4682 Warning: USE statement at (1) has no ONLY qualifier [-Wuse-without-only] 4683 4684 * The -Wuse-without-only option has been added to warn when a USE 4685 statement has no ONLY qualifier and thus implicitly imports all 4686 public entities of the used module. 4687 * Formatted READ and WRITE statements now work correctly in 4688 locale-aware programs. For more information and potential caveats, 4689 see [25]Section 5.3 Thread-safety of the runtime library in the 4690 manual. 4691 * [26]Fortran 2003: 4692 + The intrinsic IEEE modules (IEEE_FEATURES, IEEE_EXCEPTIONS and 4693 IEEE_ARITHMETIC) are now supported. 4694 * [27]Fortran 2008: 4695 + [28]Coarrays: Full experimental support of Fortran 2008's 4696 coarrays with -fcoarray=lib except for allocatable/pointer 4697 components of derived-type coarrays. GCC currently only ships 4698 with a single-image library (libcaf_single), but multi-image 4699 support based on MPI and GASNet is provided by the libraries 4700 of the [29]OpenCoarrays project. 4701 * TS18508 Additional Parallel Features in Fortran: 4702 + Support for the collective intrinsic subroutines CO_MAX, 4703 CO_MIN, CO_SUM, CO_BROADCAST and CO_REDUCE has been added, 4704 including -fcoarray=lib support. 4705 + Support for the new atomic intrinsics has been added, 4706 including -fcoarray=lib support. 4707 * Fortran 2015: 4708 + Support for IMPLICIT NONE (external, type). 4709 + ERROR STOP is now permitted in pure procedures. 4710 4711 Go 4712 4713 * GCC 5 provides a complete implementation of the Go 1.4.2 release. 4714 * Building GCC 5 with Go enabled will install two new programs: 4715 [30]go and [31]gofmt. 4716 4717 libgccjit 4718 4719 New in GCC 5 is the ability to build GCC as a shared library for 4720 embedding in other processes (such as interpreters), suitable for 4721 Just-In-Time compilation to machine code. 4722 4723 The shared library has a [32]C API and a [33]C++ wrapper API providing 4724 some "syntactic sugar". There are also bindings available from 3rd 4725 parties for [34]Python and for [35]D. 4726 4727 For example, this library can be used by interpreters for [36]compiling 4728 functions from bytecode to machine code. 4729 4730 The library can also be used for ahead-of-time compilation, enabling 4731 GCC to be plugged into a pre-existing front end. An example of using 4732 this to build a compiler for an esoteric language we'll refer to as 4733 "brainf" can be seen [37]here. 4734 4735 libgccjit is licensed under the GPLv3 (or at your option, any later 4736 version) 4737 4738 It should be regarded as experimental at this time. 4739 4740 New Targets and Target Specific Improvements 4741 4742 Reporting stack usage 4743 4744 * The BFIN, FT32, H8300, IQ2000 and M32C targets now support the 4745 -fstack-usage option. 4746 4747 AArch64 4748 4749 * Code generation for the ARM Cortex-A57 processor has been improved. 4750 A more accurate instruction scheduling model for the processor is 4751 now used, and a number of compiler tuning parameters have been set 4752 to offer increased performance when compiling with -mcpu=cortex-a57 4753 or -mtune=cortex-a57. 4754 * A workaround for the ARM Cortex-A53 erratum 835769 has been added 4755 and can be enabled by giving the -mfix-cortex-a53-835769 option. 4756 Alternatively it can be enabled by default by configuring GCC with 4757 the --enable-fix-cortex-a53-835769 option. 4758 * The optional cryptographic extensions to the ARMv8-A architecture 4759 are no longer enabled by default when specifying the 4760 -mcpu=cortex-a53, -mcpu=cortex-a57 or -mcpu=cortex-a57.cortex-a53 4761 options. To enable these extensions add +crypto to the value of 4762 -mcpu or -march e.g. -mcpu=cortex-a53+crypto. 4763 * Support has been added for the following processors (GCC 4764 identifiers in parentheses): ARM Cortex-A72 (cortex-a72) and 4765 initial support for its big.LITTLE combination with the ARM 4766 Cortex-A53 (cortex-a72.cortex-a53), Cavium ThunderX (thunderx), 4767 Applied Micro X-Gene 1 (xgene1), and Samsung Exynos M1 (exynos-m1). 4768 The GCC identifiers can be used as arguments to the -mcpu or -mtune 4769 options, for example: -mcpu=xgene1 or -mtune=cortex-a72.cortex-a53. 4770 Using -mcpu=cortex-a72 requires a version of GNU binutils that has 4771 support for the Cortex-A72. 4772 * The transitional options -mlra and -mno-lra have been removed. The 4773 AArch64 backend now uses the local register allocator (LRA) only. 4774 4775 ARM 4776 4777 * Thumb-1 assembly code is now generated in unified syntax. The new 4778 option -masm-syntax-unified specifies whether inline assembly code 4779 is using unified syntax. By default the option is off which means 4780 non-unified syntax is used. However this is subject to change in 4781 future releases. Eventually the non-unified syntax will be 4782 deprecated. 4783 * It is now a configure-time error to use the --with-cpu configure 4784 option with either of --with-tune or --with-arch. 4785 * Code generation for the ARM Cortex-A57 processor has been improved. 4786 A more accurate instruction scheduling model for the processor is 4787 now used, and a number of compiler tuning parameters have been set 4788 to offer increased performance when compiling with -mcpu=cortex-a57 4789 or -mtune=cortex-a57. 4790 * Support has been added for the following processors (GCC 4791 identifiers in parentheses): ARM Cortex-A17 (cortex-a17) and 4792 initial support for its big.LITTLE combination with the ARM 4793 Cortex-A7 (cortex-a17.cortex-a7), ARM Cortex-A72 (cortex-a72) and 4794 initial support for its big.LITTLE combination with the ARM 4795 Cortex-A53 (cortex-a72.cortex-a53), ARM Cortex-M7 (cortex-m7), 4796 Applied Micro X-Gene 1 (xgene1), and Samsung Exynos M1 (exynos-m1). 4797 The GCC identifiers can be used as arguments to the -mcpu or -mtune 4798 options, for example: -mcpu=xgene1 or -mtune=cortex-a72.cortex-a53. 4799 Using -mcpu=cortex-a72 requires a version of GNU binutils that has 4800 support for the Cortex-A72. 4801 * The deprecated option -mwords-little-endian has been removed. 4802 * The options -mapcs, -mapcs-frame, -mtpcs-frame and 4803 -mtpcs-leaf-frame which are only applicable to the old ABI have 4804 been deprecated. 4805 * The transitional options -mlra and -mno-lra have been removed. The 4806 ARM backend now uses the local register allocator (LRA) only. 4807 4808 AVR 4809 4810 * The compiler no more supports individual devices like ATmega8. 4811 Specifying, say, -mmcu=atmega8 triggers the usage of the 4812 device-specific [38]spec file specs-atmega8 which is part of the 4813 installation and describes options for the sub-processes like 4814 compiler proper, assembler and linker. You can add support for a 4815 new device -mmcu=mydevice as follows: 4816 1. In an empty directory /someplace, create a new directory 4817 device-specs. 4818 2. Copy a device spec file from the installed device-specs 4819 folder, follow the comments in that file and then save it as 4820 /someplace/device-specs/specs-mydevice. 4821 3. Add -B /someplace -mmcu=mydevice to the compiler's 4822 command-line options. Notice that /someplace must specify an 4823 absolute path and that mydevice must not start with "avr". 4824 4. Provided you have a device-specific library libmydevice.a 4825 available, you can put it at /someplace, dito for a 4826 device-specific startup file crtmydevice.o. 4827 The contents of the device spec files depend on the compiler's 4828 configuration, in particular on --with-avrlibc=no and whether or 4829 not it is configured for RTEMS. 4830 * A new command-line option -nodevicelib has been added. It prevents 4831 the compiler from linking against AVR-LibC's device-specific 4832 library libdevice.a. 4833 * The following three command-line options have been added: 4834 4835 -mrmw 4836 Set if the device supports the read-modify-write 4837 instructions LAC, LAS, LAT and XCH. 4838 4839 -mn-flash=size 4840 Specify the flash size of the device in units of 64 KiB, 4841 rounded up to the next integer as needed. This option 4842 affects the availability of the [39]AVR address-spaces. 4843 4844 -mskip-bug 4845 Set if the device is affected by the respective silicon 4846 bug. 4847 4848 In general, you don't need to set these options by hand. The new 4849 device-specific spec file will set them as needed. 4850 4851 IA-32/x86-64 4852 4853 * New [40]ISA extensions support AVX-512{BW,DQ,VL,IFMA,VBMI} of 4854 Intel's CPU codenamed Skylake Server was added to GCC. That 4855 includes inline assembly support, new intrinsics, and basic 4856 autovectorization. These new AVX-512 extensions are available via 4857 the following GCC switches: AVX-512 Vector Length EVEX feature: 4858 -mavx512vl, AVX-512 Byte and Word instructions: -mavx512bw, AVX-512 4859 Dword and Qword instructions: -mavx512dq, AVX-512 FMA-52 4860 instructions: -mavx512ifma and for AVX-512 Vector Bit Manipulation 4861 Instructions: -mavx512vbmi. 4862 * New ISA extensions support Intel MPX was added to GCC. This new 4863 extension is available via the -mmpx compiler switch. Intel MPX is 4864 a set of processor features which, with compiler, run-time library 4865 and OS support, brings increased robustness to software by run-time 4866 checking pointer references against their bounds. In GCC Intel MPX 4867 is supported by Pointer Bounds Checker and libmpx run-time 4868 libraries. 4869 * The new -mrecord-mcount option for -pg generates a Linux kernel 4870 style table of pointers to mcount or __fentry__ calls at the 4871 beginning of functions. The new -mnop-mcount option in addition 4872 also generates nops in place of the __fentry__ or mcount call, so 4873 that a call per function can be later patched in. This can be used 4874 for low overhead tracing or hot code patching. 4875 * The new -malign-data option controls how GCC aligns variables. 4876 -malign-data=compat uses increased alignment compatible with GCC 4877 4.8 and earlier, -malign-data=abi uses alignment as specified by 4878 the psABI, and -malign-data=cacheline uses increased alignment to 4879 match the cache line size. -malign-data=compat is the default. 4880 * The new -mskip-rax-setup option skips setting up the RAX register 4881 when SSE is disabled and there are no variable arguments passed in 4882 vector registers. This can be used to optimize the Linux kernel. 4883 4884 MIPS 4885 4886 * MIPS Releases 3 and 5 are now directly supported. Use the 4887 command-line options -mips32r3, -mips64r3, -mips32r5 and -mips64r5 4888 to enable code-generation for these processors. 4889 * The Imagination P5600 processor is now supported using the 4890 -march=p5600 command-line option. 4891 * The Cavium Octeon3 processor is now supported using the 4892 -march=octeon3 command-line option. 4893 * MIPS Release 6 is now supported using the -mips32r6 and -mips64r6 4894 command-line options. 4895 * The o32 ABI has been modified and extended. The o32 64-bit 4896 floating-point register support is now obsolete and has been 4897 removed. It has been replaced by three ABI extensions FPXX, FP64A, 4898 and FP64. The meaning of the -mfp64 command-line option has 4899 changed. It is now used to enable the FP64A and FP64 ABI 4900 extensions. 4901 + The FPXX extension requires that code generated to access 4902 double-precision values use even-numbered registers. Code that 4903 adheres to this extension is link-compatible with all other 4904 o32 double-precision ABI variants and will execute correctly 4905 in all hardware FPU modes. The command-line options -mabi=32 4906 -mfpxx can be used to enable this extension. MIPS II is the 4907 minimum processor required. 4908 + The o32 FP64A extension requires that floating-point registers 4909 be 64-bit and odd-numbered single-precision registers are not 4910 allowed. Code that adheres to the o32 FP64A variant is 4911 link-compatible with all other o32 double-precision ABI 4912 variants. The command-line options -mabi=32 -mfp64 4913 -mno-odd-spreg can be used to enable this extension. MIPS32R2 4914 is the minimum processor required. 4915 + The o32 FP64 extension also requires that floating-point 4916 registers be 64-bit, but permits the use of single-precision 4917 registers. Code that adheres to the o32 FP64 variant is 4918 link-compatible with o32 FPXX and o32 FP64A variants only, 4919 i.e. it is not compatible with the original o32 4920 double-precision ABI. The command-line options -mabi=32 -mfp64 4921 -modd-spreg can be used to enable this extension. MIPS32R2 is 4922 the minimum processor required. 4923 The new ABI variants can be enabled by default using the configure 4924 time options --with-fp-32=[32|xx|64] and --with(out)-odd-sp-reg-32. 4925 It is strongly recommended that all vendors begin to set o32 FPXX 4926 as the default ABI. This will be required to run the generated code 4927 on MIPSR5 cores in conjunction with future MIPS SIMD (MSA) code and 4928 MIPSR6 cores. 4929 * GCC will now pass all floating-point options to the assembler if 4930 GNU binutils 2.25 is used. As a result, any inline assembly code 4931 that uses hard-float instructions should be amended to include a 4932 .set directive to override the global assembler options when 4933 compiling for soft-float targets. 4934 4935 NDS32 4936 4937 * The variadic function ABI implementation is now compatible with 4938 past Andes toolchains where the caller uses registers to pass 4939 arguments and the callee is in charge of pushing them on stack. 4940 * The options -mforce-fp-as-gp, -mforbid-fp-as-gp, and -mex9 have 4941 been removed since they are not yet available in the nds32 port of 4942 GNU binutils. 4943 * A new option -mcmodel=[small|medium|large] supports varied code 4944 models on code generation. The -mgp-direct option became 4945 meaningless and can be discarded. 4946 4947 RX 4948 4949 * A new command line option -mno-allow-string-insns can be used to 4950 disable the generation of the SCMPU, SMOVU, SMOVB, SMOVF, SUNTIL, 4951 SWHILE and RMPA instructions. An erratum released by Renesas shows 4952 that it is unsafe to use these instructions on addresses within the 4953 I/O space of the processor. The new option can be used when the 4954 programmer is concerned that the I/O space might be accessed. The 4955 default is still to enable these instructions. 4956 4957 SH 4958 4959 * The compiler will now pass the appropriate --isa= option to the 4960 assembler. 4961 * The default handling for the GBR has been changed from call 4962 clobbered to call preserved. The old behavior can be reinstated by 4963 specifying the option -fcall-used-gbr. 4964 * Support for the SH4A fpchg instruction has been added which will be 4965 utilized when switching between single and double precision FPU 4966 modes. 4967 * The compiler no longer uses the __fpscr_values array for switching 4968 between single and double FPU precision modes on non-SH4A targets. 4969 Instead mode switching will now be performed by storing, modifying 4970 and reloading the FPSCR, so that other FPSCR bits are preserved 4971 across mode switches. The __fpscr_values array that is defined in 4972 libgcc is still present for backwards compatibility, but it will 4973 not be referenced by compiler generated code anymore. 4974 * New builtin functions __builtin_sh_get_fpscr and 4975 __builtin_sh_set_fpscr have been added. The __builtin_sh_set_fpscr 4976 function will mask the specified bits in such a way that the SZ, PR 4977 and FR mode bits will be preserved, while changing the other bits. 4978 These new functions do not reference the __fpscr_values array. The 4979 old functions __set_fpscr and __get_fpscr in libgcc which access 4980 the __fpscr_values array are still present for backwards 4981 compatibility, but their usage is highly discouraged. 4982 * Some improvements to code generated for __atomic built-in 4983 functions. 4984 * When compiling for SH2E the compiler will no longer force the usage 4985 of delay slots for conditional branch instructions bt and bf. The 4986 old behavior can be reinstated (e.g. to work around a hardware bug 4987 in the original SH7055) by specifying the new option 4988 -mcbranch-force-delay-slot. 4989 4990 Operating Systems 4991 4992 AIX 4993 4994 * GCC now supports stabs debugging continuation lines to allow long 4995 stabs debug information without overflow that generates AIX linker 4996 errors. 4997 4998 DragonFly BSD 4999 5000 * GCC now supports the DragonFly BSD operating system. 5001 5002 FreeBSD 5003 5004 * GCC now supports the FreeBSD operating system for the arm port 5005 through the arm*-*-freebsd* target triplets. 5006 5007 VxWorks MILS 5008 5009 * GCC now supports the MILS (Multiple Independent Levels of Security) 5010 variant of WindRiver's VxWorks operating system for PowerPC 5011 targets. 5012 5013 Other significant improvements 5014 5015 * The gcc-ar, gcc-nm, gcc-ranlib wrappers now understand a -B option 5016 to set the compiler to use. 5017 5018 * When the new command-line option -freport-bug is used, GCC 5019 automatically generates a developer-friendly reproducer whenever an 5020 internal compiler error is encountered. 5021 5022 GCC 5.2 5023 5024 This is the [41]list of problem reports (PRs) from GCC's bug tracking 5025 system that are known to be fixed in the 5.2 release. This list might 5026 not be complete (that is, it is possible that some PRs that have been 5027 fixed are not listed here). 5028 5029 Target Specific Changes 5030 5031 IA-32/x86-64 5032 5033 * Support for new AMD instructions monitorx and mwaitx has been 5034 added. This includes new intrinsic and built-in support. It is 5035 enabled through option -mmwaitx. The instructions monitorx and 5036 mwaitx implement the same functionality as the old monitor and 5037 mwait instructions. In addition mwaitx adds a configurable timer. 5038 The timer value is received as third argument and stored in 5039 register %ebx. 5040 5041 S/390, System z, IBM z Systems 5042 5043 * Support for the IBM z13 processor has been added. When using the 5044 -march=z13 option, the compiler will generate code making use of 5045 the new instructions and registers introduced with the vector 5046 extension facility. The -mtune=z13 option enables z13 specific 5047 instruction scheduling without making use of new instructions. 5048 Compiling code with -march=z13 reduces the default alignment of 5049 vector types bigger than 8 bytes to 8. This is an ABI change and 5050 care must be taken when linking modules compiled with different 5051 arch levels which interchange variables containing vector type 5052 values. For newly compiled code the GNU linker will emit a warning. 5053 * The -mzvector option enables a C/C++ language extension. This 5054 extension provides a new keyword vector which can be used to define 5055 vector type variables. (Note: This is not available when enforcing 5056 strict standard compliance e.g. with -std=c99. Either enable GNU 5057 extensions with e.g. -std=gnu99 or use __vector instead of vector.) 5058 Additionally a set of overloaded builtins is provided which is 5059 partially compatible to the PowerPC Altivec builtins. In order to 5060 make use of these builtins the vecintrin.h header file needs to be 5061 included. 5062 5063 GCC 5.3 5064 5065 This is the [42]list of problem reports (PRs) from GCC's bug tracking 5066 system that are known to be fixed in the 5.3 release. This list might 5067 not be complete (that is, it is possible that some PRs that have been 5068 fixed are not listed here). 5069 5070 Target Specific Changes 5071 5072 IA-32/x86-64 5073 5074 * GCC now supports the Intel CPU named Skylake with AVX-512 5075 extensions through -march=skylake-avx512. The switch enables the 5076 following ISA extensions: AVX-512F, AVX512VL, AVX-512CD, AVX-512BW, 5077 AVX-512DQ. 5078 5079 S/390, System z, IBM z Systems 5080 5081 * With this version of GCC IBM z Systems support has been added to 5082 the GO runtime environment. GCC 5.3 has proven to be able to 5083 compile larger GO applications on IBM z Systems. 5084 5085 GCC 5.4 5086 5087 This is the [43]list of problem reports (PRs) from GCC's bug tracking 5088 system that are known to be fixed in the 5.4 release. This list might 5089 not be complete (that is, it is possible that some PRs that have been 5090 fixed are not listed here). 5091 5092 GCC 5.5 5093 5094 This is the [44]list of problem reports (PRs) from GCC's bug tracking 5095 system that are known to be fixed in the 5.5 release. This list might 5096 not be complete (that is, it is possible that some PRs that have been 5097 fixed are not listed here). 5098 5099 Target Specific Changes 5100 5101 IA-32/x86-64 5102 5103 * Support for the [45]deprecated pcommit instruction has been 5104 removed. 5105 5106 5107 For questions related to the use of GCC, please consult these web 5108 pages and the [46]GCC manuals. If that fails, the 5109 [47]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 5110 web pages and the development of GCC are welcome on our developer 5111 list at [48]gcc (a] gcc.gnu.org. All of [49]our lists have public 5112 archives. 5113 5114 Copyright (C) [50]Free Software Foundation, Inc. Verbatim copying and 5115 distribution of this entire article is permitted in any medium, 5116 provided this notice is preserved. 5117 5118 These pages are [51]maintained by the GCC team. Last modified 5119 2019-11-28[52]. 5120 5121 References 5122 5123 1. http://gcc.gnu.org/gcc-5/changes.html#libstdcxx 5124 2. https://gcc.gnu.org/onlinedocs/gcc/Spec-Files.html 5125 3. https://savannah.nongnu.org/bugs/?44574 5126 4. https://gcc.gnu.org/wiki/Intel MPX support in the GCC compiler 5127 5. https://www.openmp.org/wp-content/uploads/OpenMP4.0.0.pdf 5128 6. https://www.openmp.org/wp-content/uploads/OpenMP4.0.0.Examples.pdf 5129 7. https://gcc.gnu.org/wiki/OpenACC 5130 8. https://gcc.gnu.org/install/configure.html 5131 9. https://www.cilkplus.org/ 5132 10. https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations 5133 11. http://gcc.gnu.org/projects/cxx1y.html 5134 12. https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations 5135 13. http://gcc.gnu.org/projects/cxx1y.html 5136 14. http://gcc.gnu.org/projects/cxx1y.html 5137 15. http://gcc.gnu.org/projects/cxx1y.html 5138 16. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3639.html 5139 17. http://gcc.gnu.org/onlinedocs/libstdc++/manual/using_dual_abi.html 5140 18. https://gcc.gnu.org/onlinedocs/gcc-5.1.0/libstdc++/manual/manual/status.html#status.iso.2011 5141 19. https://gcc.gnu.org/onlinedocs/gcc-5.1.0/libstdc++/manual/manual/status.html#status.iso.2014 5142 20. https://gcc.gnu.org/onlinedocs/gcc-5.1.0/libstdc++/manual/manual/status.html#status.iso.2014 5143 21. https://sourceware.org/gdb/current/onlinedocs/gdb/Xmethods-In-Python.html 5144 22. https://gcc.gnu.org/onlinedocs/gcc-5.1.0/gfortran/Error-and-Warning-Options.html 5145 23. https://gcc.gnu.org/onlinedocs/gcc-5.1.0/gcc/Language-Independent-Options.html 5146 24. https://gcc.gnu.org/install/configure.html 5147 25. https://gcc.gnu.org/onlinedocs/gcc-5.1.0/gfortran/Thread-safety-of-the-runtime-library.html 5148 26. https://gcc.gnu.org/wiki/Fortran2003Status 5149 27. https://gcc.gnu.org/wiki/Fortran2008Status 5150 28. https://gcc.gnu.org/wiki/Coarray 5151 29. http://www.opencoarrays.org/ 5152 30. https://golang.org/cmd/go/ 5153 31. https://golang.org/cmd/gofmt/ 5154 32. https://gcc.gnu.org/onlinedocs/gcc-5.1.0/jit/intro/index.html 5155 33. https://gcc.gnu.org/onlinedocs/gcc-5.1.0/jit/cp/index.html 5156 34. https://github.com/davidmalcolm/pygccjit 5157 35. https://github.com/ibuclaw/gccjitd 5158 36. https://gcc.gnu.org/onlinedocs/gcc-5.1.0/jit/intro/tutorial04.html 5159 37. https://gcc.gnu.org/onlinedocs/gcc-5.1.0/jit/intro/tutorial05.html 5160 38. https://gcc.gnu.org/onlinedocs/gcc/Spec-Files.html 5161 39. https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html 5162 40. https://software.intel.com/sites/default/files/managed/39/c5/325462-sdm-vol-1-2abcd-3abcd.pdf 5163 41. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=5.2 5164 42. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=5.3 5165 43. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=5.4 5166 44. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=5.5 5167 45. https://software.intel.com/en-us/blogs/2016/09/12/deprecate-pcommit-instruction 5168 46. https://gcc.gnu.org/onlinedocs/ 5169 47. mailto:gcc-help (a] gcc.gnu.org 5170 48. mailto:gcc (a] gcc.gnu.org 5171 49. https://gcc.gnu.org/lists.html 5172 50. https://www.fsf.org/ 5173 51. https://gcc.gnu.org/about.html 5174 52. http://validator.w3.org/check/referer 5175 ====================================================================== 5176 http://gcc.gnu.org/gcc-4.9/index.html 5177 GCC 4.9 Release Series 5178 5179 (This release series is no longer supported.) 5180 5181 Aug 3, 2016 5182 5183 The [1]GNU project and the GCC developers are pleased to announce the 5184 release of GCC 4.9.4. 5185 5186 This release is a bug-fix release, containing fixes for regressions in 5187 GCC 4.9.3 relative to previous releases of GCC. 5188 5189 Release History 5190 5191 GCC 4.9.4 5192 Aug 3, 2016 ([2]changes, [3]documentation) 5193 5194 GCC 4.9.3 5195 June 26, 2015 ([4]changes, [5]documentation) 5196 5197 GCC 4.9.2 5198 October 30, 2014 ([6]changes, [7]documentation) 5199 5200 GCC 4.9.1 5201 July 16, 2014 ([8]changes, [9]documentation) 5202 5203 GCC 4.9.0 5204 April 22, 2014 ([10]changes, [11]documentation) 5205 5206 References and Acknowledgements 5207 5208 GCC used to stand for the GNU C Compiler, but since the compiler 5209 supports several other languages aside from C, it now stands for the 5210 GNU Compiler Collection. 5211 5212 A list of [12]successful builds is updated as new information becomes 5213 available. 5214 5215 The GCC developers would like to thank the numerous people that have 5216 contributed new features, improvements, bug fixes, and other changes as 5217 well as test results to GCC. This [13]amazing group of volunteers is 5218 what makes GCC successful. 5219 5220 For additional information about GCC please refer to the [14]GCC 5221 project web site or contact the [15]GCC development mailing list. 5222 5223 To obtain GCC please use [16]our mirror sites or [17]our version 5224 control system. 5225 5226 5227 For questions related to the use of GCC, please consult these web 5228 pages and the [18]GCC manuals. If that fails, the 5229 [19]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 5230 web pages and the development of GCC are welcome on our developer 5231 list at [20]gcc (a] gcc.gnu.org. All of [21]our lists have public 5232 archives. 5233 5234 Copyright (C) [22]Free Software Foundation, Inc. Verbatim copying and 5235 distribution of this entire article is permitted in any medium, 5236 provided this notice is preserved. 5237 5238 These pages are [23]maintained by the GCC team. Last modified 5239 2020-01-14[24]. 5240 5241 References 5242 5243 1. http://www.gnu.org/ 5244 2. http://gcc.gnu.org/gcc-4.9/changes.html 5245 3. http://gcc.gnu.org/onlinedocs/4.9.4/ 5246 4. http://gcc.gnu.org/gcc-4.9/changes.html 5247 5. http://gcc.gnu.org/onlinedocs/4.9.3/ 5248 6. http://gcc.gnu.org/gcc-4.9/changes.html 5249 7. http://gcc.gnu.org/onlinedocs/4.9.2/ 5250 8. http://gcc.gnu.org/gcc-4.9/changes.html 5251 9. http://gcc.gnu.org/onlinedocs/4.9.1/ 5252 10. http://gcc.gnu.org/gcc-4.9/changes.html 5253 11. https://gcc.gnu.org/onlinedocs/4.9.0/ 5254 12. http://gcc.gnu.org/gcc-4.9/buildstat.html 5255 13. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 5256 14. http://gcc.gnu.org/index.html 5257 15. mailto:gcc (a] gcc.gnu.org 5258 16. http://gcc.gnu.org/mirrors.html 5259 17. http://gcc.gnu.org/git.html 5260 18. https://gcc.gnu.org/onlinedocs/ 5261 19. mailto:gcc-help (a] gcc.gnu.org 5262 20. mailto:gcc (a] gcc.gnu.org 5263 21. https://gcc.gnu.org/lists.html 5264 22. https://www.fsf.org/ 5265 23. https://gcc.gnu.org/about.html 5266 24. http://validator.w3.org/check/referer 5267 ====================================================================== 5268 http://gcc.gnu.org/gcc-4.9/changes.html 5269 GCC 4.9 Release Series 5270 Changes, New Features, and Fixes 5271 5272 Caveats 5273 5274 * The mudflap run time checker has been removed. The mudflap options 5275 remain, but do nothing. 5276 * Support for a number of older systems and recently unmaintained or 5277 untested target ports of GCC has been declared obsolete in GCC 4.9. 5278 Unless there is activity to revive them, the next release of GCC 5279 will have their sources permanently removed. 5280 The following ports for individual systems on particular 5281 architectures have been obsoleted: 5282 + Solaris 9 (*-*-solaris2.9). Details can be found in the 5283 [1]announcement. 5284 * On AArch64, the singleton vector types int64x1_t, uint64x1_t and 5285 float64x1_t exported by arm_neon.h are defined to be the same as 5286 their base types. This results in incorrect application of 5287 parameter passing rules to arguments of types int64x1_t and 5288 uint64x1_t, with respect to the AAPCS64 ABI specification. In 5289 addition, names of C++ functions with parameters of these types 5290 (including float64x1_t) are not mangled correctly. The current 5291 typedef declarations also unintentionally allow implicit casting 5292 between singleton vector types and their base types. These issues 5293 will be resolved in a near future release. See [2]PR60825 for more 5294 information. 5295 5296 More information on porting to GCC 4.9 from previous versions of GCC 5297 can be found in the [3]porting guide for this release. 5298 5299 General Optimizer Improvements 5300 5301 * AddressSanitizer, a fast memory error detector, is now available on 5302 ARM. 5303 * UndefinedBehaviorSanitizer (ubsan), a fast undefined behavior 5304 detector, has been added and can be enabled via 5305 -fsanitize=undefined. Various computations will be instrumented to 5306 detect undefined behavior at runtime. UndefinedBehaviorSanitizer is 5307 currently available for the C and C++ languages. 5308 * Link-time optimization (LTO) improvements: 5309 + Type merging was rewritten. The new implementation is 5310 significantly faster and uses less memory. 5311 + Better partitioning algorithm resulting in less streaming 5312 during link time. 5313 + Early removal of virtual methods reduces the size of object 5314 files and improves link-time memory usage and compile time. 5315 + Function bodies are now loaded on-demand and released early 5316 improving overall memory usage at link time. 5317 + C++ hidden keyed methods can now be optimized out. 5318 + When using a linker plugin, compiling with the -flto option 5319 now generates slim object files (.o) which only contain 5320 intermediate language representation for LTO. Use 5321 -ffat-lto-objects to create files which contain additionally 5322 the object code. To generate static libraries suitable for LTO 5323 processing, use gcc-ar and gcc-ranlib; to list symbols from a 5324 slim object file use gcc-nm. (This requires that ar, ranlib 5325 and nm have been compiled with plugin support.) 5326 Memory usage building Firefox with debug enabled was reduced from 5327 15GB to 3.5GB; link time from 1700 seconds to 350 seconds. 5328 * Inter-procedural optimization improvements: 5329 + New type inheritance analysis module improving 5330 devirtualization. Devirtualization now takes into account 5331 anonymous name-spaces and the C++11 final keyword. 5332 + New speculative devirtualization pass (controlled by 5333 -fdevirtualize-speculatively. 5334 + Calls that were speculatively made direct are turned back to 5335 indirect where direct call is not cheaper. 5336 + Local aliases are introduced for symbols that are known to be 5337 semantically equivalent across shared libraries improving 5338 dynamic linking times. 5339 * Feedback directed optimization improvements: 5340 + Profiling of programs using C++ inline functions is now more 5341 reliable. 5342 + New time profiling determines typical order in which functions 5343 are executed. 5344 + A new function reordering pass (controlled by 5345 -freorder-functions) significantly reduces startup time of 5346 large applications. Until binutils support is completed, it is 5347 effective only with link-time optimization. 5348 + Feedback driven indirect call removal and devirtualization now 5349 handle cross-module calls when link-time optimization is 5350 enabled. 5351 5352 New Languages and Language specific improvements 5353 5354 * Version 4.0 of the [4]OpenMP specification is now supported in the 5355 C and C++ compilers and starting with the 4.9.1 release also in the 5356 Fortran compiler. The new -fopenmp-simd option can be used to 5357 enable OpenMP's SIMD directives while ignoring other OpenMP 5358 directives. The new [5]-fsimd-cost-model= option permits to tune 5359 the vectorization cost model for loops annotated with OpenMP and 5360 Cilk Plus simd directives. -Wopenmp-simd warns when the current 5361 cost model overrides simd directives set by the user. 5362 * The -Wdate-time option has been added for the C, C++ and Fortran 5363 compilers, which warns when the __DATE__, __TIME__ or __TIMESTAMP__ 5364 macros are used. Those macros might prevent bit-wise-identical 5365 reproducible compilations. 5366 5367 Ada 5368 5369 * GNAT switched to Ada 2012 instead of Ada 2005 by default. 5370 5371 C family 5372 5373 * Support for colorizing diagnostics emitted by GCC has been added. 5374 The [6]-fdiagnostics-color=auto will enable it when outputting to 5375 terminals, -fdiagnostics-color=always unconditionally. The 5376 GCC_COLORS environment variable can be used to customize the colors 5377 or disable coloring. If GCC_COLORS variable is present in the 5378 environment, the default is -fdiagnostics-color=auto, otherwise 5379 -fdiagnostics-color=never. 5380 Sample diagnostics output: 5381 $ g++ -fdiagnostics-color=always -S -Wall test.C 5382 test.C: In function int foo(): 5383 test.C:1:14: warning: no return statement in function returning non-void [-W 5384 return-type] 5385 int foo () { } 5386 ^ 5387 test.C:2:46: error: template instantiation depth exceeds maximum of 900 (use 5388 -ftemplate-depth= to increase the maximum) instantiating struct X<100> 5389 template <int N> struct X { static const int value = X<N-1>::value; }; temp 5390 late struct X<1000>; 5391 ^ 5392 test.C:2:46: recursively required from const int X<999>::value 5393 test.C:2:46: required from const int X<1000>::value 5394 test.C:2:88: required from here 5395 5396 test.C:2:46: error: incomplete type X<100> used in nested name specifier 5397 5398 * With the new [7]#pragma GCC ivdep, the user can assert that there 5399 are no loop-carried dependencies which would prevent concurrent 5400 execution of consecutive iterations using SIMD (single instruction 5401 multiple data) instructions. 5402 * Support for [8]Cilk Plus has been added and can be enabled with the 5403 -fcilkplus option. Cilk Plus is an extension to the C and C++ 5404 languages to support data and task parallelism. The present 5405 implementation follows ABI version 1.2; all features but _Cilk_for 5406 have been implemented. 5407 5408 C 5409 5410 * ISO C11 atomics (the _Atomic type specifier and qualifier and the 5411 <stdatomic.h> header) are now supported. 5412 * ISO C11 generic selections (_Generic keyword) are now supported. 5413 * ISO C11 thread-local storage (_Thread_local, similar to GNU C 5414 __thread) is now supported. 5415 * ISO C11 support is now at a similar level of completeness to ISO 5416 C99 support: substantially complete modulo bugs, extended 5417 identifiers (supported except for corner cases when 5418 -fextended-identifiers is used), floating-point issues (mainly but 5419 not entirely relating to optional C99 features from Annexes F and 5420 G) and the optional Annexes K (Bounds-checking interfaces) and L 5421 (Analyzability). 5422 * A new C extension __auto_type provides a subset of the 5423 functionality of C++11 auto in GNU C. 5424 5425 C++ 5426 5427 * The G++ implementation of [9]C++1y return type deduction for normal 5428 functions has been updated to conform to [10]N3638, the proposal 5429 accepted into the working paper. Most notably, it adds 5430 decltype(auto) for getting decltype semantics rather than the 5431 template argument deduction semantics of plain auto: 5432 5433 int& f(); 5434 auto i1 = f(); // int 5435 decltype(auto) i2 = f(); // int& 5436 5437 * G++ supports [11]C++1y lambda capture initializers: 5438 5439 [x = 42]{ ... }; 5440 5441 Actually, they have been accepted since GCC 4.5, but now the 5442 compiler doesn't warn about them with -std=c++1y, and supports 5443 parenthesized and brace-enclosed initializers as well. 5444 * G++ supports [12]C++1y variable length arrays. G++ has supported 5445 GNU/C99-style VLAs for a long time, but now additionally supports 5446 initializers and lambda capture by reference. In C++1y mode G++ 5447 will complain about VLA uses that are not permitted by the draft 5448 standard, such as forming a pointer to VLA type or applying sizeof 5449 to a VLA variable. Note that it now appears that VLAs will not be 5450 part of C++14, but will be part of a separate document and then 5451 perhaps C++17. 5452 5453 void f(int n) { 5454 int a[n] = { 1, 2, 3 }; // throws std::bad_array_length if n < 3 5455 [&a]{ for (int i : a) { cout << i << endl; } }(); 5456 &a; // error, taking address of VLA 5457 } 5458 5459 * G++ supports the [13]C++1y [[deprecated]] attribute modulo bugs in 5460 the underlying [[gnu::deprecated]] attribute. Classes and functions 5461 can be marked deprecated and a diagnostic message added: 5462 5463 class A; 5464 int bar(int n); 5465 #if __cplusplus > 201103 5466 class [[deprecated("A is deprecated in C++14; Use B instead")]] A; 5467 [[deprecated("bar is unsafe; use foo() instead")]] 5468 int bar(int n); 5469 5470 int foo(int n); 5471 class B; 5472 #endif 5473 A aa; // warning: 'A' is deprecated : A is deprecated in C++14; Use B instead 5474 int j = bar(2); // warning: 'int bar(int)' is deprecated : bar is unsafe; use fo 5475 o() instead 5476 5477 * G++ supports [14]C++1y digit separators. Long numeric literals can 5478 be subdivided with a single quote ' to enhance readability: 5479 5480 int i = 1048576; 5481 int j = 1'048'576; 5482 int k = 0x10'0000; 5483 int m = 0'004'000'000; 5484 int n = 0b0001'0000'0000'0000'0000'0000; 5485 5486 double x = 1.602'176'565e-19; 5487 double y = 1.602'176'565e-1'9; 5488 5489 * G++ supports [15]C++1y generic (polymorphic) lambdas. 5490 5491 // a functional object that will increment any type 5492 auto incr = [](auto x) { return x++; }; 5493 5494 * As a GNU extension, G++ supports explicit template parameter syntax 5495 for generic lambdas. This can be combined in the expected way with 5496 the standard auto syntax. 5497 5498 // a functional object that will add two like-type objects 5499 auto add = [] <typename T> (T a, T b) { return a + b; }; 5500 5501 * G++ supports unconstrained generic functions as specified by 4.1.2 5502 and 5.1.1 of [16]N3889: Concepts Lite Specification. Briefly, auto 5503 may be used as a type-specifier in a parameter declaration of any 5504 function declarator in order to introduce an implicit function 5505 template parameter, akin to generic lambdas. 5506 5507 // the following two function declarations are equivalent 5508 auto incr(auto x) { return x++; } 5509 template <typename T> 5510 auto incr(T x) { return x++; } 5511 5512 Runtime Library (libstdc++) 5513 5514 * [17]Improved support for C++11, including: 5515 + support for <regex>; 5516 + The associative containers in <map> and <set> and the 5517 unordered associative containers in <unordered_map> and 5518 <unordered_set> meet the allocator-aware container 5519 requirements; 5520 * [18]Improved experimental support for the upcoming ISO C++ 5521 standard, C++14, including: 5522 + fixing constexpr member functions without const; 5523 + implementation of the std::exchange() utility function; 5524 + addressing tuples by type; 5525 + implemention of std::make_unique; 5526 + implemention of std::shared_lock; 5527 + making std::result_of SFINAE-friendly; 5528 + adding operator() to std::integral_constant; 5529 + adding user-defined literals for standard library types 5530 std::basic_string, std::chrono::duration, and std::complex; 5531 + adding two range overloads to non-modifying sequence oprations 5532 std::equal and std::mismatch; 5533 + adding IO manipulators for quoted strings; 5534 + adding constexpr members to <utility>, <complex>, <chrono>, 5535 and some containers; 5536 + adding compile-time std::integer_sequence; 5537 + adding cleaner transformation traits; 5538 + making <functional>s operator functors easier to use and more 5539 generic; 5540 * An implementation of std::experimental::optional. 5541 * An implementation of std::experimental::string_view. 5542 * The non-standard function std::copy_exception has been deprecated 5543 and will be removed in a future version. std::make_exception_ptr 5544 should be used instead. 5545 5546 Fortran 5547 5548 * Compatibility notice: 5549 + Module files: The version of the module files (.mod) has been 5550 incremented; additionally, module files are now compressed. 5551 Fortran MODULEs compiled by earlier GCC versions have to be 5552 recompiled, when they are USEd by files compiled with GCC 4.9. 5553 GCC 4.9 is not able to read .mod files of earlier GCC 5554 versions; attempting to do so gives an error message. Note: 5555 The ABI of the produced assembler data itself has not changed: 5556 object files and libraries are fully compatible with older 5557 versions (except as stated below). 5558 + ABI changes: 5559 o The [19]argument passing ABI has changed for scalar dummy 5560 arguments of type INTEGER, REAL, COMPLEX and LOGICAL, 5561 which have both the VALUE and the OPTIONAL attributes. 5562 o To support finalization the virtual table associated with 5563 polymorphic variables has changed. Code containing CLASS 5564 should be recompiled, including all files which define 5565 derived types involved in the type definition used by 5566 polymorphic variables. (Note: Due to the incremented 5567 module version, trying to mix old code with new code will 5568 usually give an error message.) 5569 + GNU Fortran no longer deallocates allocatable variables or 5570 allocatable components of variables declared in the main 5571 program. Since Fortran 2008, the standard explicitly states 5572 that variables declared in the Fortran main program 5573 automatically have the SAVE attribute. 5574 + When opening files, the close-on-exec flag is set if the 5575 system supports such a feature. This is generally considered 5576 good practice these days, but if there is a need to pass file 5577 descriptors to child processes the parent process must now 5578 remember to clear the close-on-exec flag by calling fcntl(), 5579 e.g. via ISO_C_BINDING, before executing the child process. 5580 * The deprecated command-line option -fno-whole-file has been 5581 removed. (-fwhole-file is the default since GCC 4.6.) 5582 -fwhole-file/-fno-whole-file continue to be accepted but do not 5583 influence the code generation. 5584 * The compiler no longer unconditionally warns about DO loops with 5585 zero iterations. This warning is now controlled by the -Wzerotrip 5586 option, which is implied by -Wall. 5587 * The new NO_ARG_CHECK attribute of the [20]!GCC$ directive can be 5588 used to disable the type-kind-rank (TKR) argument check for a dummy 5589 argument. The feature is similar to ISO/IEC TS 29133:2012's 5590 TYPE(*), except that it additionally also disables the rank check. 5591 Variables with NO_ARG_CHECK have to be dummy arguments and may only 5592 be used as argument to ISO_C_BINDING's C_LOC and as actual argument 5593 to another NO_ARG_CHECK dummy argument; also the other constraints 5594 of TYPE(*) apply. The dummy arguments should be declared as scalar 5595 or assumed-size variable of type type(*) (recommended) or of type 5596 integer, real, complex or logical. With NO_ARG_CHECK, a pointer to 5597 the data without further type or shape information is passed, 5598 similar to C's void*. Note that also TS 29113's 5599 type(*),dimension(..) accepts arguments of any type and rank; 5600 contrary to NO_ARG_CHECK assumed-rank arguments pass an array 5601 descriptor which contains the array shape and stride of the 5602 argument. 5603 * [21]Fortran 2003: 5604 + Finalization is now supported. It is currently only done for a 5605 subset of those situations in which it should occur. 5606 + Experimental support for scalar character components with 5607 deferred length (i.e. allocatable string length) in derived 5608 types has been added. (Deferred-length character variables are 5609 supported since GCC 4.6.) 5610 * [22]Fortran 2008: 5611 + When STOP or ERROR STOP are used to terminate the execution 5612 and any exception (but inexact) is signaling, a warning is 5613 printed to ERROR_UNIT, indicating which exceptions are 5614 signaling. The [23]-ffpe-summary= command-line option can be 5615 used to fine-tune for which exceptions the warning should be 5616 shown. 5617 + Rounding on input (READ) is now handled on systems where 5618 strtod honours the rounding mode. (For output, rounding is 5619 supported since GCC 4.5.) Note that for input, the compatible 5620 rounding mode is handled as nearest (i.e., rounding to an even 5621 least significant [cf. IEC 60559:1989] for a tie, while 5622 compatible rounds away from zero in that case). 5623 5624 Go 5625 5626 * GCC 4.9 provides a complete implementation of the Go 1.2.1 release. 5627 5628 New Targets and Target Specific Improvements 5629 5630 AArch64 5631 5632 * The ARMv8-A crypto and CRC instructions are now supported through 5633 intrinsics. These are enabled when the architecture supports these 5634 and are available through the -march=armv8-a+crc and 5635 -march=armv8-a+crypto options. 5636 * Initial support for ILP32 has now been added to the compiler. This 5637 is now available through the command-line option -mabi=ilp32. 5638 Support for ILP32 is considered experimental as the ABI 5639 specification is still beta. 5640 * Coverage of more of the ISA including the SIMD extensions has been 5641 added. The Advanced SIMD intrinsics have also been improved. 5642 * The new local register allocator (LRA) is now on by default for the 5643 AArch64 backend. 5644 * The REE (Redundant extension elimination) pass has now been enabled 5645 by default for the AArch64 backend. 5646 * Tuning for the Cortex-A53 and Cortex-A57 has been improved. 5647 * Initial big.LITTLE tuning support for the combination of Cortex-A57 5648 and Cortex-A53 was added through the -mcpu=cortex-a57.cortex-a53 5649 option. 5650 * A number of structural changes have been made to both the ARM and 5651 AArch64 backends to facilitate improved code-generation. 5652 * As of GCC 4.9.2 a workaround for the ARM Cortex-A53 erratum 835769 5653 has been added and can be enabled by giving the 5654 -mfix-cortex-a53-835769 option. Alternatively it can be enabled by 5655 default by configuring GCC with the --enable-fix-cortex-a53-835769 5656 option. 5657 5658 ARC 5659 5660 * A port for Synopsys Designware ARC has been contributed by Embecosm 5661 and Synopsys Inc. 5662 5663 ARM 5664 5665 * Use of Advanced SIMD (Neon) for 64-bit scalar computations has been 5666 disabled by default. This was found to generate better code in only 5667 a small number of cases. It can be turned back on with the 5668 -mneon-for-64bits option. 5669 * Further support for the ARMv8-A architecture, notably implementing 5670 the restriction around IT blocks in the Thumb32 instruction set has 5671 been added. The -mrestrict-it option can be used with 5672 -march=armv7-a or the -march=armv7ve options to make code 5673 generation fully compatible with the deprecated instructions in 5674 ARMv8-A. 5675 * Support has now been added for the ARMv7ve variant of the 5676 architecture. This can be used by the -march=armv7ve option. 5677 * The ARMv8-A crypto and CRC instructions are now supported through 5678 intrinsics and are available through the -march=armv8-a+crc and 5679 mfpu=crypto-neon-fp-armv8 options. 5680 * LRA is now on by default for the ARM target. This can be turned off 5681 using the -mno-lra option. This option is a purely transitionary 5682 command-line option and will be removed in a future release. We are 5683 interested in any bug reports regarding functional and performance 5684 regressions with LRA. 5685 * A new option -mslow-flash-data to improve performance of programs 5686 fetching data on slow flash memory has now been introduced for the 5687 ARMv7-M profile cores. 5688 * A new option -mpic-data-is-text-relative for targets that allows 5689 data segments to be relative to text segments has been added. This 5690 is on by default for all targets except VxWorks RTP. 5691 * A number of infrastructural changes have been made to both the ARM 5692 and AArch64 backends to facilitate improved code-generation. 5693 * GCC now supports Cortex-A12 and the Cortex-R7 through the 5694 -mcpu=cortex-a12 and -mcpu=cortex-r7 options. 5695 * GCC now has tuning for the Cortex-A57 and Cortex-A53 through the 5696 -mcpu=cortex-a57 and -mcpu=cortex-a53 options. 5697 * Initial big.LITTLE tuning support for the combination of Cortex-A57 5698 and Cortex-A53 was added through the -mcpu=cortex-a57.cortex-a53 5699 option. Similar support was added for the combination of Cortex-A15 5700 and Cortex-A7 through the -mcpu=cortex-a15.cortex-a7 option. 5701 * Further performance optimizations for the Cortex-A15 and the 5702 Cortex-M4 have been added. 5703 * A number of code generation improvements for Thumb2 to reduce code 5704 size when compiling for the M-profile processors. 5705 5706 AVR 5707 5708 * A new command-line option -mfract-convert-truncate has been added. 5709 It allows compiler to use truncation instead of rounding towards 5710 zero for fractional fixed-point types. 5711 5712 IA-32/x86-64 5713 5714 * -mfpmath=sse is now implied by -ffast-math on all targets where 5715 SSE2 is supported. 5716 * Intel AVX-512 support was added to GCC. That includes inline 5717 assembly support, new registers and extending existing ones, new 5718 intrinsics (covered by corresponding testsuite), and basic 5719 autovectorization. AVX-512 instructions are available via the 5720 following GCC switches: AVX-512 foundation instructions: -mavx512f, 5721 AVX-512 prefetch instructions: -mavx512pf, AVX-512 exponential and 5722 reciprocal instructions: -mavx512er, AVX-512 conflict detection 5723 instructions: -mavx512cd. 5724 * It is now possible to call x86 intrinsics from select functions in 5725 a file that are tagged with the corresponding target attribute 5726 without having to compile the entire file with the -mxxx option. 5727 This improves the usability of x86 intrinsics and is particularly 5728 useful when doing [24]Function Multiversioning. 5729 * GCC now supports the new Intel microarchitecture named Silvermont 5730 through -march=silvermont. 5731 * GCC now supports the new Intel microarchitecture named Broadwell 5732 through -march=broadwell. 5733 * Optimizing for other Intel microarchitectures have been renamed to 5734 -march=nehalem, westmere, sandybridge, ivybridge, haswell, bonnell. 5735 * -march=generic has been retuned for better support of Intel core 5736 and AMD Bulldozer architectures. Performance of AMD K7, K8, Intel 5737 Pentium-M, and Pentium4 based CPUs is no longer considered 5738 important for generic. 5739 * -mtune=intel can now be used to generate code running well on the 5740 most current Intel processors, which are Haswell and Silvermont for 5741 GCC 4.9. 5742 * Support to encode 32-bit assembly instructions in 16-bit format is 5743 now available through the -m16 command-line option. 5744 * Better inlining of memcpy and memset that is aware of value ranges 5745 and produces shorter alignment prologues. 5746 * -mno-accumulate-outgoing-args is now honored when unwind 5747 information is output. Argument accumulation is also now turned off 5748 for portions of programs optimized for size. 5749 * Support for new AMD family 15h processors (Excavator core) is now 5750 available through the -march=bdver4 and -mtune=bdver4 options. 5751 5752 MSP430 5753 5754 * A new command-line option -mcpu= has been added to the MSP430 5755 backend. This option is used to specify the ISA to be used. 5756 Accepted values are msp430 (the default), msp430x and msp430xv2. 5757 The ISA is no longer deduced from the -mmcu= option as there are 5758 far too many different MCU names. The -mmcu= option is still 5759 supported, and this is still used to select linker scripts and 5760 generate a C preprocessor symbol that will be recognised by the 5761 msp430.h header file. 5762 5763 NDS32 5764 5765 * A new nds32 port supports the 32-bit architecture from Andes 5766 Technology Corporation. 5767 * The port provides initial support for the V2, V3, V3m instruction 5768 set architectures. 5769 5770 Nios II 5771 5772 * A port for the Altera Nios II has been contributed by Mentor 5773 Graphics. 5774 5775 PowerPC / PowerPC64 / RS6000 5776 5777 * GCC now supports Power ISA 2.07, which includes support for 5778 Hardware Transactional Memory (HTM), Quadword atomics and several 5779 VMX and VSX additions, including Crypto, 64-bit integer, 128-bit 5780 integer and decimal integer operations. 5781 * Support for the POWER8 processor is now available through the 5782 -mcpu=power8 and -mtune=power8 options. 5783 * The libitm library has been modified to add a HTM fastpath that 5784 automatically uses POWER's HTM hardware instructions when it is 5785 executing on a HTM enabled processor. 5786 * Support for the new powerpc64le-linux platform has been added. It 5787 defaults to generating code that conforms to the ELFV2 ABI. 5788 5789 S/390, System z 5790 5791 * Support for the Transactional Execution Facility included with the 5792 IBM zEnterprise zEC12 processor has been added. A set of GCC style 5793 builtins as well as XLC style builtins are provided. The builtins 5794 are enabled by default when using the -march=zEC12 option but can 5795 explicitly be disabled with -mno-htm. Using the GCC builtins also 5796 libitm supports hardware transactions on S/390. 5797 * The hotpatch features allows to prepare functions for hotpatching. 5798 A certain amount of bytes is reserved before the function entry 5799 label plus a NOP is inserted at its very beginning to implement a 5800 backward jump when applying a patch. The feature can either be 5801 enabled per compilation unit via the command-line option -mhotpatch 5802 or per function using the hotpatch attribute. 5803 * The shrink wrap optimization is now supported on S/390 and enabled 5804 by default. 5805 * A major rework of the routines to determine which registers need to 5806 be saved and restored in function prologue/epilogue now allow to 5807 use floating point registers as save slots. This will happen for 5808 certain leaf function with -march=z10 or higher. 5809 * The LRA rtl pass replaces reload by default on S/390. 5810 5811 RX 5812 5813 * The port now allows to specify the RX100, RX200, and RX600 5814 processors with the command-line options -mcpu=rx100, -mcpu=rx200 5815 and -mcpu=rx600. 5816 5817 SH 5818 5819 * Minor improvements to code generated for integer arithmetic and 5820 code that involves the T bit. 5821 * Added support for the SH2A clips and clipu instructions. The 5822 compiler will now try to utilize them for min/max expressions such 5823 as max (-128, min (127, x)). 5824 * Added support for the cmp/str instruction through built-in 5825 functions such as __builtin_strlen. When not optimizing for size, 5826 the compiler will now expand calls to e.g. strlen as an inlined 5827 sequences which utilize the cmp/str instruction. 5828 * Improved code generated around volatile memory loads and stores. 5829 * The option -mcbranchdi has been deprecated. Specifying it will 5830 result in a warning and will not influence code generation. 5831 * The option -mcmpeqdi has been deprecated. Specifying it will result 5832 in a warning and will not influence code generation. 5833 5834 GCC 4.9.1 5835 5836 This is the [25]list of problem reports (PRs) from GCC's bug tracking 5837 system that are known to be fixed in the 4.9.1 release. This list might 5838 not be complete (that is, it is possible that some PRs that have been 5839 fixed are not listed here). 5840 5841 Version 4.0 of the OpenMP specification is supported even in Fortran, 5842 not just C and C++. 5843 5844 GCC 4.9.2 5845 5846 This is the [26]list of problem reports (PRs) from GCC's bug tracking 5847 system that are known to be fixed in the 4.9.2 release. This list might 5848 not be complete (that is, it is possible that some PRs that have been 5849 fixed are not listed here). 5850 5851 GCC 4.9.3 5852 5853 This is the [27]list of problem reports (PRs) from GCC's bug tracking 5854 system that are known to be fixed in the 4.9.3 release. This list might 5855 not be complete (that is, it is possible that some PRs that have been 5856 fixed are not listed here). 5857 5858 GCC 4.9.4 5859 5860 This is the [28]list of problem reports (PRs) from GCC's bug tracking 5861 system that are known to be fixed in the 4.9.4 release. This list might 5862 not be complete (that is, it is possible that some PRs that have been 5863 fixed are not listed here). 5864 5865 5866 For questions related to the use of GCC, please consult these web 5867 pages and the [29]GCC manuals. If that fails, the 5868 [30]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 5869 web pages and the development of GCC are welcome on our developer 5870 list at [31]gcc (a] gcc.gnu.org. All of [32]our lists have public 5871 archives. 5872 5873 Copyright (C) [33]Free Software Foundation, Inc. Verbatim copying and 5874 distribution of this entire article is permitted in any medium, 5875 provided this notice is preserved. 5876 5877 These pages are [34]maintained by the GCC team. Last modified 5878 2019-11-28[35]. 5879 5880 References 5881 5882 1. https://gcc.gnu.org/ml/gcc-patches/2013-05/msg00728.html 5883 2. https://gcc.gnu.org/PR60825 5884 3. https://gcc.gnu.org/gcc-4.9/porting_to.html 5885 4. https://www.openmp.org/specifications/ 5886 5. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/Optimize-Options.html#index-fsimd-cost-model-908 5887 6. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/Language-Independent-Options.html#index-fdiagnostics-color-252 5888 7. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/Loop-Specific-Pragmas.html 5889 8. https://www.cilkplus.org/ 5890 9. http://gcc.gnu.org/projects/cxx1y.html 5891 10. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3638.html 5892 11. http://gcc.gnu.org/projects/cxx1y.html 5893 12. http://gcc.gnu.org/projects/cxx1y.html 5894 13. http://gcc.gnu.org/projects/cxx1y.html 5895 14. http://gcc.gnu.org/projects/cxx1y.html 5896 15. http://gcc.gnu.org/projects/cxx1y.html 5897 16. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3889.pdf 5898 17. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/libstdc++/manual/manual/status.html#status.iso.2011 5899 18. https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#status.iso.2014 5900 19. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gfortran/Argument-passing-conventions.html 5901 20. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gfortran/GNU-Fortran-Compiler-Directives.html 5902 21. https://gcc.gnu.org/wiki/Fortran2003Status 5903 22. https://gcc.gnu.org/wiki/Fortran2008Status 5904 23. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gfortran/Debugging-Options.html 5905 24. https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/Function-Multiversioning.html 5906 25. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.9.1 5907 26. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.9.2 5908 27. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.9.3 5909 28. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.9.4 5910 29. https://gcc.gnu.org/onlinedocs/ 5911 30. mailto:gcc-help (a] gcc.gnu.org 5912 31. mailto:gcc (a] gcc.gnu.org 5913 32. https://gcc.gnu.org/lists.html 5914 33. https://www.fsf.org/ 5915 34. https://gcc.gnu.org/about.html 5916 35. http://validator.w3.org/check/referer 5917 ====================================================================== 5918 http://gcc.gnu.org/gcc-4.8/index.html 5919 GCC 4.8 Release Series 5920 5921 (This release series is no longer supported.) 5922 5923 June 23, 2015 5924 5925 The [1]GNU project and the GCC developers are pleased to announce the 5926 release of GCC 4.8.5. 5927 5928 This release is a bug-fix release, containing fixes for regressions in 5929 GCC 4.8.4 relative to previous releases of GCC. 5930 5931 Release History 5932 5933 GCC 4.8.5 5934 June 23, 2015 ([2]changes, [3]documentation) 5935 5936 GCC 4.8.4 5937 December 19, 2014 ([4]changes, [5]documentation) 5938 5939 GCC 4.8.3 5940 May 22, 2014 ([6]changes, [7]documentation) 5941 5942 GCC 4.8.2 5943 October 16, 2013 ([8]changes, [9]documentation) 5944 5945 GCC 4.8.1 5946 May 31, 2013 ([10]changes, [11]documentation) 5947 5948 GCC 4.8.0 5949 March 22, 2013 ([12]changes, [13]documentation) 5950 5951 References and Acknowledgements 5952 5953 GCC used to stand for the GNU C Compiler, but since the compiler 5954 supports several other languages aside from C, it now stands for the 5955 GNU Compiler Collection. 5956 5957 A list of [14]successful builds is updated as new information becomes 5958 available. 5959 5960 The GCC developers would like to thank the numerous people that have 5961 contributed new features, improvements, bug fixes, and other changes as 5962 well as test results to GCC. This [15]amazing group of volunteers is 5963 what makes GCC successful. 5964 5965 For additional information about GCC please refer to the [16]GCC 5966 project web site or contact the [17]GCC development mailing list. 5967 5968 To obtain GCC please use [18]our mirror sites or [19]our version 5969 control system. 5970 5971 5972 For questions related to the use of GCC, please consult these web 5973 pages and the [20]GCC manuals. If that fails, the 5974 [21]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 5975 web pages and the development of GCC are welcome on our developer 5976 list at [22]gcc (a] gcc.gnu.org. All of [23]our lists have public 5977 archives. 5978 5979 Copyright (C) [24]Free Software Foundation, Inc. Verbatim copying and 5980 distribution of this entire article is permitted in any medium, 5981 provided this notice is preserved. 5982 5983 These pages are [25]maintained by the GCC team. Last modified 5984 2020-01-14[26]. 5985 5986 References 5987 5988 1. http://www.gnu.org/ 5989 2. http://gcc.gnu.org/gcc-4.8/changes.html 5990 3. https://gcc.gnu.org/onlinedocs/4.8.5/ 5991 4. http://gcc.gnu.org/gcc-4.8/changes.html 5992 5. https://gcc.gnu.org/onlinedocs/4.8.4/ 5993 6. http://gcc.gnu.org/gcc-4.8/changes.html 5994 7. https://gcc.gnu.org/onlinedocs/4.8.3/ 5995 8. http://gcc.gnu.org/gcc-4.8/changes.html 5996 9. https://gcc.gnu.org/onlinedocs/4.8.2/ 5997 10. http://gcc.gnu.org/gcc-4.8/changes.html 5998 11. https://gcc.gnu.org/onlinedocs/4.8.1/ 5999 12. http://gcc.gnu.org/gcc-4.8/changes.html 6000 13. https://gcc.gnu.org/onlinedocs/4.8.0/ 6001 14. http://gcc.gnu.org/gcc-4.8/buildstat.html 6002 15. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 6003 16. http://gcc.gnu.org/index.html 6004 17. mailto:gcc (a] gcc.gnu.org 6005 18. http://gcc.gnu.org/mirrors.html 6006 19. http://gcc.gnu.org/git.html 6007 20. https://gcc.gnu.org/onlinedocs/ 6008 21. mailto:gcc-help (a] gcc.gnu.org 6009 22. mailto:gcc (a] gcc.gnu.org 6010 23. https://gcc.gnu.org/lists.html 6011 24. https://www.fsf.org/ 6012 25. https://gcc.gnu.org/about.html 6013 26. http://validator.w3.org/check/referer 6014 ====================================================================== 6015 http://gcc.gnu.org/gcc-4.8/changes.html 6016 GCC 4.8 Release Series 6017 Changes, New Features, and Fixes 6018 6019 Caveats 6020 6021 GCC now uses C++ as its implementation language. This means that to 6022 build GCC from sources, you will need a C++ compiler that understands 6023 C++ 2003. For more details on the rationale and specific changes, 6024 please refer to the [1]C++ conversion page. 6025 6026 To enable the Graphite framework for loop optimizations you now need 6027 CLooG version 0.18.0 and ISL version 0.11.1. Both can be obtained from 6028 the [2]GCC infrastructure directory. The installation manual contains 6029 more information about requirements to build GCC. 6030 6031 GCC now uses a more aggressive analysis to derive an upper bound for 6032 the number of iterations of loops using constraints imposed by language 6033 standards. This may cause non-conforming programs to no longer work as 6034 expected, such as SPEC CPU 2006 464.h264ref and 416.gamess. A new 6035 option, -fno-aggressive-loop-optimizations, was added to disable this 6036 aggressive analysis. In some loops that have known constant number of 6037 iterations, but undefined behavior is known to occur in the loop before 6038 reaching or during the last iteration, GCC will warn about the 6039 undefined behavior in the loop instead of deriving lower upper bound of 6040 the number of iterations for the loop. The warning can be disabled with 6041 -Wno-aggressive-loop-optimizations. 6042 6043 On ARM, a bug has been fixed in GCC's implementation of the AAPCS rules 6044 for the layout of vectors that could lead to wrong code being 6045 generated. Vectors larger than 8 bytes in size are now by default 6046 aligned to an 8-byte boundary. This is an ABI change: code that makes 6047 explicit use of vector types may be incompatible with binary objects 6048 built with older versions of GCC. Auto-vectorized code is not affected 6049 by this change. 6050 6051 On AVR, support has been removed for the command-line option 6052 -mshort-calls deprecated in GCC 4.7. 6053 6054 On AVR, the configure option --with-avrlibc supported since GCC 4.7.2 6055 is turned on per default for all non-RTEMS configurations. This option 6056 arranges for a better integration of [3]AVR Libc with avr-gcc. For 6057 technical details, see [4]PR54461. To turn off the option in non-RTEMS 6058 configurations, use --with-avrlibc=no. If the compiler is configured 6059 for RTEMS, the option is always turned off. 6060 6061 More information on porting to GCC 4.8 from previous versions of GCC 6062 can be found in the [5]porting guide for this release. 6063 6064 General Optimizer Improvements (and Changes) 6065 6066 * DWARF4 is now the default when generating DWARF debug information. 6067 When -g is used on a platform that uses DWARF debugging 6068 information, GCC will now default to -gdwarf-4 6069 -fno-debug-types-section. 6070 GDB 7.5, Valgrind 3.8.0 and elfutils 0.154 debug information 6071 consumers support DWARF4 by default. Before GCC 4.8 the default 6072 version used was DWARF2. To make GCC 4.8 generate an older DWARF 6073 version use -g together with -gdwarf-2 or -gdwarf-3. The default 6074 for Darwin and VxWorks is still -gdwarf-2 -gstrict-dwarf. 6075 * A new general optimization level, -Og, has been introduced. It 6076 addresses the need for fast compilation and a superior debugging 6077 experience while providing a reasonable level of run-time 6078 performance. Overall experience for development should be better 6079 than the default optimization level -O0. 6080 * A new option -ftree-partial-pre was added to control the partial 6081 redundancy elimination (PRE) optimization. This option is enabled 6082 by default at the -O3 optimization level, and it makes PRE more 6083 aggressive. 6084 * The option -fconserve-space has been removed; it was no longer 6085 useful on most targets since GCC supports putting variables into 6086 BSS without making them common. 6087 * The struct reorg and matrix reorg optimizations (command-line 6088 options -fipa-struct-reorg and -fipa-matrix-reorg) have been 6089 removed. They did not always work correctly, nor did they work with 6090 link-time optimization (LTO), hence were only applicable to 6091 programs consisting of a single translation unit. 6092 * Several scalability bottle-necks have been removed from GCC's 6093 optimization passes. Compilation of extremely large functions, e.g. 6094 due to the use of the flatten attribute in the "Eigen" C++ linear 6095 algebra templates library, is significantly faster than previous 6096 releases of GCC. 6097 * Link-time optimization (LTO) improvements: 6098 + LTO partitioning has been rewritten for better reliability and 6099 maintanibility. Several important bugs leading to link 6100 failures have been fixed. 6101 * Interprocedural optimization improvements: 6102 + A new symbol table has been implemented. It builds on existing 6103 callgraph and varpool modules and provide a new API. Unusual 6104 symbol visibilities and aliases are handled more consistently 6105 leading to, for example, more aggressive unreachable code 6106 removal with LTO. 6107 + The inline heuristic can now bypass limits on the size of of 6108 inlined functions when the inlining is particularly 6109 profitable. This happens, for example, when loop bounds or 6110 array strides get propagated. 6111 + Values passed through aggregates (either by value or 6112 reference) are now propagated at the inter-procedural level 6113 leading to better inlining decisions (for example in the case 6114 of Fortran array descriptors) and devirtualization. 6115 * [6]AddressSanitizer , a fast memory error detector, has been added 6116 and can be enabled via -fsanitize=address. Memory access 6117 instructions will be instrumented to detect heap-, stack-, and 6118 global-buffer overflow as well as use-after-free bugs. To get nicer 6119 stacktraces, use -fno-omit-frame-pointer. The AddressSanitizer is 6120 available on IA-32/x86-64/x32/PowerPC/PowerPC64 GNU/Linux and on 6121 x86-64 Darwin. 6122 * [7]ThreadSanitizer has been added and can be enabled via 6123 -fsanitize=thread. Instructions will be instrumented to detect data 6124 races. The ThreadSanitizer is available on x86-64 GNU/Linux. 6125 * A new local register allocator (LRA) has been implemented, which 6126 replaces the 26 year old reload pass and improves generated code 6127 quality. For now it is active on the IA-32 and x86-64 targets. 6128 * Support for transactional memory has been implemented on the 6129 following architectures: IA-32/x86-64, ARM, PowerPC, SH, SPARC, and 6130 Alpha. 6131 6132 New Languages and Language specific improvements 6133 6134 C family 6135 6136 * Each diagnostic emitted now includes the original source line and a 6137 caret '^' indicating the column. The option 6138 -fno-diagnostics-show-caret suppresses this information. 6139 * The option -ftrack-macro-expansion=2 is now enabled by default. 6140 This allows the compiler to display the macro expansion stack in 6141 diagnostics. Combined with the caret information, an example 6142 diagnostic showing these two features is: 6143 6144 t.c:1:94: error: invalid operands to binary < (have struct mystruct and float 6145 ) 6146 #define MYMAX(A,B) __extension__ ({ __typeof__(A) __a = (A); __typeof__(B) _ 6147 _b = (B); __a < __b ? __b : __a; }) 6148 6149 ^ 6150 t.c:7:7: note: in expansion of macro 'MYMAX' 6151 X = MYMAX(P, F); 6152 ^ 6153 6154 * A new -Wsizeof-pointer-memaccess warning has been added (also 6155 enabled by -Wall) to warn about suspicious length parameters to 6156 certain string and memory built-in functions if the argument uses 6157 sizeof. This warning warns e.g. about memset (ptr, 0, sizeof 6158 (ptr)); if ptr is not an array, but a pointer, and suggests a 6159 possible fix, or about memcpy (&foo, ptr, sizeof (&foo));. 6160 * The new option -Wpedantic is an alias for -pedantic, which is now 6161 deprecated. The forms -Wno-pedantic, -Werror=pedantic, and 6162 -Wno-error=pedantic work in the same way as for any other -W 6163 option. One caveat is that -Werror=pedantic is not equivalent to 6164 -pedantic-errors, since the latter makes into errors some warnings 6165 that are not controlled by -Wpedantic, and the former only affects 6166 diagnostics that are disabled when using -Wno-pedantic. 6167 * The option -Wshadow no longer warns if a declaration shadows a 6168 function declaration, unless the former declares a function or 6169 pointer to function, because this is [8]a common and valid case in 6170 real-world code. 6171 6172 C++ 6173 6174 * G++ now implements the [9]C++11 thread_local keyword; this differs 6175 from the GNU __thread keyword primarily in that it allows dynamic 6176 initialization and destruction semantics. Unfortunately, this 6177 support requires a run-time penalty for references to 6178 non-function-local thread_local variables defined in a different 6179 translation unit even if they don't need dynamic initialization, so 6180 users may want to continue to use __thread for TLS variables with 6181 static initialization semantics. 6182 If the programmer can be sure that no use of the variable in a 6183 non-defining TU needs to trigger dynamic initialization (either 6184 because the variable is statically initialized, or a use of the 6185 variable in the defining TU will be executed before any uses in 6186 another TU), they can avoid this overhead with the 6187 -fno-extern-tls-init option. 6188 OpenMP threadprivate variables now also support dynamic 6189 initialization and destruction by the same mechanism. 6190 * G++ now implements the [10]C++11 attribute syntax, e.g. 6191 6192 [[noreturn]] void f(); 6193 6194 and also the alignment specifier, e.g. 6195 6196 alignas(double) int i; 6197 6198 * G++ now implements [11]C++11 inheriting constructors, e.g. 6199 6200 struct A { A(int); }; 6201 struct B: A { using A::A; }; // defines B::B(int) 6202 B b(42); // OK 6203 6204 * As of GCC 4.8.1, G++ implements the change to decltype semantics 6205 from [12]N3276. 6206 6207 struct A f(); 6208 decltype(f()) g(); // OK, return type of f() is not required to be complete. 6209 6210 * As of GCC 4.8.1, G++ implements [13]C++11 ref-qualifiers, e.g. 6211 6212 struct A { int f() &; }; 6213 int i = A().f(); // error, f() requires an lvalue object 6214 6215 * G++ now supports a -std=c++1y option for experimentation with 6216 features proposed for the next revision of the standard, expected 6217 around 2014. Currently the only difference from -std=c++11 is 6218 support for return type deduction in normal functions, as proposed 6219 in [14]N3386. Status of C++1y features in GCC 4.8 can be found 6220 [15]here. 6221 * The G++ namespace association extension, __attribute ((strong)), 6222 has been deprecated. Inline namespaces should be used instead. 6223 * G++ now supports a -fext-numeric-literal option to control whether 6224 GNU numeric literal suffixes are accepted as extensions or 6225 processed as C++11 user-defined numeric literal suffixes. The flag 6226 is on (use suffixes for GNU literals) by default for -std=gnu++*, 6227 and -std=c++98. The flag is off (use suffixes for user-defined 6228 literals) by default for -std=c++11 and later. 6229 6230 Runtime Library (libstdc++) 6231 6232 * [16]Improved experimental support for the new ISO C++ standard, 6233 C++11, including: 6234 + forward_list meets the allocator-aware container requirements; 6235 + this_thread::sleep_for(), this_thread::sleep_until() and 6236 this_thread::yield() are defined without requiring the 6237 configure option --enable-libstdcxx-time; 6238 * Improvements to <random>: 6239 + SSE optimized normal_distribution. 6240 + Use of hardware RNG instruction for random_device on new x86 6241 processors (requires the assembler to support the 6242 instruction.) 6243 and <ext/random>: 6244 + New random number engine simd_fast_mersenne_twister_engine 6245 with an optimized SSE implementation. 6246 + New random number distributions beta_distribution, 6247 normal_mv_distribution, rice_distribution, 6248 nakagami_distribution, pareto_distribution, k_distribution, 6249 arcsine_distribution, hoyt_distribution. 6250 * Added --disable-libstdcxx-verbose configure option to disable 6251 diagnostic messages issued when a process terminates abnormally. 6252 This may be useful for embedded systems to reduce the size of 6253 executables that link statically to the library. 6254 6255 Fortran 6256 6257 * Compatibility notice: 6258 + Module files: The version of module files (.mod) has been 6259 incremented. Fortran MODULEs compiled by earlier GCC versions 6260 have to be recompiled, when they are USEd by files compiled 6261 with GCC 4.8. GCC 4.8 is not able to read .mod files created 6262 by earlier versions; attempting to do so gives an error 6263 message. 6264 Note: The ABI of the produced assembler data itself has not 6265 changed; object files and libraries are fully compatible with 6266 older versions except as noted below. 6267 + ABI: Some internal names (used in the assembler/object file) 6268 have changed for symbols declared in the specification part of 6269 a module. If an affected module or a file using it via use 6270 association is recompiled, the module and all files which 6271 directly use such symbols have to be recompiled as well. This 6272 change only affects the following kind of module symbols: 6273 o Procedure pointers. Note: C-interoperable function 6274 pointers (type(c_funptr)) are not affected nor are 6275 procedure-pointer components. 6276 o Deferred-length character strings. 6277 * The [17]BACKTRACE intrinsic subroutine has been added. It shows a 6278 backtrace at an arbitrary place in user code; program execution 6279 continues normally afterwards. 6280 * The [18]-Wc-binding-type warning option has been added (disabled by 6281 default). It warns if the a variable might not be C interoperable; 6282 in particular, if the variable has been declared using an intrinsic 6283 type with default kind instead of using a kind parameter defined 6284 for C interoperability in the intrinsic ISO_C_Binding module. 6285 Before, this warning was always printed. The -Wc-binding-type 6286 option is enabled by -Wall. 6287 * The [19]-Wrealloc-lhs and -Wrealloc-lhs-all warning command-line 6288 options have been added, which diagnose when code is inserted for 6289 automatic (re)allocation of a variable during assignment. This 6290 option can be used to decide whether it is safe to use 6291 [20]-fno-realloc-lhs. Additionally, it can be used to find 6292 automatic (re)allocation in hot loops. (For arrays, replacing 6293 "var=" by "var(:)=" disables the automatic reallocation.) 6294 * The [21]-Wcompare-reals command-line option has been added. When 6295 this is set, warnings are issued when comparing REAL or COMPLEX 6296 types for equality and inequality; consider replacing a == b by 6297 abs(ab) < eps with a suitable eps. -Wcompare-reals is enabled by 6298 -Wextra. 6299 * The [22]-Wtarget-lifetime command-line option has been added 6300 (enabled with -Wall), which warns if the pointer in a pointer 6301 assignment might outlive its target. 6302 * Reading floating point numbers which use "q" for the exponential 6303 (such as 4.0q0) is now supported as vendor extension for better 6304 compatibility with old data files. It is strongly recommended to 6305 use for I/O the equivalent but standard conforming "e" (such as 6306 4.0e0). 6307 (For Fortran source code, consider replacing the "q" in 6308 floating-point literals by a kind parameter (e.g. 4.0e0_qp with a 6309 suitable qp). Note that in Fortran source code replacing "q" by 6310 a simple "e" is not equivalent.) 6311 * The GFORTRAN_TMPDIR environment variable for specifying a 6312 non-default directory for files opened with STATUS="SCRATCH", is 6313 not used anymore. Instead gfortran checks the POSIX/GNU standard 6314 TMPDIR environment variable. If TMPDIR is not defined, gfortran 6315 falls back to other methods to determine the directory for 6316 temporary files as documented in the [23]user manual. 6317 * [24]Fortran 2003: 6318 + Support for unlimited polymorphic variables (CLASS(*)) has 6319 been added. Nonconstant character lengths are not yet 6320 supported. 6321 * [25]TS 29113: 6322 + Assumed types (TYPE(*)) are now supported. 6323 + Experimental support for assumed-rank arrays (dimension(..)) 6324 has been added. Note that currently gfortran's own array 6325 descriptor is used, which is different from the one defined in 6326 TS29113, see [26]gfortran's header file or use the [27]Chasm 6327 Language Interoperability Tools. 6328 6329 Go 6330 6331 * GCC 4.8.2 provides a complete implementation of the Go 1.1.2 6332 release. 6333 * GCC 4.8.0 and 4.8.1 implement a preliminary version of the Go 1.1 6334 release. The library support is not quite complete. 6335 * Go has been tested on GNU/Linux and Solaris platforms for various 6336 processors including x86, x86_64, PowerPC, SPARC, and Alpha. It may 6337 work on other platforms as well. 6338 6339 New Targets and Target Specific Improvements 6340 6341 AArch64 6342 6343 * A new port has been added to support AArch64, the new 64-bit 6344 architecture from ARM. Note that this is a separate port from the 6345 existing 32-bit ARM port. 6346 * The port provides initial support for the Cortex-A53 and the 6347 Cortex-A57 processors with the command line options 6348 -mcpu=cortex-a53 and -mcpu=cortex-a57. 6349 * As of GCC 4.8.4 a workaround for the ARM Cortex-A53 erratum 835769 6350 has been added and can be enabled by giving the 6351 -mfix-cortex-a53-835769 option. Alternatively it can be enabled by 6352 default by configuring GCC with the --enable-fix-cortex-a53-835769 6353 option. 6354 6355 ARM 6356 6357 * Initial support has been added for the AArch32 extensions defined 6358 in the ARMv8 architecture. 6359 * Code generation improvements for the Cortex-A7 and Cortex-A15 CPUs. 6360 * A new option, -mcpu=marvell-pj4, has been added to generate code 6361 for the Marvell PJ4 processor. 6362 * The compiler can now automatically generate the VFMA, VFMS, REVSH 6363 and REV16 instructions. 6364 * A new vectorizer cost model for Advanced SIMD configurations to 6365 improve the auto-vectorization strategies used. 6366 * The scheduler now takes into account the number of live registers 6367 to reduce the amount of spilling that can occur. This should 6368 improve code performance in large functions. The limit can be 6369 removed by using the option -fno-sched-pressure. 6370 * Improvements have been made to the Marvell iWMMX code generation 6371 and support for the iWMMX2 SIMD unit has been added. The option 6372 -mcpu=iwmmxt2 can be used to enable code generation for the latter. 6373 * A number of code generation improvements for Thumb2 to reduce code 6374 size when compiling for the M-profile processors. 6375 * The RTEMS (arm-rtems) port has been updated to use the EABI. 6376 * Code generation support for the old FPA and Maverick floating-point 6377 architectures has been removed. Ports that previously relied on 6378 these features have also been removed. This includes the targets: 6379 + arm*-*-linux-gnu (use arm*-*-linux-gnueabi) 6380 + arm*-*-elf (use arm*-*-eabi) 6381 + arm*-*-uclinux* (use arm*-*-uclinux*eabi) 6382 + arm*-*-ecos-elf (no alternative) 6383 + arm*-*-freebsd (no alternative) 6384 + arm*-wince-pe* (no alternative). 6385 6386 AVR 6387 6388 * Support for the "Embedded C" fixed-point has been added. For 6389 details, see the [28]GCC wiki and the [29]user manual. The support 6390 is not complete. 6391 * A new print modifier %r for register operands in inline assembler 6392 is supported. It will print the raw register number without the 6393 register prefix 'r': 6394 /* Return the most significant byte of 'val', a 64-bit value. */ 6395 6396 unsigned char msb (long long val) 6397 { 6398 unsigned char c; 6399 __asm__ ("mov %0, %r1+7" : "=r" (c) : "r" (val)); 6400 return c; 6401 } 6402 The inline assembler in this example will generate code like 6403 mov r24, 8+7 6404 provided c is allocated to R24 and val is allocated to R8R15. This 6405 works because the GNU assembler accepts plain register numbers 6406 without register prefix. 6407 * Static initializers with 3-byte symbols are supported now: 6408 extern const __memx char foo; 6409 const __memx void *pfoo = &foo; 6410 This requires at least Binutils 2.23. 6411 6412 IA-32/x86-64 6413 6414 * Allow -mpreferred-stack-boundary=3 for the x86-64 architecture with 6415 SSE extensions disabled. Since the x86-64 ABI requires 16 byte 6416 stack alignment, this is ABI incompatible and intended to be used 6417 in controlled environments where stack space is an important 6418 limitation. This option will lead to wrong code when functions 6419 compiled with 16 byte stack alignment (such as functions from a 6420 standard library) are called with misaligned stack. In this case, 6421 SSE instructions may lead to misaligned memory access traps. In 6422 addition, variable arguments will be handled incorrectly for 16 6423 byte aligned objects (including x87 long double and __int128), 6424 leading to wrong results. You must build all modules with 6425 -mpreferred-stack-boundary=3, including any libraries. This 6426 includes the system libraries and startup modules. 6427 * Support for the new Intel processor codename Broadwell with RDSEED, 6428 ADCX, ADOX, PREFETCHW is available through -madx, -mprfchw, 6429 -mrdseed command-line options. 6430 * Support for the Intel RTM and HLE intrinsics, built-in functions 6431 and code generation is available via -mrtm and -mhle. 6432 * Support for the Intel FXSR, XSAVE and XSAVEOPT instruction sets. 6433 Intrinsics and built-in functions are available via -mfxsr, -mxsave 6434 and -mxsaveopt respectively. 6435 * New -maddress-mode=[short|long] options for x32. 6436 -maddress-mode=short overrides default 64-bit addresses to 32-bit 6437 by emitting the 0x67 address-size override prefix. This is the 6438 default address mode for x32. 6439 * New built-in functions to detect run-time CPU type and ISA: 6440 + A built-in function __builtin_cpu_is has been added to detect 6441 if the run-time CPU is of a particular type. It returns a 6442 positive integer on a match and zero otherwise. It accepts one 6443 string literal argument, the CPU name. For example, 6444 __builtin_cpu_is("westmere") returns a positive integer if the 6445 run-time CPU is an Intel Core i7 Westmere processor. Please 6446 refer to the [30]user manual for the list of valid CPU names 6447 recognized. 6448 + A built-in function __builtin_cpu_supports has been added to 6449 detect if the run-time CPU supports a particular ISA feature. 6450 It returns a positive integer on a match and zero otherwise. 6451 It accepts one string literal argument, the ISA feature. For 6452 example, __builtin_cpu_supports("ssse3") returns a positive 6453 integer if the run-time CPU supports SSSE3 instructions. 6454 Please refer to the [31]user manual for the list of valid ISA 6455 names recognized. 6456 Caveat: If these built-in functions are called before any static 6457 constructors are invoked, like during IFUNC initialization, then 6458 the CPU detection initialization must be explicitly run using this 6459 newly provided built-in function, __builtin_cpu_init. The 6460 initialization needs to be done only once. For example, this is how 6461 the invocation would look like inside an IFUNC initializer: 6462 static void (*some_ifunc_resolver(void))(void) 6463 { 6464 __builtin_cpu_init(); 6465 if (__builtin_cpu_is("amdfam10h") ... 6466 if (__builtin_cpu_supports("popcnt") ... 6467 } 6468 6469 * Function Multiversioning Support with G++: 6470 It is now possible to create multiple function versions each 6471 targeting a specific processor and/or ISA. Function versions have 6472 the same signature but different target attributes. For example, 6473 here is a program with function versions: 6474 __attribute__ ((target ("default"))) 6475 int foo(void) 6476 { 6477 return 1; 6478 } 6479 6480 __attribute__ ((target ("sse4.2"))) 6481 int foo(void) 6482 { 6483 return 2; 6484 } 6485 6486 int main (void) 6487 { 6488 int (*p) = &foo; 6489 assert ((*p)() == foo()); 6490 return 0; 6491 } 6492 6493 Please refer to this [32]wiki for more information. 6494 * The x86 back end has been improved to allow option -fschedule-insns 6495 to work reliably. This option can be used to schedule instructions 6496 better and leads to improved performace in certain cases. 6497 * Windows MinGW-w64 targets (*-w64-mingw*) require at least r5437 6498 from the Mingw-w64 trunk. 6499 * Support for new AMD family 15h processors (Steamroller core) is now 6500 available through the -march=bdver3 and -mtune=bdver3 options. 6501 * Support for new AMD family 16h processors (Jaguar core) is now 6502 available through the -march=btver2 and -mtune=btver2 options. 6503 6504 FRV 6505 6506 * This target now supports the -fstack-usage command-line option. 6507 6508 MIPS 6509 6510 * GCC can now generate code specifically for the R4700, Broadcom XLP 6511 and MIPS 34kn processors. The associated -march options are 6512 -march=r4700, -march=xlp and -march=34kn respectively. 6513 * GCC now generates better DSP code for MIPS 74k cores thanks to 6514 further scheduling optimizations. 6515 * The MIPS port now supports the -fstack-check option. 6516 * GCC now passes the -mmcu and -mno-mcu options to the assembler. 6517 * Previous versions of GCC would silently accept -fpic and -fPIC for 6518 -mno-abicalls targets like mips*-elf. This combination was not 6519 intended or supported, and did not generate position-independent 6520 code. GCC 4.8 now reports an error when this combination is used. 6521 6522 PowerPC / PowerPC64 / RS6000 6523 6524 * SVR4 configurations (GNU/Linux, FreeBSD, NetBSD) no longer save, 6525 restore or update the VRSAVE register by default. The respective 6526 operating systems manage the VRSAVE register directly. 6527 * Large TOC support has been added for AIX through the command line 6528 option -mcmodel=large. 6529 * Native Thread-Local Storage support has been added for AIX. 6530 * VMX (Altivec) and VSX instruction sets now are enabled implicitly 6531 when targetting processors that support those hardware features on 6532 AIX 6.1 and above. 6533 6534 RX 6535 6536 * This target will now issue a warning message whenever multiple fast 6537 interrupt handlers are found in the same compilation unit. This 6538 feature can be turned off by the new 6539 -mno-warn-multiple-fast-interrupts command-line option. 6540 6541 S/390, System z 6542 6543 * Support for the IBM zEnterprise zEC12 processor has been added. 6544 When using the -march=zEC12 option, the compiler will generate code 6545 making use of the following new instructions: 6546 + load and trap instructions 6547 + 2 new compare and trap instructions 6548 + rotate and insert selected bits - without CC clobber 6549 The -mtune=zEC12 option enables zEC12 specific instruction 6550 scheduling without making use of new instructions. 6551 * Register pressure sensitive instruction scheduling is enabled by 6552 default. 6553 * The ifunc function attribute is enabled by default. 6554 * memcpy and memcmp invokations on big memory chunks or with run time 6555 lengths are not generated inline anymore when tuning for z10 or 6556 higher. The purpose is to make use of the IFUNC optimized versions 6557 in Glibc. 6558 6559 SH 6560 6561 * The default alignment settings have been reduced to be less 6562 aggressive. This results in more compact code for optimization 6563 levels other than -Os. 6564 * Improved support for the __atomic built-in functions: 6565 + A new option -matomic-model=model selects the model for the 6566 generated atomic sequences. The following models are 6567 supported: 6568 6569 soft-gusa 6570 Software gUSA sequences (SH3* and SH4* only). On 6571 SH4A targets this will now also partially utilize 6572 the movco.l and movli.l instructions. This is the 6573 default when the target is sh3*-*-linux* or 6574 sh4*-*-linux*. 6575 6576 hard-llcs 6577 Hardware movco.l / movli.l sequences (SH4A only). 6578 6579 soft-tcb 6580 Software thread control block sequences. 6581 6582 soft-imask 6583 Software interrupt flipping sequences (privileged 6584 mode only). This is the default when the target is 6585 sh1*-*-linux* or sh2*-*-linux*. 6586 6587 none 6588 Generates function calls to the respective __atomic 6589 built-in functions. This is the default for SH64 6590 targets or when the target is not sh*-*-linux*. 6591 6592 + The option -msoft-atomic has been deprecated. It is now an 6593 alias for -matomic-model=soft-gusa. 6594 + A new option -mtas makes the compiler generate the tas.b 6595 instruction for the __atomic_test_and_set built-in function 6596 regardless of the selected atomic model. 6597 + The __sync functions in libgcc now reflect the selected atomic 6598 model when building the toolchain. 6599 * Added support for the mov.b and mov.w instructions with 6600 displacement addressing. 6601 * Added support for the SH2A instructions movu.b and movu.w. 6602 * Various improvements to code generated for integer arithmetic. 6603 * Improvements to conditional branches and code that involves the T 6604 bit. A new option -mzdcbranch tells the compiler to favor 6605 zero-displacement branches. This is enabled by default for SH4* 6606 targets. 6607 * The pref instruction will now be emitted by the __builtin_prefetch 6608 built-in function for SH3* targets. 6609 * The fmac instruction will now be emitted by the fmaf standard 6610 function and the __builtin_fmaf built-in function. 6611 * The -mfused-madd option has been deprecated in favor of the 6612 machine-independent -ffp-contract option. Notice that the fmac 6613 instruction will now be generated by default for expressions like a 6614 * b + c. This is due to the compiler default setting 6615 -ffp-contract=fast. 6616 * Added new options -mfsrra and -mfsca to allow the compiler using 6617 the fsrra and fsca instructions on targets other than SH4A (where 6618 they are already enabled by default). 6619 * Added support for the __builtin_bswap32 built-in function. It is 6620 now expanded as a sequence of swap.b and swap.w instructions 6621 instead of a library function call. 6622 * The behavior of the -mieee option has been fixed and the negative 6623 form -mno-ieee has been added to control the IEEE conformance of 6624 floating point comparisons. By default -mieee is now enabled and 6625 the option -ffinite-math-only implicitly sets -mno-ieee. 6626 * Added support for the built-in functions __builtin_thread_pointer 6627 and __builtin_set_thread_pointer. This assumes that GBR is used to 6628 hold the thread pointer of the current thread. Memory loads and 6629 stores relative to the address returned by __builtin_thread_pointer 6630 will now also utilize GBR based displacement address modes. 6631 * The -mdiv= option for targets other than SHmedia has been fixed and 6632 documented. 6633 6634 SPARC 6635 6636 * Added optimized instruction scheduling for Niagara4. 6637 6638 TILE-Gx 6639 6640 * Added support for the -mcmodel=MODEL command-line option. The 6641 models supported are small and large. 6642 6643 V850 6644 6645 * This target now supports the E3V5 architecture via the use of the 6646 new -mv850e3v5 command-line option. It also has experimental 6647 support for the e3v5 LOOP instruction which can be enabled via the 6648 new -mloop command-line option. 6649 6650 XStormy16 6651 6652 * This target now supports the -fstack-usage command-line option. 6653 6654 Operating Systems 6655 6656 OpenBSD 6657 6658 * Support for OpenBSD/amd64 (x86_64-*-openbsd*) has been added and 6659 support for OpenBSD/i386 (i386-*-openbsd*) has been rejuvenated. 6660 6661 Windows (Cygwin) 6662 6663 * Executables are now linked against shared libgcc by default. The 6664 previous default was to link statically, which can still be done by 6665 explicitly specifying -static or static-libgcc on the command line. 6666 However it is strongly advised against, as it will cause problems 6667 for any application that makes use of DLLs compiled by GCC. It 6668 should be alright for a monolithic stand-alone application that 6669 only links against the Windows DLLs, but offers little or no 6670 benefit. 6671 6672 GCC 4.8.1 6673 6674 This is the [33]list of problem reports (PRs) from GCC's bug tracking 6675 system that are known to be fixed in the 4.8.1 release. This list might 6676 not be complete (that is, it is possible that some PRs that have been 6677 fixed are not listed here). 6678 6679 The C++11 <chrono> std::chrono::system_clock and 6680 std::chrono::steady_clock classes have changed ABI in GCC 4.8.1, they 6681 both are now separate (never typedefs of each other), both use 6682 std::chrono::nanoseconds resolution, on most GNU/Linux configurations 6683 std::chrono::steady_clock is now finally monotonic, and both classes 6684 are mangled differently than in the previous GCC releases. 6685 std::chrono::system_clock::now() with std::chrono::microseconds resp. 6686 std::chrono::seconds resolution is still exported for backwards 6687 compatibility with default configured libstdc++. Note that libstdc++ 6688 configured with --enable-libstdcxx-time= used to be ABI incompatible 6689 with default configured libstdc++ for those two classes and no ABI 6690 compatibility can be offered for those configurations, so any C++11 6691 code that uses those classes and has been compiled and linked against 6692 libstdc++ configured with the non-default --enable-libstdcxx-time= 6693 configuration option needs to be recompiled. 6694 6695 GCC 4.8.2 6696 6697 This is the [34]list of problem reports (PRs) from GCC's bug tracking 6698 system that are known to be fixed in the 4.8.2 release. This list might 6699 not be complete (that is, it is possible that some PRs that have been 6700 fixed are not listed here). 6701 6702 GCC 4.8.3 6703 6704 This is the [35]list of problem reports (PRs) from GCC's bug tracking 6705 system that are known to be fixed in the 4.8.3 release. This list might 6706 not be complete (that is, it is possible that some PRs that have been 6707 fixed are not listed here). 6708 6709 Support for the new powerpc64le-linux platform has been added. It 6710 defaults to generating code that conforms to the ELFV2 ABI. 6711 6712 GCC 4.8.4 6713 6714 This is the [36]list of problem reports (PRs) from GCC's bug tracking 6715 system that are known to be fixed in the 4.8.4 release. This list might 6716 not be complete (that is, it is possible that some PRs that have been 6717 fixed are not listed here). 6718 6719 GCC 4.8.5 6720 6721 This is the [37]list of problem reports (PRs) from GCC's bug tracking 6722 system that are known to be fixed in the 4.8.5 release. This list might 6723 not be complete (that is, it is possible that some PRs that have been 6724 fixed are not listed here). 6725 6726 6727 For questions related to the use of GCC, please consult these web 6728 pages and the [38]GCC manuals. If that fails, the 6729 [39]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 6730 web pages and the development of GCC are welcome on our developer 6731 list at [40]gcc (a] gcc.gnu.org. All of [41]our lists have public 6732 archives. 6733 6734 Copyright (C) [42]Free Software Foundation, Inc. Verbatim copying and 6735 distribution of this entire article is permitted in any medium, 6736 provided this notice is preserved. 6737 6738 These pages are [43]maintained by the GCC team. Last modified 6739 2019-11-28[44]. 6740 6741 References 6742 6743 1. https://gcc.gnu.org/wiki/cxx-conversion 6744 2. ftp://gcc.gnu.org/pub/gcc/infrastructure/ 6745 3. http://www.nongnu.org/avr-libc/ 6746 4. https://gcc.gnu.org/PR54461 6747 5. https://gcc.gnu.org/gcc-4.8/porting_to.html 6748 6. https://github.com/google/sanitizers 6749 7. https://code.google.com/archive/p/data-race-test/wikis/ThreadSanitizer.wiki 6750 8. https://lkml.org/lkml/2006/11/28/239 6751 9. http://gcc.gnu.org/gcc-4.8/cxx0x_status.html 6752 10. http://gcc.gnu.org/gcc-4.8/cxx0x_status.html 6753 11. http://gcc.gnu.org/gcc-4.8/cxx0x_status.html 6754 12. http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3276.pdf 6755 13. http://gcc.gnu.org/gcc-4.8/cxx0x_status.html 6756 14. http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2012/n3386.html 6757 15. http://gcc.gnu.org/projects/cxx1y.html 6758 16. https://gcc.gnu.org/onlinedocs/gcc-4.8.4/libstdc++/manual/manual/status.html#status.iso.2011 6759 17. https://gcc.gnu.org/onlinedocs/gfortran/BACKTRACE.html 6760 18. https://gcc.gnu.org/onlinedocs/gfortran/Error-and-Warning-Options.html 6761 19. https://gcc.gnu.org/onlinedocs/gfortran/Error-and-Warning-Options.html 6762 20. https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html 6763 21. https://gcc.gnu.org/onlinedocs/gfortran/Error-and-Warning-Options.html 6764 22. https://gcc.gnu.org/onlinedocs/gfortran/Error-and-Warning-Options.html 6765 23. https://gcc.gnu.org/onlinedocs/gfortran/TMPDIR.html 6766 24. https://gcc.gnu.org/wiki/Fortran2003Status 6767 25. https://gcc.gnu.org/wiki/TS29113Status 6768 26. https://gcc.gnu.org/viewcvs/trunk/libgfortran/libgfortran.h?content-type=text/plain&view=co 6769 27. http://chasm-interop.sourceforge.net/ 6770 28. https://gcc.gnu.org/wiki/avr-gcc#Fixed-Point_Support 6771 29. https://gcc.gnu.org/onlinedocs/gcc/Fixed-Point.html 6772 30. https://gcc.gnu.org/onlinedocs/gcc/x86-Built-in-Functions.html 6773 31. https://gcc.gnu.org/onlinedocs/gcc/x86-Built-in-Functions.html 6774 32. https://gcc.gnu.org/wiki/FunctionMultiVersioning 6775 33. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.8.1 6776 34. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.8.2 6777 35. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.8.3 6778 36. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.8.4 6779 37. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.8.5 6780 38. https://gcc.gnu.org/onlinedocs/ 6781 39. mailto:gcc-help (a] gcc.gnu.org 6782 40. mailto:gcc (a] gcc.gnu.org 6783 41. https://gcc.gnu.org/lists.html 6784 42. https://www.fsf.org/ 6785 43. https://gcc.gnu.org/about.html 6786 44. http://validator.w3.org/check/referer 6787 ====================================================================== 6788 http://gcc.gnu.org/gcc-4.7/index.html 6789 GCC 4.7 Release Series 6790 6791 (This release series is no longer supported.) 6792 6793 June 12, 2014 6794 6795 The [1]GNU project and the GCC developers are pleased to announce the 6796 release of GCC 4.7.4. 6797 6798 This release is a bug-fix release, containing fixes for regressions in 6799 GCC 4.7.3 relative to previous releases of GCC. 6800 6801 Release History 6802 6803 GCC 4.7.4 6804 June 12, 2014 ([2]changes, [3]documentation) 6805 6806 GCC 4.7.3 6807 April 11, 2013 ([4]changes, [5]documentation) 6808 6809 GCC 4.7.2 6810 September 20, 2012 ([6]changes, [7]documentation) 6811 6812 GCC 4.7.1 6813 June 14, 2012 ([8]changes, [9]documentation) 6814 6815 GCC 4.7.0 6816 March 22, 2012 ([10]changes, [11]documentation) 6817 6818 References and Acknowledgements 6819 6820 GCC used to stand for the GNU C Compiler, but since the compiler 6821 supports several other languages aside from C, it now stands for the 6822 GNU Compiler Collection. 6823 6824 A list of [12]successful builds is updated as new information becomes 6825 available. 6826 6827 The GCC developers would like to thank the numerous people that have 6828 contributed new features, improvements, bug fixes, and other changes as 6829 well as test results to GCC. This [13]amazing group of volunteers is 6830 what makes GCC successful. 6831 6832 For additional information about GCC please refer to the [14]GCC 6833 project web site or contact the [15]GCC development mailing list. 6834 6835 To obtain GCC please use [16]our mirror sites or [17]our version 6836 control system. 6837 6838 6839 For questions related to the use of GCC, please consult these web 6840 pages and the [18]GCC manuals. If that fails, the 6841 [19]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 6842 web pages and the development of GCC are welcome on our developer 6843 list at [20]gcc (a] gcc.gnu.org. All of [21]our lists have public 6844 archives. 6845 6846 Copyright (C) [22]Free Software Foundation, Inc. Verbatim copying and 6847 distribution of this entire article is permitted in any medium, 6848 provided this notice is preserved. 6849 6850 These pages are [23]maintained by the GCC team. Last modified 6851 2020-01-14[24]. 6852 6853 References 6854 6855 1. http://www.gnu.org/ 6856 2. http://gcc.gnu.org/gcc-4.7/changes.html 6857 3. https://gcc.gnu.org/onlinedocs/4.7.4/ 6858 4. http://gcc.gnu.org/gcc-4.7/changes.html 6859 5. https://gcc.gnu.org/onlinedocs/4.7.3/ 6860 6. http://gcc.gnu.org/gcc-4.7/changes.html 6861 7. https://gcc.gnu.org/onlinedocs/4.7.2/ 6862 8. http://gcc.gnu.org/gcc-4.7/changes.html 6863 9. https://gcc.gnu.org/onlinedocs/4.7.1/ 6864 10. http://gcc.gnu.org/gcc-4.7/changes.html 6865 11. https://gcc.gnu.org/onlinedocs/4.7.0/ 6866 12. http://gcc.gnu.org/gcc-4.7/buildstat.html 6867 13. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 6868 14. http://gcc.gnu.org/index.html 6869 15. mailto:gcc (a] gcc.gnu.org 6870 16. http://gcc.gnu.org/mirrors.html 6871 17. http://gcc.gnu.org/git.html 6872 18. https://gcc.gnu.org/onlinedocs/ 6873 19. mailto:gcc-help (a] gcc.gnu.org 6874 20. mailto:gcc (a] gcc.gnu.org 6875 21. https://gcc.gnu.org/lists.html 6876 22. https://www.fsf.org/ 6877 23. https://gcc.gnu.org/about.html 6878 24. http://validator.w3.org/check/referer 6879 ====================================================================== 6880 http://gcc.gnu.org/gcc-4.7/changes.html 6881 GCC 4.7 Release Series 6882 Changes, New Features, and Fixes 6883 6884 Caveats 6885 6886 * The -fconserve-space flag has been deprecated. The flag had no 6887 effect for most targets: only targets without a global .bss section 6888 and without support for switchable sections. Furthermore, the flag 6889 only had an effect for G++, where it could result in wrong 6890 semantics (please refer to the GCC manual for further details). The 6891 flag will be removed in GCC 4.8 6892 * Support for a number of older systems and recently unmaintained or 6893 untested target ports of GCC has been declared obsolete in GCC 4.7. 6894 Unless there is activity to revive them, the next release of GCC 6895 will have their sources permanently removed. 6896 All GCC ports for the following processor architectures have been 6897 declared obsolete: 6898 + picoChip (picochip-*) 6899 The following ports for individual systems on particular 6900 architectures have been obsoleted: 6901 + IRIX 6.5 (mips-sgi-irix6.5) 6902 + MIPS OpenBSD (mips*-*-openbsd*) 6903 + Solaris 8 (*-*-solaris2.8). Details can be found in the 6904 [1]announcement. 6905 + Tru64 UNIX V5.1 (alpha*-dec-osf5.1*) 6906 * On ARM, when compiling for ARMv6 (but not ARMv6-M), ARMv7-A, 6907 ARMv7-R, or ARMv7-M, the new option -munaligned-access is active by 6908 default, which for some sources generates code that accesses memory 6909 on unaligned addresses. This requires the kernel of those systems 6910 to enable such accesses (controlled by CP15 register c1, refer to 6911 ARM documentation). Alternatively, or for compatibility with 6912 kernels where unaligned accesses are not supported, all code has to 6913 be compiled with -mno-unaligned-access. Upstream Linux kernel 6914 releases have automatically and unconditionally supported unaligned 6915 accesses as emitted by GCC due to this option being active since 6916 version 2.6.28. 6917 * Support on ARM for the legacy floating-point accelerator (FPA) and 6918 the mixed-endian floating-point format that it used has been 6919 obsoleted. The ports that still use this format have been obsoleted 6920 as well. Many legacy ARM ports already provide an alternative that 6921 uses the VFP floating-point format. The obsolete ports will be 6922 deleted in the next release. 6923 The obsolete ports with alternatives are: 6924 + arm*-*-rtems (use arm*-*-rtemseabi) 6925 + arm*-*-linux-gnu (use arm*-*-linux-gnueabi) 6926 + arm*-*-elf (use arm*-*-eabi) 6927 + arm*-*-uclinux* (use arm*-*-uclinux*eabi) 6928 Note, however, that these alternatives are not binary compatible 6929 with their legacy counterparts (although some can support running 6930 legacy applications). 6931 The obsolete ports that currently lack a modern alternative are: 6932 + arm*-*-ecos-elf 6933 + arm*-*-freebsd 6934 + arm*-wince-pe* 6935 New ports that support more recent versions of the architecture are 6936 welcome. 6937 * Support for the Maverick co-processor on ARM has been obsoleted. 6938 Code to support it will be deleted in the next release. 6939 * Support has been removed for Unix International threads on Solaris 6940 2, so the --enable-threads=solaris configure option and the 6941 -threads compiler option don't work any longer. 6942 * Support has been removed for the Solaris BSD Compatibility Package, 6943 which lives in /usr/ucbinclude and /usr/ucblib. It has been removed 6944 from Solaris 11, and was only intended as a migration aid from 6945 SunOS 4 to SunOS 5. The -compat-bsd compiler option is not 6946 recognized any longer. 6947 * The AVR port's libgcc has been improved and its multilib structure 6948 has been enhanced. As a result, all objects contributing to an 6949 application must either be compiled with GCC versions up to 4.6.x 6950 or with GCC versions 4.7.1 or later. If the compiler is used with 6951 AVR Libc, you need a version that supports the new layout, i.e. 6952 implements [2]#35407. 6953 * The AVR port's -mshort-calls command-line option has been 6954 deprecated. It will be removed in the GCC 4.8 release. See -mrelax 6955 for a replacement. 6956 * The AVR port only references startup code that clears .bss and the 6957 common section resp. initializes the .data and .rodata section 6958 provided respective sections (or subsections thereof) are not 6959 empty, see [3]PR18145. Applications that put all static storage 6960 objects into non-standard sections and / or define all static 6961 storage objects in assembler modules, must reference __do_clear_bss 6962 resp. __do_copy_data by hand or undefine the symbol(s) by means of 6963 -Wl,-u,__do_clear_bss resp. -Wl,-u,__do_copy_data. 6964 * The ARM port's -mwords-little-endian option has been deprecated. It 6965 will be removed in a future release. 6966 * Support has been removed for the NetWare x86 configuration 6967 obsoleted in GCC 4.6. 6968 * It is no longer possible to use the "l" constraint in MIPS16 asm 6969 statements. 6970 * GCC versions 4.7.0 and 4.7.1 had changes to the C++ standard 6971 library which affected the ABI in C++11 mode: a data member was 6972 added to std::list changing its size and altering the definitions 6973 of some member functions, and std::pair's move constructor was 6974 non-trivial which altered the calling convention for functions with 6975 std::pair arguments or return types. The ABI incompatibilities have 6976 been fixed for GCC version 4.7.2 but as a result C++11 code 6977 compiled with GCC 4.7.0 or 4.7.1 may be incompatible with C++11 6978 code compiled with different GCC versions and with C++98/C++03 code 6979 compiled with any version. 6980 * On ARM, a bug has been fixed in GCC's implementation of the AAPCS 6981 rules for the layout of vectors that could lead to wrong code being 6982 generated. Vectors larger than 8 bytes in size are now by default 6983 aligned to an 8-byte boundary. This is an ABI change: code that 6984 makes explicit use of vector types may be incompatible with binary 6985 objects built with older versions of GCC. Auto-vectorized code is 6986 not affected by this change. (This change affects GCC versions 6987 4.7.2 and later.) 6988 * More information on porting to GCC 4.7 from previous versions of 6989 GCC can be found in the [4]porting guide for this release. 6990 6991 General Optimizer Improvements 6992 6993 * Support for a new parameter --param case-values-threshold=n was 6994 added to allow users to control the cutoff between doing switch 6995 statements as a series of if statements and using a jump table. 6996 * Link-time optimization (LTO) improvements: 6997 + Improved scalability and reduced memory usage. Link time 6998 optimization of Firefox now requires 3GB of RAM on a 64-bit 6999 system, while over 8GB was needed previously. Linking time has 7000 been improved, too. The serial stage of linking Firefox has 7001 been sped up by about a factor of 10. 7002 + Reduced size of object files and temporary storage used during 7003 linking. 7004 + Streaming performance (both outbound and inbound) has been 7005 improved. 7006 + ld -r is now supported with LTO. 7007 + Several bug fixes, especially in symbol table handling and 7008 merging. 7009 * Interprocedural optimization improvements: 7010 + Heuristics now take into account that after inlining code will 7011 be optimized out because of known values (or properties) of 7012 function parameters. For example: 7013 void foo(int a) 7014 { 7015 if (a > 10) 7016 ... huge code ... 7017 } 7018 void bar (void) 7019 { 7020 foo (0); 7021 } 7022 7023 The call of foo will be inlined into bar even when optimizing 7024 for code size. Constructs based on __builtin_constant_p are 7025 now understood by the inliner and code size estimates are 7026 evaluated a lot more realistically. 7027 + The representation of C++ virtual thunks and aliases (both 7028 implicit and defined via the alias attribute) has been 7029 re-engineered. Aliases no longer pose optimization barriers 7030 and calls to an alias can be inlined and otherwise optimized. 7031 + The inter-procedural constant propagation pass has been 7032 rewritten. It now performs generic function specialization. 7033 For example when compiling the following: 7034 void foo(bool flag) 7035 { 7036 if (flag) 7037 ... do something ... 7038 else 7039 ... do something else ... 7040 } 7041 void bar (void) 7042 { 7043 foo (false); 7044 foo (true); 7045 foo (false); 7046 foo (true); 7047 foo (false); 7048 foo (true); 7049 } 7050 7051 GCC will now produce two copies of foo. One with flag being 7052 true, while other with flag being false. This leads to 7053 performance improvements previously possible only by inlining 7054 all calls. Cloning causes a lot less code size growth. 7055 * A string length optimization pass has been added. It attempts to 7056 track string lengths and optimize various standard C string 7057 functions like strlen, strchr, strcpy, strcat, stpcpy and their 7058 _FORTIFY_SOURCE counterparts into faster alternatives. This pass is 7059 enabled by default at -O2 or above, unless optimizing for size, and 7060 can be disabled by the -fno-optimize-strlen option. The pass can 7061 e.g. optimize 7062 char *bar (const char *a) 7063 { 7064 size_t l = strlen (a) + 2; 7065 char *p = malloc (l); if (p == NULL) return p; 7066 strcpy (p, a); strcat (p, "/"); return p; 7067 } 7068 7069 into: 7070 char *bar (const char *a) 7071 { 7072 size_t tmp = strlen (a); 7073 char *p = malloc (tmp + 2); if (p == NULL) return p; 7074 memcpy (p, a, tmp); memcpy (p + tmp, "/", 2); return p; 7075 } 7076 7077 or for hosted compilations where stpcpy is available in the runtime 7078 and headers provide its prototype, e.g. 7079 void foo (char *a, const char *b, const char *c, const char *d) 7080 { 7081 strcpy (a, b); strcat (a, c); strcat (a, d); 7082 } 7083 7084 can be optimized into: 7085 void foo (char *a, const char *b, const char *c, const char *d) 7086 { 7087 strcpy (stpcpy (stpcpy (a, b), c), d); 7088 } 7089 7090 New Languages and Language specific improvements 7091 7092 * Version 3.1 of the OpenMP specification is now supported for the C, 7093 C++, and Fortran compilers. 7094 7095 Ada 7096 7097 * The command-line option -feliminate-unused-debug-types has been 7098 re-enabled by default, as it is for the other languages, leading to 7099 a reduction in debug info size of 12.5% and more for relevant 7100 cases, as well as to a small compilation speedup. 7101 7102 C family 7103 7104 * A new built-in, __builtin_assume_aligned, has been added, through 7105 which the compiler can be hinted about pointer alignment and can 7106 use it to improve generated code. 7107 * A new warning option -Wunused-local-typedefs was added for C, C++, 7108 Objective-C and Objective-C++. This warning diagnoses typedefs 7109 locally defined in a function, and otherwise not used. 7110 * A new experimental command-line option -ftrack-macro-expansion was 7111 added for C, C++, Objective-C, Objective-C++ and Fortran. It allows 7112 the compiler to emit diagnostic about the current macro expansion 7113 stack when a compilation error occurs in a macro expansion. 7114 * Experimental support for transactional memory has been added. It 7115 includes support in the compiler, as well as a supporting runtime 7116 library called libitm. To compile code with transactional memory 7117 constructs, use the -fgnu-tm option. 7118 Support is currently available for Alpha, ARM, PowerPC, SH, SPARC, 7119 and 32-bit/64-bit x86 platforms. 7120 For more details on transactional memory see [5]the GCC WiKi. 7121 * Support for atomic operations specifying the C++11/C11 memory model 7122 has been added. These new __atomic routines replace the existing 7123 __sync built-in routines. 7124 Atomic support is also available for memory blocks. Lock-free 7125 instructions will be used if a memory block is the same size and 7126 alignment as a supported integer type. Atomic operations which do 7127 not have lock-free support are left as function calls. A set of 7128 library functions is available on the GCC atomic wiki in the 7129 "External Atomics Library" section. 7130 For more details on the memory models and features, see the 7131 [6]atomic wiki. 7132 * When a binary operation is performed on vector types and one of the 7133 operands is a uniform vector, it is possible to replace the vector 7134 with the generating element. For example: 7135 typedef int v4si __attribute__ ((vector_size (16))); 7136 v4si res, a = {1,2,3,4}; 7137 int x; 7138 7139 res = 2 + a; /* means {2,2,2,2} + a */ 7140 res = a - x; /* means a - {x,x,x,x} */ 7141 7142 C 7143 7144 * There is support for some more features from the C11 revision of 7145 the ISO C standard. GCC now accepts the options -std=c11 and 7146 -std=gnu11, in addition to the previous -std=c1x and -std=gnu1x. 7147 + Unicode strings (previously supported only with options such 7148 as -std=gnu11, now supported with -std=c11), and the 7149 predefined macros __STDC_UTF_16__ and __STDC_UTF_32__. 7150 + Nonreturning functions (_Noreturn and <stdnoreturn.h>). 7151 + Alignment support (_Alignas, _Alignof, max_align_t, 7152 <stdalign.h>). 7153 + A built-in function __builtin_complex is provided to support C 7154 library implementation of the CMPLX family of macros. 7155 7156 C++ 7157 7158 * G++ now accepts the -std=c++11, -std=gnu++11, and -Wc++11-compat 7159 options, which are equivalent to -std=c++0x, -std=gnu++0x, and 7160 -Wc++0x-compat, respectively. 7161 * G++ now implements [7]C++11 extended friend syntax: 7162 7163 template<class W> 7164 class Q 7165 { 7166 static const int I = 2; 7167 public: 7168 friend W; 7169 }; 7170 7171 struct B 7172 { 7173 int ar[Q<B>::I]; 7174 }; 7175 7176 * Thanks to Ville Voutilainen, G++ now implements [8]C++11 explicit 7177 override control. 7178 7179 struct B { 7180 virtual void f() const final; 7181 virtual void f(int); 7182 }; 7183 7184 struct D : B { 7185 void f() const; // error: D::f attempts to override final B::f 7186 void f(long) override; // error: doesn't override anything 7187 void f(int) override; // ok 7188 }; 7189 7190 struct E final { }; 7191 struct F: E { }; // error: deriving from final class 7192 7193 * G++ now implements [9]C++11 non-static data member initializers. 7194 7195 struct A { 7196 int i = 42; 7197 } a; // initializes a.i to 42 7198 7199 * Thanks to Ed Smith-Rowland, G++ now implements [10]C++11 7200 user-defined literals. 7201 7202 // Not actually a good approximation. :) 7203 constexpr long double operator"" _degrees (long double d) { return d * 0.0175; } 7204 long double pi = 180.0_degrees; 7205 7206 * G++ now implements [11]C++11 alias-declarations. 7207 7208 template <class T> using Ptr = T*; 7209 Ptr<int> ip; // decltype(ip) is int* 7210 7211 * Thanks to Ville Voutilainen and Pedro Lamaro, G++ now implements 7212 [12]C++11 delegating constructors. 7213 7214 struct A { 7215 A(int); 7216 A(): A(42) { } // delegate to the A(int) constructor 7217 }; 7218 7219 * G++ now fully implements C++11 atomic classes rather than just 7220 integer derived classes. 7221 7222 class POD { 7223 int a; 7224 int b; 7225 }; 7226 std::atomic<POD> my_atomic_POD; 7227 7228 * G++ now sets the predefined macro __cplusplus to the correct value, 7229 199711L for C++98/03, and 201103L for C++11. 7230 * G++ now correctly implements the two-phase lookup rules such that 7231 an unqualified name used in a template must have an appropriate 7232 declaration found either in scope at the point of definition of the 7233 template or by argument-dependent lookup at the point of 7234 instantiation. As a result, code that relies on a second 7235 unqualified lookup at the point of instantiation to find functions 7236 declared after the template or in dependent bases will be rejected. 7237 The compiler will suggest ways to fix affected code, and using the 7238 -fpermissive compiler flag will allow the code to compile with a 7239 warning. 7240 7241 template <class T> 7242 void f() { g(T()); } // error, g(int) not found by argument-dependent lookup 7243 void g(int) { } // fix by moving this declaration before the declaration of f 7244 7245 template <class T> 7246 struct A: T { 7247 // error, B::g(B) not found by argument-dependent lookup 7248 void f() { g(T()); } // fix by using this->g or A::g 7249 }; 7250 7251 struct B { void g(B); }; 7252 7253 int main() 7254 { 7255 f<int>(); 7256 A<B>().f(); 7257 } 7258 7259 * G++ now properly re-uses stack space allocated for temporary 7260 objects when their lifetime ends, which can significantly lower 7261 stack consumption for some C++ functions. As a result of this, some 7262 code with undefined behavior will now break: 7263 7264 const int &f(const int &i) { return i; } 7265 .... 7266 const int &x = f(1); 7267 const int &y = f(2); 7268 7269 Here, x refers to the temporary allocated to hold the 1 argument, 7270 which only lives until the end of the initialization; it 7271 immediately becomes a dangling reference. So the next statement 7272 re-uses the stack slot to hold the 2 argument, and users of x get 7273 that value instead. 7274 Note that this should not cause any change of behavior for 7275 temporaries of types with non-trivial destructors, as they are 7276 already destroyed at end of full-expression; the change is that now 7277 the storage is released as well. 7278 * A new command-line option -Wdelete-non-virtual-dtor has been added 7279 to warn when delete is used to destroy an instance of a class which 7280 has virtual functions and non-virtual destructor. It is unsafe to 7281 delete an instance of a derived class through a pointer to a base 7282 class if the base class does not have a virtual destructor. This 7283 warning is enabled by -Wall. 7284 * A new command-line option -Wzero-as-null-pointer-constant has been 7285 added to warn when a literal '0' is used as null pointer constant. 7286 It can be useful to facilitate the conversion to nullptr in C++11. 7287 * As per C++98, access-declarations are now deprecated by G++. 7288 Using-declarations are to be used instead. Furthermore, some 7289 efforts have been made to improve the support of class scope 7290 using-declarations. In particular, using-declarations referring to 7291 a dependent type now work as expected ([13]bug c++/14258). 7292 * The ELF symbol visibility of a template instantiation is now 7293 properly constrained by the visibility of its template arguments 7294 ([14]bug c++/35688). 7295 7296 Runtime Library (libstdc++) 7297 7298 * [15]Improved experimental support for the new ISO C++ standard, 7299 C++11, including: 7300 + using noexcept in most of the library; 7301 + implementations of pointer_traits, allocator_traits and 7302 scoped_allocator_adaptor; 7303 + uses-allocator construction for tuple; 7304 + vector meets the allocator-aware container requirements; 7305 + replacing monotonic_clock with steady_clock; 7306 + enabling the thread support library on most POSIX targets; 7307 + many small improvements to conform to the FDIS. 7308 * Added --enable-clocale=newlib configure option. 7309 * Debug Mode iterators for unordered associative containers. 7310 * Avoid polluting the global namespace and do not include <unistd.h>. 7311 7312 Fortran 7313 7314 * The compile flag [16]-fstack-arrays has been added, which causes 7315 all local arrays to be put on stack memory. For some programs this 7316 will improve the performance significantly. If your program uses 7317 very large local arrays, it is possible that you will have to 7318 extend your runtime limits for stack memory. 7319 * The [17]-Ofast flag now also implies [18]-fno-protect-parens and 7320 [19]-fstack-arrays. 7321 * Front-end optimizations can now be selected by the 7322 [20]-ffrontend-optimize option and deselected by the 7323 -fno-frontend-optimize option. 7324 * When front-end optimization removes a function call, 7325 [21]-Wfunction-elimination warns about that. 7326 * When performing front-end-optimization, the 7327 [22]-faggressive-function-elimination option allows the removal of 7328 duplicate function calls even for impure functions. 7329 * The flag [23]-Wreal-q-constant has been added, which warns if 7330 floating-point literals have been specified using q (such as 7331 1.0q0); the q marker is now supported as a vendor extension to 7332 denote quad precision (REAL(16) or, if not available, REAL(10)). 7333 Consider using a kind parameter (such as in 1.0_qp) instead, which 7334 can be obtained via [24]SELECTED_REAL_KIND. 7335 * The GFORTRAN_USE_STDERR environment variable has been removed. GNU 7336 Fortran now always prints error messages to standard error. If you 7337 wish to redirect standard error, please consult the manual for your 7338 OS, shell, batch environment etc. as appropriate. 7339 * The -fdump-core option and GFORTRAN_ERROR_DUMPCORE environment 7340 variable have been removed. When encountering a serious error, 7341 gfortran will now always abort the program. Whether a core dump is 7342 generated depends on the user environment settings; see the ulimit 7343 -c setting for POSIX shells, limit coredumpsize for C shells, and 7344 the [25]WER user-mode dumps settings on Windows. 7345 * The [26]-fbacktrace option is now enabled by default. When 7346 encountering a fatal error, gfortran will attempt to print a 7347 backtrace to standard error before aborting. It can be disabled 7348 with -fno-backtrace. Note: On POSIX targets with the addr2line 7349 utility from GNU binutils, GNU Fortran can print a backtrace with 7350 function name, file name, line number information in addition to 7351 the addresses; otherwise only the addresses are printed. 7352 * [27]Fortran 2003: 7353 + Generic interface names which have the same name as derived 7354 types are now supported, which allows to write constructor 7355 functions. Note that Fortran does not support static 7356 constructor functions; only default initialization or an 7357 explicit structure-constructor initialization are available. 7358 + [28]Polymorphic (class) arrays are now supported. 7359 * [29]Fortran 2008: 7360 + Support for the DO CONCURRENT construct has been added, which 7361 allows the user to specify that individual loop iterations 7362 have no interdependencies. 7363 + [30]Coarrays: Full single-image support except for polymorphic 7364 coarrays. Additionally, preliminary support for multiple 7365 images via an MPI-based [31]coarray communication library has 7366 been added. Note: The library version is not yet usable as 7367 remote coarray access is not yet possible. 7368 * [32]TS 29113: 7369 + New flag [33]-std=f2008ts permits programs that are expected 7370 to conform to the Fortran 2008 standard and the draft 7371 Technical Specification (TS) 29113 on Further Interoperability 7372 of Fortran with C. 7373 + The OPTIONAL attribute is now allowed for dummy arguments of 7374 BIND(C) procedures. 7375 + The RANK intrinsic has been added. 7376 + The implementation of the ASYNCHRONOUS attribute in GCC is 7377 compatible with the candidate draft of TS 29113 (since GCC 7378 4.6). 7379 7380 Go 7381 7382 * GCC 4.7 implements the [34]Go 1 language standard. The library 7383 support in 4.7.0 is not quite complete, due to release timing. 7384 Release 4.7.1 includes complete support for Go 1. The Go library is 7385 from the Go 1.0.1 release. 7386 * Go has been tested on GNU/Linux and Solaris platforms. It may work 7387 on other platforms as well. 7388 7389 New Targets and Target Specific Improvements 7390 7391 ARM 7392 7393 * GCC now supports the Cortex-A7 processor implementing the v7-a 7394 version of the architecture using the option -mcpu=cortex-a7. 7395 * The default vector size in auto-vectorization for NEON is now 128 7396 bits. If vectorization fails thusly, the vectorizer tries again 7397 with 64-bit vectors. 7398 * A new option -mvectorize-with-neon-double was added to allow users 7399 to change the vector size to 64 bits. 7400 7401 AVR 7402 7403 * GCC now supports the XMEGA architecture. This requires GNU binutils 7404 2.22 or later. 7405 * Support for the [35]named address spaces __flash, __flash1, , 7406 __flash5 and __memx has been added. These address spaces locate 7407 read-only data in flash memory and allow reading from flash memory 7408 by means of ordinary C code, i.e. without the need of (inline) 7409 assembler code: 7410 7411 const __flash int values[] = { 42, 31 }; 7412 7413 int add_values (const __flash int *p, int i) 7414 { 7415 return values[i] + *p; 7416 } 7417 7418 * Support has been added for the AVR-specific configure option 7419 --with-avrlibc=yes in order to arrange for better integration of 7420 [36]AVR-Libc. This configure option is supported in avr-gcc 4.7.2 7421 and newer and will only take effect in non-RTEMS configurations. If 7422 avr-gcc is configured for RTEMS, the option will be ignored which 7423 is the same as specifying --with-avrlibc=no. See [37]PR54461 for 7424 more technical details. 7425 * Support for AVR-specific [38]built-in functions has been added. 7426 * Support has been added for the signed and unsigned 24-bit scalar 7427 integer types __int24 and __uint24. 7428 * New command-line options -maccumulate-args, -mbranch-cost=cost and 7429 -mstrict-X were added to allow better fine-tuning of code 7430 optimization. 7431 * The command-line option -fdata-sections now also takes affect on 7432 the section names of variables with the progmem attribute. 7433 * A new inline assembler print modifier %i to print a RAM address as 7434 I/O address has been added: 7435 7436 #include <avr/io.h> /* Port Definitions from AVR-LibC */ 7437 7438 void set_portb (uint8_t value) 7439 { 7440 asm volatile ("out %i0, %1" :: "n" (&PORTB), "r" (value) : "memory"); 7441 } 7442 7443 The offset between an I/O address and the RAM address for that I/O 7444 location is device-specific. This offset is taken into account when 7445 printing a RAM address with the %i modifier so that the address is 7446 suitable to be used as operand in an I/O command. The address must 7447 be a constant integer known at compile time. 7448 * The inline assembler constraint "R" to represent integers in the 7449 range 6 5 has been removed without replacement. 7450 * Many optimizations to: 7451 + 64-bit integer arithmetic 7452 + Widening multiplication 7453 + Integer division by a constant 7454 + Avoid constant reloading in multi-byte instructions. 7455 + Micro-optimizations for special instruction sequences. 7456 + Generic built-in functions like __builtin_ffs*, 7457 __builtin_clz*, etc. 7458 + If-else decision trees generated by switch instructions 7459 + Merging of data located in flash memory 7460 + New libgcc variants for devices with 8-bit wide stack pointer 7461 + 7462 * Better documentation: 7463 + Handling of EIND and indirect jumps on devices with more than 7464 128 KiB of program memory. 7465 + Handling of the RAMPD, RAMPX, RAMPY and RAMPZ special function 7466 registers. 7467 + Function attributes OS_main and OS_task. 7468 + AVR-specific built-in macros. 7469 7470 C6X 7471 7472 * Support has been added for the Texas Instruments C6X family of 7473 processors. 7474 7475 CR16 7476 7477 * Support has been added for National Semiconductor's CR16 7478 architecture. 7479 7480 Epiphany 7481 7482 * Support has been added for Adapteva's Epiphany architecture. 7483 7484 IA-32/x86-64 7485 7486 * Support for Intel AVX2 intrinsics, built-in functions and code 7487 generation is available via -mavx2. 7488 * Support for Intel BMI2 intrinsics, built-in functions and code 7489 generation is available via -mbmi2. 7490 * Implementation and automatic generation of __builtin_clz* using the 7491 lzcnt instruction is available via -mlzcnt. 7492 * Support for Intel FMA3 intrinsics and code generation is available 7493 via -mfma. 7494 * A new -mfsgsbase command-line option is available that makes GCC 7495 generate new segment register read/write instructions through 7496 dedicated built-ins. 7497 * Support for the new Intel rdrnd instruction is available via 7498 -mrdrnd. 7499 * Two additional AVX vector conversion instructions are available via 7500 -mf16c. 7501 * Support for new Intel processor codename IvyBridge with RDRND, 7502 FSGSBASE and F16C is available through -march=core-avx-i. 7503 * Support for the new Intel processor codename Haswell with AVX2, 7504 FMA, BMI, BMI2, LZCNT is available through -march=core-avx2. 7505 * Support for new AMD family 15h processors (Piledriver core) is now 7506 available through -march=bdver2 and -mtune=bdver2 options. 7507 * Support for [39]the x32 psABI is now available through the -mx32 7508 option. 7509 * Windows mingw targets are using the -mms-bitfields option by 7510 default. 7511 * Windows x86 targets are using the __thiscall calling convention for 7512 C++ class-member functions. 7513 * Support for the configure option --with-threads=posix for Windows 7514 mingw targets. 7515 7516 MIPS 7517 7518 * GCC now supports thread-local storage (TLS) for MIPS16. This 7519 requires GNU binutils 2.22 or later. 7520 * GCC can now generate code specifically for the Cavium Octeon+ and 7521 Octeon2 processors. The associated command-line options are 7522 -march=octeon+ and -march=octeon2 respectively. Both options 7523 require GNU binutils 2.22 or later. 7524 * GCC can now work around certain 24k errata, under the control of 7525 the command-line option -mfix-24k. These workarounds require GNU 7526 binutils 2.20 or later. 7527 * 32-bit MIPS GNU/Linux targets such as mips-linux-gnu can now build 7528 n32 and n64 multilibs. The result is effectively a 64-bit GNU/Linux 7529 toolchain that generates 32-bit code by default. Use the 7530 configure-time option --enable-targets=all to select these extra 7531 multilibs. 7532 * Passing -fno-delayed-branch now also stops the assembler from 7533 automatically filling delay slots. 7534 7535 PowerPC/PowerPC64 7536 7537 * Vectors of type vector long long or vector long are passed and 7538 returned using the same method as other vectors with the VSX 7539 instruction set. Previously GCC did not adhere to the ABI for 7540 128-bit vectors with 64-bit integer base types (PR 48857). This 7541 will also be fixed in the GCC 4.6.1 and 4.5.4 releases. 7542 * A new option -mno-pointers-to-nested-functions was added to allow 7543 AIX 32-bit/64-bit and GNU/Linux 64-bit PowerPC users to specify 7544 that the compiler should not load up the chain register (r11) 7545 before calling a function through a pointer. If you use this 7546 option, you cannot call nested functions through a pointer, or call 7547 other languages that might use the static chain. 7548 * A new option msave-toc-indirect was added to allow AIX 7549 32-bit/64-bit and GNU/Linux 64-bit PowerPC users control whether we 7550 save the TOC in the prologue for indirect calls or generate the 7551 save inline. This can speed up some programs that call through a 7552 function pointer a lot, but it can slow down other functions that 7553 only call through a function pointer in exceptional cases. 7554 * The PowerPC port will now enable machine-specific built-in 7555 functions when the user switches the target machine using the 7556 #pragma GCC target or __attribute__ ((__target__ ("target"))) code 7557 sequences. In addition, the target macros are updated. However, due 7558 to the way the -save-temps switch is implemented, you won't see the 7559 effect of these additional macros being defined in preprocessor 7560 output. 7561 7562 SH 7563 7564 * A new option -msoft-atomic has been added. When it is specified, 7565 GCC will generate GNU/Linux-compatible gUSA atomic sequences for 7566 the new __atomic routines. 7567 * Since it is neither supported by GAS nor officially documented, 7568 code generation for little endian SH2A has been disabled. 7569 Specifying -ml with -m2a* will now result in a compiler error. 7570 * The defunct -mbranch-cost option has been fixed. 7571 * Some improvements to the generated code of: 7572 + Utilization of the tst #imm,R0 instruction. 7573 + Dynamic shift instructions on SH2A. 7574 + Integer absolute value calculations. 7575 * The -mdiv= option for targets other than SHmedia has been fixed and 7576 documented. 7577 7578 SPARC 7579 7580 * The option -mflat has been reinstated. When it is specified, the 7581 compiler will generate code for a single register window model. 7582 This is essentially a new implementation and the corresponding 7583 debugger support has been added to GDB 7.4. 7584 * Support for the options -mtune=native and -mcpu=native has been 7585 added on selected native platforms (GNU/Linux and Solaris). 7586 * Support for the SPARC T3 (Niagara 3) processor has been added. 7587 * VIS: 7588 + An intrinsics header visintrin.h has been added. 7589 + Builtin intrinsics for the VIS 1.0 edge handling and pixel 7590 compare instructions have been added. 7591 + The little-endian version of alignaddr is now supported. 7592 + When possible, VIS builtins are marked const, which should 7593 increase the compiler's ability to optimize VIS operations. 7594 + The compiler now properly tracks the %gsr register and how it 7595 behaves as an input for various VIS instructions. 7596 + Akin to fzero, the compiler can now generate fone instructions 7597 in order to set all of the bits of a floating-point register 7598 to 1. 7599 + The documentation for the VIS intrinsics in the GCC manual has 7600 been brought up to date and many inaccuracies were fixed. 7601 + Intrinsics for the VIS 2.0 bmask, bshuffle, and 7602 non-condition-code setting edge instructions have been added. 7603 Their availability is controlled by the new -mvis2 and 7604 -mno-vis2 options. They are enabled by default on 7605 UltraSPARC-III and later CPUs. 7606 * Support for UltraSPARC Fused Multiply-Add floating-point extensions 7607 has been added. These instructions are enabled by default on SPARC 7608 T3 (Niagara 3) and later CPUs. 7609 7610 TILE-Gx/TILEPro 7611 7612 * Support has been added for the Tilera TILE-Gx and TILEPro families 7613 of processors. 7614 7615 Other significant improvements 7616 7617 * A new option (-grecord-gcc-switches) was added that appends 7618 compiler command-line options that might affect code generation to 7619 the DW_AT_producer attribute string in the DWARF debugging 7620 information. 7621 * GCC now supports various new GNU extensions to the DWARF debugging 7622 information format, like [40]entry value and [41]call site 7623 information, [42]typed DWARF stack or [43]a more compact macro 7624 representation. Support for these extensions has been added to GDB 7625 7.4. They can be disabled through the -gstrict-dwarf command-line 7626 option. 7627 7628 GCC 4.7.1 7629 7630 This is the [44]list of problem reports (PRs) from GCC's bug tracking 7631 system that are known to be fixed in the 4.7.1 release. This list might 7632 not be complete (that is, it is possible that some PRs that have been 7633 fixed are not listed here). 7634 7635 The Go front end in the 4.7.1 release fully supports the [45]Go 1 7636 language standard. 7637 7638 GCC 4.7.2 7639 7640 This is the [46]list of problem reports (PRs) from GCC's bug tracking 7641 system that are known to be fixed in the 4.7.2 release. This list might 7642 not be complete (that is, it is possible that some PRs that have been 7643 fixed are not listed here). 7644 7645 GCC 4.7.3 7646 7647 This is the [47]list of problem reports (PRs) from GCC's bug tracking 7648 system that are known to be fixed in the 4.7.3 release. This list might 7649 not be complete (that is, it is possible that some PRs that have been 7650 fixed are not listed here). 7651 7652 GCC 4.7.4 7653 7654 This is the [48]list of problem reports (PRs) from GCC's bug tracking 7655 system that are known to be fixed in the 4.7.4 release. This list might 7656 not be complete (that is, it is possible that some PRs that have been 7657 fixed are not listed here). 7658 7659 7660 For questions related to the use of GCC, please consult these web 7661 pages and the [49]GCC manuals. If that fails, the 7662 [50]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 7663 web pages and the development of GCC are welcome on our developer 7664 list at [51]gcc (a] gcc.gnu.org. All of [52]our lists have public 7665 archives. 7666 7667 Copyright (C) [53]Free Software Foundation, Inc. Verbatim copying and 7668 distribution of this entire article is permitted in any medium, 7669 provided this notice is preserved. 7670 7671 These pages are [54]maintained by the GCC team. Last modified 7672 2019-11-28[55]. 7673 7674 References 7675 7676 1. https://gcc.gnu.org/ml/gcc-patches/2011-03/msg01263.html 7677 2. http://savannah.nongnu.org/bugs/?35407 7678 3. https://gcc.gnu.org/PR18145 7679 4. https://gcc.gnu.org/gcc-4.7/porting_to.html 7680 5. https://gcc.gnu.org/wiki/TransactionalMemory 7681 6. https://gcc.gnu.org/wiki/Atomic/GCCMM 7682 7. http://gcc.gnu.org/gcc-4.7/cxx0x_status.html 7683 8. http://gcc.gnu.org/gcc-4.7/cxx0x_status.html 7684 9. http://gcc.gnu.org/gcc-4.7/cxx0x_status.html 7685 10. http://gcc.gnu.org/gcc-4.7/cxx0x_status.html 7686 11. http://gcc.gnu.org/gcc-4.7/cxx0x_status.html 7687 12. http://gcc.gnu.org/gcc-4.7/cxx0x_status.html 7688 13. https://gcc.gnu.org/PR14258 7689 14. https://gcc.gnu.org/PR35688 7690 15. https://gcc.gnu.org/onlinedocs/gcc-4.7.4/libstdc++/manual/manual/status.html#status.iso.2011 7691 16. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfstack-arrays_007d-254 7692 17. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/Optimize-Options.html#index-Ofast-689 7693 18. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfno-protect-parens_007d-270 7694 19. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfstack-arrays_007d-254 7695 20. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfrontend-optimize_007d-275 7696 21. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Error-and-Warning-Options.html#index-g_t_0040code_007bWfunction-elimination_007d-170 7697 22. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfaggressive-function-elimination_007d-270 7698 23. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Error-and-Warning-Options.html#index-g_t_0040code_007bWreal-q-constant_007d-149 7699 24. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/SELECTED_005fREAL_005fKIND.html 7700 25. https://docs.microsoft.com/en-us/windows/win32/wer/collecting-user-mode-dumps 7701 26. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Debugging-Options.html#index-g_t_0040code_007bfno-backtrace_007d-183 7702 27. https://gcc.gnu.org/wiki/Fortran2003Status 7703 28. https://gcc.gnu.org/wiki/OOP 7704 29. https://gcc.gnu.org/wiki/Fortran2008Status 7705 30. https://gcc.gnu.org/wiki/Coarray 7706 31. https://gcc.gnu.org/wiki/CoarrayLib 7707 32. https://gcc.gnu.org/wiki/TS29113Status 7708 33. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gfortran/Fortran-Dialect-Options.html#index-g_t_0040code_007bstd_003d_007d_0040var_007bstd_007d-option-53 7709 34. https://golang.org/doc/go1 7710 35. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/Named-Address-Spaces.html 7711 36. http://nongnu.org/avr-libc/ 7712 37. https://gcc.gnu.org/PR54461 7713 38. https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/AVR-Built_002din-Functions.html 7714 39. https://sites.google.com/site/x32abi/ 7715 40. http://www.dwarfstd.org/ShowIssue.php?issue=100909.1 7716 41. http://www.dwarfstd.org/ShowIssue.php?issue=100909.2 7717 42. http://www.dwarfstd.org/ShowIssue.php?issue=140425.1 7718 43. http://www.dwarfstd.org/ShowIssue.php?issue=110722.1 7719 44. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.7.1 7720 45. https://golang.org/doc/go1 7721 46. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.7.2 7722 47. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.7.3 7723 48. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.7.4 7724 49. https://gcc.gnu.org/onlinedocs/ 7725 50. mailto:gcc-help (a] gcc.gnu.org 7726 51. mailto:gcc (a] gcc.gnu.org 7727 52. https://gcc.gnu.org/lists.html 7728 53. https://www.fsf.org/ 7729 54. https://gcc.gnu.org/about.html 7730 55. http://validator.w3.org/check/referer 7731 ====================================================================== 7732 http://gcc.gnu.org/gcc-4.6/index.html 7733 GCC 4.6 Release Series 7734 7735 (This release series is no longer supported.) 7736 7737 April 12, 2013 7738 7739 The [1]GNU project and the GCC developers are pleased to announce the 7740 release of GCC 4.6.4. 7741 7742 This release is a bug-fix release, containing fixes for regressions in 7743 GCC 4.6.3 relative to previous releases of GCC. 7744 7745 Release History 7746 7747 GCC 4.6.4 7748 April 12, 2013 ([2]changes, [3]documentation) 7749 7750 GCC 4.6.3 7751 March 1, 2012 ([4]changes, [5]documentation) 7752 7753 GCC 4.6.2 7754 October 26, 2011 ([6]changes, [7]documentation) 7755 7756 GCC 4.6.1 7757 June 27, 2011 ([8]changes, [9]documentation) 7758 7759 GCC 4.6.0 7760 March 25, 2011 ([10]changes, [11]documentation) 7761 7762 References and Acknowledgements 7763 7764 GCC used to stand for the GNU C Compiler, but since the compiler 7765 supports several other languages aside from C, it now stands for the 7766 GNU Compiler Collection. 7767 7768 A list of [12]successful builds is updated as new information becomes 7769 available. 7770 7771 The GCC developers would like to thank the numerous people that have 7772 contributed new features, improvements, bug fixes, and other changes as 7773 well as test results to GCC. This [13]amazing group of volunteers is 7774 what makes GCC successful. 7775 7776 For additional information about GCC please refer to the [14]GCC 7777 project web site or contact the [15]GCC development mailing list. 7778 7779 To obtain GCC please use [16]our mirror sites or [17]our version 7780 control system. 7781 7782 7783 For questions related to the use of GCC, please consult these web 7784 pages and the [18]GCC manuals. If that fails, the 7785 [19]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 7786 web pages and the development of GCC are welcome on our developer 7787 list at [20]gcc (a] gcc.gnu.org. All of [21]our lists have public 7788 archives. 7789 7790 Copyright (C) [22]Free Software Foundation, Inc. Verbatim copying and 7791 distribution of this entire article is permitted in any medium, 7792 provided this notice is preserved. 7793 7794 These pages are [23]maintained by the GCC team. Last modified 7795 2020-01-14[24]. 7796 7797 References 7798 7799 1. http://www.gnu.org/ 7800 2. http://gcc.gnu.org/gcc-4.6/changes.html 7801 3. https://gcc.gnu.org/onlinedocs/4.6.4/ 7802 4. http://gcc.gnu.org/gcc-4.6/changes.html 7803 5. https://gcc.gnu.org/onlinedocs/4.6.3/ 7804 6. http://gcc.gnu.org/gcc-4.6/changes.html 7805 7. https://gcc.gnu.org/onlinedocs/4.6.2/ 7806 8. http://gcc.gnu.org/gcc-4.6/changes.html 7807 9. https://gcc.gnu.org/onlinedocs/4.6.1/ 7808 10. http://gcc.gnu.org/gcc-4.6/changes.html 7809 11. https://gcc.gnu.org/onlinedocs/4.6.0/ 7810 12. http://gcc.gnu.org/gcc-4.6/buildstat.html 7811 13. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 7812 14. http://gcc.gnu.org/index.html 7813 15. mailto:gcc (a] gcc.gnu.org 7814 16. http://gcc.gnu.org/mirrors.html 7815 17. http://gcc.gnu.org/git.html 7816 18. https://gcc.gnu.org/onlinedocs/ 7817 19. mailto:gcc-help (a] gcc.gnu.org 7818 20. mailto:gcc (a] gcc.gnu.org 7819 21. https://gcc.gnu.org/lists.html 7820 22. https://www.fsf.org/ 7821 23. https://gcc.gnu.org/about.html 7822 24. http://validator.w3.org/check/referer 7823 ====================================================================== 7824 http://gcc.gnu.org/gcc-4.6/changes.html 7825 GCC 4.6 Release Series 7826 Changes, New Features, and Fixes 7827 7828 Caveats 7829 7830 * The options -b <machine> and -V <version> have been removed because 7831 they were unreliable. Instead, users should directly run 7832 <machine>-gcc when cross-compiling, or <machine>-gcc-<version> to 7833 run a different version of gcc. 7834 * GCC now has stricter checks for invalid command-line options. In 7835 particular, when gcc was called to link object files rather than 7836 compile source code, it would previously accept and ignore all 7837 options starting with --, including linker options such as 7838 --as-needed and --export-dynamic, although such options would 7839 result in errors if any source code was compiled. Such options, if 7840 unknown to the compiler, are now rejected in all cases; if the 7841 intent was to pass them to the linker, options such as 7842 -Wl,--as-needed should be used. 7843 * Versions of the GNU C library up to and including 2.11.1 included 7844 an [1]incorrect implementation of the cproj function. GCC optimizes 7845 its builtin cproj according to the behavior specified and allowed 7846 by the ISO C99 standard. If you want to avoid discrepancies between 7847 the C library and GCC's builtin transformations when using cproj in 7848 your code, use GLIBC 2.12 or later. If you are using an older GLIBC 7849 and actually rely on the incorrect behavior of cproj, then you can 7850 disable GCC's transformations using -fno-builtin-cproj. 7851 * The C-only intermodule optimization framework (IMA, enabled by 7852 -combine) has been removed in favor of the new generic link-time 7853 optimization framework (LTO) introduced in [2]GCC 4.5.0. 7854 * GCC now ships with the LGPL-licensed libquadmath library, which 7855 provides quad-precision mathematical functions for targets with a 7856 __float128 datatype. __float128 is available for targets on 32-bit 7857 x86, x86-64 and Itanium architectures. The libquadmath library is 7858 automatically built on such targets when building the Fortran 7859 compiler. 7860 * New -Wunused-but-set-variable and -Wunused-but-set-parameter 7861 warnings were added for C, C++, Objective-C and Objective-C++. 7862 These warnings diagnose variables respective parameters which are 7863 only set in the code and never otherwise used. Usually such 7864 variables are useless and often even the value assigned to them is 7865 computed needlessly, sometimes expensively. The 7866 -Wunused-but-set-variable warning is enabled by default by -Wall 7867 flag and -Wunused-but-set-parameter by -Wall -Wextra flags. 7868 * On ARM, a bug has been fixed in GCC's implementation of the AAPCS 7869 rules for the layout of vectors that could lead to wrong code being 7870 generated. Vectors larger than 8 bytes in size are now by default 7871 aligned to an 8-byte boundary. This is an ABI change: code that 7872 makes explicit use of vector types may be incompatible with binary 7873 objects built with older versions of GCC. Auto-vectorized code is 7874 not affected by this change. (This change affects GCC versions 7875 4.6.4 and later, with the exception of versions 4.7.0 and 4.7.1.) 7876 * On AVR, variables with the progmem attribute to locate data in 7877 flash memory must be qualified as const. 7878 * Support for a number of older systems and recently unmaintained or 7879 untested target ports of GCC has been declared obsolete in GCC 4.6. 7880 Unless there is activity to revive them, the next release of GCC 7881 will have their sources permanently removed. 7882 All GCC ports for the following processor architectures have been 7883 declared obsolete: 7884 + Argonaut ARC (arc-*) 7885 + National Semiconductor CRX (crx-*) 7886 + Motorola 68HC11 and 68HC12 (m68hc11-*-*, m6811-*-*, 7887 m68hc12-*-*, m6812-*-*) 7888 + Sunplus S+core (score-*) 7889 The following ports for individual systems on particular 7890 architectures have been obsoleted: 7891 + Interix (i[34567]86-*-interix3*) 7892 + NetWare x86 (i[3456x]86-*-netware*) 7893 + Generic ARM PE (arm-*-pe* other than arm*-wince-pe*) 7894 + MCore PE (mcore-*-pe*) 7895 + SH SymbianOS (sh*-*-symbianelf*) 7896 + GNU Hurd on Alpha and PowerPC (alpha*-*-gnu*, powerpc*-*-gnu*) 7897 + M68K uClinux old ABI (m68k-*-uclinuxoldabi*) 7898 + a.out NetBSD (arm*-*-netbsd*, i[34567]86-*-netbsd*, 7899 vax-*-netbsd*, but not *-*-netbsdelf*) 7900 The i[34567]86-*-pe alias for Cygwin targets has also been 7901 obsoleted; users should configure for i[34567]86-*-cygwin* instead. 7902 Certain configure options to control the set of libraries built 7903 with GCC on some targets have been obsoleted. On ARM targets, the 7904 options --disable-fpu, --disable-26bit, --disable-underscore, 7905 --disable-interwork, --disable-biendian and --disable-nofmult have 7906 been obsoleted. On MIPS targets, the options 7907 --disable-single-float, --disable-biendian and --disable-softfloat 7908 have been obsoleted. 7909 * Support has been removed for all the [3]configurations obsoleted in 7910 GCC 4.5. 7911 * More information on porting to GCC 4.6 from previous versions of 7912 GCC can be found in the [4]porting guide for this release. 7913 7914 General Optimizer Improvements 7915 7916 * A new general optimization level, -Ofast, has been introduced. It 7917 combines the existing optimization level -O3 with options that can 7918 affect standards compliance but result in better optimized code. 7919 For example, -Ofast enables -ffast-math. 7920 * Link-time optimization improvements: 7921 + The [5]Scalable Whole Program Optimizer (WHOPR) project has 7922 stabilized to the point of being usable. It has become the 7923 default mode when using the LTO optimization model. Link time 7924 optimization can now split itself into multiple parallel 7925 compilations. Parallelism is controlled with -flto=n (where n 7926 specifies the number of compilations to execute in parallel). 7927 GCC can also cooperate with a GNU make job server by 7928 specifying the -flto=jobserver option and adding + to the 7929 beginning of the Makefile rule executing the linker. 7930 Classical LTO mode can be enforced by -flto-partition=none. 7931 This may result in small code quality improvements. 7932 + A large number of bugs were fixed. GCC itself, Mozilla Firefox 7933 and other large applications can be built with LTO enabled. 7934 + The linker plugin support improvements 7935 o Linker plugin is now enabled by default when the linker 7936 is detected to have plugin support. This is the case for 7937 GNU ld 2.21.51 or newer (on ELF and Cygwin targets) and 7938 the Gold linker on ELF targets. Plugin support of the 7939 Apple linker on Darwin is not compatible with GCC. The 7940 linker plugin can also be controlled by the 7941 -fuse-linker-plugin command-line option. 7942 o Resolution information from the linker plugin is used to 7943 drive whole program assumptions. Use of the linker plugin 7944 results in more aggressive optimization on binaries and 7945 on shared libraries that use the hidden visibility 7946 attribute. Consequently the use of -fwhole-program is not 7947 necessary in addition to LTO. 7948 + Hidden symbols used from non-LTO objects now have to be 7949 explicitly annotated with externally_visible when the linker 7950 plugin is not used. 7951 + C++ inline functions and virtual tables are now privatized 7952 more aggressively, leading to better inter-procedural 7953 optimization and faster dynamic linking. 7954 + Memory usage and intermediate language streaming performance 7955 have been improved. 7956 + Static constructors and destructors from individual units are 7957 inlined into a single function. This can significantly improve 7958 startup times of large C++ applications where static 7959 constructors are very common. For example, static constructors 7960 are used when including the iostream header. 7961 + Support for the Ada language has been added. 7962 * Interprocedural optimization improvements 7963 + The interprocedural framework was re-tuned for link time 7964 optimization. Several scalability issues were resolved. 7965 + Improved auto-detection of const and pure functions. Newly, 7966 noreturn functions are auto-detected. 7967 The [6]-Wsuggest-attribute=[const|pure|noreturn] flag is 7968 available that informs users when adding attributes to headers 7969 might improve code generation. 7970 + A number of inlining heuristic improvements. In particular: 7971 o Partial inlining is now supported and enabled by default 7972 at -O2 and greater. The feature can be controlled via 7973 -fpartial-inlining. 7974 Partial inlining splits functions with short hot path to 7975 return. This allows more aggressive inlining of the hot 7976 path leading to better performance and often to code size 7977 reductions (because cold parts of functions are not 7978 duplicated). 7979 o Scalability for large compilation units was improved 7980 significantly. 7981 o Inlining of callbacks is now more aggressive. 7982 o Virtual methods are considered for inlining when the 7983 caller is inlined and devirtualization is then possible. 7984 o Inlining when optimizing for size (either in cold regions 7985 of a program or when compiling with -Os) was improved to 7986 better handle C++ programs with larger abstraction 7987 penalty, leading to smaller and faster code. 7988 + The IPA reference optimization pass detecting global variables 7989 used or modified by functions was strengthened and sped up. 7990 + Functions whose address was taken are now optimized out when 7991 all references to them are dead. 7992 + A new inter-procedural static profile estimation pass detects 7993 functions that are executed once or unlikely to be executed. 7994 Unlikely executed functions are optimized for size. Functions 7995 executed once are optimized for size except for the inner 7996 loops. 7997 + On most targets with named section support, functions used 7998 only at startup (static constructors and main), functions used 7999 only at exit and functions detected to be cold are placed into 8000 separate text segment subsections. This extends the 8001 -freorder-functions feature and is controlled by the same 8002 switch. The goal is to improve the startup time of large C++ 8003 programs. 8004 Proper function placement requires linker support. GNU ld 8005 2.21.51 on ELF targets was updated to place those functions 8006 together within the text section leading to better code 8007 locality and faster startup times of large C++ programs. The 8008 feature is also supported in the Apple linker. Support in the 8009 gold linker is planned. 8010 * A new switch -fstack-usage has been added. It makes the compiler 8011 output stack usage information for the program, on a per-function 8012 basis, in an auxiliary file. 8013 * A new switch -fcombine-stack-adjustments has been added. It can be 8014 used to enable or disable the compiler's stack-slot combining pass 8015 which before was enabled automatically at -O1 and above, but could 8016 not be controlled on its own. 8017 * A new switch -fstrict-volatile-bitfields has been added. Using it 8018 indicates that accesses to volatile bitfields should use a single 8019 access of the width of the field's type. This option can be useful 8020 for precisely defining and accessing memory-mapped peripheral 8021 registers from C or C++. 8022 8023 Compile time and memory usage improvements 8024 8025 * Datastructures used by the dataflow framework in GCC were 8026 reorganized for better memory usage and more cache locality. 8027 Compile time is improved especially on units with large functions 8028 (possibly resulting from a lot of inlining) not fitting into the 8029 processor cache. The compile time of the GCC C compiler binary with 8030 link-time optimization went down by over 10% (benchmarked on x86-64 8031 target). 8032 8033 New Languages and Language specific improvements 8034 8035 Ada 8036 8037 * Stack checking has been improved on selected architectures (Alpha, 8038 IA-32/x86-64, RS/6000 and SPARC): it now will detect stack 8039 overflows in all cases on these architectures. 8040 * Initial support for Ada 2012 has been added. 8041 8042 C family 8043 8044 * A new warning, enabled by -Wdouble-promotion, has been added that 8045 warns about cases where a value of type float is implicitly 8046 promoted to double. This is especially helpful for CPUs that handle 8047 the former in hardware, but emulate the latter in software. 8048 * A new function attribute leaf was introduced. This attribute allows 8049 better inter-procedural optimization across calls to functions that 8050 return to the current unit only via returning or exception 8051 handling. This is the case for most library functions that have no 8052 callbacks. 8053 * Support for a new data type __int128 for targets having wide enough 8054 machine-mode support. 8055 * The new function attribute callee_pop_aggregate allows to specify 8056 if the caller or callee is responsible for popping the aggregate 8057 return pointer value from the stack. 8058 * Support for selectively enabling and disabling warnings via #pragma 8059 GCC diagnostic has been added. For instance: 8060 #pragma GCC diagnostic error "-Wuninitialized" 8061 foo(a); /* error is given for this one */ 8062 #pragma GCC diagnostic push 8063 #pragma GCC diagnostic ignored "-Wuninitialized" 8064 foo(b); /* no diagnostic for this one */ 8065 #pragma GCC diagnostic pop 8066 foo(c); /* error is given for this one */ 8067 #pragma GCC diagnostic pop 8068 foo(d); /* depends on command-line options */ 8069 8070 * The -fmax-errors=N option is now supported. Using this option 8071 causes the compiler to exit after N errors have been issued. 8072 8073 C 8074 8075 * There is now experimental support for some features from the 8076 upcoming C1X revision of the ISO C standard. This support may be 8077 selected with -std=c1x, or -std=gnu1x for C1X with GNU extensions. 8078 Note that this support is experimental and may change incompatibly 8079 in future releases for consistency with changes to the C1X standard 8080 draft. The following features are newly supported as described in 8081 the N1539 draft of C1X (with changes agreed at the March 2011 WG14 8082 meeting); some other features were already supported with no 8083 compiler changes being needed, or have some support but not in full 8084 accord with N1539 (as amended). 8085 + Static assertions (_Static_assert keyword) 8086 + Typedef redefinition 8087 + New macros in <float.h> 8088 + Anonymous structures and unions 8089 * The new -fplan9-extensions option directs the compiler to support 8090 some extensions for anonymous struct fields which are implemented 8091 by the Plan 9 compiler. A pointer to a struct may be automatically 8092 converted to a pointer to an anonymous field when calling a 8093 function, in order to make the types match. An anonymous struct 8094 field whose type is a typedef name may be referred to using the 8095 typedef name. 8096 8097 C++ 8098 8099 * Improved [7]experimental support for the upcoming C++0x ISO C++ 8100 standard, including support for constexpr (thanks to Gabriel Dos 8101 Reis and Jason Merrill), nullptr (thanks to Magnus Fromreide), 8102 noexcept, unrestricted unions, range-based for loops (thanks to 8103 Rodrigo Rivas Costa), opaque enum declarations (thanks also to 8104 Rodrigo), implicitly deleted functions and implicit move 8105 constructors. 8106 * When an extern declaration within a function does not match a 8107 declaration in the enclosing context, G++ now properly declares the 8108 name within the namespace of the function rather than the namespace 8109 which was open just before the function definition ([8]c++/43145). 8110 * GCC now warns by default when casting integers to larger pointer 8111 types. These warnings can be disabled with the option 8112 -Wno-int-to-pointer-cast, which is now also available in C++. 8113 * G++ no longer optimizes using the assumption that a value of 8114 enumeration type will fall within the range specified by the 8115 standard, since that assumption is easily violated with a 8116 conversion from integer type ([9]c++/43680). The old behavior can 8117 be restored with -fstrict-enums. 8118 * The new -fnothrow-opt flag changes the semantics of a throw() 8119 exception specification to match the proposed semantics of the 8120 noexcept specification: just call terminate if an exception tries 8121 to propagate out of a function with such an exception 8122 specification. This dramatically reduces or eliminates the code 8123 size overhead from adding the exception specification. 8124 * The new -Wnoexcept flag will suggest adding a noexcept qualifier to 8125 a function that the compiler can tell doesn't throw if it would 8126 change the value of a noexcept expression. 8127 * The -Wshadow option now warns if a local variable or type 8128 declaration shadows another type in C++. Note that the compiler 8129 will not warn if a local variable shadows a struct/class/enum, but 8130 will warn if it shadows an explicit typedef. 8131 * When an identifier is not found in the current scope, G++ now 8132 offers suggestions about which identifier might have been intended. 8133 * G++ now issues clearer diagnostics for missing semicolons after 8134 class, struct, and union definitions. 8135 * G++ now issues clearer diagnostics for missing semicolons after 8136 class member declarations. 8137 * G++ now issues clearer diagnostics when a colon is used in a place 8138 where a double-colon was intended. 8139 * G++ no longer accepts mutable on reference members ([10]c++/33558). 8140 Use -fpermissive to allow the old, non-conforming behaviour. 8141 * A few mangling fixes have been made, to attribute const/volatile on 8142 function pointer types, decltype of a plain decl, and use of a 8143 function parameter in the declaration of another parameter. By 8144 default the compiler still uses the old mangling, but emits aliases 8145 with the new mangling on targets that support strong aliases. Users 8146 can switch over entirely to the new mangling with -fabi-version=5 8147 or -fabi-version=0. -Wabi will now warn about code that uses the 8148 old mangling. 8149 * In 4.6.0 and 4.6.1 G++ no longer allows objects of const-qualified 8150 type to be default initialized unless the type has a user-declared 8151 default constructor. In 4.6.2 G++ implements the proposed 8152 resolution of [11]DR 253, so default initialization is allowed if 8153 it initializes all subobjects. Code that fails to compile can be 8154 fixed by providing an initializer e.g. 8155 struct A { A(); }; 8156 struct B : A { int i; }; 8157 const B b = B(); 8158 Use -fpermissive to allow the old, non-conforming behaviour. 8159 8160 Runtime Library (libstdc++) 8161 8162 * [12]Improved experimental support for the upcoming ISO C++ 8163 standard, C++0x, including using constexpr and nullptr. 8164 * Performance improvements to the [13]Debug Mode, thanks to Franois 8165 Dumont. 8166 * Atomic operations used for reference-counting are annotated so that 8167 they can be understood by race detectors such as Helgrind, see 8168 [14]Data Race Hunting. 8169 * Most libstdc++ standard headers have been changed to no longer 8170 include the cstddef header as an implementation detail. Code that 8171 relied on that header being included as side-effect of including 8172 other standard headers will need to include cstddef explicitly. 8173 8174 Fortran 8175 8176 * On systems supporting the libquadmath library, GNU Fortran now also 8177 supports a quad-precision, kind=16 floating-point data type 8178 (REAL(16), COMPLEX(16)). As the data type is not fully supported in 8179 hardware, calculations might be one to two orders of magnitude 8180 slower than with the 4, 8 or 10 bytes floating-point data types. 8181 This change does not affect systems which support REAL(16) in 8182 hardware nor those which do not support libquadmath. 8183 * Much improved compile time for large array constructors. 8184 * In order to reduce execution time and memory consumption, use of 8185 temporary arrays in assignment expressions is avoided for many 8186 cases. The compiler now reverses loops in order to avoid generating 8187 a temporary array where possible. 8188 * Improved diagnostics, especially with -fwhole-file. 8189 * The -fwhole-file flag is now enabled by default. This improves code 8190 generation and diagnostics. It can be disabled using the deprecated 8191 -fno-whole-file flag. 8192 * Support the generation of Makefile dependencies via the [15]-M... 8193 flags of GCC; you may need to specify the -cpp option in addition. 8194 The dependencies take modules, Fortran's include, and CPP's 8195 #include into account. Note: Using -M for the module path is no 8196 longer supported, use -J instead. 8197 * The flag -Wconversion has been modified to only issue warnings 8198 where a conversion leads to information loss. This drastically 8199 reduces the number of warnings; -Wconversion is thus now enabled 8200 with -Wall. The flag -Wconversion-extra has been added and also 8201 warns about other conversions; -Wconversion-extra typically issues 8202 a huge number of warnings, most of which can be ignored. 8203 * A new command-line option -Wunused-dummy-argument warns about 8204 unused dummy arguments and is included in -Wall. Before, 8205 -Wunused-variable also warned about unused dummy arguments. 8206 * Fortran 2003 support has been extended: 8207 + Improved support for polymorphism between libraries and 8208 programs and for complicated inheritance patterns (cf. 8209 [16]object-oriented programming). 8210 + Experimental support of the ASSOCIATE construct. 8211 + In pointer assignments it is now possible to specify the lower 8212 bounds of the pointer and, for a rank-1 or a simply contiguous 8213 data-target, to remap the bounds. 8214 + Automatic (re)allocation: In intrinsic assignments to 8215 allocatable variables the left-hand side will be automatically 8216 allocated (if unallocated) or reallocated (if the shape or 8217 type parameter is different). To avoid the small performance 8218 penalty, you can use a(:) = ... instead of a = ... for arrays 8219 and character strings or disable the feature using -std=f95 8220 or -fno-realloc-lhs. 8221 + Deferred type parameter: For scalar allocatable and pointer 8222 variables the character length can be deferred. 8223 + Namelist variables with allocatable and pointer attribute and 8224 nonconstant length type parameter are supported. 8225 * Fortran 2008 support has been extended: 8226 + Experimental [17]coarray support (for one image only, i.e. 8227 num_images() == 1); use the [18]-fcoarray=single flag to 8228 enable it. 8229 + The STOP and the new ERROR STOP statements now support all 8230 constant expressions. 8231 + Support for the CONTIGUOUS attribute. 8232 + Support for ALLOCATE with MOLD. 8233 + Support for the STORAGE_SIZE intrinsic inquiry function. 8234 + Support of the NORM2 and PARITY intrinsic functions. 8235 + The following bit intrinsics were added: POPCNT and POPPAR for 8236 counting the number of 1 bits and returning the parity; BGE, 8237 BGT, BLE, and BLT for bitwise comparisons; DSHIFTL and DSHIFTR 8238 for combined left and right shifts, MASKL and MASKR for simple 8239 left and right justified masks, MERGE_BITS for a bitwise merge 8240 using a mask, SHIFTA, SHIFTL and SHIFTR for shift operations, 8241 and the transformational bit intrinsics IALL, IANY and 8242 IPARITY. 8243 + Support of the EXECUTE_COMMAND_LINE intrinsic subroutine. 8244 + Support for the IMPURE attribute for procedures, which allows 8245 for ELEMENTAL procedures without the restrictions of PURE. 8246 + Null pointers (including NULL()) and not allocated variables 8247 can be used as actual argument to optional non-pointer, 8248 non-allocatable dummy arguments, denoting an absent argument. 8249 + Non-pointer variables with TARGET attribute can be used as 8250 actual argument to POINTER dummies with INTENT(IN) 8251 + Pointers including procedure pointers and those in a derived 8252 type (pointer components) can now be initialized by a target 8253 instead of only by NULL. 8254 + The EXIT statement (with construct-name) can now be used to 8255 leave not only the DO but also the ASSOCIATE, BLOCK, IF, 8256 SELECT CASE and SELECT TYPE constructs. 8257 + Internal procedures can now be used as actual argument. 8258 + The named constants INTEGER_KINDS, LOGICAL_KINDS, REAL_KINDS 8259 and CHARACTER_KINDS of the intrinsic module ISO_FORTRAN_ENV 8260 have been added; these arrays contain the supported kind 8261 values for the respective types. 8262 + The module procedures C_SIZEOF of the intrinsic module 8263 ISO_C_BINDINGS and COMPILER_VERSION and COMPILER_OPTIONS of 8264 ISO_FORTRAN_ENV have been implemented. 8265 + Minor changes: obsolescence diagnostics for ENTRY was added 8266 for -std=f2008; a line may start with a semicolon; for 8267 internal and module procedures END can be used instead of END 8268 SUBROUTINE and END FUNCTION; SELECTED_REAL_KIND now also takes 8269 a RADIX argument; intrinsic types are supported for 8270 TYPE(intrinsic-type-spec); multiple type-bound procedures can 8271 be declared in a single PROCEDURE statement; implied-shape 8272 arrays are supported for named constants (PARAMETER). The 8273 transformational, three argument versions of BESSEL_JN and 8274 BESSEL_YN were added the elemental, two-argument version had 8275 been added in GCC 4.4; note that the transformational 8276 functions use a recurrence algorithm. 8277 8278 Go 8279 8280 Support for the [19]Go programming language has been added to GCC. It 8281 is not enabled by default when you build GCC; use the 8282 --enable-languages configure option to build it. The driver program for 8283 compiling Go code is gccgo. 8284 8285 Go is currently known to work on GNU/Linux and RTEMS. Solaris support 8286 is in progress. It may or may not work on other platforms. 8287 8288 Objective-C and Objective-C++ 8289 8290 * The -fobjc-exceptions flag is now required to enable Objective-C 8291 exception and synchronization syntax (introduced by the keywords 8292 @try, @catch, @finally and @synchronized). 8293 * A number of Objective-C 2.0 features and extensions are now 8294 supported by GCC. These features are enabled by default; you can 8295 disable them by using the new -fobjc-std=objc1 command-line option. 8296 * The Objective-C 2.0 dot-syntax is now supported. It is an 8297 alternative syntax for using getters and setters; object.count is 8298 automatically converted into [object count] or [object setCount: 8299 ...] depending on context; for example if (object.count > 0) is 8300 automatically compiled into the equivalent of if ([object count] > 8301 0) while object.count = 0; is automatically compiled into the 8302 equivalent ot [object setCount: 0];. The dot-syntax can be used 8303 with instance and class objects and with any setters or getters, no 8304 matter if they are part of a declared property or not. 8305 * Objective-C 2.0 declared properties are now supported. They are 8306 declared using the new @property keyword, and are most commonly 8307 used in conjunction with the new Objective-C 2.0 dot-syntax. The 8308 nonatomic, readonly, readwrite, assign, retain, copy, setter and 8309 getter attributes are all supported. Marking declared properties 8310 with __attribute__ ((deprecated)) is supported too. 8311 * The Objective-C 2.0 @synthesize and @dynamic keywords are 8312 supported. @synthesize causes the compiler to automatically 8313 synthesize a declared property, while @dynamic is used to disable 8314 all warnings for a declared property for which no implementation is 8315 provided at compile time. Synthesizing declared properties requires 8316 runtime support in most useful cases; to be able to use it with the 8317 GNU runtime, appropriate helper functions have been added to the 8318 GNU Objective-C runtime ABI, and are implemented by the GNU 8319 Objective-C runtime library shipped with GCC. 8320 * The Objective-C 2.0 fast enumeration syntax is supported in 8321 Objective-C. This is currently not yet available in Objective-C++. 8322 Fast enumeration requires support in the runtime, and such support 8323 has been added to the GNU Objective-C runtime library (shipped with 8324 GCC). 8325 * The Objective-C 2.0 @optional keyword is supported. It allows you 8326 to mark methods or properties in a protocol as optional as opposed 8327 to required. 8328 * The Objective-C 2.0 @package keyword is supported. It has currently 8329 the same effect as the @public keyword. 8330 * Objective-C 2.0 method attributes are supported. Currently the 8331 supported attributes are deprecated, sentinel, noreturn and format. 8332 * Objective-C 2.0 method argument attributes are supported. The most 8333 widely used attribute is unused, to mark an argument as unused in 8334 the implementation. 8335 * Objective-C 2.0 class and protocol attributes are supported. 8336 Currently the only supported attribute is deprecated. 8337 * Objective-C 2.0 class extensions are supported. A class extension 8338 has the same syntax as a category declaration with no category 8339 name, and the methods and properties declared in it are added 8340 directly to the main class. It is mostly used as an alternative to 8341 a category to add methods to a class without advertising them in 8342 the public headers, with the advantage that for class extensions 8343 the compiler checks that all the privately declared methods are 8344 actually implemented. 8345 * As a result of these enhancements, GCC can now be used to build 8346 Objective-C and Objective-C++ software that uses Foundation and 8347 other important system frameworks with the NeXT runtime on Darwin 9 8348 and Darwin 10 (OSX 10.5 and 10.6). 8349 * Many bugs in the compiler have been fixed in this release; in 8350 particular, LTO can now be used when compiling Objective-C and 8351 Objective-C++ and the parser is much more robust in dealing with 8352 invalid code. 8353 8354 Runtime Library (libobjc) 8355 8356 * The GNU Objective-C runtime library now defines the macro 8357 __GNU_LIBOBJC__ (with a value that is increased at every release 8358 where there is any change to the API) in objc/objc.h, making it 8359 easy to determine if the GNU Objective-C runtime library is being 8360 used, and if so, which version. Previous versions of the GNU 8361 Objective-C runtime library (and other Objective-C runtime 8362 libraries such as the Apple one) do not define this macro. 8363 * A new Objective-C 2.0 API, almost identical to the one implemented 8364 by the Apple Objective-C runtime, has been implemented in the GNU 8365 Objective-C runtime library. The new API hides the internals of 8366 most runtime structures but provides a more extensive set of 8367 functions to operate on them. It is much easier, for example, to 8368 create or modify classes at runtime. The new API also makes it 8369 easier to port software from Apple to GNU as almost no changes 8370 should be required. The old API is still supported for backwards 8371 compatibility; including the old objc/objc-api.h header file 8372 automatically selects the old API, while including the new 8373 objc/runtime.h header file automatically selects the new API. 8374 Support for the old API is being phased out and upgrading the 8375 software to use the new API is strongly recommended. To check for 8376 the availability of the new API, the __GNU_LIBOBJC__ macro can be 8377 used as older versions of the GNU Objective-C runtime library, 8378 which do not support the new API, do not define such a macro. 8379 * Runtime support for @synchronized has been added. 8380 * Runtime support for Objective-C 2.0 synthesized property accessors 8381 has been added. 8382 * Runtime support for Objective-C 2.0 fast enumeration has been 8383 added. 8384 8385 New Targets and Target Specific Improvements 8386 8387 ARM 8388 8389 * GCC now supports the Cortex-M4 processor implementing the v7-em 8390 version of the architecture using the option -mcpu=cortex-m4. 8391 * Scheduling descriptions for the Cortex-M4, the Neon and the 8392 floating point units of the Cortex-A9 and a pipeline description 8393 for the Cortex-A5 have been added. 8394 * Synchronization primitives such as __sync_fetch_and_add and friends 8395 are now inlined for supported architectures rather than calling 8396 into a kernel helper function. 8397 * SSA loop prefetching is enabled by default for the Cortex-A9 at 8398 -O3. 8399 * Several improvements were committed to improve code generation for 8400 the ARM architecture including a rewritten implementation for load 8401 and store multiples. 8402 * Several enhancements were committed to improve SIMD code generation 8403 for NEON by adding support for widening instructions, misaligned 8404 loads and stores, vector conditionals and support for 64 bit 8405 arithmetic. 8406 * Support was added for the Faraday cores fa526, fa606te, fa626te, 8407 fmp626te, fmp626 and fa726te and can be used with the respective 8408 names as parameters to the -mcpu= option. 8409 * Basic support was added for Cortex-A15 and is available through 8410 -mcpu=cortex-a15. 8411 * GCC for AAPCS configurations now more closely adheres to the AAPCS 8412 specification by enabling -fstrict-volatile-bitfields by default. 8413 8414 IA-32/x86-64 8415 8416 * The new -fsplit-stack option permits programs to use a 8417 discontiguous stack. This is useful for threaded programs, in that 8418 it is no longer necessary to specify the maximum stack size when 8419 creating a thread. This feature is currently only implemented for 8420 32-bit and 64-bit x86 GNU/Linux targets. 8421 * Support for emitting profiler counter calls before function 8422 prologues. This is enabled via a new command-line option -mfentry. 8423 * Optimization for the Intel Core 2 processors is now available 8424 through the -march=core2 and -mtune=core2 options. 8425 * Support for Intel Core i3/i5/i7 processors is now available through 8426 the -march=corei7 and -mtune=corei7 options. 8427 * Support for Intel Core i3/i5/i7 processors with AVX is now 8428 available through the -march=corei7-avx and -mtune=corei7-avx 8429 options. 8430 * Support for AMD Bobcat (family 14) processors is now available 8431 through the -march=btver1 and -mtune=btver1 options. 8432 * Support for AMD Bulldozer (family 15) processors is now available 8433 through the -march=bdver1 and -mtune=bdver1 options. 8434 * The default setting (when not optimizing for size) for 32-bit 8435 GNU/Linux and Darwin x86 targets has been changed to 8436 -fomit-frame-pointer. The default can be reverted to 8437 -fno-omit-frame-pointer by configuring GCC with the 8438 --enable-frame-pointer configure option. 8439 * Darwin, FreeBSD, Solaris 2, MinGW and Cygwin now all support 8440 __float128 on 32-bit and 64-bit x86 targets. 8441 * AVX floating-point arithmetic can now be enabled by default at 8442 configure time with the new --with-fpmath=avx option. 8443 * The SSA loop prefetching pass is enabled when using -O3 when 8444 optimizing for CPUs where prefetching is beneficial (AMD CPUs newer 8445 than K6). 8446 * Support for TBM (Trailing Bit Manipulation) built-in functions and 8447 code generation is available via -mtbm. 8448 * Support for AMD's BMI (Bit Manipulation) built-in functions and 8449 code generation is available via -mbmi. 8450 8451 MicroBlaze 8452 8453 * Support has been added for the Xilinx MicroBlaze softcore processor 8454 (microblaze-elf) embedded target. This configurable processor is 8455 supported on several Xilinx Spartan and Virtex FPGAs. 8456 8457 MIPS 8458 8459 * GCC now supports the Loongson 3A processor. Its canonical -march= 8460 and -mtune= name is loongson3a. 8461 8462 MN10300 / AM33 8463 8464 * The inline assembly register constraint "A" has been renamed "c". 8465 This constraint is used to select a floating-point register that 8466 can be used as the destination of a multiply-accumulate 8467 instruction. 8468 * New inline assembly register constraints "A" and "D" have been 8469 added. These constraint letters resolve to all general registers 8470 when compiling for AM33, and resolve to address registers only or 8471 data registers only when compiling for MN10300. 8472 * The MDR register is represented in the compiler. One can access the 8473 register via the "z" constraint in inline assembly. It can be 8474 marked as clobbered or used as a local register variable via the 8475 "mdr" name. The compiler uses the RETF instruction if the function 8476 does not modify the MDR register, so it is important that inline 8477 assembly properly annotate any usage of the register. 8478 8479 PowerPC/PowerPC64 8480 8481 * GCC now supports the Applied Micro Titan processor with 8482 -mcpu=titan. 8483 * The -mrecip option has been added, which indicates whether the 8484 reciprocal and reciprocal square root instructions should be used. 8485 * The -mveclibabi=mass option can be used to enable the compiler to 8486 autovectorize mathematical functions using the Mathematical 8487 Acceleration Subsystem library. 8488 * The -msingle-pic-base option has been added, which instructs the 8489 compiler to avoid loading the PIC base register in function 8490 prologues. The PIC base register must be initialized by the runtime 8491 system. 8492 * The -mblock-move-inline-limit option has been added, which enables 8493 the user to control the maximum size of inlined memcpy calls and 8494 similar. 8495 * PowerPC64 GNU/Linux support for applications requiring a large TOC 8496 section has been improved. A new command-line option, 8497 -mcmodel=MODEL, controls this feature; valid values for MODEL are 8498 small, medium, or large. 8499 * The Altivec builtin functions vec_ld and vec_st have been modified 8500 to generate the Altivec memory instructions LVX and STVX, even if 8501 the -mvsx option is used. In the initial GCC 4.5 release, these 8502 builtin functions were changed to generate VSX memory reference 8503 instructions instead of Altivec memory instructions, but there are 8504 differences between the two instructions. If the VSX instruction 8505 set is available, you can now use the new builtin functions 8506 vec_vsx_ld and vec_vsx_st which always generates the VSX memory 8507 instructions. 8508 * The GCC compiler on AIX now defaults to a process layout with a 8509 larger data space allowing larger programs to be compiled. 8510 * The GCC long double type on AIX 6.1 and above has reverted to 64 8511 bit double precision, matching the AIX XL compiler default, because 8512 of missing C99 symbols required by the GCC runtime. 8513 * The default processor scheduling model and tuning for PowerPC64 8514 GNU/Linux and for AIX 6.1 and above now is POWER7. 8515 * Starting with GCC 4.6.1, vectors of type vector long long or vector 8516 long are passed and returned in the same method as other vectors 8517 with the VSX instruction set. Previously the GCC compiler did not 8518 adhere to the ABI for 128-bit vectors with 64-bit integer base 8519 types (PR 48857). This is also fixed in the GCC 4.5.4 release. 8520 8521 S/390, zSeries and System z9/z10, IBM zEnterprise z196 8522 8523 * Support for the zEnterprise z196 processor has been added. When 8524 using the -march=z196 option, the compiler will generate code 8525 making use of the following instruction facilities: 8526 + Conditional load/store 8527 + Distinct-operands 8528 + Floating-point-extension 8529 + Interlocked-access 8530 + Population-count 8531 The -mtune=z196 option avoids the compare and branch instructions 8532 as well as the load address instruction with an index register as 8533 much as possible and performs instruction scheduling appropriate 8534 for the new out-of-order pipeline architecture. 8535 * When using the -m31 -mzarch options the generated code still 8536 conforms to the 32-bit ABI but uses the general purpose registers 8537 as 64-bit registers internally. This requires a Linux kernel saving 8538 the whole 64-bit registers when doing a context switch. Kernels 8539 providing that feature indicate that by the 'highgprs' string in 8540 /proc/cpuinfo. 8541 * The SSA loop prefetching pass is enabled when using -O3. 8542 8543 SPARC 8544 8545 * GCC now supports the LEON series of SPARC V8 processors. The code 8546 generated by the compiler can either be tuned to it by means of the 8547 --with-tune=leon configure option and -mtune=leon compilation 8548 option, or the compiler can be built for the sparc-leon-{elf,linux} 8549 and sparc-leon3-{elf,linux} targets directly. 8550 * GCC has stopped sign/zero-extending parameter registers in the 8551 callee for functions taking parameters with sub-word size in 32-bit 8552 mode, since this is redundant with the specification of the ABI. 8553 GCC has never done so in 64-bit mode since this is also redundant. 8554 * The command-line option -mfix-at697f has been added to enable the 8555 documented workaround for the single erratum of the Atmel AT697F 8556 processor. 8557 8558 Operating Systems 8559 8560 Android 8561 8562 * GCC now supports the Bionic C library and provides a convenient way 8563 of building native libraries and applications for the Android 8564 platform. Refer to the documentation of the -mandroid and -mbionic 8565 options for details on building native code. At the moment, Android 8566 support is enabled only for ARM. 8567 8568 Darwin/Mac OS X 8569 8570 * General 8571 + Initial support for CFString types has been added. 8572 This allows GCC to build projects including the system Core 8573 Foundation frameworks. The GCC Objective-C family supports 8574 CFString "toll-free bridged" as per the Mac OS X system tools. 8575 CFString is also recognized in the context of format 8576 attributes and arguments (see the documentation for format 8577 attributes for limitations). At present, 8-bit character types 8578 are supported. 8579 + Object file size reduction. 8580 The Darwin zeroed memory allocators have been re-written to 8581 make more use of .zerofill sections. For non-debug code, this 8582 can reduce object file size significantly. 8583 + Objective-C family 64-bit support (NeXT ABI 2). 8584 Initial support has been added to support 64-bit Objective-C 8585 code using the Darwin/OS X native (NeXT) runtime. ABI version 8586 2 will be selected automatically when 64-bit code is built. 8587 + Objective-C family 32-bit ABI 1. 8588 For 32-bit code ABI 1 is also now also allowed. At present it 8589 must be selected manually using -fobjc-abi-version=1 where 8590 applicable - i.e. on Darwin 9/10 (OS X 10.5/10.6). 8591 * x86 Architecture 8592 + The -mdynamic-no-pic option has been enabled. 8593 Code supporting -mdynamic-no-pic optimization has been added 8594 and is applicable to -m32 builds. The compiler bootstrap uses 8595 the option where appropriate. 8596 + The default value for -mtune= has been changed. 8597 Since Darwin systems are primarily Xeon, Core-2 or similar the 8598 default tuning has been changed to -mtune=core2. 8599 + Enable 128-bit long double (__float128) support on Darwin. 8600 * PPC Architecture 8601 + Darwin64 ABI. 8602 Several significant bugs have been fixed, such that GCC now 8603 produces code compatible with the Darwin64 PowerPC ABI. 8604 + libffi and boehm-gc. 8605 The Darwin ports of the libffi and boehm-gc libraries have 8606 been upgraded to include a Darwin64 implementation. This means 8607 that powerpc*-*-darwin9 platforms may now, for example, build 8608 Java applications with -m64 enabled. 8609 + Plug-in support has been enabled. 8610 + The -fsection-anchors option is now available although, 8611 presently, not heavily tested. 8612 8613 Solaris 2 8614 8615 New Features 8616 8617 * Support symbol versioning with the Sun linker. 8618 * Allow libstdc++ to leverage full ISO C99 support on Solaris 10+. 8619 * Support thread-local storage (TLS) with the Sun assembler on 8620 Solaris 2/x86. 8621 * Support TLS on Solaris 8/9 if prerequisites are met. 8622 * Support COMDAT group with the GNU assembler and recent Sun linker. 8623 * Support the Sun assembler visibility syntax. 8624 * Default Solaris 2/x86 to -march=pentium4 (Solaris 10+) resp. 8625 -march=pentiumpro (Solaris 8/9). 8626 * Don't use SSE on Solaris 8/9 x86 by default. 8627 * Enable 128-bit long double (__float128) support on Solaris 2/x86. 8628 8629 ABI Change 8630 8631 * Change the ABI for returning 8-byte vectors like __m64 in MMX 8632 registers on Solaris 10+/x86 to match the Sun Studio 12.1+ 8633 compilers. This is an incompatible change. If you use such types, 8634 you must either recompile all your code with the new compiler or 8635 use the new -mvect8-ret-in-mem option to remain compatible with 8636 previous versions of GCC and Sun Studio. 8637 8638 Windows x86/x86_64 8639 8640 * Initial support for decimal floating point. 8641 * Support for the __thiscall calling-convention. 8642 * Support for hot-patchable function prologues via the 8643 ms_hook_prologue attribute for x86_64 in addition to 32-bit x86. 8644 * Improvements of stack-probing and stack-allocation mechanisms. 8645 * Support of push/pop-macro pragma as preprocessor command. 8646 With #pragma push_macro("macro-name") the current definition of 8647 macro-name is saved and can be restored with #pragma 8648 pop_macro("macro-name") to its saved definition. 8649 * Enable 128-bit long double (__float128) support on MinGW and 8650 Cygwin. 8651 8652 Other significant improvements 8653 8654 Installation changes 8655 8656 * An install-strip make target is provided that installs stripped 8657 executables, and may install libraries with unneeded or debugging 8658 sections stripped. 8659 * On Power7 systems, there is a potential problem if you build the 8660 GCC compiler with a host compiler using options that enable the VSX 8661 instruction set generation. If the host compiler has been patched 8662 so that the vec_ld and vec_st builtin functions generate Altivec 8663 memory instructions instead of VSX memory instructions, then you 8664 should be able to build the compiler with VSX instruction 8665 generation. 8666 8667 Changes for GCC Developers 8668 8669 Note: these changes concern developers that develop GCC itself or 8670 software that integrates with GCC, such as plugins, and not the general 8671 GCC users. 8672 * The gengtype utility, which previously was internal to the GCC 8673 build process, has been enchanced to provide GC root information 8674 for plugins as necessary. 8675 * The old GC allocation interface of ggc_alloc and friends was 8676 replaced with a type-safe alternative. 8677 8678 GCC 4.6.1 8679 8680 This is the [20]list of problem reports (PRs) from GCC's bug tracking 8681 system that are known to be fixed in the 4.6.1 release. This list might 8682 not be complete (that is, it is possible that some PRs that have been 8683 fixed are not listed here). 8684 8685 GCC 4.6.2 8686 8687 This is the [21]list of problem reports (PRs) from GCC's bug tracking 8688 system that are known to be fixed in the 4.6.2 release. This list might 8689 not be complete (that is, it is possible that some PRs that have been 8690 fixed are not listed here). 8691 8692 GCC 4.6.3 8693 8694 This is the [22]list of problem reports (PRs) from GCC's bug tracking 8695 system that are known to be fixed in the 4.6.3 release. This list might 8696 not be complete (that is, it is possible that some PRs that have been 8697 fixed are not listed here). 8698 8699 GCC 4.6.4 8700 8701 This is the [23]list of problem reports (PRs) from GCC's bug tracking 8702 system that are known to be fixed in the 4.6.4 release. This list might 8703 not be complete (that is, it is possible that some PRs that have been 8704 fixed are not listed here). 8705 8706 8707 For questions related to the use of GCC, please consult these web 8708 pages and the [24]GCC manuals. If that fails, the 8709 [25]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 8710 web pages and the development of GCC are welcome on our developer 8711 list at [26]gcc (a] gcc.gnu.org. All of [27]our lists have public 8712 archives. 8713 8714 Copyright (C) [28]Free Software Foundation, Inc. Verbatim copying and 8715 distribution of this entire article is permitted in any medium, 8716 provided this notice is preserved. 8717 8718 These pages are [29]maintained by the GCC team. Last modified 8719 2019-11-28[30]. 8720 8721 References 8722 8723 1. https://sourceware.org/bugzilla/show_bug.cgi?id=10401 8724 2. http://gcc.gnu.org/gcc-4.5/changes.html 8725 3. http://gcc.gnu.org/gcc-4.5/changes.html#obsoleted 8726 4. http://gcc.gnu.org/gcc-4.6/porting_to.html 8727 5. http://gcc.gnu.org/projects/lto/whopr.pdf 8728 6. https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#Warning-Options 8729 7. http://gcc.gnu.org/gcc-4.6/cxx0x_status.html 8730 8. https://gcc.gnu.org/PR43145 8731 9. https://gcc.gnu.org/PR43680 8732 10. https://gcc.gnu.org/PR33558 8733 11. http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#253 8734 12. https://gcc.gnu.org/onlinedocs/gcc-4.6.4/libstdc++/manual/manual/status.html#status.iso.200x 8735 13. https://gcc.gnu.org/onlinedocs/libstdc++/manual/debug_mode.html 8736 14. https://gcc.gnu.org/onlinedocs/libstdc++/manual/debug.html#debug.races 8737 15. https://gcc.gnu.org/onlinedocs/gcc/Preprocessor-Options.html 8738 16. https://gcc.gnu.org/wiki/OOP 8739 17. https://gcc.gnu.org/wiki/Coarray 8740 18. https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfcoarray_007d-233 8741 19. https://golang.org/ 8742 20. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.6.1 8743 21. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.6.2 8744 22. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.6.3 8745 23. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.6.4 8746 24. https://gcc.gnu.org/onlinedocs/ 8747 25. mailto:gcc-help (a] gcc.gnu.org 8748 26. mailto:gcc (a] gcc.gnu.org 8749 27. https://gcc.gnu.org/lists.html 8750 28. https://www.fsf.org/ 8751 29. https://gcc.gnu.org/about.html 8752 30. http://validator.w3.org/check/referer 8753 ====================================================================== 8754 http://gcc.gnu.org/gcc-4.5/index.html 8755 GCC 4.5 Release Series 8756 8757 (This release series is no longer supported.) 8758 8759 Jul 2, 2012 8760 8761 The [1]GNU project and the GCC developers are pleased to announce the 8762 release of GCC 4.5.4. 8763 8764 This release is a bug-fix release, containing fixes for regressions in 8765 GCC 4.5.3 relative to previous releases of GCC. 8766 8767 Release History 8768 8769 GCC 4.5.4 8770 Jul 2, 2012 ([2]changes) 8771 8772 GCC 4.5.3 8773 Apr 28, 2011 ([3]changes) 8774 8775 GCC 4.5.2 8776 Dec 16, 2010 ([4]changes) 8777 8778 GCC 4.5.1 8779 Jul 31, 2010 ([5]changes) 8780 8781 GCC 4.5.0 8782 April 14, 2010 ([6]changes) 8783 8784 References and Acknowledgements 8785 8786 GCC used to stand for the GNU C Compiler, but since the compiler 8787 supports several other languages aside from C, it now stands for the 8788 GNU Compiler Collection. 8789 8790 A list of [7]successful builds is updated as new information becomes 8791 available. 8792 8793 The GCC developers would like to thank the numerous people that have 8794 contributed new features, improvements, bug fixes, and other changes as 8795 well as test results to GCC. This [8]amazing group of volunteers is 8796 what makes GCC successful. 8797 8798 For additional information about GCC please refer to the [9]GCC project 8799 web site or contact the [10]GCC development mailing list. 8800 8801 To obtain GCC please use [11]our mirror sites or [12]our version 8802 control system. 8803 8804 8805 For questions related to the use of GCC, please consult these web 8806 pages and the [13]GCC manuals. If that fails, the 8807 [14]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 8808 web pages and the development of GCC are welcome on our developer 8809 list at [15]gcc (a] gcc.gnu.org. All of [16]our lists have public 8810 archives. 8811 8812 Copyright (C) [17]Free Software Foundation, Inc. Verbatim copying and 8813 distribution of this entire article is permitted in any medium, 8814 provided this notice is preserved. 8815 8816 These pages are [18]maintained by the GCC team. Last modified 8817 2020-01-14[19]. 8818 8819 References 8820 8821 1. http://www.gnu.org/ 8822 2. http://gcc.gnu.org/gcc-4.5/changes.html 8823 3. http://gcc.gnu.org/gcc-4.5/changes.html 8824 4. http://gcc.gnu.org/gcc-4.5/changes.html 8825 5. http://gcc.gnu.org/gcc-4.5/changes.html 8826 6. http://gcc.gnu.org/gcc-4.5/changes.html 8827 7. http://gcc.gnu.org/gcc-4.5/buildstat.html 8828 8. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 8829 9. http://gcc.gnu.org/index.html 8830 10. mailto:gcc (a] gcc.gnu.org 8831 11. http://gcc.gnu.org/mirrors.html 8832 12. http://gcc.gnu.org/git.html 8833 13. https://gcc.gnu.org/onlinedocs/ 8834 14. mailto:gcc-help (a] gcc.gnu.org 8835 15. mailto:gcc (a] gcc.gnu.org 8836 16. https://gcc.gnu.org/lists.html 8837 17. https://www.fsf.org/ 8838 18. https://gcc.gnu.org/about.html 8839 19. http://validator.w3.org/check/referer 8840 ====================================================================== 8841 http://gcc.gnu.org/gcc-4.5/changes.html 8842 GCC 4.5 Release Series 8843 Changes, New Features, and Fixes 8844 8845 Caveats 8846 8847 * GCC now requires the [1]MPC library in order to build. See the 8848 [2]prerequisites page for version requirements. 8849 * Support for a number of older systems and recently unmaintained or 8850 untested target ports of GCC has been declared obsolete in GCC 4.5. 8851 Unless there is activity to revive them, the next release of GCC 8852 will have their sources permanently removed. 8853 The following ports for individual systems on particular 8854 architectures have been obsoleted: 8855 + IRIX releases before 6.5 (mips-sgi-irix5*, 8856 mips-sgi-irix6.[0-4]) 8857 + Solaris 7 (*-*-solaris2.7) 8858 + Tru64 UNIX releases before V5.1 (alpha*-dec-osf4*, 8859 alpha-dec-osf5.0*) 8860 + Details for the IRIX, Solaris 7, and Tru64 UNIX obsoletions 8861 can be found in the [3]announcement. 8862 Support for the classic POWER architecture implemented in the 8863 original RIOS and RIOS2 processors of the old IBM RS/6000 product 8864 line has been obsoleted in the rs6000 port. This does not affect 8865 the new generation Power and PowerPC architectures. 8866 * Support has been removed for all the [4]configurations obsoleted in 8867 GCC 4.4. 8868 * Support has been removed for the protoize and unprotoize utilities, 8869 obsoleted in GCC 4.4. 8870 * Support has been removed for tuning for Itanium1 (Merced) variants. 8871 Note that code tuned for Itanium2 should also run correctly on 8872 Itanium1. 8873 * GCC now generates unwind info also for epilogues. DWARF debuginfo 8874 generated by GCC now uses more features of DWARF3 than before, and 8875 also some DWARF4 features. GDB older than 7.0 is not able to handle 8876 either of these, so to debug GCC 4.5 generated binaries or 8877 libraries GDB 7.0 or later is needed. You can disable use of DWARF4 8878 features with the -gdwarf-3 -gstrict-dwarf options, or use 8879 -gdwarf-2 -gstrict-dwarf to restrict GCC to just DWARF2, but 8880 epilogue unwind info is emitted unconditionally whenever unwind 8881 info is emitted. 8882 * On x86 targets, code containing floating-point calculations may run 8883 significantly more slowly when compiled with GCC 4.5 in strict C99 8884 conformance mode than they did with earlier GCC versions. This is 8885 due to stricter standard conformance of the compiler and can be 8886 avoided by using the option -fexcess-precision=fast; also see 8887 [5]below. 8888 * The function attribute noinline no longer prevents GCC from cloning 8889 the function. A new attribute noclone has been introduced for this 8890 purpose. Cloning a function means that it is duplicated and the new 8891 copy is specialized for certain contexts (for example when a 8892 parameter is a known constant). 8893 8894 General Optimizer Improvements 8895 8896 * The -save-temps now takes an optional argument. The -save-temps and 8897 -save-temps=cwd switches write the temporary files in the current 8898 working directory based on the original source file. The 8899 -save-temps=obj switch will write files into the directory 8900 specified with the -o option, and the intermediate filenames are 8901 based on the output file. This will allow the user to get the 8902 compiler intermediate files when doing parallel builds without two 8903 builds of the same filename located in different directories from 8904 interfering with each other. 8905 * Debugging dumps are now created in the same directory as the object 8906 file rather than in the current working directory. This allows the 8907 user to get debugging dumps when doing parallel builds without two 8908 builds of the same filename interfering with each other. 8909 * GCC has been integrated with the MPC library. This allows GCC to 8910 evaluate complex arithmetic at compile time [6]more accurately. It 8911 also allows GCC to evaluate calls to complex built-in math 8912 functions having constant arguments and replace them at compile 8913 time with their mathematically equivalent results. In doing so, GCC 8914 can generate correct results regardless of the math library 8915 implementation or floating point precision of the host platform. 8916 This also allows GCC to generate identical results regardless of 8917 whether one compiles in native or cross-compile configurations to a 8918 particular target. The following built-in functions take advantage 8919 of this new capability: cacos, cacosh, casin, casinh, catan, 8920 catanh, ccos, ccosh, cexp, clog, cpow, csin, csinh, csqrt, ctan, 8921 and ctanh. The float and long double variants of these functions 8922 (e.g. csinf and csinl) are also handled. 8923 * A new link-time optimizer has been added ([7]-flto). When this 8924 option is used, GCC generates a bytecode representation of each 8925 input file and writes it to specially-named sections in each object 8926 file. When the object files are linked together, all the function 8927 bodies are read from these named sections and instantiated as if 8928 they had been part of the same translation unit. This enables 8929 interprocedural optimizations to work across different files (and 8930 even different languages), potentially improving the performance of 8931 the generated code. To use the link-timer optimizer, -flto needs to 8932 be specified at compile time and during the final link. If the 8933 program does not require any symbols to be exported, it is possible 8934 to combine -flto and the experimental [8]-fwhopr with 8935 [9]-fwhole-program to allow the interprocedural optimizers to use 8936 more aggressive assumptions. 8937 * The automatic parallelization pass was enhanced to support 8938 parallelization of outer loops. 8939 * Automatic parallelization can be enabled as part of Graphite. In 8940 addition to -ftree-parallelize-loops=, specify 8941 -floop-parallelize-all to enable the Graphite-based optimization. 8942 * The infrastructure for optimizing based on [10]restrict qualified 8943 pointers has been rewritten and should result in code generation 8944 improvements. Optimizations based on restrict qualified pointers 8945 are now also available when using -fno-strict-aliasing. 8946 * There is a new optimization pass that attempts to change prototype 8947 of functions to avoid unused parameters, pass only relevant parts 8948 of structures and turn arguments passed by reference to arguments 8949 passed by value when possible. It is enabled by -O2 and above as 8950 well as -Os and can be manually invoked using the new command-line 8951 switch -fipa-sra. 8952 * GCC now optimize exception handling code. In particular cleanup 8953 regions that are proved to not have any effect are optimized out. 8954 8955 New Languages and Language specific improvements 8956 8957 All languages 8958 8959 * The -fshow-column option is now on by default. This means error 8960 messages now have a column associated with them. 8961 8962 Ada 8963 8964 * Compilation of programs heavily using discriminated record types 8965 with variant parts has been sped up and generates more compact 8966 code. 8967 * Stack checking now works reasonably well on most plaforms. In some 8968 specific cases, stack overflows may still fail to be detected, but 8969 a compile-time warning will be issued for these cases. 8970 8971 C family 8972 8973 * If a header named in a #include directive is not found, the 8974 compiler exits immediately. This avoids a cascade of errors arising 8975 from declarations expected to be found in that header being 8976 missing. 8977 * A new built-in function __builtin_unreachable() has been added that 8978 tells the compiler that control will never reach that point. It may 8979 be used after asm statements that terminate by transferring control 8980 elsewhere, and in other places that are known to be unreachable. 8981 * The -Wlogical-op option now warns for logical expressions such as 8982 (c == 1 && c == 2) and (c != 1 || c != 2), which are likely to be 8983 mistakes. This option is disabled by default. 8984 * An asm goto feature has been added to allow asm statements that 8985 jump to C labels. 8986 * C++0x raw strings are supported for C++ and for C with -std=gnu99. 8987 * The deprecated attribute now takes an optional string argument, for 8988 example, __attribute__((deprecated("text string"))), that will be 8989 printed together with the deprecation warning. 8990 8991 C 8992 8993 * The -Wenum-compare option, which warns when comparing values of 8994 different enum types, now works for C. It formerly only worked for 8995 C++. This warning is enabled by -Wall. It may be avoided by using a 8996 type cast. 8997 * The -Wcast-qual option now warns about casts which are unsafe in 8998 that they permit const-correctness to be violated without further 8999 warnings. Specifically, it warns about cases where a qualifier is 9000 added when all the lower types are not const. For example, it warns 9001 about a cast from char ** to const char **. 9002 * The -Wc++-compat option is significantly improved. It issues new 9003 warnings for: 9004 + Using C++ reserved operator names as identifiers. 9005 + Conversions to enum types without explicit casts. 9006 + Using va_arg with an enum type. 9007 + Using different enum types in the two branches of ?:. 9008 + Using ++ or -- on a variable of enum type. 9009 + Using the same name as both a struct, union or enum tag and a 9010 typedef, unless the typedef refers to the tagged type itself. 9011 + Using a struct, union, or enum which is defined within another 9012 struct or union. 9013 + A struct field defined using a typedef if there is a field in 9014 the struct, or an enclosing struct, whose name is the typedef 9015 name. 9016 + Duplicate definitions at file scope. 9017 + Uninitialized const variables. 9018 + A global variable with an anonymous struct, union, or enum 9019 type. 9020 + Using a string constant to initialize a char array whose size 9021 is the length of the string. 9022 * The new -Wjump-misses-init option warns about cases where a goto or 9023 switch skips the initialization of a variable. This sort of branch 9024 is an error in C++ but not in C. This warning is enabled by 9025 -Wc++-compat. 9026 * GCC now ensures that a C99-conforming <stdint.h> is present on most 9027 targets, and uses information about the types in this header to 9028 implement the Fortran bindings to those types. GCC does not ensure 9029 the presence of such a header, and does not implement the Fortran 9030 bindings, on the following targets: NetBSD, VxWorks, VMS, 9031 SymbianOS, WinCE, LynxOS, Netware, QNX, Interix, TPF. 9032 * GCC now implements C90- and C99-conforming rules for constant 9033 expressions. This may cause warnings or errors for some code using 9034 expressions that can be folded to a constant but are not constant 9035 expressions as defined by ISO C. 9036 * All known target-independent C90 and C90 Amendment 1 conformance 9037 bugs, and all known target-independent C99 conformance bugs not 9038 related to floating point or extended identifiers, have been fixed. 9039 * The C decimal floating point support now includes support for the 9040 FLOAT_CONST_DECIMAL64 pragma. 9041 * The named address space feature from ISO/IEC TR 18037 is now 9042 supported. This is currently only implemented for the SPU 9043 processor. 9044 9045 C++ 9046 9047 * Improved [11]experimental support for the upcoming C++0x ISO C++ 9048 standard, including support for raw strings, lambda expressions and 9049 explicit type conversion operators. 9050 * When printing the name of a class template specialization, G++ will 9051 now omit any template arguments which come from default template 9052 arguments. This behavior (and the pretty-printing of function 9053 template specializations as template signature and arguments) can 9054 be disabled with the -fno-pretty-templates option. 9055 * Access control is now applied to typedef names used in a template, 9056 which may cause G++ to reject some ill-formed code that was 9057 accepted by earlier releases. The -fno-access-control option can be 9058 used as a temporary workaround until the code is corrected. 9059 * Compilation time for code that uses templates should now scale 9060 linearly with the number of instantiations rather than 9061 quadratically, as template instantiations are now looked up using 9062 hash tables. 9063 * Declarations of functions that look like builtin declarations of 9064 library functions are only considered to be redeclarations if they 9065 are declared with extern "C". This may cause problems with code 9066 that omits extern "C" on hand-written declarations of C library 9067 functions such as abort or memcpy. Such code is ill-formed, but was 9068 accepted by earlier releases. 9069 * Diagnostics that used to complain about passing non-POD types to 9070 ... or jumping past the declaration of a non-POD variable now check 9071 for triviality rather than PODness, as per C++0x. 9072 * In C++0x mode local and anonymous classes are now allowed as 9073 template arguments, and in declarations of variables and functions 9074 with linkage, so long as any such declaration that is used is also 9075 defined ([12]DR 757). 9076 * Labels may now have attributes, as has been permitted for a while 9077 in C. This is only permitted when the label definition and the 9078 attribute specifier is followed by a semicoloni.e., the label 9079 applies to an empty statement. The only useful attribute for a 9080 label is unused. 9081 * G++ now implements [13]DR 176. Previously G++ did not support using 9082 the injected-class-name of a template base class as a type name, 9083 and lookup of the name found the declaration of the template in the 9084 enclosing scope. Now lookup of the name finds the 9085 injected-class-name, which can be used either as a type or as a 9086 template, depending on whether or not the name is followed by a 9087 template argument list. As a result of this change, some code that 9088 was previously accepted may be ill-formed because 9089 1. The injected-class-name is not accessible because it's from a 9090 private base, or 9091 2. The injected-class-name cannot be used as an argument for a 9092 template template parameter. 9093 In either of these cases, the code can be fixed by adding a 9094 nested-name-specifier to explicitly name the template. The first 9095 can be worked around with -fno-access-control; the second is only 9096 rejected with -pedantic. 9097 * A new standard mangling for SIMD vector types has been added, to 9098 avoid name clashes on systems with vectors of varying length. By 9099 default the compiler still uses the old mangling, but emits aliases 9100 with the new mangling on targets that support strong aliases. Users 9101 can switch over entirely to the new mangling with -fabi-version=4 9102 or -fabi-version=0. -Wabi will now warn about code that uses the 9103 old mangling. 9104 * The command-line option -ftemplate-depth-N is now written as 9105 -ftemplate-depth=N and the old form is deprecated. 9106 * Conversions between NULL and non-pointer types are now warned by 9107 default. The new option -Wno-conversion-null disables these 9108 warnings. Previously these warnings were only available when using 9109 -Wconversion explicitly. 9110 9111 Runtime Library (libstdc++) 9112 9113 * Improved experimental support for the upcoming ISO C++ standard, 9114 C++0x, including: 9115 + Support for <future>, <functional>, and <random>. 9116 + Existing facilities now exploit explicit operators and the 9117 newly implemented core C++0x features. 9118 + The header <cstdatomic> has been renamed to <atomic>. 9119 * An experimental [14]profile mode has been added. This is an 9120 implementation of many C++ standard library constructs with an 9121 additional analysis layer that gives performance improvement advice 9122 based on recognition of suboptimal usage patterns. For example, 9123 #include <vector> 9124 int main() 9125 { 9126 std::vector<int> v; 9127 for (int k = 0; k < 1024; ++k) 9128 v.insert(v.begin(), k); 9129 } 9130 9131 When instrumented via the profile mode, can return suggestions 9132 about the initial size and choice of the container used as follows: 9133 vector-to-list: improvement = 5: call stack = 0x804842c ... 9134 : advice = change std::vector to std::list 9135 vector-size: improvement = 3: call stack = 0x804842c ... 9136 : advice = change initial container size from 0 to 1024 9137 9138 These constructs can be substituted for the normal libstdc++ 9139 constructs on a piecemeal basis, or all existing components can be 9140 transformed via the -D_GLIBCXX_PROFILE macro. 9141 * [15]Support for decimal floating-point arithmetic (aka ISO C++ TR 9142 24733) has been added. This support is in header file 9143 <decimal/decimal>, uses namespace std::decimal, and includes 9144 classes decimal32, decimal64, and decimal128. 9145 * Sources have been audited for application of function attributes 9146 nothrow, const, pure, and noreturn. 9147 * Python pretty-printers have been added for many standard library 9148 components that simplify the internal representation and present a 9149 more intuitive view of components when used with 9150 appropriately-advanced versions of GDB. For more information, 9151 please consult the more [16]detailed description. 9152 * The default behavior for comparing typeinfo names has changed, so 9153 in <typeinfo>, __GXX_MERGED_TYPEINFO_NAMES now defaults to zero. 9154 * The new -static-libstdc++ option directs g++ to link the C++ 9155 library statically, even if the default would normally be to link 9156 it dynamically. 9157 9158 Fortran 9159 9160 * The COMMON default padding has been changed instead of adding the 9161 padding before a variable it is now added afterwards, which 9162 increases the compatibility with other vendors and helps to obtain 9163 the correct output in some cases. Cf. also the -falign-commons 9164 option ([17]added in 4.4). 9165 * The -finit-real= option now also supports the value snan for 9166 signaling not-a-number; to be effective, one additionally needs to 9167 enable trapping (e.g. via -ffpe-trap=). Note: Compile-time 9168 optimizations can turn a signaling NaN into a quiet one. 9169 * The new option -fcheck= has been added with the options bounds, 9170 array-temps, do, pointer, and recursive. The bounds and array-temps 9171 options are equivalent to -fbounds-check and 9172 -fcheck-array-temporaries. The do option checks for invalid 9173 modification of loop iteration variables, and the recursive option 9174 tests for recursive calls to subroutines/functions which are not 9175 marked as recursive. With pointer pointer association checks in 9176 calls are performed; however, neither undefined pointers nor 9177 pointers in expressions are handled. Using -fcheck=all enables all 9178 these run-time checks. 9179 * The run-time checking -fcheck=bounds now warns about invalid string 9180 lengths of character dummy arguments. Additionally, more 9181 compile-time checks have been added. 9182 * The new option [18]-fno-protect-parens has been added; if set, the 9183 compiler may reorder REAL and COMPLEX expressions without regard to 9184 parentheses. 9185 * GNU Fortran no longer links against libgfortranbegin. As before, 9186 MAIN__ (assembler symbol name) is the actual Fortran main program, 9187 which is invoked by the main function. However, main is now 9188 generated and put in the same object file as MAIN__. For the time 9189 being, libgfortranbegin still exists for backward compatibility. 9190 For details see the new [19]Mixed-Language Programming chapter in 9191 the manual. 9192 * The I/O library was restructured for performance and cleaner code. 9193 * Array assignments and WHERE are now run in parallel when OpenMP's 9194 WORKSHARE is used. 9195 * The experimental option -fwhole-file was added. The option allows 9196 whole-file checking of procedure arguments and allows for better 9197 optimizations. It can also be used with -fwhole-program, which is 9198 now also supported in gfortran. 9199 * More Fortran 2003 and Fortran 2008 mathematical functions can now 9200 be used as initialization expressions. 9201 * Some extended attributes such as STDCALL are now supported via the 9202 [20]GCC$ compiler directive. 9203 * For Fortran 77 compatibility: If -fno-sign-zero is used, the SIGN 9204 intrinsic behaves now as if zero were always positive. 9205 * For legacy compatibiliy: On Cygwin and MinGW, the special files 9206 CONOUT$ and CONIN$ (and CONERR$ which maps to CONOUT$) are now 9207 supported. 9208 * Fortran 2003 support has been extended: 9209 + Procedure-pointer function results and procedure-pointer 9210 components (including PASS), 9211 + allocatable scalars (experimental), 9212 + DEFERRED type-bound procedures, 9213 + the ERRMSG= argument of the ALLOCATE and DEALLOCATE statements 9214 have been implemented. 9215 + The ALLOCATE statement supports type-specs and the SOURCE= 9216 argument. 9217 + OPERATOR(*) and ASSIGNMENT(=) are now allowed as GENERIC 9218 type-bound procedure (i.e. as type-bound operators). 9219 + Rounding (ROUND=, RZ, ...) for output is now supported. 9220 + The INT_FAST{8,16,32,64,128}_T kind type parameters of the 9221 intrinsic module ISO_C_BINDING are now supported, except for 9222 the targets listed above as ones where GCC does not have 9223 <stdint.h> type information. 9224 + Extensible derived types with type-bound procedure or 9225 procedure pointer with PASS attribute now have to use CLASS in 9226 line with the Fortran 2003 standard; the workaround to use 9227 TYPE is no longer supported. 9228 + [21]Experimental, incomplete support for polymorphism, 9229 including CLASS, SELECT TYPE and dynamic dispatch of 9230 type-bound procedure calls. Some features do not work yet such 9231 as unlimited polymorphism (CLASS(*)). 9232 * Fortran 2008 support has been extended: 9233 + The OPEN statement now supports the NEWUNIT= option, which 9234 returns a unique file unit, thus preventing inadvertent use of 9235 the same unit in different parts of the program. 9236 + Support for unlimited format items has been added. 9237 + The INT{8,16,32} and REAL{32,64,128} kind type parameters of 9238 the intrinsic module ISO_FORTRAN_ENV are now supported. 9239 + Using complex arguments with TAN, SINH, COSH, TANH, ASIN, 9240 ACOS, and ATAN is now possible; the functions ASINH, ACOSH, 9241 and ATANH have been added (for real and complex arguments) and 9242 ATAN(Y,X) is now an alias for ATAN2(Y,X). 9243 + The BLOCK construct has been implemented. 9244 9245 New Targets and Target Specific Improvements 9246 9247 AIX 9248 9249 * Full cross-toolchain support now available with GNU Binutils 9250 9251 ARM 9252 9253 * GCC now supports the Cortex-M0 and Cortex-A5 processors. 9254 * GCC now supports the ARM v7E-M architecture. 9255 * GCC now supports VFPv4-based FPUs and FPUs with 9256 single-precision-only VFP. 9257 * GCC has many improvements to optimization for other ARM processors, 9258 including scheduling support for the integer pipeline on Cortex-A9. 9259 * GCC now supports the IEEE 754-2008 half-precision floating-point 9260 type, and a variant ARM-specific half-precision type. This type is 9261 specified using __fp16, with the layout determined by 9262 -mfp16-format. With appropriate -mfpu options, the Cortex-A9 and 9263 VFPv4 half-precision instructions will be used. 9264 * GCC now supports the variant of AAPCS that uses VFP registers for 9265 parameter passing and return values. 9266 9267 AVR 9268 9269 * The -mno-tablejump option has been removed because it has the same 9270 effect as the -fno-jump-tables option. 9271 * Added support for these new AVR devices: 9272 + ATmega8U2 9273 + ATmega16U2 9274 + ATmega32U2 9275 9276 IA-32/x86-64 9277 9278 * GCC now will set the default for -march= based on the configure 9279 target. 9280 * GCC now supports handling floating-point excess precision arising 9281 from use of the x87 floating-point unit in a way that conforms to 9282 ISO C99. This is enabled with -fexcess-precision=standard and with 9283 standards conformance options such as -std=c99, and may be disabled 9284 using -fexcess-precision=fast. 9285 * Support for the Intel Atom processor is now available through the 9286 -march=atom and -mtune=atom options. 9287 * A new -mcrc32 option is now available to enable crc32 intrinsics. 9288 * A new -mmovbe option is now available to enable GCC to use the 9289 movbe instruction to implement __builtin_bswap32 and 9290 __builtin_bswap64. 9291 * SSE math now can be enabled by default at configure time with the 9292 new --with-fpmath=sse option. 9293 * There is a new intrinsic header file, <x86intrin.h>. It should be 9294 included before using any IA-32/x86-64 intrinsics. 9295 * Support for the XOP, FMA4, and LWP instruction sets for the AMD 9296 Orochi processors are now available with the -mxop, -mfma4, and 9297 -mlwp options. 9298 * The -mabm option enables GCC to use the popcnt and lzcnt 9299 instructions on AMD processors. 9300 * The -mpopcnt option enables GCC to use the popcnt instructions on 9301 both AMD and Intel processors. 9302 9303 M68K/ColdFire 9304 9305 * GCC now supports ColdFire 51xx, 5221x, 5225x, 52274, 52277, 5301x 9306 and 5441x devices. 9307 * GCC now supports thread-local storage (TLS) on M68K and ColdFire 9308 processors. 9309 9310 MeP 9311 9312 Support has been added for the Toshiba Media embedded Processor (MeP, 9313 or mep-elf) embedded target. 9314 9315 MIPS 9316 9317 * GCC now supports MIPS 1004K processors. 9318 * GCC can now be configured with options --with-arch-32, 9319 --with-arch-64, --with-tune-32 and --with-tune-64 to control the 9320 default optimization separately for 32-bit and 64-bit modes. 9321 * MIPS targets now support an alternative _mcount interface, in which 9322 register $12 points to the function's save slot for register $31. 9323 This interface is selected by the -mcount-ra-address option; see 9324 the documentation for more details. 9325 * GNU/Linux targets can now generate read-only .eh_frame sections. 9326 This optimization requires GNU binutils 2.20 or above, and is only 9327 available if GCC is configured with a suitable version of binutils. 9328 * GNU/Linux targets can now attach special relocations to indirect 9329 calls, so that the linker can turn them into direct jumps or 9330 branches. This optimization requires GNU binutils 2.20 or later, 9331 and is automatically selected if GCC is configured with an 9332 appropriate version of binutils. It can be explicitly enabled or 9333 disabled using the -mrelax-pic-calls command-line option. 9334 * GCC now generates more heavily-optimized atomic operations on 9335 Octeon processors. 9336 * MIPS targets now support the -fstack-protector option. 9337 * GCC now supports an -msynci option, which specifies that synci is 9338 enough to flush the instruction cache, without help from the 9339 operating system. GCC uses this information to optimize 9340 automatically-generated cache flush operations, such as those used 9341 for nested functions in C. There is also a --with-synci 9342 configure-time option, which makes -msynci the default. 9343 * GCC supports four new function attributes for interrupt handlers: 9344 interrupt, use_shadow_register_set, keep_interrupts_masked and 9345 use_debug_exception_return. See the documentation for more details 9346 about these attributes. 9347 9348 RS/6000 (POWER/PowerPC) 9349 9350 * GCC now supports the Power ISA 2.06, which includes the VSX 9351 instructions that add vector 64-bit floating point support, new 9352 population count instructions, and conversions between floating 9353 point and unsigned types. 9354 * Support for the power7 processor is now available through the 9355 -mcpu=power7 and -mtune=power7. 9356 * GCC will now vectorize loops that contain simple math functions 9357 like copysign when generating code for altivec or VSX targets. 9358 * Support for the A2 processor is now available through the -mcpu=a2 9359 and -mtune=a2 options. 9360 * Support for the 476 processor is now available through the 9361 -mcpu={476,476fp} and -mtune={476,476fp} options. 9362 * Support for the e500mc64 processor is now available through the 9363 -mcpu=e500mc64 and -mtune=e500mc64 options. 9364 * GCC can now be configured with options --with-cpu-32, 9365 --with-cpu-64, --with-tune-32 and --with-tune-64 to control the 9366 default optimization separately for 32-bit and 64-bit modes. 9367 * Starting with GCC 4.5.4, vectors of type vector long long or vector 9368 long are passed and returned in the same method as other vectors 9369 with the VSX instruction set. Previously the GCC compiler did not 9370 adhere to the ABI for 128-bit vectors with 64-bit integer base 9371 types (PR 48857). This is also fixed in the GCC 4.6.1 release. 9372 9373 RX 9374 9375 Support has been added for the Renesas RX Processor (rx-elf) target. 9376 9377 Operating Systems 9378 9379 Windows (Cygwin and MinGW) 9380 9381 * GCC now installs all the major language runtime libraries as DLLs 9382 when configured with the --enable-shared option. 9383 * GCC now makes use of the new support for aligned common variables 9384 in versions of binutils >= 2.20 to fix bugs in the support for SSE 9385 data types. 9386 * Improvements to the libffi support library increase the reliability 9387 of code generated by GCJ on all Windows platforms. Libgcj is 9388 enabled by default for the first time. 9389 * Libtool improvements simplify installation by placing the generated 9390 DLLs in the correct binaries directory. 9391 * Numerous other minor bugfixes and improvements, and substantial 9392 enhancements to the Fortran language support library. 9393 9394 > 9395 9396 Other significant improvements 9397 9398 Plugins 9399 9400 * It is now possible to extend the compiler without having to modify 9401 its source code. A new option -fplugin=file.so tells GCC to load 9402 the shared object file.so and execute it as part of the compiler. 9403 The internal documentation describes the details on how plugins can 9404 interact with the compiler. 9405 9406 Installation changes 9407 9408 * The move to newer autotools changed default installation 9409 directories and switches to control them: The --with-datarootdir, 9410 --with-docdir, --with-pdfdir, and --with-htmldir switches are not 9411 used any more. Instead, you can now use --datarootdir, --docdir, 9412 --htmldir, and --pdfdir. The default installation directories have 9413 changed as follows according to the GNU Coding Standards: 9414 9415 datarootdir read-only architecture-independent data root [PREFIX/share] 9416 localedir locale-specific message catalogs [DATAROOTDIR/locale] 9417 docdir documentation root [DATAROOTDIR/doc/PACKAGE] 9418 htmldir html documentation [DOCDIR] 9419 dvidir dvi documentation [DOCDIR] 9420 pdfdir pdf documentation [DOCDIR] 9421 psdir ps documentation [DOCDIR] 9422 The following variables have new default values: 9423 9424 datadir read-only architecture-independent data [DATAROOTDIR] 9425 infodir info documentation [DATAROOTDIR/info] 9426 mandir man documentation [DATAROOTDIR/man] 9427 9428 GCC 4.5.1 9429 9430 This is the [22]list of problem reports (PRs) from GCC's bug tracking 9431 system that are known to be fixed in the 4.5.1 release. This list might 9432 not be complete (that is, it is possible that some PRs that have been 9433 fixed are not listed here). 9434 9435 All languages 9436 9437 * GCC's new link-time optimizer ([23]-flto) now also works on a few 9438 non-ELF targets: 9439 + Cygwin (*-cygwin*) 9440 + MinGW (*-mingw*) 9441 + Darwin on x86-64 (x86_64-apple-darwin*) 9442 LTO is not enabled by default for these targets. To enable LTO, you 9443 should configure with the --enable-lto option. 9444 9445 GCC 4.5.2 9446 9447 This is the [24]list of problem reports (PRs) from GCC's bug tracking 9448 system that are known to be fixed in the 4.5.2 release. This list might 9449 not be complete (that is, it is possible that some PRs that have been 9450 fixed are not listed here). 9451 9452 GCC 4.5.3 9453 9454 This is the [25]list of problem reports (PRs) from GCC's bug tracking 9455 system that are known to be fixed in the 4.5.3 release. This list might 9456 not be complete (that is, it is possible that some PRs that have been 9457 fixed are not listed here). 9458 9459 On the PowerPC compiler, the Altivec builtin functions vec_ld and 9460 vec_st have been modified to generate the Altivec memory instructions 9461 LVX and STVX, even if the -mvsx option is used. In the initial GCC 4.5 9462 release, these builtin functions were changed to generate VSX memory 9463 reference instructions instead of Altivec memory instructions, but 9464 there are differences between the two instructions. If the VSX 9465 instruction set is available, you can now use the new builtin functions 9466 vec_vsx_ld and vec_vsx_st which always generates the VSX memory 9467 instructions. 9468 9469 GCC 4.5.4 9470 9471 This is the [26]list of problem reports (PRs) from GCC's bug tracking 9472 system that are known to be fixed in the 4.5.4 release. This list might 9473 not be complete (that is, it is possible that some PRs that have been 9474 fixed are not listed here). 9475 9476 9477 For questions related to the use of GCC, please consult these web 9478 pages and the [27]GCC manuals. If that fails, the 9479 [28]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 9480 web pages and the development of GCC are welcome on our developer 9481 list at [29]gcc (a] gcc.gnu.org. All of [30]our lists have public 9482 archives. 9483 9484 Copyright (C) [31]Free Software Foundation, Inc. Verbatim copying and 9485 distribution of this entire article is permitted in any medium, 9486 provided this notice is preserved. 9487 9488 These pages are [32]maintained by the GCC team. Last modified 9489 2019-11-28[33]. 9490 9491 References 9492 9493 1. http://www.multiprecision.org/mpc/ 9494 2. https://gcc.gnu.org/install/prerequisites.html 9495 3. https://gcc.gnu.org/ml/gcc/2010-01/msg00510.html 9496 4. http://gcc.gnu.org/gcc-4.4/changes.html#obsoleted 9497 5. http://gcc.gnu.org/gcc-4.5/changes.html#x86 9498 6. https://gcc.gnu.org/PR30789 9499 7. https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#index-flto-801 9500 8. https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#index-fwhopr-802 9501 9. https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#index-fwhole-program-800 9502 10. https://gcc.gnu.org/onlinedocs/gcc/Restricted-Pointers.html 9503 11. http://gcc.gnu.org/gcc-4.5/cxx0x_status.html 9504 12. http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#757 9505 13. http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#176 9506 14. https://gcc.gnu.org/onlinedocs/libstdc++/manual/profile_mode.html 9507 15. https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#status.iso.tr24733 9508 16. https://sourceware.org/gdb/wiki/STLSupport 9509 17. http://gcc.gnu.org/gcc-4.4/changes.html 9510 18. https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html 9511 19. https://gcc.gnu.org/onlinedocs/gfortran/Mixed-Language-Programming.html 9512 20. https://gcc.gnu.org/onlinedocs/gfortran/GNU-Fortran-Compiler-Directives.html 9513 21. https://gcc.gnu.org/wiki/OOP 9514 22. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.5.1 9515 23. https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html#index-flto-801 9516 24. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.5.2 9517 25. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.5.3 9518 26. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.5.4 9519 27. https://gcc.gnu.org/onlinedocs/ 9520 28. mailto:gcc-help (a] gcc.gnu.org 9521 29. mailto:gcc (a] gcc.gnu.org 9522 30. https://gcc.gnu.org/lists.html 9523 31. https://www.fsf.org/ 9524 32. https://gcc.gnu.org/about.html 9525 33. http://validator.w3.org/check/referer 9526 ====================================================================== 9527 http://gcc.gnu.org/gcc-4.4/index.html 9528 GCC 4.4 Release Series 9529 9530 This release series is no longer maintained. 9531 9532 March 13, 2012 9533 9534 The [1]GNU project and the GCC developers are pleased to announce the 9535 release of GCC 4.4.7. 9536 9537 This release is a bug-fix release, containing fixes for regressions in 9538 GCC 4.4.6 relative to previous releases of GCC. 9539 9540 Release History 9541 9542 GCC 4.4.7 9543 March 13, 2012 ([2]changes) 9544 9545 GCC 4.4.6 9546 April 16, 2011 ([3]changes) 9547 9548 GCC 4.4.5 9549 October 1, 2010 ([4]changes) 9550 9551 GCC 4.4.4 9552 April 29, 2010 ([5]changes) 9553 9554 GCC 4.4.3 9555 January 21, 2010 ([6]changes) 9556 9557 GCC 4.4.2 9558 October 15, 2009 ([7]changes) 9559 9560 GCC 4.4.1 9561 July 22, 2009 ([8]changes) 9562 9563 GCC 4.4.0 9564 April 21, 2009 ([9]changes) 9565 9566 References and Acknowledgements 9567 9568 GCC used to stand for the GNU C Compiler, but since the compiler 9569 supports several other languages aside from C, it now stands for the 9570 GNU Compiler Collection. 9571 9572 A list of [10]successful builds is updated as new information becomes 9573 available. 9574 9575 The GCC developers would like to thank the numerous people that have 9576 contributed new features, improvements, bug fixes, and other changes as 9577 well as test results to GCC. This [11]amazing group of volunteers is 9578 what makes GCC successful. 9579 9580 For additional information about GCC please refer to the [12]GCC 9581 project web site or contact the [13]GCC development mailing list. 9582 9583 To obtain GCC please use [14]our mirror sites or [15]our version 9584 control system. 9585 9586 9587 For questions related to the use of GCC, please consult these web 9588 pages and the [16]GCC manuals. If that fails, the 9589 [17]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 9590 web pages and the development of GCC are welcome on our developer 9591 list at [18]gcc (a] gcc.gnu.org. All of [19]our lists have public 9592 archives. 9593 9594 Copyright (C) [20]Free Software Foundation, Inc. Verbatim copying and 9595 distribution of this entire article is permitted in any medium, 9596 provided this notice is preserved. 9597 9598 These pages are [21]maintained by the GCC team. Last modified 9599 2020-01-14[22]. 9600 9601 References 9602 9603 1. http://www.gnu.org/ 9604 2. http://gcc.gnu.org/gcc-4.4/changes.html 9605 3. http://gcc.gnu.org/gcc-4.4/changes.html 9606 4. http://gcc.gnu.org/gcc-4.4/changes.html 9607 5. http://gcc.gnu.org/gcc-4.4/changes.html 9608 6. http://gcc.gnu.org/gcc-4.4/changes.html 9609 7. http://gcc.gnu.org/gcc-4.4/changes.html 9610 8. http://gcc.gnu.org/gcc-4.4/changes.html 9611 9. http://gcc.gnu.org/gcc-4.4/changes.html 9612 10. http://gcc.gnu.org/gcc-4.4/buildstat.html 9613 11. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 9614 12. http://gcc.gnu.org/index.html 9615 13. mailto:gcc (a] gcc.gnu.org 9616 14. http://gcc.gnu.org/mirrors.html 9617 15. http://gcc.gnu.org/git.html 9618 16. https://gcc.gnu.org/onlinedocs/ 9619 17. mailto:gcc-help (a] gcc.gnu.org 9620 18. mailto:gcc (a] gcc.gnu.org 9621 19. https://gcc.gnu.org/lists.html 9622 20. https://www.fsf.org/ 9623 21. https://gcc.gnu.org/about.html 9624 22. http://validator.w3.org/check/referer 9625 ====================================================================== 9626 http://gcc.gnu.org/gcc-4.4/changes.html 9627 GCC 4.4 Release Series 9628 Changes, New Features, and Fixes 9629 9630 The latest release in the 4.4 release series is [1]GCC 4.4.7. 9631 9632 Caveats 9633 9634 * __builtin_stdarg_start has been completely removed from GCC. 9635 Support for <varargs.h> had been deprecated since GCC 4.0. Use 9636 __builtin_va_start as a replacement. 9637 * Some of the errors issued by the C++ front end that could be 9638 downgraded to warnings in previous releases by using -fpermissive 9639 are now warnings by default. They can be converted into errors by 9640 using -pedantic-errors. 9641 * Use of the cpp assertion extension will now emit a warning when 9642 -Wdeprecated or -pedantic is used. This extension has been 9643 deprecated for many years, but never warned about. 9644 * Packed bit-fields of type char were not properly bit-packed on many 9645 targets prior to GCC 4.4. On these targets, the fix in GCC 4.4 9646 causes an ABI change. For example there is no longer a 4-bit 9647 padding between field a and b in this structure: 9648 struct foo 9649 { 9650 char a:4; 9651 char b:8; 9652 } __attribute__ ((packed)); 9653 There is a new warning to help identify fields that are affected: 9654 foo.c:5: note: Offset of packed bit-field 'b' has changed in GCC 4.4 9655 The warning can be disabled with -Wno-packed-bitfield-compat. 9656 * On ARM EABI targets, the C++ mangling of the va_list type has been 9657 changed to conform to the current revision of the EABI. This does 9658 not affect the libstdc++ library included with GCC. 9659 * The SCOUNT and POS bits of the MIPS DSP control register are now 9660 treated as global. Previous versions of GCC treated these fields as 9661 call-clobbered instead. 9662 * The MIPS port no longer recognizes the h asm constraint. It was 9663 necessary to remove this constraint in order to avoid generating 9664 unpredictable code sequences. 9665 One of the main uses of the h constraint was to extract the high 9666 part of a multiplication on 64-bit targets. For example: 9667 asm ("dmultu\t%1,%2" : "=h" (result) : "r" (x), "r" (y)); 9668 You can now achieve the same effect using 128-bit types: 9669 typedef unsigned int uint128_t __attribute__((mode(TI))); 9670 result = ((uint128_t) x * y) >> 64; 9671 The second sequence is better in many ways. For example, if x and y 9672 are constants, the compiler can perform the multiplication at 9673 compile time. If x and y are not constants, the compiler can 9674 schedule the runtime multiplication better than it can schedule an 9675 asm statement. 9676 * Support for a number of older systems and recently unmaintained or 9677 untested target ports of GCC has been declared obsolete in GCC 4.4. 9678 Unless there is activity to revive them, the next release of GCC 9679 will have their sources permanently removed. 9680 The following ports for individual systems on particular 9681 architectures have been obsoleted: 9682 + Generic a.out on IA32 and m68k (i[34567]86-*-aout*, 9683 m68k-*-aout*) 9684 + Generic COFF on ARM, H8300, IA32, m68k and SH (arm-*-coff*, 9685 armel-*-coff*, h8300-*-*, i[34567]86-*-coff*, m68k-*-coff*, 9686 sh-*-*). This does not affect other more specific targets 9687 using the COFF object format on those architectures, or the 9688 more specific H8300 and SH targets (h8300-*-rtems*, 9689 h8300-*-elf*, sh-*-elf*, sh-*-symbianelf*, sh-*-linux*, 9690 sh-*-netbsdelf*, sh-*-rtems*, sh-wrs-vxworks). 9691 + 2BSD on PDP-11 (pdp11-*-bsd) 9692 + AIX 4.1 and 4.2 on PowerPC (rs6000-ibm-aix4.[12]*, 9693 powerpc-ibm-aix4.[12]*) 9694 + Tuning support for Itanium1 (Merced) variants. Note that code 9695 tuned for Itanium2 should also run correctly on Itanium1. 9696 * The protoize and unprotoize utilities have been obsoleted and will 9697 be removed in GCC 4.5. These utilities have not been installed by 9698 default since GCC 3.0. 9699 * Support has been removed for all the [2]configurations obsoleted in 9700 GCC 4.3. 9701 * Unknown -Wno-* options are now silently ignored by GCC if no other 9702 diagnostics are issued. If other diagnostics are issued, then GCC 9703 warns about the unknown options. 9704 * More information on porting to GCC 4.4 from previous versions of 9705 GCC can be found in the [3]porting guide for this release. 9706 9707 General Optimizer Improvements 9708 9709 * A new command-line switch -findirect-inlining has been added. When 9710 turned on it allows the inliner to also inline indirect calls that 9711 are discovered to have known targets at compile time thanks to 9712 previous inlining. 9713 * A new command-line switch -ftree-switch-conversion has been added. 9714 This new pass turns simple initializations of scalar variables in 9715 switch statements into initializations from a static array, given 9716 that all the values are known at compile time and the ratio between 9717 the new array size and the original switch branches does not exceed 9718 the parameter --param switch-conversion-max-branch-ratio (default 9719 is eight). 9720 * A new command-line switch -ftree-builtin-call-dce has been added. 9721 This optimization eliminates unnecessary calls to certain builtin 9722 functions when the return value is not used, in cases where the 9723 calls can not be eliminated entirely because the function may set 9724 errno. This optimization is on by default at -O2 and above. 9725 * A new command-line switch -fconserve-stack directs the compiler to 9726 minimize stack usage even if it makes the generated code slower. 9727 This affects inlining decisions. 9728 * When the assembler supports it, the compiler will now emit unwind 9729 information using assembler .cfi directives. This makes it possible 9730 to use such directives in inline assembler code. The new option 9731 -fno-dwarf2-cfi-asm directs the compiler to not use .cfi 9732 directives. 9733 * The [4]Graphite branch has been merged. This merge has brought in a 9734 new framework for loop optimizations based on a polyhedral 9735 intermediate representation. These optimizations apply to all the 9736 languages supported by GCC. The following new code transformations 9737 are available in GCC 4.4: 9738 + -floop-interchange performs loop interchange transformations 9739 on loops. Interchanging two nested loops switches the inner 9740 and outer loops. For example, given a loop like: 9741 DO J = 1, M 9742 DO I = 1, N 9743 A(J, I) = A(J, I) * C 9744 ENDDO 9745 ENDDO 9746 9747 loop interchange will transform the loop as if the user had 9748 written: 9749 DO I = 1, N 9750 DO J = 1, M 9751 A(J, I) = A(J, I) * C 9752 ENDDO 9753 ENDDO 9754 9755 which can be beneficial when N is larger than the caches, 9756 because in Fortran, the elements of an array are stored in 9757 memory contiguously by column, and the original loop iterates 9758 over rows, potentially creating at each access a cache miss. 9759 + -floop-strip-mine performs loop strip mining transformations 9760 on loops. Strip mining splits a loop into two nested loops. 9761 The outer loop has strides equal to the strip size and the 9762 inner loop has strides of the original loop within a strip. 9763 For example, given a loop like: 9764 DO I = 1, N 9765 A(I) = A(I) + C 9766 ENDDO 9767 9768 loop strip mining will transform the loop as if the user had 9769 written: 9770 DO II = 1, N, 4 9771 DO I = II, min (II + 3, N) 9772 A(I) = A(I) + C 9773 ENDDO 9774 ENDDO 9775 9776 + -floop-block performs loop blocking transformations on loops. 9777 Blocking strip mines each loop in the loop nest such that the 9778 memory accesses of the element loops fit inside caches. For 9779 example, given a loop like: 9780 DO I = 1, N 9781 DO J = 1, M 9782 A(J, I) = B(I) + C(J) 9783 ENDDO 9784 ENDDO 9785 9786 loop blocking will transform the loop as if the user had 9787 written: 9788 DO II = 1, N, 64 9789 DO JJ = 1, M, 64 9790 DO I = II, min (II + 63, N) 9791 DO J = JJ, min (JJ + 63, M) 9792 A(J, I) = B(I) + C(J) 9793 ENDDO 9794 ENDDO 9795 ENDDO 9796 ENDDO 9797 9798 which can be beneficial when M is larger than the caches, 9799 because the innermost loop will iterate over a smaller amount 9800 of data that can be kept in the caches. 9801 * A new register allocator has replaced the old one. It is called 9802 integrated register allocator (IRA) because coalescing, register 9803 live range splitting, and hard register preferencing are done 9804 on-the-fly during coloring. It also has better integration with the 9805 reload pass. IRA is a regional register allocator which uses modern 9806 Chaitin-Briggs coloring instead of Chow's priority coloring used in 9807 the old register allocator. More info about IRA internals and 9808 options can be found in the GCC manuals. 9809 * A new instruction scheduler and software pipeliner, based on the 9810 selective scheduling approach, has been added. The new pass 9811 performs instruction unification, register renaming, substitution 9812 through register copies, and speculation during scheduling. The 9813 software pipeliner is able to pipeline non-countable loops. The new 9814 pass is targeted at scheduling-eager in-order platforms. In GCC 4.4 9815 it is available for the Intel Itanium platform working by default 9816 as the second scheduling pass (after register allocation) at the 9817 -O3 optimization level. 9818 * When using -fprofile-generate with a multi-threaded program, the 9819 profile counts may be slightly wrong due to race conditions. The 9820 new -fprofile-correction option directs the compiler to apply 9821 heuristics to smooth out the inconsistencies. By default the 9822 compiler will give an error message when it finds an inconsistent 9823 profile. 9824 * The new -fprofile-dir=PATH option permits setting the directory 9825 where profile data files are stored when using -fprofile-generate 9826 and friends, and the directory used when reading profile data files 9827 using -fprofile-use and friends. 9828 9829 New warning options 9830 9831 * The new -Wframe-larger-than=NUMBER option directs GCC to emit a 9832 warning if any stack frame is larger than NUMBER bytes. This may be 9833 used to help ensure that code fits within a limited amount of stack 9834 space. 9835 * The command-line option -Wlarger-than-N is now written as 9836 -Wlarger-than=N and the old form is deprecated. 9837 * The new -Wno-mudflap option disables warnings about constructs 9838 which can not be instrumented when using -fmudflap. 9839 9840 New Languages and Language specific improvements 9841 9842 * Version 3.0 of the OpenMP specification is now supported for the C, 9843 C++, and Fortran compilers. 9844 * New character data types, per [5]TR 19769: New character types in 9845 C, are now supported for the C compiler in -std=gnu99 mode, as 9846 __CHAR16_TYPE__ and __CHAR32_TYPE__, and for the C++ compiler in 9847 -std=c++0x and -std=gnu++0x modes, as char16_t and char32_t too. 9848 9849 C family 9850 9851 * A new optimize attribute was added to allow programmers to change 9852 the optimization level and particular optimization options for an 9853 individual function. You can also change the optimization options 9854 via the GCC optimize pragma for functions defined after the pragma. 9855 The GCC push_options pragma and the GCC pop_options pragma allow 9856 you temporarily save and restore the options used. The GCC 9857 reset_options pragma restores the options to what was specified on 9858 the command line. 9859 * Uninitialized warnings do not require enabling optimization 9860 anymore, that is, -Wuninitialized can be used together with -O0. 9861 Nonetheless, the warnings given by -Wuninitialized will probably be 9862 more accurate if optimization is enabled. 9863 * -Wparentheses now warns about expressions such as (!x | y) and (!x 9864 & y). Using explicit parentheses, such as in ((!x) | y), silences 9865 this warning. 9866 * -Wsequence-point now warns within if, while,do while and for 9867 conditions, and within for begin/end expressions. 9868 * A new option -dU is available to dump definitions of preprocessor 9869 macros that are tested or expanded. 9870 9871 C++ 9872 9873 * [6]Improved experimental support for the upcoming ISO C++ standard, 9874 C++0x. Including support for auto, inline namespaces, generalized 9875 initializer lists, defaulted and deleted functions, new character 9876 types, and scoped enums. 9877 * Those errors that may be downgraded to warnings to build legacy 9878 code now mention -fpermissive when -fdiagnostics-show-option is 9879 enabled. 9880 * -Wconversion now warns if the result of a static_cast to enumeral 9881 type is unspecified because the value is outside the range of the 9882 enumeral type. 9883 * -Wuninitialized now warns if a non-static reference or non-static 9884 const member appears in a class without constructors. 9885 * G++ now properly implements value-initialization, so objects with 9886 an initializer of () and an implicitly defined default constructor 9887 will be zero-initialized before the default constructor is called. 9888 9889 Runtime Library (libstdc++) 9890 9891 * Improved experimental support for the upcoming ISO C++ standard, 9892 C++0x, including: 9893 + Support for <chrono>, <condition_variable>, <cstdatomic>, 9894 <forward_list>, <initializer_list>, <mutex>, <ratio>, 9895 <system_error>, and <thread>. 9896 + unique_ptr, <algorithm> additions, exception propagation, and 9897 support for the new character types in <string> and <limits>. 9898 + Existing facilities now exploit initializer lists, defaulted 9899 and deleted functions, and the newly implemented core C++0x 9900 features. 9901 + Some standard containers are more efficient together with 9902 stateful allocators, i.e., no allocator is constructed on the 9903 fly at element construction time. 9904 * Experimental support for non-standard pointer types in containers. 9905 * The long standing libstdc++/30928 has been fixed for targets 9906 running glibc 2.10 or later. 9907 * As usual, many small and larger bug fixes, in particular quite a 9908 few corner cases in <locale>. 9909 9910 Fortran 9911 9912 * GNU Fortran now employs libcpp directly instead of using cc1 as an 9913 external preprocessor. The [7]-cpp option was added to allow manual 9914 invocation of the preprocessor without relying on filename 9915 extensions. 9916 * The [8]-Warray-temporaries option warns about array temporaries 9917 generated by the compiler, as an aid to optimization. 9918 * The [9]-fcheck-array-temporaries option has been added, printing a 9919 notification at run time, when an array temporary had to be created 9920 for an function argument. Contrary to -Warray-temporaries the 9921 warning is only printed if the array is noncontiguous. 9922 * Improved generation of DWARF debugging symbols 9923 * If using an intrinsic not part of the selected standard (via -std= 9924 and -fall-intrinsics) gfortran will now treat it as if this 9925 procedure were declared EXTERNAL and try to link to a user-supplied 9926 procedure. -Wintrinsics-std will warn whenever this happens. The 9927 now-useless option -Wnonstd-intrinsic was removed. 9928 * The flag -falign-commons has been added to control the alignment of 9929 variables in COMMON blocks, which is enabled by default in line 9930 with previous GCC version. Using -fno-align-commons one can force 9931 commons to be contiguous in memory as required by the Fortran 9932 standard, however, this slows down the memory access. The option 9933 -Walign-commons, which is enabled by default, warns when padding 9934 bytes were added for alignment. The proper solution is to sort the 9935 common objects by decreasing storage size, which avoids the 9936 alignment problems. 9937 * Fortran 2003 support has been extended: 9938 + Wide characters (ISO 10646, UCS-4, kind=4) and UTF-8 I/O is 9939 now supported (except internal reads from/writes to wide 9940 strings). [10]-fbackslash now supports also \unnnn and 9941 \Unnnnnnnn to enter Unicode characters. 9942 + Asynchronous I/O (implemented as synchronous I/O) and the 9943 decimal=, size=, sign=, pad=, blank=, and delim= specifiers 9944 are now supported in I/O statements. 9945 + Support for Fortran 2003 structure constructors and for array 9946 constructor with typespec has been added. 9947 + Procedure Pointers (but not yet as component in derived types 9948 and as function results) are now supported. 9949 + Abstract types, type extension, and type-bound procedures 9950 (both PROCEDURE and GENERIC but not as operators). Note: As 9951 CLASS/polymorphyic types are not implemented, type-bound 9952 procedures with PASS accept as non-standard extension TYPE 9953 arguments. 9954 * Fortran 2008 support has been added: 9955 + The -std=f2008 option and support for the file extensions 9956 .f2008 and .F2008 has been added. 9957 + The g0 format descriptor is now supported. 9958 + The Fortran 2008 mathematical intrinsics ASINH, ACOSH, ATANH, 9959 ERF, ERFC, GAMMA, LOG_GAMMA, BESSEL_*, HYPOT, and ERFC_SCALED 9960 are now available (some of them existed as GNU extension 9961 before). Note: The hyperbolic functions are not yet supporting 9962 complex arguments and the three- argument version of BESSEL_*N 9963 is not available. 9964 + The bit intrinsics LEADZ and TRAILZ have been added. 9965 9966 Java (GCJ) 9967 9968 Ada 9969 9970 * The Ada runtime now supports multilibs on many platforms including 9971 x86_64, SPARC and PowerPC. Their build is enabled by default. 9972 9973 New Targets and Target Specific Improvements 9974 9975 ARM 9976 9977 * GCC now supports optimizing for the Cortex-A9, Cortex-R4 and 9978 Cortex-R4F processors and has many other improvements to 9979 optimization for ARM processors. 9980 * GCC now supports the VFPv3 variant with 16 double-precision 9981 registers with -mfpu=vfpv3-d16. The option -mfpu=vfp3 has been 9982 renamed to -mfpu=vfpv3. 9983 * GCC now supports the -mfix-cortex-m3-ldrd option to work around an 9984 erratum on Cortex-M3 processors. 9985 * GCC now supports the __sync_* atomic operations for ARM EABI 9986 GNU/Linux. 9987 * The section anchors optimization is now enabled by default when 9988 optimizing for ARM. 9989 * GCC now uses a new EABI-compatible profiling interface for EABI 9990 targets. This requires a function __gnu_mcount_nc, which is 9991 provided by GNU libc versions 2.8 and later. 9992 9993 AVR 9994 9995 * The -mno-tablejump option has been deprecated because it has the 9996 same effect as the -fno-jump-tables option. 9997 * Added support for these new AVR devices: 9998 + ATA6289 9999 + ATtiny13A 10000 + ATtiny87 10001 + ATtiny167 10002 + ATtiny327 10003 + ATmega8C1 10004 + ATmega16C1 10005 + ATmega32C1 10006 + ATmega8M1 10007 + ATmega16M1 10008 + ATmega32M1 10009 + ATmega32U4 10010 + ATmega16HVB 10011 + ATmega4HVD 10012 + ATmega8HVD 10013 + ATmega64C1 10014 + ATmega64M1 10015 + ATmega16U4 10016 + ATmega32U6 10017 + ATmega128RFA1 10018 + AT90PWM81 10019 + AT90SCR100 10020 + M3000F 10021 + M3000S 10022 + M3001B 10023 10024 IA-32/x86-64 10025 10026 * Support for Intel AES built-in functions and code generation is 10027 available via -maes. 10028 * Support for Intel PCLMUL built-in function and code generation is 10029 available via -mpclmul. 10030 * Support for Intel AVX built-in functions and code generation is 10031 available via -mavx. 10032 * Automatically align the stack for local variables with alignment 10033 requirement. 10034 * GCC can now utilize the SVML library for vectorizing calls to a set 10035 of C99 functions if -mveclibabi=svml is specified and you link to 10036 an SVML ABI compatible library. 10037 * On x86-64, the ABI has been changed in the following cases to 10038 conform to the x86-64 ABI: 10039 + Passing/returning structures with flexible array member: 10040 struct foo 10041 { 10042 int i; 10043 int flex[]; 10044 }; 10045 + Passing/returning structures with complex float member: 10046 struct foo 10047 { 10048 int i; 10049 __complex__ float f; 10050 }; 10051 + Passing/returning unions with long double member: 10052 union foo 10053 { 10054 int x; 10055 long double ld; 10056 }; 10057 Code built with previous versions of GCC that uses any of these is 10058 not compatible with code built with GCC 4.4.0 or later. 10059 * A new target attribute was added to allow programmers to change the 10060 target options like -msse2 or -march=k8 for an individual function. 10061 You can also change the target options via the GCC target pragma 10062 for functions defined after the pragma. 10063 * GCC can now be configured with options --with-arch-32, 10064 --with-arch-64, --with-cpu-32, --with-cpu-64, --with-tune-32 and 10065 --with-tune-64 to control the default optimization separately for 10066 32-bit and 64-bit modes. 10067 10068 IA-32/IA64 10069 10070 * Support for __float128 (TFmode) IEEE quad type and corresponding 10071 TCmode IEEE complex quad type is available via the soft-fp library 10072 on IA-32/IA64 targets. This includes basic arithmetic operations 10073 (addition, subtraction, negation, multiplication and division) on 10074 __float128 real and TCmode complex values, the full set of IEEE 10075 comparisons between __float128 values, conversions to and from 10076 float, double and long double floating point types, as well as 10077 conversions to and from signed or unsigned integer, signed or 10078 unsigned long integer and signed or unsigned quad (TImode, IA64 10079 only) integer types. Additionally, all operations generate the full 10080 set of IEEE exceptions and support the full set of IEEE rounding 10081 modes. 10082 10083 M68K/ColdFire 10084 10085 * GCC now supports instruction scheduling for ColdFire V1, V3 and V4 10086 processors. (Scheduling support for ColdFire V2 processors was 10087 added in GCC 4.3.) 10088 * GCC now supports the -mxgot option to support programs requiring 10089 many GOT entries on ColdFire. 10090 * The m68k-*-linux-gnu target now builds multilibs by default. 10091 10092 MIPS 10093 10094 * MIPS Technologies have extended the original MIPS SVR4 ABI to 10095 include support for procedure linkage tables (PLTs) and copy 10096 relocations. These extensions allow GNU/Linux executables to use a 10097 significantly more efficient code model than the one defined by the 10098 original ABI. 10099 GCC support for this code model is available via a new command-line 10100 option, -mplt. There is also a new configure-time option, 10101 --with-mips-plt, to make -mplt the default. 10102 The new code model requires support from the assembler, the linker, 10103 and the runtime C library. This support is available in binutils 10104 2.19 and GLIBC 2.9. 10105 * GCC can now generate MIPS16 code for 32-bit GNU/Linux executables 10106 and 32-bit GNU/Linux shared libraries. This feature requires GNU 10107 binutils 2.19 or above. 10108 * Support for RMI's XLR processor is now available through the 10109 -march=xlr and -mtune=xlr options. 10110 * 64-bit targets can now perform 128-bit multiplications inline, 10111 instead of relying on a libgcc function. 10112 * Native GNU/Linux toolchains now support -march=native and 10113 -mtune=native, which select the host processor. 10114 * GCC now supports the R10K, R12K, R14K and R16K processors. The 10115 canonical -march= and -mtune= names for these processors are 10116 r10000, r12000, r14000 and r16000 respectively. 10117 * GCC can now work around the side effects of speculative execution 10118 on R10K processors. Please see the documentation of the 10119 -mr10k-cache-barrier option for details. 10120 * Support for the MIPS64 Release 2 instruction set has been added. 10121 The option -march=mips64r2 enables generation of these 10122 instructions. 10123 * GCC now supports Cavium Networks' Octeon processor. This support is 10124 available through the -march=octeon and -mtune=octeon options. 10125 * GCC now supports STMicroelectronics' Loongson 2E/2F processors. The 10126 canonical -march= and -mtune= names for these processors are 10127 loongson2e and loongson2f. 10128 10129 picochip 10130 10131 Picochip is a 16-bit processor. A typical picoChip contains over 250 10132 small cores, each with small amounts of memory. There are three 10133 processor variants (STAN, MEM and CTRL) with different instruction sets 10134 and memory configurations and they can be chosen using the -mae option. 10135 10136 This port is intended to be a "C" only port. 10137 10138 Power Architecture and PowerPC 10139 10140 * GCC now supports the e300c2, e300c3 and e500mc processors. 10141 * GCC now supports Xilinx processors with a single-precision FPU. 10142 * Decimal floating point is now supported for e500 processors. 10143 10144 S/390, zSeries and System z9/z10 10145 10146 * Support for the IBM System z10 EC/BC processor has been added. When 10147 using the -march=z10 option, the compiler will generate code making 10148 use of instructions provided by the General-Instruction-Extension 10149 Facility and the Execute-Extension Facility. 10150 10151 VxWorks 10152 10153 * GCC now supports the thread-local storage mechanism used on 10154 VxWorks. 10155 10156 Xtensa 10157 10158 * GCC now supports thread-local storage (TLS) for Xtensa processor 10159 configurations that include the Thread Pointer option. TLS also 10160 requires support from the assembler and linker; this support is 10161 provided in the GNU binutils beginning with version 2.19. 10162 10163 Documentation improvements 10164 10165 Other significant improvements 10166 10167 GCC 4.4.1 10168 10169 This is the [11]list of problem reports (PRs) from GCC's bug tracking 10170 system that are known to be fixed in the 4.4.1 release. This list might 10171 not be complete (that is, it is possible that some PRs that have been 10172 fixed are not listed here). 10173 10174 GCC 4.4.2 10175 10176 This is the [12]list of problem reports (PRs) from GCC's bug tracking 10177 system that are known to be fixed in the 4.4.2 release. This list might 10178 not be complete (that is, it is possible that some PRs that have been 10179 fixed are not listed here). 10180 10181 GCC 4.4.3 10182 10183 This is the [13]list of problem reports (PRs) from GCC's bug tracking 10184 system that are known to be fixed in the 4.4.3 release. This list might 10185 not be complete (that is, it is possible that some PRs that have been 10186 fixed are not listed here). 10187 10188 GCC 4.4.4 10189 10190 This is the [14]list of problem reports (PRs) from GCC's bug tracking 10191 system that are known to be fixed in the 4.4.4 release. This list might 10192 not be complete (that is, it is possible that some PRs that have been 10193 fixed are not listed here). 10194 10195 GCC 4.4.5 10196 10197 This is the [15]list of problem reports (PRs) from GCC's bug tracking 10198 system that are known to be fixed in the 4.4.5 release. This list might 10199 not be complete (that is, it is possible that some PRs that have been 10200 fixed are not listed here). 10201 10202 GCC 4.4.6 10203 10204 This is the [16]list of problem reports (PRs) from GCC's bug tracking 10205 system that are known to be fixed in the 4.4.6 release. This list might 10206 not be complete (that is, it is possible that some PRs that have been 10207 fixed are not listed here). 10208 10209 GCC 4.4.7 10210 10211 This is the [17]list of problem reports (PRs) from GCC's bug tracking 10212 system that are known to be fixed in the 4.4.7 release. This list might 10213 not be complete (that is, it is possible that some PRs that have been 10214 fixed are not listed here). 10215 10216 10217 For questions related to the use of GCC, please consult these web 10218 pages and the [18]GCC manuals. If that fails, the 10219 [19]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 10220 web pages and the development of GCC are welcome on our developer 10221 list at [20]gcc (a] gcc.gnu.org. All of [21]our lists have public 10222 archives. 10223 10224 Copyright (C) [22]Free Software Foundation, Inc. Verbatim copying and 10225 distribution of this entire article is permitted in any medium, 10226 provided this notice is preserved. 10227 10228 These pages are [23]maintained by the GCC team. Last modified 10229 2019-11-28[24]. 10230 10231 References 10232 10233 1. http://gcc.gnu.org/gcc-4.4/changes.html#4.4.7 10234 2. http://gcc.gnu.org/gcc-4.3/changes.html#obsoleted 10235 3. http://gcc.gnu.org/gcc-4.4/porting_to.html 10236 4. https://gcc.gnu.org/wiki/Graphite 10237 5. http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1040.pdf 10238 6. http://gcc.gnu.org/gcc-4.4/cxx0x_status.html 10239 7. https://gcc.gnu.org/onlinedocs/gfortran/Preprocessing-Options.html 10240 8. https://gcc.gnu.org/onlinedocs/gfortran/Error-and-Warning-Options.html#index-g_t_0040code_007bWarray-temporaries_007d-125 10241 9. https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfcheck-array-temporaries_007d-221 10242 10. https://gcc.gnu.org/onlinedocs/gfortran/Fortran-Dialect-Options.html#index-g_t_0040code_007bbackslash_007d-34 10243 11. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.1 10244 12. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.2 10245 13. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.3 10246 14. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.4 10247 15. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.5 10248 16. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.6 10249 17. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.4.7 10250 18. https://gcc.gnu.org/onlinedocs/ 10251 19. mailto:gcc-help (a] gcc.gnu.org 10252 20. mailto:gcc (a] gcc.gnu.org 10253 21. https://gcc.gnu.org/lists.html 10254 22. https://www.fsf.org/ 10255 23. https://gcc.gnu.org/about.html 10256 24. http://validator.w3.org/check/referer 10257 ====================================================================== 10258 http://gcc.gnu.org/gcc-4.3/index.html 10259 GCC 4.3 Release Series 10260 10261 (This release series is no longer supported.) 10262 10263 Jun 27, 2011 10264 10265 The [1]GNU project and the GCC developers are pleased to announce the 10266 release of GCC 4.3.6. 10267 10268 This release is a bug-fix release, containing fixes for regressions in 10269 GCC 4.3.5 relative to previous releases of GCC. 10270 10271 Release History 10272 10273 GCC 4.3.6 10274 Jun 27, 2011 ([2]changes) 10275 10276 GCC 4.3.5 10277 May 22, 2010 ([3]changes) 10278 10279 GCC 4.3.4 10280 August 4, 2009 ([4]changes) 10281 10282 GCC 4.3.3 10283 January 24, 2009 ([5]changes) 10284 10285 GCC 4.3.2 10286 August 27, 2008 ([6]changes) 10287 10288 GCC 4.3.1 10289 June 6, 2008 ([7]changes) 10290 10291 GCC 4.3.0 10292 March 5, 2008 ([8]changes) 10293 10294 References and Acknowledgements 10295 10296 GCC used to stand for the GNU C Compiler, but since the compiler 10297 supports several other languages aside from C, it now stands for the 10298 GNU Compiler Collection. 10299 10300 A list of [9]successful builds is updated as new information becomes 10301 available. 10302 10303 The GCC developers would like to thank the numerous people that have 10304 contributed new features, improvements, bug fixes, and other changes as 10305 well as test results to GCC. This [10]amazing group of volunteers is 10306 what makes GCC successful. 10307 10308 For additional information about GCC please refer to the [11]GCC 10309 project web site or contact the [12]GCC development mailing list. 10310 10311 To obtain GCC please use [13]our mirror sites or [14]our version 10312 control system. 10313 10314 10315 For questions related to the use of GCC, please consult these web 10316 pages and the [15]GCC manuals. If that fails, the 10317 [16]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 10318 web pages and the development of GCC are welcome on our developer 10319 list at [17]gcc (a] gcc.gnu.org. All of [18]our lists have public 10320 archives. 10321 10322 Copyright (C) [19]Free Software Foundation, Inc. Verbatim copying and 10323 distribution of this entire article is permitted in any medium, 10324 provided this notice is preserved. 10325 10326 These pages are [20]maintained by the GCC team. Last modified 10327 2020-01-14[21]. 10328 10329 References 10330 10331 1. http://www.gnu.org/ 10332 2. http://gcc.gnu.org/gcc-4.3/changes.html 10333 3. http://gcc.gnu.org/gcc-4.3/changes.html 10334 4. http://gcc.gnu.org/gcc-4.3/changes.html 10335 5. http://gcc.gnu.org/gcc-4.3/changes.html 10336 6. http://gcc.gnu.org/gcc-4.3/changes.html 10337 7. http://gcc.gnu.org/gcc-4.3/changes.html 10338 8. http://gcc.gnu.org/gcc-4.3/changes.html 10339 9. http://gcc.gnu.org/gcc-4.3/buildstat.html 10340 10. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 10341 11. http://gcc.gnu.org/index.html 10342 12. mailto:gcc (a] gcc.gnu.org 10343 13. http://gcc.gnu.org/mirrors.html 10344 14. http://gcc.gnu.org/git.html 10345 15. https://gcc.gnu.org/onlinedocs/ 10346 16. mailto:gcc-help (a] gcc.gnu.org 10347 17. mailto:gcc (a] gcc.gnu.org 10348 18. https://gcc.gnu.org/lists.html 10349 19. https://www.fsf.org/ 10350 20. https://gcc.gnu.org/about.html 10351 21. http://validator.w3.org/check/referer 10352 ====================================================================== 10353 http://gcc.gnu.org/gcc-4.3/changes.html 10354 GCC 4.3 Release Series 10355 Changes, New Features, and Fixes 10356 10357 The latest release in the 4.3 release series is [1]GCC 4.3.5. 10358 10359 Caveats 10360 10361 * GCC requires the [2]GMP and [3]MPFR libraries for building all the 10362 various front-end languages it supports. See the [4]prerequisites 10363 page for version requirements. 10364 * ColdFire targets now treat long double as having the same format as 10365 double. In earlier versions of GCC, they used the 68881 long double 10366 format instead. 10367 * The m68k-uclinux target now uses the same calling conventions as 10368 m68k-linux-gnu. You can select the original calling conventions by 10369 configuring for m68k-uclinuxoldabi instead. Note that 10370 m68k-uclinuxoldabi also retains the original 80-bit long double on 10371 ColdFire targets. 10372 * The -fforce-mem option has been removed because it has had no 10373 effect in the last few GCC releases. 10374 * The i386 -msvr3-shlib option has been removed since it is no longer 10375 used. 10376 * Fastcall for i386 has been changed not to pass aggregate arguments 10377 in registers, following Microsoft compilers. 10378 * Support for the AOF assembler has been removed from the ARM back 10379 end; this affects only the targets arm-semi-aof and armel-semi-aof, 10380 which are no longer recognized. We removed these targets without a 10381 deprecation period because we discovered that they have been 10382 unusable since GCC 4.0.0. 10383 * Support for the TMS320C3x/C4x processor (targets c4x-* and tic4x-*) 10384 has been removed. This support had been deprecated since GCC 4.0.0. 10385 * Support for a number of older systems and recently unmaintained or 10386 untested target ports of GCC has been declared obsolete in GCC 4.3. 10387 Unless there is activity to revive them, the next release of GCC 10388 will have their sources permanently removed. 10389 All GCC ports for the following processor architectures have been 10390 declared obsolete: 10391 + Morpho MT (mt-*) 10392 The following aliases for processor architectures have been 10393 declared obsolete. Users should use the indicated generic target 10394 names instead, with compile-time options such as -mcpu or 10395 configure-time options such as --with-cpu to control the 10396 configuration more precisely. 10397 + strongarm*-*-*, ep9312*-*-*, xscale*-*-* (use arm*-*-* 10398 instead). 10399 + parisc*-*-* (use hppa*-*-* instead). 10400 + m680[012]0-*-* (use m68k-*-* instead). 10401 All GCC ports for the following operating systems have been 10402 declared obsolete: 10403 + BeOS (*-*-beos*) 10404 + kaOS (*-*-kaos*) 10405 + GNU/Linux using the a.out object format (*-*-linux*aout*) 10406 + GNU/Linux using version 1 of the GNU C Library 10407 (*-*-linux*libc1*) 10408 + Solaris versions before Solaris 7 (*-*-solaris2.[0-6], 10409 *-*-solaris2.[0-6].*) 10410 + Miscellaneous System V (*-*-sysv*) 10411 + WindISS (*-*-windiss*) 10412 Also, those for some individual systems on particular architectures 10413 have been obsoleted: 10414 + UNICOS/mk on DEC Alpha (alpha*-*-unicosmk*) 10415 + CRIS with a.out object format (cris-*-aout) 10416 + BSD 4.3 on PA-RISC (hppa1.1-*-bsd*) 10417 + OSF/1 on PA-RISC (hppa1.1-*-osf*) 10418 + PRO on PA-RISC (hppa1.1-*-pro*) 10419 + Sequent PTX on IA32 (i[34567]86-sequent-ptx4*, 10420 i[34567]86-sequent-sysv4*) 10421 + SCO Open Server 5 on IA32 (i[34567]86-*-sco3.2v5*) 10422 + UWIN on IA32 (i[34567]86-*-uwin*) (support for UWIN as a host 10423 was previously [5]removed in 2001, leaving only the support 10424 for UWIN as a target now being deprecated) 10425 + ChorusOS on PowerPC (powerpc-*-chorusos*) 10426 + All VAX configurations apart from NetBSD and OpenBSD 10427 (vax-*-bsd*, vax-*-sysv*, vax-*-ultrix*) 10428 * The [6]-Wconversion option has been modified. Its purpose now is to 10429 warn for implicit conversions that may alter a value. This new 10430 behavior is available for both C and C++. Warnings about 10431 conversions between signed and unsigned integers can be disabled by 10432 using -Wno-sign-conversion. In C++, they are disabled by default 10433 unless -Wsign-conversion is explicitly requested. The old behavior 10434 of -Wconversion, that is, warn for prototypes causing a type 10435 conversion that is different from what would happen to the same 10436 argument in the absence of a prototype, has been moved to a new 10437 option -Wtraditional-conversion, which is only available for C. 10438 * The -m386, -m486, -mpentium and -mpentiumpro tuning options have 10439 been removed because they were deprecated for more than 3 GCC major 10440 releases. Use -mtune=i386, -mtune=i486, -mtune=pentium or 10441 -mtune=pentiumpro as a replacement. 10442 * The -funsafe-math-optimizations option now automatically turns on 10443 -fno-trapping-math in addition to -fno-signed-zeros, as it enables 10444 reassociation and thus may introduce or remove traps. 10445 * The -ftree-vectorize option is now on by default under -O3. In 10446 order to generate code for a SIMD extension, it has to be enabled 10447 as well: use -maltivec for PowerPC platforms and -msse/-msse2 for 10448 i?86 and x86_64. 10449 * More information on porting to GCC 4.3 from previous versions of 10450 GCC can be found in the [7]porting guide for this release. 10451 10452 General Optimizer Improvements 10453 10454 * The GCC middle-end has been integrated with the MPFR library. This 10455 allows GCC to evaluate and replace at compile-time calls to 10456 built-in math functions having constant arguments with their 10457 mathematically equivalent results. In making use of MPFR, GCC can 10458 generate correct results regardless of the math library 10459 implementation or floating point precision of the host platform. 10460 This also allows GCC to generate identical results regardless of 10461 whether one compiles in native or cross-compile configurations to a 10462 particular target. The following built-in functions take advantage 10463 of this new capability: acos, acosh, asin, asinh, atan2, atan, 10464 atanh, cbrt, cos, cosh, drem, erf, erfc, exp10, exp2, exp, expm1, 10465 fdim, fma, fmax, fmin, gamma_r, hypot, j0, j1, jn, lgamma_r, log10, 10466 log1p, log2, log, pow10, pow, remainder, remquo, sin, sincos, sinh, 10467 tan, tanh, tgamma, y0, y1 and yn. The float and long double 10468 variants of these functions (e.g. sinf and sinl) are also handled. 10469 The sqrt and cabs functions with constant arguments were already 10470 optimized in prior GCC releases. Now they also use MPFR. 10471 * A new forward propagation pass on RTL was added. The new pass 10472 replaces several slower transformations, resulting in compile-time 10473 improvements as well as better code generation in some cases. 10474 * A new command-line switch -frecord-gcc-switches has been added to 10475 GCC, although it is only enabled for some targets. The switch 10476 causes the command line that was used to invoke the compiler to be 10477 recorded into the object file that is being created. The exact 10478 format of this recording is target and binary file format 10479 dependent, but it usually takes the form of a note section 10480 containing ASCII text. The switch is related to the -fverbose-asm 10481 switch, but that one only records the information in the assembler 10482 output file as comments, so the information never reaches the 10483 object file. 10484 * The inliner heuristic is now aware of stack frame consumption. New 10485 command-line parameters --param large-stack-frame and --param 10486 large-stack-frame-growth can be used to limit stack frame size 10487 growth caused by inlining. 10488 * During feedback directed optimizations, the expected block size the 10489 memcpy, memset and bzero functions operate on is discovered and for 10490 cases of commonly used small sizes, specialized inline code is 10491 generated. 10492 * __builtin_expect no longer requires its argument to be a compile 10493 time constant. 10494 * Interprocedural optimization was reorganized to work on functions 10495 in SSA form. This enables more precise and cheaper dataflow 10496 analysis and makes writing interprocedural optimizations easier. 10497 The following improvements have been implemented on top of this 10498 framework: 10499 + Pre-inline optimization: Selected local optimization passes 10500 are run before the inliner (and other interprocedural passes) 10501 are executed. This significantly improves the accuracy of code 10502 growth estimates used by the inliner and reduces the overall 10503 memory footprint for large compilation units. 10504 + Early inlining (a simple bottom-up inliner pass inlining only 10505 functions whose body is smaller than the expected call 10506 overhead) is now executed with the early optimization passes, 10507 thus inlining already optimized function bodies into an 10508 unoptimized function that is subsequently optimized by early 10509 optimizers. This enables the compiler to quickly eliminate 10510 abstraction penalty in C++ programs. 10511 + Interprocedural constant propagation now operate on SSA form 10512 increasing accuracy of the analysis. 10513 * A new internal representation for GIMPLE statements has been 10514 contributed, resulting in compile-time memory savings. 10515 * The vectorizer was enhanced to support vectorization of outer 10516 loops, intra-iteration parallelism (loop-aware SLP), vectorization 10517 of strided accesses and loops with multiple data-types. Run-time 10518 dependency testing using loop versioning was added. The cost model, 10519 turned on by -fvect-cost-model, was developed. 10520 10521 New Languages and Language specific improvements 10522 10523 * We have added new command-line options 10524 -finstrument-functions-exclude-function-list and 10525 -finstrument-functions-exclude-file-list. They provide more control 10526 over which functions are annotated by the -finstrument-functions 10527 option. 10528 10529 C family 10530 10531 * Implicit conversions between generic vector types are now only 10532 permitted when the two vectors in question have the same number of 10533 elements and compatible element types. (Note that the restriction 10534 involves compatible element types, not implicitly-convertible 10535 element types: thus, a vector type with element type int may not be 10536 implicitly converted to a vector type with element type unsigned 10537 int.) This restriction, which is in line with specifications for 10538 SIMD architectures such as AltiVec, may be relaxed using the flag 10539 -flax-vector-conversions. This flag is intended only as a 10540 compatibility measure and should not be used for new code. 10541 * -Warray-bounds has been added and is now enabled by default for 10542 -Wall . It produces warnings for array subscripts that can be 10543 determined at compile time to be always out of bounds. 10544 -Wno-array-bounds will disable the warning. 10545 * The constructor and destructor function attributes now accept 10546 optional priority arguments which control the order in which the 10547 constructor and destructor functions are run. 10548 * New [8]command-line options -Wtype-limits, -Wold-style-declaration, 10549 -Wmissing-parameter-type, -Wempty-body, -Wclobbered and 10550 -Wignored-qualifiers have been added for finer control of the 10551 diverse warnings enabled by -Wextra. 10552 * A new function attribute alloc_size has been added to mark up 10553 malloc style functions. For constant sized allocations this can be 10554 used to find out the size of the returned pointer using the 10555 __builtin_object_size() function for buffer overflow checking and 10556 similar. This supplements the already built-in malloc and calloc 10557 constant size handling. 10558 * Integer constants written in binary are now supported as a GCC 10559 extension. They consist of a prefix 0b or 0B, followed by a 10560 sequence of 0 and 1 digits. 10561 * A new predefined macro __COUNTER__ has been added. It expands to 10562 sequential integral values starting from 0. In conjunction with the 10563 ## operator, this provides a convenient means to generate unique 10564 identifiers. 10565 * A new command-line option -fdirectives-only has been added. It 10566 enables a special preprocessing mode which improves the performance 10567 of applications like distcc and ccache. 10568 * Fixed-point data types and operators have been added. They are 10569 based on Chapter 4 of the Embedded-C specification (n1169.pdf). 10570 Currently, only MIPS targets are supported. 10571 * Decimal floating-point arithmetic based on draft ISO/IEC TR 24732, 10572 N1241, is now supported as a GCC extension to C for targets 10573 i[34567]86-*-linux-gnu, powerpc*-*-linux-gnu, s390*-ibm-linux-gnu, 10574 and x86_64-*-linux-gnu. The feature introduces new data types 10575 _Decimal32, _Decimal64, and _Decimal128 with constant suffixes DF, 10576 DD, and DL. 10577 10578 C++ 10579 10580 * [9]Experimental support for the upcoming ISO C++ standard, C++0x. 10581 * -Wc++0x-compat has been added and is now enabled by default for 10582 -Wall. It produces warnings for constructs whose meaning differs 10583 between ISO C++ 1998 and C++0x. 10584 * The -Wparentheses option now works for C++ as it does for C. It 10585 warns if parentheses are omitted when operators with confusing 10586 precedence are nested. It also warns about ambiguous else 10587 statements. Since -Wparentheses is enabled by -Wall, this may cause 10588 additional warnings with existing C++ code which uses -Wall. These 10589 new warnings may be disabled by using -Wall -Wno-parentheses. 10590 * The -Wmissing-declarations now works for C++ as it does for C. 10591 * The -fvisibility-ms-compat flag was added, to make it easier to 10592 port larger projects using shared libraries from Microsoft's Visual 10593 Studio to ELF and Mach-O systems. 10594 * C++ attribute handling has been overhauled for template arguments 10595 (ie dependent types). In particular, __attribute__((aligned(T))); 10596 works for C++ types. 10597 10598 Runtime Library (libstdc++) 10599 10600 * [10]Experimental support for the upcoming ISO C++ standard, C++0x. 10601 * Support for TR1 mathematical special functions and regular 10602 expressions. 10603 * Default what implementations give more elaborate exception strings 10604 for bad_cast, bad_typeid, bad_exception, and bad_alloc. 10605 * Header dependencies have been streamlined, reducing unnecessary 10606 includes and pre-processed bloat. 10607 * Variadic template implementations of items in <tuple> and 10608 <functional>. 10609 * An experimental [11]parallel mode has been added. This is a 10610 parallel implementation of many C++ Standard library algorithms, 10611 like std::accumulate, std::for_each, std::transform, or std::sort, 10612 to give but four examples. These algorithms can be substituted for 10613 the normal (sequential) libstdc++ algorithms on a piecemeal basis, 10614 or all existing algorithms can be transformed via the 10615 -D_GLIBCXX_PARALLEL macro. 10616 * Debug mode versions of classes in <unordered_set> and 10617 <unordered_map>. 10618 * Formal deprecation of <ext/hash_set> and <ext/hash_map>, which are 10619 now <backward/hash_set> and <backward/hash_map>. This code: 10620 #include <ext/hash_set> 10621 __gnu_cxx::hash_set<int> s; 10622 10623 Can be transformed (in order of preference) to: 10624 #include <tr1/unordered_set> 10625 std::tr1::unordered_set<int> s; 10626 10627 or 10628 #include <backward/hash_set> 10629 __gnu_cxx::hash_set<int> s; 10630 10631 Similar transformations apply to __gnu_cxx::hash_map, 10632 __gnu_cxx::hash_multimap, __gnu_cxx::hash_set, 10633 __gnu_cxx::hash_multiset. 10634 10635 Fortran 10636 10637 * Due to the fact that the GMP and MPFR libraries are required for 10638 all languages, Fortran is no longer special in this regard and is 10639 available by default. 10640 * The [12]-fexternal-blas option has been added, which generates 10641 calls to BLAS routines for intrinsic matrix operations such as 10642 matmul rather than using the built-in algorithms. 10643 * Support to give a backtrace (compiler flag -fbacktrace or 10644 environment variable GFORTRAN_ERROR_BACKTRACE; on glibc systems 10645 only) or a core dump (-fdump-core, GFORTRAN_ERROR_DUMPCORE) when a 10646 run-time error occured. 10647 * GNU Fortran now defines __GFORTRAN__ when it runs the C 10648 preprocessor (CPP). 10649 * The [13]-finit-local-zero, -finit-real, -finit-integer, 10650 -finit-character, and -finit-logical options have been added, which 10651 can be used to initialize local variables. 10652 * The intrinsic procedures [14]GAMMA and [15]LGAMMA have been added, 10653 which calculate the Gamma function and its logarithm. Use EXTERNAL 10654 gamma if you want to use your own gamma function. 10655 * GNU Fortran now regards the backslash character as literal (as 10656 required by the Fortran 2003 standard); using [16]-fbackslash GNU 10657 Fortran interprets backslashes as C-style escape characters. 10658 * The [17]interpretation of binary, octal and hexadecimal (BOZ) 10659 literal constants has been changed. Before they were always 10660 interpreted as integer; now they are bit-wise transferred as 10661 argument of INT, REAL, DBLE and CMPLX as required by the Fortran 10662 2003 standard, and for real and complex variables in DATA 10663 statements or when directly assigned to real and complex variables. 10664 Everywhere else and especially in expressions they are still 10665 regarded as integer constants. 10666 * Fortran 2003 support has been extended: 10667 + Intrinsic statements IMPORT, PROTECTED, VALUE and VOLATILE 10668 + Pointer intent 10669 + Intrinsic module ISO_ENV_FORTRAN 10670 + Interoperability with C (ISO C Bindings) 10671 + ABSTRACT INTERFACES and PROCEDURE statements (without POINTER 10672 attribute) 10673 + Fortran 2003 BOZ 10674 10675 Java (GCJ) 10676 10677 * GCJ now uses the Eclipse Java compiler for its Java parsing needs. 10678 This enables the use of all 1.5 language features, and fixes most 10679 existing front end bugs. 10680 * libgcj now supports all 1.5 language features which require runtime 10681 support: foreach, enum, annotations, generics, and auto-boxing. 10682 * We've made many changes to the tools shipped with gcj. 10683 + The old jv-scan tool has been removed. This tool never really 10684 worked properly. There is no replacement. 10685 + gcjh has been rewritten. Some of its more obscure options no 10686 longer work, but are still recognized in an attempt at 10687 compatibility. gjavah is a new program with similar 10688 functionality but different command-line options. 10689 + grmic and grmiregistry have been rewritten. grmid has been 10690 added. 10691 + gjar replaces the old fastjar. 10692 + gjarsigner (used for signing jars), gkeytool (used for key 10693 management), gorbd (for CORBA), gserialver (computes 10694 serialization UIDs), and gtnameserv (also for CORBA) are now 10695 installed. 10696 * The ability to dump the contents of the java run time heap to a 10697 file for off-line analysis has been added. The heap dumps may be 10698 analyzed with the new gc-analyze tool. They may be generated on 10699 out-of-memory conditions or on demand and are controlled by the new 10700 run time class gnu.gcj.util.GCInfo. 10701 * java.util.TimeZone can now read files from /usr/share/zoneinfo to 10702 provide correct, updated, timezone information. This means that 10703 packagers no longer have to update libgcj when a time zone change 10704 is published. 10705 10706 New Targets and Target Specific Improvements 10707 10708 IA-32/x86-64 10709 10710 * Tuning for Intel Core 2 processors is available via -mtune=core2 10711 and -march=core2. 10712 * Tuning for AMD Geode processors is available via -mtune=geode and 10713 -march=geode. 10714 * Code generation of block move (memcpy) and block set (memset) was 10715 rewritten. GCC can now pick the best algorithm (loop, unrolled 10716 loop, instruction with rep prefix or a library call) based on the 10717 size of the block being copied and the CPU being optimized for. A 10718 new option -minline-stringops-dynamically has been added. With this 10719 option string operations of unknown size are expanded such that 10720 small blocks are copied by in-line code, while for large blocks a 10721 library call is used. This results in faster code than 10722 -minline-all-stringops when the library implementation is capable 10723 of using cache hierarchy hints. The heuristic choosing the 10724 particular algorithm can be overwritten via -mstringop-strategy. 10725 Newly also memset of values different from 0 is inlined. 10726 * GCC no longer places the cld instruction before string operations. 10727 Both i386 and x86-64 ABI documents mandate the direction flag to be 10728 clear at the entry of a function. It is now invalid to set the flag 10729 in asm statement without reseting it afterward. 10730 * Support for SSSE3 built-in functions and code generation are 10731 available via -mssse3. 10732 * Support for SSE4.1 built-in functions and code generation are 10733 available via -msse4.1. 10734 * Support for SSE4.2 built-in functions and code generation are 10735 available via -msse4.2. 10736 * Both SSE4.1 and SSE4.2 support can be enabled via -msse4. 10737 * A new set of options -mpc32, -mpc64 and -mpc80 have been added to 10738 allow explicit control of x87 floating point precision. 10739 * Support for __float128 (TFmode) IEEE quad type and corresponding 10740 TCmode IEEE complex quad type is available via the soft-fp library 10741 on x86_64 targets. This includes basic arithmetic operations 10742 (addition, subtraction, negation, multiplication and division) on 10743 __float128 real and TCmode complex values, the full set of IEEE 10744 comparisons between __float128 values, conversions to and from 10745 float, double and long double floating point types, as well as 10746 conversions to and from signed or unsigned integer, signed or 10747 unsigned long integer and signed or unsigned quad (TImode) integer 10748 types. Additionally, all operations generate the full set of IEEE 10749 exceptions and support the full set of IEEE rounding modes. 10750 * GCC can now utilize the ACML library for vectorizing calls to a set 10751 of C99 functions on x86_64 if -mveclibabi=acml is specified and you 10752 link to an ACML ABI compatible library. 10753 10754 ARM 10755 10756 * Compiler and Library support for Thumb-2 and the ARMv7 architecture 10757 has been added. 10758 10759 CRIS 10760 10761 New features 10762 10763 * Compiler and Library support for the CRIS v32 architecture, as 10764 found in Axis Communications ETRAX FS and ARTPEC-3 chips, has been 10765 added. 10766 10767 Configuration changes 10768 10769 * The cris-*-elf target now includes support for CRIS v32, including 10770 libraries, through the -march=v32 option. 10771 * A new crisv32-*-elf target defaults to generate code for CRIS v32. 10772 * A new crisv32-*-linux* target defaults to generate code for CRIS 10773 v32. 10774 * The cris-*-aout target has been obsoleted. 10775 10776 Improved support for built-in functions 10777 10778 * GCC can now use the lz and swapwbr instructions to implement the 10779 __builtin_clz, __builtin_ctz and __builtin_ffs family of functions. 10780 * __builtin_bswap32 is now implemented using the swapwb instruction, 10781 when available. 10782 10783 m68k and ColdFire 10784 10785 New features 10786 10787 * Support for several new ColdFire processors has been added. You can 10788 generate code for them using the new -mcpu option. 10789 * All targets now support ColdFire processors. 10790 * m68k-uclinux targets have improved support for C++ constructors and 10791 destructors, and for shared libraries. 10792 * It is now possible to set breakpoints on the first or last line of 10793 a function, even if there are no statements on that line. 10794 10795 Optimizations 10796 10797 * Support for sibling calls has been added. 10798 * More use is now made of the ColdFire mov3q instruction. 10799 * __builtin_clz is now implemented using the ff1 ColdFire 10800 instruction, when available. 10801 * GCC now honors the -m68010 option. 68010 code now uses clr rather 10802 than move to zero volatile memory. 10803 * 68020 targets and above can now use symbol(index.size*scale) 10804 addresses for indexed array accesses. Earlier compilers would 10805 always load the symbol into a base register first. 10806 10807 Configuration changes 10808 10809 * All m68k and ColdFire targets now allow the default processor to be 10810 set at configure time using --with-cpu. 10811 * A --with-arch configuration option has been added. This option 10812 allows you to restrict a target to ColdFire or non-ColdFire 10813 processors. 10814 10815 Preprocessor macros 10816 10817 * An __mcfv*__ macro is now defined for all ColdFire targets. 10818 (Earlier versions of GCC only defined __mcfv4e__.) 10819 * __mcf_cpu_*, __mcf_family_* and __mcffpu__ macros have been added. 10820 * All targets now define __mc68010 and __mc68010__ when generating 10821 68010 code. 10822 10823 Command-line changes 10824 10825 * New command-line options -march, -mcpu, -mtune and -mhard-float 10826 have been added. These options apply to both m68k and ColdFire 10827 targets. 10828 * -mno-short, -mno-bitfield and -mno-rtd are now accepted as negative 10829 versions of -mshort, etc. 10830 * -fforce-addr has been removed. It is now ignored by the compiler. 10831 10832 Other improvements 10833 10834 * ColdFire targets now try to maintain a 4-byte-aligned stack where 10835 possible. 10836 * m68k-uclinux targets now try to avoid situations that lead to the 10837 load-time error: BINFMT_FLAT: reloc outside program. 10838 10839 MIPS 10840 10841 Changes to existing configurations 10842 10843 * libffi and libjava now support all three GNU/Linux ABIs: o32, n32 10844 and n64. Every GNU/Linux configuration now builds these libraries 10845 by default. 10846 * GNU/Linux configurations now generate -mno-shared code unless 10847 overridden by -fpic, -fPIC, -fpie or -fPIE. 10848 * mipsisa32*-linux-gnu configurations now generate hard-float code by 10849 default, just like other mipsisa32* and mips*-linux-gnu 10850 configurations. You can build a soft-float version of any 10851 mips*-linux-gnu configuration by passing --with-float=soft to 10852 configure. 10853 * mips-wrs-vxworks now supports run-time processes (RTPs). 10854 10855 Changes to existing command-line options 10856 10857 * The -march and -mtune options no longer accept 24k as a processor 10858 name. Please use 24kc, 24kf2_1 or 24kf1_1 instead. 10859 * The -march and -mtune options now accept 24kf2_1, 24kef2_1 and 10860 34kf2_1 as synonyms for 24kf, 24kef and 34kf respectively. The 10861 options also accept 24kf1_1, 24kef1_1 and 34kf1_1 as synonyms for 10862 24kx, 24kex and 34kx. 10863 10864 New configurations 10865 10866 GCC now supports the following configurations: 10867 * mipsisa32r2*-linux-gnu*, which generates MIPS32 revision 2 code by 10868 default. Earlier releases also recognized this configuration, but 10869 they treated it in the same way as mipsisa32*-linux-gnu*. Note that 10870 you can customize any mips*-linux-gnu* configuration to a 10871 particular ISA or processor by passing an appropriate --with-arch 10872 option to configure. 10873 * mipsisa*-sde-elf*, which provides compatibility with MIPS 10874 Technologies' SDE toolchains. The configuration uses the SDE 10875 libraries by default, but you can use it like other newlib-based 10876 ELF configurations by passing --with-newlib to configure. It is the 10877 only configuration besides mips64vr*-elf* to build MIPS16 as well 10878 as non-MIPS16 libraries. 10879 * mipsisa*-elfoabi*, which is similar to the general mipsisa*-elf* 10880 configuration, but uses the o32 and o64 ABIs instead of the 32-bit 10881 and 64-bit forms of the EABI. 10882 10883 New processors and application-specific extensions 10884 10885 * Support for the SmartMIPS ASE is available through the new 10886 -msmartmips option. 10887 * Support for revision 2 of the DSP ASE is available through the new 10888 -mdspr2 option. A new preprocessor macro called __mips_dsp_rev 10889 indicates the revision of the ASE in use. 10890 * Support for the 4KS and 74K families of processors is available 10891 through the -march and -mtune options. 10892 10893 Improved support for built-in functions 10894 10895 * GCC can now use load-linked, store-conditional and sync 10896 instructions to implement atomic built-in functions such as 10897 __sync_fetch_and_add. The memory reference must be 4 bytes wide for 10898 32-bit targets and either 4 or 8 bytes wide for 64-bit targets. 10899 * GCC can now use the clz and dclz instructions to implement the 10900 __builtin_ctz and __builtin_ffs families of functions. 10901 * There is a new __builtin___clear_cache function for flushing the 10902 instruction cache. GCC expands this function inline on MIPS32 10903 revision 2 targets, otherwise it calls the function specified by 10904 -mcache-flush-func. 10905 10906 MIPS16 improvements 10907 10908 * GCC can now compile objects that contain a mixture of MIPS16 and 10909 non-MIPS16 code. There are two new attributes, mips16 and nomips16, 10910 for specifying which mode a function should use. 10911 * A new option called -minterlink-mips16 makes non-MIPS16 code 10912 link-compatible with MIPS16 code. 10913 * After many bug fixes, the long-standing MIPS16 -mhard-float support 10914 should now work fairly reliably. 10915 * GCC can now use the MIPS16e save and restore instructions. 10916 * -fsection-anchors now works in MIPS16 mode. MIPS16 code compiled 10917 with -G0 -fsection-anchors is often smaller than code compiled with 10918 -G8. However, please note that you must usually compile all objects 10919 in your application with the same -G option; see the documentation 10920 of -G for details. 10921 * A new option called-mcode-readable specifies which instructions are 10922 allowed to load from the code segment. -mcode-readable=yes is the 10923 default and says that any instruction may load from the code 10924 segment. The other alternatives are -mcode-readable=pcrel, which 10925 says that only PC-relative MIPS16 instructions may load from the 10926 code segment, and -mcode-readable=no, which says that no 10927 instruction may do so. Please see the documentation for more 10928 details, including example uses. 10929 10930 Small-data improvements 10931 10932 There are three new options for controlling small data: 10933 * -mno-extern-sdata, which disables small-data accesses for 10934 externally-defined variables. Code compiled with -Gn 10935 -mno-extern-sdata will be link-compatible with any -G setting 10936 between -G0 and -Gn inclusive. 10937 * -mno-local-sdata, which disables the use of small-data sections for 10938 data that is not externally visible. This option can be a useful 10939 way of reducing small-data usage in less performance-critical parts 10940 of an application. 10941 * -mno-gpopt, which disables the use of the $gp register while still 10942 honoring the -G limit when placing externally-visible data. This 10943 option implies -mno-extern-sdata and -mno-local-sdata and it can be 10944 useful in situations where $gp does not necessarily hold the 10945 expected value. 10946 10947 Miscellaneous improvements 10948 10949 * There is a new option called -mbranch-cost for tweaking the 10950 perceived cost of branches. 10951 * If GCC is configured to use a version of GAS that supports the 10952 .gnu_attribute directive, it will use that directive to record 10953 certain properties of the output code. .gnu_attribute is new to GAS 10954 2.18. 10955 * There are two new function attributes, near and far, for overriding 10956 the command-line setting of -mlong-calls on a function-by-function 10957 basis. 10958 * -mfp64, which previously required a 64-bit target, now works with 10959 MIPS32 revision 2 targets as well. The mipsisa*-elfoabi* and 10960 mipsisa*-sde-elf* configurations provide suitable library support. 10961 * GCC now recognizes the -mdmx and -mmt options and passes them down 10962 to the assembler. It does nothing else with the options at present. 10963 10964 SPU (Synergistic Processor Unit) of the Cell Broadband Engine Architecture 10965 (BEA) 10966 10967 * Support has been added for this new architecture. 10968 10969 RS6000 (POWER/PowerPC) 10970 10971 * Support for the PowerPC 750CL paired-single instructions has been 10972 added with a new powerpc-*-linux*paired* target configuration. It 10973 is enabled by an associated -mpaired option and can be accessed 10974 using new built-in functions. 10975 * Support for auto-detecting architecture and system configuration to 10976 auto-select processor optimization tuning. 10977 * Support for VMX on AIX 5.3 has been added. 10978 * Support for AIX Version 6.1 has been added. 10979 10980 S/390, zSeries and System z9 10981 10982 * Support for the IBM System z9 EC/BC processor (z9 GA3) has been 10983 added. When using the -march=z9-ec option, the compiler will 10984 generate code making use of instructions provided by the decimal 10985 floating point facility and the floating point conversion facility 10986 (pfpo). Besides the instructions used to implement decimal floating 10987 point operations these facilities also contain instructions to move 10988 between general purpose and floating point registers and to modify 10989 and copy the sign-bit of floating point values. 10990 * When the -march=z9-ec option is used the new 10991 -mhard-dfp/-mno-hard-dfp options can be used to specify whether the 10992 decimal floating point hardware instructions will be used or not. 10993 If none of them is given the hardware support is enabled by 10994 default. 10995 * The -mstack-guard option can now be omitted when using stack 10996 checking via -mstack-size in order to let GCC choose a sensible 10997 stack guard value according to the frame size of each function. 10998 * Various changes to improve performance of generated code have been 10999 implemented, including: 11000 + The condition code set by an add logical with carry 11001 instruction is now available for overflow checks like: a + b + 11002 carry < b. 11003 + The test data class instruction is now used to implement 11004 sign-bit and infinity checks of binary and decimal floating 11005 point numbers. 11006 11007 SPARC 11008 11009 * Support for the Sun UltraSPARC T2 (Niagara 2) processor has been 11010 added. 11011 11012 Xtensa 11013 11014 * Stack unwinding for exception handling now uses by default a 11015 specialized version of DWARF unwinding. This is not 11016 binary-compatible with the setjmp/longjmp (sjlj) unwinding used for 11017 Xtensa with previous versions of GCC. 11018 * For Xtensa processors that include the Conditional Store option, 11019 the built-in functions for atomic memory access are now implemented 11020 using S32C1I instructions. 11021 * If the Xtensa NSA option is available, GCC will use it to implement 11022 the __builtin_ctz and __builtin_clz functions. 11023 11024 Documentation improvements 11025 11026 * Existing libstdc++ documentation has been edited and restructured 11027 into a single DocBook XML manual. The results can be viewed online 11028 [18]here. 11029 11030 Other significant improvements 11031 11032 * The compiler's --help command-line option has been extended so that 11033 it now takes an optional set of arguments. These arguments restrict 11034 the information displayed to specific classes of command-line 11035 options, and possibly only a subset of those options. It is also 11036 now possible to replace the descriptive text associated with each 11037 displayed option with an indication of its current value, or for 11038 binary options, whether it has been enabled or disabled. 11039 Here are some examples. The following will display all the options 11040 controlling warning messages: 11041 --help=warnings 11042 11043 Whereas this will display all the undocumented, target specific 11044 options: 11045 --help=target,undocumented 11046 11047 This sequence of commands will display the binary optimizations 11048 that are enabled by -O3: 11049 gcc -c -Q -O3 --help=optimizers > /tmp/O3-opts 11050 gcc -c -Q -O2 --help=optimizers > /tmp/O2-opts 11051 diff /tmp/O2-opts /tmp/O3-opts | grep enabled 11052 11053 * The configure options --with-pkgversion and --with-bugurl have been 11054 added. These allow distributors of GCC to include a 11055 distributor-specific string in manuals and --version output and to 11056 specify the URL for reporting bugs in their versions of GCC. 11057 11058 GCC 4.3.1 11059 11060 This is the [19]list of problem reports (PRs) from GCC's bug tracking 11061 system that are known to be fixed in the 4.3.1 release. This list might 11062 not be complete (that is, it is possible that some PRs that have been 11063 fixed are not listed here). 11064 11065 Target Specific Changes 11066 11067 IA-32/x86-64 11068 11069 ABI changes 11070 11071 * Starting with GCC 4.3.1, decimal floating point variables are 11072 aligned to their natural boundaries when they are passed on the 11073 stack for i386. 11074 11075 Command-line changes 11076 11077 * Starting with GCC 4.3.1, the -mcld option has been added to 11078 automatically generate a cld instruction in the prologue of 11079 functions that use string instructions. This option is used for 11080 backward compatibility on some operating systems and can be enabled 11081 by default for 32-bit x86 targets by configuring GCC with the 11082 --enable-cld configure option. 11083 11084 GCC 4.3.2 11085 11086 This is the [20]list of problem reports (PRs) from GCC's bug tracking 11087 system that are known to be fixed in the 4.3.2 release. This list might 11088 not be complete (that is, it is possible that some PRs that have been 11089 fixed are not listed here). 11090 11091 GCC 4.3.3 11092 11093 This is the [21]list of problem reports (PRs) from GCC's bug tracking 11094 system that are known to be fixed in the 4.3.3 release. This list might 11095 not be complete (that is, it is possible that some PRs that have been 11096 fixed are not listed here). 11097 11098 GCC 4.3.4 11099 11100 This is the [22]list of problem reports (PRs) from GCC's bug tracking 11101 system that are known to be fixed in the 4.3.4 release. This list might 11102 not be complete (that is, it is possible that some PRs that have been 11103 fixed are not listed here). 11104 11105 GCC 4.3.5 11106 11107 This is the [23]list of problem reports (PRs) from GCC's bug tracking 11108 system that are known to be fixed in the 4.3.5 release. This list might 11109 not be complete (that is, it is possible that some PRs that have been 11110 fixed are not listed here). 11111 11112 GCC 4.3.6 11113 11114 This is the [24]list of problem reports (PRs) from GCC's bug tracking 11115 system that are known to be fixed in the 4.3.6 release. This list might 11116 not be complete (that is, it is possible that some PRs that have been 11117 fixed are not listed here). 11118 11119 11120 For questions related to the use of GCC, please consult these web 11121 pages and the [25]GCC manuals. If that fails, the 11122 [26]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 11123 web pages and the development of GCC are welcome on our developer 11124 list at [27]gcc (a] gcc.gnu.org. All of [28]our lists have public 11125 archives. 11126 11127 Copyright (C) [29]Free Software Foundation, Inc. Verbatim copying and 11128 distribution of this entire article is permitted in any medium, 11129 provided this notice is preserved. 11130 11131 These pages are [30]maintained by the GCC team. Last modified 11132 2019-11-28[31]. 11133 11134 References 11135 11136 1. http://gcc.gnu.org/gcc-4.3/changes.html#4.3.5 11137 2. https://gmplib.org/ 11138 3. https://www.mpfr.org/ 11139 4. https://gcc.gnu.org/install/prerequisites.html 11140 5. https://gcc.gnu.org/ml/gcc-announce/2001/msg00000.html 11141 6. https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#Warning-Options 11142 7. http://gcc.gnu.org/gcc-4.3/porting_to.html 11143 8. https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html 11144 9. http://gcc.gnu.org/gcc-4.3/cxx0x_status.html 11145 10. http://gcc.gnu.org/gcc-4.3/cxx0x_status.html 11146 11. https://gcc.gnu.org/onlinedocs/libstdc++/manual/parallel_mode.html 11147 12. https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html#Code-Gen-Options 11148 13. https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html#index-g_t_0040code_007bfinit-local-zero_007d-167 11149 14. https://gcc.gnu.org/onlinedocs/gcc-4.3.0/gfortran/GAMMA.html 11150 15. https://gcc.gnu.org/onlinedocs/gcc-4.3.0/gfortran/LGAMMA.html 11151 16. https://gcc.gnu.org/onlinedocs/gfortran/Fortran-Dialect-Options.html 11152 17. https://gcc.gnu.org/onlinedocs/gfortran/BOZ-literal-constants.html 11153 18. https://gcc.gnu.org/onlinedocs/libstdc++/ 11154 19. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.3.1 11155 20. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.3.2 11156 21. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.3.3 11157 22. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.3.4 11158 23. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.3.5 11159 24. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.3.6 11160 25. https://gcc.gnu.org/onlinedocs/ 11161 26. mailto:gcc-help (a] gcc.gnu.org 11162 27. mailto:gcc (a] gcc.gnu.org 11163 28. https://gcc.gnu.org/lists.html 11164 29. https://www.fsf.org/ 11165 30. https://gcc.gnu.org/about.html 11166 31. http://validator.w3.org/check/referer 11167 ====================================================================== 11168 http://gcc.gnu.org/gcc-4.2/index.html 11169 GCC 4.2 Release Series 11170 11171 (This release series is no longer supported.) 11172 11173 May 19, 2008 11174 11175 The [1]GNU project and the GCC developers are pleased to announce the 11176 release of GCC 4.2.4. 11177 11178 This release is a bug-fix release, containing fixes for regressions in 11179 GCC 4.2.3 relative to previous releases of GCC. 11180 11181 Release History 11182 11183 GCC 4.2.4 11184 May 19, 2008 ([2]changes) 11185 11186 GCC 4.2.3 11187 February 1, 2008 ([3]changes) 11188 11189 GCC 4.2.2 11190 October 7, 2007 ([4]changes) 11191 11192 GCC 4.2.1 11193 July 18, 2007 ([5]changes) 11194 11195 GCC 4.2.0 11196 May 13, 2007 ([6]changes) 11197 11198 References and Acknowledgements 11199 11200 GCC used to stand for the GNU C Compiler, but since the compiler 11201 supports several other languages aside from C, it now stands for the 11202 GNU Compiler Collection. 11203 11204 A list of [7]successful builds is updated as new information becomes 11205 available. 11206 11207 The GCC developers would like to thank the numerous people that have 11208 contributed new features, improvements, bug fixes, and other changes as 11209 well as test results to GCC. This [8]amazing group of volunteers is 11210 what makes GCC successful. 11211 11212 For additional information about GCC please refer to the [9]GCC project 11213 web site or contact the [10]GCC development mailing list. 11214 11215 To obtain GCC please use [11]our mirror sites or [12]our version 11216 control system. 11217 11218 11219 For questions related to the use of GCC, please consult these web 11220 pages and the [13]GCC manuals. If that fails, the 11221 [14]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 11222 web pages and the development of GCC are welcome on our developer 11223 list at [15]gcc (a] gcc.gnu.org. All of [16]our lists have public 11224 archives. 11225 11226 Copyright (C) [17]Free Software Foundation, Inc. Verbatim copying and 11227 distribution of this entire article is permitted in any medium, 11228 provided this notice is preserved. 11229 11230 These pages are [18]maintained by the GCC team. Last modified 11231 2020-01-14[19]. 11232 11233 References 11234 11235 1. http://www.gnu.org/ 11236 2. http://gcc.gnu.org/gcc-4.2/changes.html 11237 3. http://gcc.gnu.org/gcc-4.2/changes.html 11238 4. http://gcc.gnu.org/gcc-4.2/changes.html 11239 5. http://gcc.gnu.org/gcc-4.2/changes.html 11240 6. http://gcc.gnu.org/gcc-4.2/changes.html 11241 7. http://gcc.gnu.org/gcc-4.2/buildstat.html 11242 8. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 11243 9. http://gcc.gnu.org/index.html 11244 10. mailto:gcc (a] gcc.gnu.org 11245 11. http://gcc.gnu.org/mirrors.html 11246 12. http://gcc.gnu.org/git.html 11247 13. https://gcc.gnu.org/onlinedocs/ 11248 14. mailto:gcc-help (a] gcc.gnu.org 11249 15. mailto:gcc (a] gcc.gnu.org 11250 16. https://gcc.gnu.org/lists.html 11251 17. https://www.fsf.org/ 11252 18. https://gcc.gnu.org/about.html 11253 19. http://validator.w3.org/check/referer 11254 ====================================================================== 11255 http://gcc.gnu.org/gcc-4.2/changes.html 11256 GCC 4.2 Release Series 11257 Changes, New Features, and Fixes 11258 11259 Caveats 11260 11261 * GCC no longer accepts the -fshared-data option. This option has had 11262 no effect in any GCC 4 release; the targets to which the option 11263 used to apply had been removed before GCC 4.0. 11264 11265 General Optimizer Improvements 11266 11267 * New command-line options specify the possible relationships among 11268 parameters and between parameters and global data. For example, 11269 -fargument-noalias-anything specifies that arguments do not alias 11270 any other storage. 11271 Each language will automatically use whatever option is required by 11272 the language standard. You should not need to use these options 11273 yourself. 11274 11275 New Languages and Language specific improvements 11276 11277 * [1]OpenMP is now supported for the C, C++ and Fortran compilers. 11278 * New command-line options -fstrict-overflow and -Wstrict-overflow 11279 have been added. -fstrict-overflow tells the compiler that it may 11280 assume that the program follows the strict signed overflow 11281 semantics permitted for the language: for C and C++ this means that 11282 the compiler may assume that signed overflow does not occur. For 11283 example, a loop like 11284 for (i = 1; i > 0; i *= 2) 11285 11286 is presumably intended to continue looping until i overflows. With 11287 -fstrict-overflow, the compiler may assume that signed overflow 11288 will not occur, and transform this into an infinite loop. 11289 -fstrict-overflow is turned on by default at -O2, and may be 11290 disabled via -fno-strict-overflow. The -Wstrict-overflow option may 11291 be used to warn about cases where the compiler assumes that signed 11292 overflow will not occur. It takes five different levels: 11293 -Wstrict-overflow=1 to 5. See the [2]documentation for details. 11294 -Wstrict-overflow=1 is enabled by -Wall. 11295 * The new command-line option -fno-toplevel-reorder directs GCC to 11296 emit top-level functions, variables, and asm statements in the same 11297 order that they appear in the input file. This is intended to 11298 support existing code which relies on a particular ordering (for 11299 example, code which uses top-level asm statements to switch 11300 sections). For new code, it is generally better to use function and 11301 variable attributes. The -fno-toplevel-reorder option may be used 11302 for most cases which currently use -fno-unit-at-a-time. The 11303 -fno-unit-at-a-time option will be removed in some future version 11304 of GCC. If you know of a case which requires -fno-unit-at-a-time 11305 which is not fixed by -fno-toplevel-reorder, please open a bug 11306 report. 11307 11308 C family 11309 11310 * The pragma redefine_extname will now macro expand its tokens for 11311 compatibility with SunPRO. 11312 * In the next release of GCC, 4.3, -std=c99 or -std=gnu99 will direct 11313 GCC to handle inline functions as specified in the C99 standard. In 11314 preparation for this, GCC 4.2 will warn about any use of non-static 11315 inline functions in gnu99 or c99 mode. This new warning may be 11316 disabled with the new gnu_inline function attribute or the new 11317 -fgnu89-inline command-line option. Also, GCC 4.2 and later will 11318 define one of the preprocessor macros __GNUC_GNU_INLINE__ or 11319 __GNUC_STDC_INLINE__ to indicate the semantics of inline functions 11320 in the current compilation. 11321 * A new command-line option -Waddress has been added to warn about 11322 suspicious uses of memory addresses as, for example, using the 11323 address of a function in a conditional expression, and comparisons 11324 against the memory address of a string literal. This warning is 11325 enabled by -Wall. 11326 11327 C++ 11328 11329 * C++ visibility handling has been overhauled. 11330 Restricted visiblity is propagated from classes to members, from 11331 functions to local statics, and from templates and template 11332 arguments to instantiations, unless the latter has explicitly 11333 declared visibility. 11334 The visibility attribute for a class must come between the 11335 class-key and the name, not after the closing brace. 11336 Attributes are now allowed for enums and elaborated-type-specifiers 11337 that only declare a type. 11338 Members of the anonymous namespace are now local to a particular 11339 translation unit, along with any other declarations which use them, 11340 though they are still treated as having external linkage for 11341 language semantics. 11342 * The (undocumented) extension which permitted templates with default 11343 arguments to be bound to template template parameters with fewer 11344 parameters has been removed. For example: 11345 template <template <typename> class C> 11346 void f(C<double>) {} 11347 11348 template <typename T, typename U = int> 11349 struct S {}; 11350 11351 template void f(S<double>); 11352 11353 is no longer accepted by G++. The reason this code is not accepted 11354 is that S is a template with two parameters; therefore, it cannot 11355 be bound to C which has only one parameter. 11356 * The <?, >?, <?=, and >?= operators, deprecated in previous GCC 11357 releases, have been removed. 11358 * The command-line option -fconst-strings, deprecated in previous GCC 11359 releases, has been removed. 11360 * The configure variable enable-__cxa_atexit is now enabled by 11361 default for more targets. Enabling this variable is necessary in 11362 order for static destructors to be executed in the correct order, 11363 but it depends upon the presence of a non-standard C library in the 11364 target library in order to work. The variable is now enabled for 11365 more targets which are known to have suitable C libraries. 11366 * -Wextra will produce warnings for if statements with a semicolon as 11367 the only body, to catch code like: 11368 if (a); 11369 return 1; 11370 return 0; 11371 11372 To suppress the warning in valid cases, use { } instead. 11373 * The C++ front end now also produces strict aliasing warnings when 11374 -fstrict-aliasing -Wstrict-aliasing is in effect. 11375 11376 Runtime Library (libstdc++) 11377 11378 * Added support for TR1 <random>, <complex>, and C compatibility 11379 headers. In addition, a lock-free version of shared_ptr was 11380 contributed as part of Phillip Jordan's Google Summer of Code 11381 project on lock-free containers. 11382 * In association with the Summer of Code work on lock-free 11383 containers, the interface for atomic builtins was adjusted, 11384 creating simpler alternatives for non-threaded code paths. Also, 11385 usage was consolidated and all elements were moved from namespace 11386 std to namespace__gnu_cxx. Affected interfaces are the functions 11387 __exchange_and_add, __atomic_add, and the objects __mutex, 11388 __recursive_mutex, and __scoped_lock. 11389 * Support for versioning weak symbol names via namespace association 11390 was added. However, as this changes the names of exported symbols, 11391 this is turned off by default in the current ABI. Intrepid users 11392 can enable this feature by using 11393 --enable-symvers=gnu-versioned-namespace during configuration. 11394 * Revised, simplified, and expanded policy-based associative 11395 containers, including data types for tree and trie forms 11396 (basic_tree, tree, trie), lists (list_update), and both 11397 collision-chaining and probing hash-based containers 11398 (basic_hash_table, cc_hash_table, gp_hash_table). More details per 11399 the [3]documentation. 11400 * The implementation of the debug mode was modified, whereby the 11401 debug namespaces were nested inside of namespace std and namespace 11402 __gnu_cxx in order to resolve some long standing corner cases 11403 involving name lookup. Debug functionality from the policy-based 11404 data structures was consolidated and enabled with the single macro, 11405 _GLIBCXX_DEBUG. See PR 26142 for more information. 11406 * Added extensions for type traits: __conditional_type, 11407 __numeric_traits, __add_unsigned, __removed_unsigned, __enable_if. 11408 * Added a typelist implementation for compile-time meta-programming. 11409 Elements for typelist construction and operation can be found 11410 within namespace __gnu_cxx::typelist. 11411 * Added a new allocator, __gnu_cxx::throw_allocator, for testing 11412 exception-safety. 11413 * Enabled library-wide visibility control, allowing -fvisibility to 11414 be used. 11415 * Consolidated all nested namespaces and the conversion of 11416 __gnu_internal implementation-private details to anonymous 11417 namespaces whenever possible. 11418 * Implemented LWG resolutions DR 431 and DR 538. 11419 11420 Fortran 11421 11422 * Support for allocatable components has been added (TR 15581 and 11423 Fortran 2003). 11424 * Support for the Fortran 2003 streaming IO extension has been added. 11425 * The GNU Fortran compiler now uses 4-byte record markers by default 11426 for unformatted files to be compatible with g77 and most other 11427 compilers. The implementation allows for records greater than 2 GB 11428 and is compatible with several other compilers. Older versions of 11429 gfortran used 8-byte record markers by default (on most systems). 11430 In order to change the length of the record markers, e.g. to read 11431 unformatted files created by older gfortran versions, the 11432 [4]-frecord-marker=8 option can be used. 11433 11434 Java (GCJ) 11435 11436 * A new command-line option -static-libgcj has been added for targets 11437 that use a linker compatible with GNU Binutils. As its name 11438 implies, this causes libgcj to be linked statically. In some cases 11439 this causes the resulting executable to start faster and use less 11440 memory than if the shared version of libgcj were used. However 11441 caution should be used as it can also cause essential parts of the 11442 library to be omitted. Some of these issues are discussed in: 11443 [5]https://gcc.gnu.org/wiki/Statically_linking_libgcj 11444 * fastjar is no longer bundled with GCC. To build libgcj, you will 11445 need either InfoZIP (both zip and unzip) or an external jar 11446 program. In the former case, the GCC build will install a jar shell 11447 script that is based on InfoZIP and provides the same functionality 11448 as fastjar. 11449 11450 New Targets and Target Specific Improvements 11451 11452 IA-32/x86-64 11453 11454 * -mtune=generic can now be used to generate code running well on 11455 common x86 chips. This includes AMD Athlon, AMD Opteron, Intel 11456 Pentium-M, Intel Pentium 4 and Intel Core 2. 11457 * -mtune=native and -march=native will produce code optimized for the 11458 host architecture as detected using the cpuid instruction. 11459 * Added a new command-line option -fstackrealign and and 11460 __attribute__ ((force_align_arg_pointer)) to realign the stack at 11461 runtime. This allows functions compiled with a vector-aligned stack 11462 to be invoked from legacy objects that keep only word-alignment. 11463 11464 SPARC 11465 11466 * The default CPU setting has been changed from V7 to V9 in 32-bit 11467 mode on Solaris 7 and above. This is already the case in 64-bit 11468 mode. It can be overridden by specifying --with-cpu at configure 11469 time. 11470 * Back-end support of built-in functions for atomic memory access has 11471 been implemented. 11472 * Support for the Sun UltraSPARC T1 (Niagara) processor has been 11473 added. 11474 11475 M32C 11476 11477 * Various bug fixes have made some functions (notably, functions 11478 returning structures) incompatible with previous releases. 11479 Recompiling all libraries is recommended. Note that code quality 11480 has considerably improved since 4.1, making a recompile even more 11481 beneficial. 11482 11483 MIPS 11484 11485 * Added support for the Broadcom SB-1A core. 11486 11487 IA-64 11488 11489 * Added support for IA-64 data and control speculation. By default 11490 speculation is enabled only during second scheduler pass. A number 11491 of machine flags was introduced to control the usage of speculation 11492 for both scheduler passes. 11493 11494 HPPA 11495 11496 * Added Java language support (libffi and libjava) for 32-bit HP-UX 11497 11 target. 11498 11499 Obsolete Systems 11500 11501 Documentation improvements 11502 11503 PDF Documentation 11504 11505 * A make pdf target has been added to the top-level makefile, 11506 enabling automated production of PDF documentation files. 11507 (Front-ends external to GCC should modify their Make-lang.in file 11508 to add a lang.pdf: target.) 11509 11510 Other significant improvements 11511 11512 Build system improvements 11513 11514 * All the components of the compiler are now bootstrapped by default. 11515 This improves the resilience to bugs in the system compiler or 11516 binary compatibility problems, as well as providing better testing 11517 of GCC 4.2 itself. In addition, if you build the compiler from a 11518 combined tree, the assembler, linker, etc. will also be 11519 bootstrapped (i.e. built with themselves). 11520 You can disable this behavior, and go back to the pre-GCC 4.2 set 11521 up, by configuring GCC with --disable-bootstrap. 11522 * The rules that configure follows to find target tools resemble more 11523 closely the locations that the built compiler will search. In 11524 addition, you can use the new configure option --with-target-tools 11525 to specify where to find the target tools used during the build, 11526 without affecting what the built compiler will use. 11527 This can be especially useful when building packages of GCC. For 11528 example, you may want to build GCC with GNU as or ld, even if the 11529 resulting compiler to work with the native assembler and linker. To 11530 do so, you can use --with-target-tools to point to the native 11531 tools. 11532 11533 Incompatible changes to the build system 11534 11535 * Front-ends external to GCC should modify their Make-lang.in file to 11536 replace double-colon rules (e.g. dvi::) with normal rules (like 11537 lang.dvi:). Front-end makefile hooks do not use double-colon rules 11538 anymore. 11539 * Up to GCC 4.1, a popular way to specify the target tools used 11540 during the build was to create directories named gas, binutils, 11541 etc. in the build tree, and create links to the tools from there. 11542 This does not work any more when the compiler is bootstrapped. The 11543 new configure option --with-target-tools provides a better way to 11544 achieve the same effect, and works for all native and cross 11545 settings. 11546 11547 11548 For questions related to the use of GCC, please consult these web 11549 pages and the [6]GCC manuals. If that fails, the 11550 [7]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 11551 web pages and the development of GCC are welcome on our developer 11552 list at [8]gcc (a] gcc.gnu.org. All of [9]our lists have public archives. 11553 11554 Copyright (C) [10]Free Software Foundation, Inc. Verbatim copying and 11555 distribution of this entire article is permitted in any medium, 11556 provided this notice is preserved. 11557 11558 These pages are [11]maintained by the GCC team. Last modified 11559 2019-11-28[12]. 11560 11561 References 11562 11563 1. http://gcc.gnu.org/projects/gomp/ 11564 2. https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html 11565 3. https://gcc.gnu.org/onlinedocs/libstdc++/ext/pb_ds/index.html 11566 4. https://gcc.gnu.org/onlinedocs/gfortran/Runtime-Options.html 11567 5. https://gcc.gnu.org/wiki/Statically_linking_libgcj 11568 6. https://gcc.gnu.org/onlinedocs/ 11569 7. mailto:gcc-help (a] gcc.gnu.org 11570 8. mailto:gcc (a] gcc.gnu.org 11571 9. https://gcc.gnu.org/lists.html 11572 10. https://www.fsf.org/ 11573 11. https://gcc.gnu.org/about.html 11574 12. http://validator.w3.org/check/referer 11575 ====================================================================== 11576 http://gcc.gnu.org/gcc-4.1/index.html 11577 GCC 4.1 Release Series 11578 11579 (This release series is no longer supported.) 11580 11581 February 13, 2007 11582 11583 The [1]GNU project and the GCC developers are pleased to announce the 11584 release of GCC 4.1.2. 11585 11586 This release is a bug-fix release, containing fixes for regressions in 11587 GCC 4.1.1 relative to previous releases of GCC. 11588 11589 Release History 11590 11591 GCC 4.1.2 11592 February 13, 2007 ([2]changes) 11593 11594 GCC 4.1.1 11595 May 24, 2006 ([3]changes) 11596 11597 GCC 4.1.0 11598 February 28, 2006 ([4]changes) 11599 11600 References and Acknowledgements 11601 11602 GCC used to stand for the GNU C Compiler, but since the compiler 11603 supports several other languages aside from C, it now stands for the 11604 GNU Compiler Collection. 11605 11606 A list of [5]successful builds is updated as new information becomes 11607 available. 11608 11609 The GCC developers would like to thank the numerous people that have 11610 contributed new features, improvements, bug fixes, and other changes as 11611 well as test results to GCC. This [6]amazing group of volunteers is 11612 what makes GCC successful. 11613 11614 For additional information about GCC please refer to the [7]GCC project 11615 web site or contact the [8]GCC development mailing list. 11616 11617 To obtain GCC please use [9]our mirror sites or [10]our version control 11618 system. 11619 11620 11621 For questions related to the use of GCC, please consult these web 11622 pages and the [11]GCC manuals. If that fails, the 11623 [12]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 11624 web pages and the development of GCC are welcome on our developer 11625 list at [13]gcc (a] gcc.gnu.org. All of [14]our lists have public 11626 archives. 11627 11628 Copyright (C) [15]Free Software Foundation, Inc. Verbatim copying and 11629 distribution of this entire article is permitted in any medium, 11630 provided this notice is preserved. 11631 11632 These pages are [16]maintained by the GCC team. Last modified 11633 2020-01-14[17]. 11634 11635 References 11636 11637 1. http://www.gnu.org/ 11638 2. http://gcc.gnu.org/gcc-4.1/changes.html#4.1.2 11639 3. http://gcc.gnu.org/gcc-4.1/changes.html 11640 4. http://gcc.gnu.org/gcc-4.1/changes.html 11641 5. http://gcc.gnu.org/gcc-4.1/buildstat.html 11642 6. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 11643 7. http://gcc.gnu.org/index.html 11644 8. mailto:gcc (a] gcc.gnu.org 11645 9. http://gcc.gnu.org/mirrors.html 11646 10. http://gcc.gnu.org/git.html 11647 11. https://gcc.gnu.org/onlinedocs/ 11648 12. mailto:gcc-help (a] gcc.gnu.org 11649 13. mailto:gcc (a] gcc.gnu.org 11650 14. https://gcc.gnu.org/lists.html 11651 15. https://www.fsf.org/ 11652 16. https://gcc.gnu.org/about.html 11653 17. http://validator.w3.org/check/referer 11654 ====================================================================== 11655 http://gcc.gnu.org/gcc-4.1/changes.html 11656 GCC 4.1 Release Series 11657 Changes, New Features, and Fixes 11658 11659 The latest release in the 4.1 release series is [1]GCC 4.1.2. 11660 11661 Caveats 11662 11663 General Optimizer Improvements 11664 11665 * GCC now has infrastructure for inter-procedural optimizations and 11666 the following inter-procedural optimizations are implemented: 11667 + Profile guided inlining. When doing profile feedback guided 11668 optimization, GCC can now use the profile to make better 11669 informed decisions on whether inlining of a function is 11670 profitable or not. This means that GCC will no longer inline 11671 functions at call sites that are not executed very often, and 11672 that functions at hot call sites are more likely to be 11673 inlined. 11674 A new parameter min-inline-recursive-probability is also now 11675 available to throttle recursive inlining of functions with 11676 small average recursive depths. 11677 + Discovery of pure and const functions, a form of side-effects 11678 analysis. While older GCC releases could also discover such 11679 special functions, the new IPA-based pass runs earlier so that 11680 the results are available to more optimizers. The pass is also 11681 simply more powerful than the old one. 11682 + Analysis of references to static variables and type escape 11683 analysis, also forms of side-effects analysis. The results of 11684 these passes allow the compiler to be less conservative about 11685 call-clobbered variables and references. This results in more 11686 redundant loads being eliminated and in making static 11687 variables candidates for register promotion. 11688 + Improvement of RTL-based alias analysis. The results of type 11689 escape analysis are fed to the RTL type-based alias analyzer, 11690 allowing it to disambiguate more memory references. 11691 + Interprocedural constant propagation and function versioning. 11692 This pass looks for functions that are always called with the 11693 same constant value for one or more of the function arguments, 11694 and propagates those constants into those functions. 11695 + GCC will now eliminate static variables whose usage was 11696 optimized out. 11697 + -fwhole-program --combine can now be used to make all 11698 functions in program static allowing whole program 11699 optimization. As an exception, the main function and all 11700 functions marked with the new externally_visible attribute are 11701 kept global so that programs can link with runtime libraries. 11702 * GCC can now do a form of partial dead code elimination (PDCE) that 11703 allows code motion of expressions to the paths where the result of 11704 the expression is actually needed. This is not always a win, so the 11705 pass has been limited to only consider profitable cases. Here is an 11706 example: 11707 int foo (int *, int *); 11708 int 11709 bar (int d) 11710 { 11711 int a, b, c; 11712 b = d + 1; 11713 c = d + 2; 11714 a = b + c; 11715 if (d) 11716 { 11717 foo (&b, &c); 11718 a = b + c; 11719 } 11720 printf ("%d\n", a); 11721 } 11722 11723 The a = b + c can be sunk to right before the printf. Normal code 11724 sinking will not do this, it will sink the first one above into the 11725 else-branch of the conditional jump, which still gives you two 11726 copies of the code. 11727 * GCC now has a value range propagation pass. This allows the 11728 compiler to eliminate bounds checks and branches. The results of 11729 the pass can also be used to accurately compute branch 11730 probabilities. 11731 * The pass to convert PHI nodes to straight-line code (a form of 11732 if-conversion for GIMPLE) has been improved significantly. The two 11733 most significant improvements are an improved algorithm to 11734 determine the order in which the PHI nodes are considered, and an 11735 improvement that allow the pass to consider if-conversions of basic 11736 blocks with more than two predecessors. 11737 * Alias analysis improvements. GCC can now differentiate between 11738 different fields of structures in Tree-SSA's virtual operands form. 11739 This lets stores/loads from non-overlapping structure fields not 11740 conflict. A new algorithm to compute points-to sets was contributed 11741 that can allows GCC to see now that p->a and p->b, where p is a 11742 pointer to a structure, can never point to the same field. 11743 * Various enhancements to auto-vectorization: 11744 + Incrementally preserve SSA form when vectorizing. 11745 + Incrementally preserve loop-closed form when vectorizing. 11746 + Improvements to peeling for alignment: generate better code 11747 when the misalignment of an access is known at compile time, 11748 or when different accesses are known to have the same 11749 misalignment, even if the misalignment amount itself is 11750 unknown. 11751 + Consider dependence distance in the vectorizer. 11752 + Externalize generic parts of data reference analysis to make 11753 this analysis available to other passes. 11754 + Vectorization of conditional code. 11755 + Reduction support. 11756 * GCC can now partition functions in sections of hot and cold code. 11757 This can significantly improve performance due to better 11758 instruction cache locality. This feature works best together with 11759 profile feedback driven optimization. 11760 * A new pass to avoid saving of unneeded arguments to the stack in 11761 vararg functions if the compiler can prove that they will not be 11762 needed. 11763 * Transition of basic block profiling to tree level implementation 11764 has been completed. The new implementation should be considerably 11765 more reliable (hopefully avoiding profile mismatch errors when 11766 using -fprofile-use or -fbranch-probabilities) and can be used to 11767 drive higher level optimizations, such as inlining. 11768 The -ftree-based-profiling command-line option was removed and 11769 -fprofile-use now implies disabling old RTL level loop optimizer 11770 (-fno-loop-optimize). Speculative prefetching optimization 11771 (originally enabled by -fspeculative-prefetching) was removed. 11772 11773 New Languages and Language specific improvements 11774 11775 C and Objective-C 11776 11777 * The old Bison-based C and Objective-C parser has been replaced by a 11778 new, faster hand-written recursive-descent parser. 11779 11780 Ada 11781 11782 * The build infrastructure for the Ada runtime library and tools has 11783 been changed to be better integrated with the rest of the build 11784 infrastructure of GCC. This should make doing cross builds of Ada a 11785 bit easier. 11786 11787 C++ 11788 11789 * ARM-style name-injection of friend declarations is no longer the 11790 default. For example: 11791 struct S { 11792 friend void f(); 11793 }; 11794 11795 void g() { f(); } 11796 will not be accepted; instead a declaration of f will need to be 11797 present outside of the scope of S. The new -ffriend-injection 11798 option will enable the old behavior. 11799 * The (undocumented) extension which permitted templates with default 11800 arguments to be bound to template template parameters with fewer 11801 parameters has been deprecated, and will be removed in the next 11802 major release of G++. For example: 11803 template <template <typename> class C> 11804 void f(C<double>) {} 11805 11806 template <typename T, typename U = int> 11807 struct S {}; 11808 11809 template void f(S<double>); 11810 11811 makes use of the deprecated extension. The reason this code is not 11812 valid ISO C++ is that S is a template with two parameters; 11813 therefore, it cannot be bound to C which has only one parameter. 11814 11815 Runtime Library (libstdc++) 11816 11817 * Optimization work: 11818 + A new implementation of std::search_n is provided, better 11819 performing in case of random access iterators. 11820 + Added further efficient specializations of istream functions, 11821 i.e., character array and string extractors. 11822 + Other smaller improvements throughout. 11823 * Policy-based associative containers, designed for high-performance, 11824 flexibility and semantic safety are delivered in ext/pb_assoc. 11825 * A versatile string class, __gnu_cxx::__versa_string, providing 11826 facilities conforming to the standard requirements for 11827 basic_string, is delivered in <ext/vstring.h>. In particular: 11828 + Two base classes are provided: the default one avoids 11829 reference counting and is optimized for short strings; the 11830 alternate one, still uses it while improving in a few low 11831 level areas (e.g., alignment). See vstring_fwd.h for some 11832 useful typedefs. 11833 + Various algorithms have been rewritten (e.g., replace), the 11834 code streamlined and simple optimizations added. 11835 + Option 3 of DR 431 is implemented for both available bases, 11836 thus improving the support for stateful allocators. 11837 * As usual, many bugs have been fixed (e.g., libstdc++/13583, 11838 libstdc++/23953) and LWG resolutions put into effect for the first 11839 time (e.g., DR 280, DR 464, N1780 recommendations for DR 233, TR1 11840 Issue 6.19). The implementation status of TR1 is now tracked in the 11841 docs in tr1.html. 11842 11843 Objective-C++ 11844 11845 * A new language front end for Objective-C++ has been added. This 11846 language allows users to mix the object oriented features of 11847 Objective-C with those of C++. 11848 11849 Java (GCJ) 11850 11851 * Core library (libgcj) updates based on GNU Classpath 0.15 - 0.19 11852 features (plus some 0.20 bug-fixes) 11853 + Networking 11854 o The java.net.HttpURLConnection implementation no longer 11855 buffers the entire response body in memory. This means 11856 that response bodies larger than available memory can now 11857 be handled. 11858 + (N)IO 11859 o NIO FileChannel.map implementation, fast bulk put 11860 implementation for DirectByteBuffer (speeds up this 11861 method 10x). 11862 o FileChannel.lock() and FileChannel.force() implemented. 11863 + XML 11864 o gnu.xml fix for nodes created outside a namespace 11865 context. 11866 o Add support for output indenting and 11867 cdata-section-elements output instruction in 11868 xml.transform. 11869 o xml.xpath corrections for cases where elements/attributes 11870 might have been created in non-namespace-aware mode. 11871 Corrections to handling of XSL variables and minor 11872 conformance updates. 11873 + AWT 11874 o GNU JAWT implementation, the AWT Native Interface, which 11875 allows direct access to native screen resources from 11876 within a Canvas's paint method. GNU Classpath Examples 11877 comes with a Demo, see libjava/classpath/examples/README. 11878 o awt.datatransfer updated to 1.5 with support for 11879 FlavorEvents. The gtk+ awt peers now allow copy/paste of 11880 text, images, URIs/files and serialized objects with 11881 other applications and tracking clipboard change events 11882 with gtk+ 2.6 (for gtk+ 2.4 only text and serialized 11883 objects are supported). A GNU Classpath Examples 11884 datatransfer Demo was added to show the new 11885 functionality. 11886 o Split gtk+ awt peers event handling in two threads and 11887 improve gdk lock handling (solves several awt lock ups). 11888 o Speed up awt Image loading. 11889 o Better gtk+ scrollbar peer implementation when using gtk+ 11890 >= 2.6. 11891 o Handle image loading errors correctly for gdkpixbuf and 11892 MediaTracker. 11893 o Better handle GDK lock. Properly prefix gtkpeer native 11894 functions (cp_gtk). 11895 o GdkGraphics2D has been updated to use Cairo 0.5.x or 11896 higher. 11897 o BufferedImage and GtkImage rewrites. All image drawing 11898 operations should now work correctly (flipping requires 11899 gtk+ >= 2.6) 11900 o Future Graphics2D, image and text work is documented at: 11901 [2]http://developer.classpath.org/mediation/ClasspathGrap 11902 hicsImagesText 11903 o When gtk+ 2.6 or higher is installed the default log 11904 handler will produce stack traces whenever a WARNING, 11905 CRITICAL or ERROR message is produced. 11906 + Free Swing 11907 o The RepaintManager has been reworked for more efficient 11908 painting, especially for large GUIs. 11909 o The layout manager OverlayLayout has been implemented, 11910 the BoxLayout has been rewritten to make use of the 11911 SizeRequirements utility class and caching for more 11912 efficient layout. 11913 o Improved accessibility support. 11914 o Significant progress has been made in the implementation 11915 of the javax.swing.plaf.metal package, with most UI 11916 delegates in a working state now. Please test this with 11917 your own applications and provide feedback that will help 11918 us to improve this package. 11919 o The GUI demo (gnu.classpath.examples.swing.Demo) has been 11920 extended to highlight various features in our Free Swing 11921 implementation. And it includes a look and feel switcher 11922 for Metal (default), Ocean and GNU themes. 11923 o The javax.swing.plaf.multi package is now implemented. 11924 o Editing and several key actions for JTree and JTable were 11925 implemented. 11926 o Lots of icons and look and feel improvements for Free 11927 Swing basic and metal themes were added. Try running the 11928 GNU Classpath Swing Demo in examples 11929 (gnu.classpath.examples.swing.Demo) with: 11930 -Dswing.defaultlaf=javax.swing.plaf.basic.BasicLookAndFee 11931 l or 11932 -Dswing.defaultlaf=javax.swing.plaf.metal.MetalLookAndFee 11933 l 11934 o Start of styled text capabilites for java.swing.text. 11935 o DefaultMutableTreeNode pre-order, post-order, depth-first 11936 and breadth-first traversal enumerations implemented. 11937 o JInternalFrame colors and titlebar draw properly. 11938 o JTree is working up to par (icons, selection and keyboard 11939 traversal). 11940 o JMenus were made more compatible in visual and 11941 programmatic behavior. 11942 o JTable changeSelection and multiple selections 11943 implemented. 11944 o JButton and JToggleButton change states work properly 11945 now. 11946 o JFileChooser fixes. 11947 o revalidate() and repaint() fixes which make Free Swing 11948 much more responsive. 11949 o MetalIconFactory implemented. 11950 o Free Swing Top-Level Compatibility. JFrame, JDialog, 11951 JApplet, JInternalFrame, and JWindow are now 1.5 11952 compatible in the sense that you can call add() and 11953 setLayout() directly on them, which will have the same 11954 effect as calling getContentPane().add() and 11955 getContentPane().setLayout(). 11956 o The JTree interface has been completed. JTrees now 11957 recognizes mouse clicks and selections work. 11958 o BoxLayout works properly now. 11959 o Fixed GrayFilter to actually work. 11960 o Metal SplitPane implemented. 11961 o Lots of Free Swing text and editor stuff work now. 11962 + Free RMI and Corba 11963 o Andrew Watson, Vice President and Technical Director of 11964 the Object Management Group, has officially assigned us 11965 20 bit Vendor Minor Code Id: 0x47430 ("GC") that will 11966 mark remote classpath-specific system exceptions. 11967 Obtaining the VMCID means that GNU Classpath now is a 11968 recogniseable type of node in a highly interoperable 11969 CORBA world. 11970 o GNU Classpath now includes the first working draft to 11971 support the RMI over IIOP protocol. The current 11972 implementation is capable of remote invocations, 11973 transferring various Serializables and Externalizables 11974 via RMI-IIOP protocol. It can flatten graphs and, at 11975 least for the simple cases, is interoperable with 1.5 11976 JDKs. 11977 o org.omg.PortableInterceptor and related functionality in 11978 other packages is now implemented: 11979 # The sever and client interceptors work as required 11980 since 1.4. 11981 # The IOR interceptor works as needed for 1.5. 11982 o The org.omg.DynamicAny package is completed and passes 11983 the prepared tests. 11984 o The Portable Object Adapter should now support the output 11985 of the recent IDL to java compilers. These compilers now 11986 generate servants and not CORBA objects as before, making 11987 the output depend on the existing POA implementation. 11988 Completing POA means that such code can already be tried 11989 to run on Classpath. Our POA is tested for the following 11990 usager scenarios: 11991 # POA converts servant to the CORBA object. 11992 # Servant provides to the CORBA object. 11993 # POA activates new CORBA object with the given Object 11994 Id (byte array) that is later accessible for the 11995 servant. 11996 # During the first call, the ServantActivator provides 11997 servant for this and all subsequent calls on the 11998 current object. 11999 # During each call, the ServantLocator provides 12000 servant for this call only. 12001 # ServantLocator or ServantActivator forwards call to 12002 another server. 12003 # POA has a single servant, responsible for all 12004 objects. 12005 # POA has a default servant, but some objects are 12006 explicitly connected to they specific servants. 12007 The POA is verified using tests from the former 12008 cost.omg.org. 12009 o The CORBA implementation is now a working prototype that 12010 should support features up to 1.3 inclusive. We invite 12011 groups writing CORBA dependent applications to try 12012 Classpath implementation, reporting any possible bugs. 12013 The CORBA prototype is interoperable with Sun's 12014 implementation v 1.4, transferring object references, 12015 primitive types, narrow and wide strings, arrays, 12016 structures, trees, abstract interfaces and value types 12017 (feature of CORBA 2.3) between these two platforms. 12018 Remote exceptions are transferred and handled correctly. 12019 The stringified object references (IORs) from various 12020 sources are parsed as required. The transient (for 12021 current session) and permanent (till jre restart) 12022 redirections work. Both Little and Big Endian encoded 12023 messages are accepted. The implementation is verified 12024 using tests from the former cost.omg.org. The current 12025 release includes working examples (see the examples 12026 directory), demonstrating the client-server 12027 communication, using either CORBA Request or IDL-based 12028 stub (usually generated by a IDL to java compiler). These 12029 examples also show how to use the Classpath CORBA naming 12030 service. The IDL to java compiler is not yet written, but 12031 as our library must be compatible, it naturally accepts 12032 the output of other idlj implementations. 12033 + Misc 12034 o Updated TimeZone data against Olson tzdata2005l. 12035 o Make zip and jar packages UTF-8 clean. 12036 o "native" code builds and compiles (warning free) on 12037 Darwin and Solaris. 12038 o java.util.logging.FileHandler now rotates files. 12039 o Start of a generic JDWP framework in gnu/classpath/jdwp. 12040 This is unfinished, but feedback (at classpath (a] gnu.org) 12041 from runtime hackers is greatly appreciated. Although 12042 most of the work is currently being done around gcj/gij 12043 we want this framework to be as VM neutral as possible. 12044 Early design is described in: 12045 [3]https://gcc.gnu.org/ml/java/2005-05/msg00260.html 12046 o QT4 AWT peers, enable by giving configure 12047 --enable-qt-peer. Included, but not ready for production 12048 yet. They are explicitly disabled and not supported. But 12049 if you want to help with the development of these new 12050 features we are interested in feedback. You will have to 12051 explicitly enable them to try them out (and they will 12052 most likely contain bugs). 12053 o Documentation fixes all over the place. See 12054 [4]http://developer.classpath.org/doc/ 12055 12056 New Targets and Target Specific Improvements 12057 12058 IA-32/x86-64 12059 12060 * The x86-64 medium model (that allows building applications whose 12061 data segment exceeds 4GB) was redesigned to match latest ABI draft. 12062 New implementation split large datastructures into separate segment 12063 improving performance of accesses to small datastructures and also 12064 allows linking of small model libraries into medium model programs 12065 as long as the libraries are not accessing the large datastructures 12066 directly. Medium model is also supported in position independent 12067 code now. 12068 The ABI change results in partial incompatibility among medium 12069 model objects. Linking medium model libraries (or objects) compiled 12070 with new compiler into medium model program compiled with older 12071 will likely result in exceeding ranges of relocations. 12072 Binutils 2.16.91 or newer are required for compiling medium model 12073 now. 12074 12075 RS6000 (POWER/PowerPC) 12076 12077 * The AltiVec vector primitives in <altivec.h> are now implemented in 12078 a way that puts a smaller burden on the preprocessor, instead 12079 processing the "overloading" in the front ends. This should benefit 12080 compilation speed on AltiVec vector code. 12081 * AltiVec initializers now are generated more efficiently. 12082 * The popcountb instruction available on POWER5 now is generated. 12083 * The floating point round to integer instructions available on 12084 POWER5+ now is generated. 12085 * Floating point divides can be synthesized using the floating point 12086 reciprocal estimate instructions. 12087 * Double precision floating point constants are initialized as single 12088 precision values if they can be represented exactly. 12089 12090 S/390, zSeries and System z9 12091 12092 * Support for the IBM System z9 109 processor has been added. When 12093 using the -march=z9-109 option, the compiler will generate code 12094 making use of instructions provided by the extended immediate 12095 facility. 12096 * Support for 128-bit IEEE floating point has been added. When using 12097 the -mlong-double-128 option, the compiler will map the long double 12098 data type to 128-bit IEEE floating point. Using this option 12099 constitutes an ABI change, and requires glibc support. 12100 * Various changes to improve performance of generated code have been 12101 implemented, including: 12102 + In functions that do not require a literal pool, register %r13 12103 (which is traditionally reserved as literal pool pointer), can 12104 now be freely used for other purposes by the compiler. 12105 + More precise tracking of register use allows the compiler to 12106 generate more efficient function prolog and epilog code in 12107 certain cases. 12108 + The SEARCH STRING, COMPARE LOGICAL STRING, and MOVE STRING 12109 instructions are now used to implement C string functions. 12110 + The MOVE CHARACTER instruction with single byte overlap is now 12111 used to implement the memset function with non-zero fill byte. 12112 + The LOAD ZERO instructions are now used where appropriate. 12113 + The INSERT CHARACTERS UNDER MASK, STORE CHARACTERS UNDER MASK, 12114 and INSERT IMMEDIATE instructions are now used more frequently 12115 to optimize bitfield operations. 12116 + The BRANCH ON COUNT instruction is now used more frequently. 12117 In particular, the fact that a loop contains a subroutine call 12118 no longer prevents the compiler from using this instruction. 12119 + The compiler is now aware that all shift and rotate 12120 instructions implicitly truncate the shift count to six bits. 12121 * Back-end support for the following generic features has been 12122 implemented: 12123 + The full set of [5]built-in functions for atomic memory 12124 access. 12125 + The -fstack-protector feature. 12126 + The optimization pass avoiding unnecessary stores of incoming 12127 argument registers in functions with variable argument list. 12128 12129 SPARC 12130 12131 * The default code model in 64-bit mode has been changed from 12132 Medium/Anywhere to Medium/Middle on Solaris. 12133 * TLS support is disabled by default on Solaris prior to release 10. 12134 It can be enabled on TLS-capable Solaris 9 versions (4/04 release 12135 and later) by specifying --enable-tls at configure time. 12136 12137 MorphoSys 12138 12139 * Support has been added for this new architecture. 12140 12141 Obsolete Systems 12142 12143 Documentation improvements 12144 12145 Other significant improvements 12146 12147 * GCC can now emit code for protecting applications from 12148 stack-smashing attacks. The protection is realized by buffer 12149 overflow detection and reordering of stack variables to avoid 12150 pointer corruption. 12151 * Some built-in functions have been fortified to protect them against 12152 various buffer overflow (and format string) vulnerabilities. 12153 Compared to the mudflap bounds checking feature, the safe builtins 12154 have far smaller overhead. This means that programs built using 12155 safe builtins should not experience any measurable slowdown. 12156 12157 GCC 4.1.2 12158 12159 This is the [6]list of problem reports (PRs) from GCC's bug tracking 12160 system that are known to be fixed in the 4.1.2 release. This list might 12161 not be complete (that is, it is possible that some PRs that have been 12162 fixed are not listed here). 12163 12164 When generating code for a shared library, GCC now recognizes that 12165 global functions may be replaced when the program runs. Therefore, it 12166 is now more conservative in deducing information from the bodies of 12167 functions. For example, in this example: 12168 void f() {} 12169 void g() { 12170 try { f(); } 12171 catch (...) { 12172 cout << "Exception"; 12173 } 12174 } 12175 12176 G++ would previously have optimized away the catch clause, since it 12177 would have concluded that f cannot throw exceptions. Because users may 12178 replace f with another function in the main body of the program, this 12179 optimization is unsafe, and is no longer performed. If you wish G++ to 12180 continue to optimize as before, you must add a throw() clause to the 12181 declaration of f to make clear that it does not throw exceptions. 12182 12183 12184 For questions related to the use of GCC, please consult these web 12185 pages and the [7]GCC manuals. If that fails, the 12186 [8]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 12187 web pages and the development of GCC are welcome on our developer 12188 list at [9]gcc (a] gcc.gnu.org. All of [10]our lists have public 12189 archives. 12190 12191 Copyright (C) [11]Free Software Foundation, Inc. Verbatim copying and 12192 distribution of this entire article is permitted in any medium, 12193 provided this notice is preserved. 12194 12195 These pages are [12]maintained by the GCC team. Last modified 12196 2019-11-28[13]. 12197 12198 References 12199 12200 1. http://gcc.gnu.org/gcc-4.1/changes.html#4.1.2 12201 2. http://developer.classpath.org/mediation/ClasspathGraphicsImagesText 12202 3. https://gcc.gnu.org/ml/java/2005-05/msg00260.html 12203 4. http://developer.classpath.org/doc/ 12204 5. https://gcc.gnu.org/onlinedocs/gcc-4.1.0/gcc/Atomic-Builtins.html 12205 6. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.1.2 12206 7. https://gcc.gnu.org/onlinedocs/ 12207 8. mailto:gcc-help (a] gcc.gnu.org 12208 9. mailto:gcc (a] gcc.gnu.org 12209 10. https://gcc.gnu.org/lists.html 12210 11. https://www.fsf.org/ 12211 12. https://gcc.gnu.org/about.html 12212 13. http://validator.w3.org/check/referer 12213 ====================================================================== 12214 http://gcc.gnu.org/gcc-4.0/index.html 12215 GCC 4.0 Release Series 12216 12217 (This release series is no longer supported.) 12218 12219 January 31, 2007 12220 12221 The [1]GNU project and the GCC developers are pleased to announce the 12222 release of GCC 4.0.4. 12223 12224 This release is a bug-fix release, containing fixes for regressions in 12225 GCC 4.0.3 relative to previous releases of GCC. 12226 12227 Release History 12228 12229 GCC 4.0.4 12230 January 31, 2007 ([2]changes) 12231 12232 GCC 4.0.3 12233 March 10, 2006 ([3]changes) 12234 12235 GCC 4.0.2 12236 September 28, 2005 ([4]changes) 12237 12238 GCC 4.0.1 12239 July 7, 2005 ([5]changes) 12240 12241 GCC 4.0.0 12242 April 20, 2005 ([6]changes) 12243 12244 References and Acknowledgements 12245 12246 GCC used to stand for the GNU C Compiler, but since the compiler 12247 supports several other languages aside from C, it now stands for the 12248 GNU Compiler Collection. 12249 12250 A list of [7]successful builds is updated as new information becomes 12251 available. 12252 12253 The GCC developers would like to thank the numerous people that have 12254 contributed new features, improvements, bug fixes, and other changes as 12255 well as test results to GCC. This [8]amazing group of volunteers is 12256 what makes GCC successful. 12257 12258 For additional information about GCC please refer to the [9]GCC project 12259 web site or contact the [10]GCC development mailing list. 12260 12261 To obtain GCC please use [11]our mirror sites, or [12]our version 12262 control system. 12263 12264 12265 For questions related to the use of GCC, please consult these web 12266 pages and the [13]GCC manuals. If that fails, the 12267 [14]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 12268 web pages and the development of GCC are welcome on our developer 12269 list at [15]gcc (a] gcc.gnu.org. All of [16]our lists have public 12270 archives. 12271 12272 Copyright (C) [17]Free Software Foundation, Inc. Verbatim copying and 12273 distribution of this entire article is permitted in any medium, 12274 provided this notice is preserved. 12275 12276 These pages are [18]maintained by the GCC team. Last modified 12277 2020-01-14[19]. 12278 12279 References 12280 12281 1. http://www.gnu.org/ 12282 2. http://gcc.gnu.org/gcc-4.0/changes.html#4.0.4 12283 3. http://gcc.gnu.org/gcc-4.0/changes.html#4.0.3 12284 4. http://gcc.gnu.org/gcc-4.0/changes.html#4.0.2 12285 5. http://gcc.gnu.org/gcc-4.0/changes.html#4.0.1 12286 6. http://gcc.gnu.org/gcc-4.0/changes.html 12287 7. http://gcc.gnu.org/gcc-4.0/buildstat.html 12288 8. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 12289 9. http://gcc.gnu.org/index.html 12290 10. mailto:gcc (a] gcc.gnu.org 12291 11. http://gcc.gnu.org/mirrors.html 12292 12. http://gcc.gnu.org/git.html 12293 13. https://gcc.gnu.org/onlinedocs/ 12294 14. mailto:gcc-help (a] gcc.gnu.org 12295 15. mailto:gcc (a] gcc.gnu.org 12296 16. https://gcc.gnu.org/lists.html 12297 17. https://www.fsf.org/ 12298 18. https://gcc.gnu.org/about.html 12299 19. http://validator.w3.org/check/referer 12300 ====================================================================== 12301 http://gcc.gnu.org/gcc-4.0/changes.html 12302 GCC 4.0 Release Series 12303 Changes, New Features, and Fixes 12304 12305 The latest release in the 4.0 release series is [1]GCC 4.0.4. 12306 12307 Caveats 12308 12309 * GCC now generates location lists by default when compiling with 12310 debug info and optimization. 12311 + GDB 6.0 and older crashes when it sees location lists. GDB 6.1 12312 or later is needed to debug binaries containing location 12313 lists. 12314 + When you are trying to view a value of a variable in a part of 12315 a function where it has no location (for example when the 12316 variable is no longer used and thus its location was used for 12317 something else) GDB will say that it is not available. 12318 You can disable generating location lists by -fno-var-tracking. 12319 * GCC no longer accepts the -fwritable-strings option. Use named 12320 character arrays when you need a writable string. 12321 * The options -freduce-all-givs and -fmove-all-movables have been 12322 discontinued. They were used to circumvent a shortcoming in the 12323 heuristics of the old loop optimization code with respect to common 12324 Fortran constructs. The new (tree) loop optimizer works differently 12325 and doesn't need those work-arounds. 12326 * The graph-coloring register allocator, formerly enabled by the 12327 option -fnew-ra, has been discontinued. 12328 * -I- has been deprecated. -iquote is meant to replace the need for 12329 this option. 12330 * The MIPS -membedded-pic and -mrnames options have been removed. 12331 * All MIPS targets now require the GNU assembler. In particular, IRIX 12332 configurations can no longer use the MIPSpro assemblers, although 12333 they do still support the MIPSpro linkers. 12334 * The SPARC option -mflat has been removed. 12335 * English-language diagnostic messages will now use Unicode quotation 12336 marks in UTF-8 locales. (Non-English messages already used the 12337 quotes appropriate for the language in previous releases.) If your 12338 terminal does not support UTF-8 but you are using a UTF-8 locale 12339 (such locales are the default on many GNU/Linux systems) then you 12340 should set LC_CTYPE=C in the environment to disable that locale. 12341 Programs that parse diagnostics and expect plain ASCII 12342 English-language messages should set LC_ALL=C. See [2]Markus Kuhn's 12343 explanation of Unicode quotation marks for more information. 12344 * The specs file is no longer installed on most platforms. Most users 12345 will be totally unaffected. However, if you are accustomed to 12346 editing the specs file yourself, you will now have to use the 12347 -dumpspecs option to generate the specs file, and then edit the 12348 resulting file. 12349 12350 General Optimizer Improvements 12351 12352 * The [3]tree ssa branch has been merged. This merge has brought in a 12353 completely new optimization framework based on a higher level 12354 intermediate representation than the existing RTL representation. 12355 Numerous new code transformations based on the new framework are 12356 available in GCC 4.0, including: 12357 + Scalar replacement of aggregates 12358 + Constant propagation 12359 + Value range propagation 12360 + Partial redundancy elimination 12361 + Load and store motion 12362 + Strength reduction 12363 + Dead store elimination 12364 + Dead and unreachable code elimination 12365 + [4]Autovectorization 12366 + Loop interchange 12367 + Tail recursion by accumulation 12368 Many of these passes outperform their counterparts from previous 12369 GCC releases. 12370 * [5]Swing Modulo Scheduling (SMS). An RTL level instruction 12371 scheduling optimization intended for loops that perform heavy 12372 computations. 12373 12374 New Languages and Language specific improvements 12375 12376 C family 12377 12378 * The sentinel attribute has been added to GCC. This function 12379 attribute allows GCC to warn when variadic functions such as execl 12380 are not NULL terminated. See the GCC manual for a complete 12381 description of its behavior. 12382 * Given __attribute__((alias("target"))) it is now an error if target 12383 is not a symbol, defined in the same translation unit. This also 12384 applies to aliases created by #pragma weak alias=target. This is 12385 because it's meaningless to define an alias to an undefined symbol. 12386 On Solaris, the native assembler would have caught this error, but 12387 GNU as does not. 12388 12389 C and Objective-C 12390 12391 * The -Wstrict-aliasing=2 option has been added. This warning catches 12392 all unsafe cases, but it may also give a warning for some cases 12393 that are safe. 12394 * The cast-as-lvalue, conditional-expression-as-lvalue and 12395 compound-expression-as-lvalue extensions, which were deprecated in 12396 3.3.4 and 3.4, have been removed. 12397 * The -fwritable-strings option, which was deprecated in 3.4, has 12398 been removed. 12399 * #pragma pack() semantics have been brought closer to those used by 12400 other compilers. This also applies to C++. 12401 * Taking the address of a variable with register storage is invalid 12402 in C. GCC now issues an error instead of a warning. 12403 * Arrays of incomplete element type are invalid in C. GCC now issues 12404 an error for such arrays. Declarations such as extern struct s x[]; 12405 (where struct s has not been defined) can be moved after the 12406 definition of struct s. Function parameters declared as arrays of 12407 incomplete type can instead be declared as pointers. 12408 12409 C++ 12410 12411 * When compiling without optimizations (-O0), the C++ front end is 12412 much faster than in any previous versions of GCC. Independent 12413 testers have measured speed-ups up to 25% in real-world production 12414 code, compared to the 3.4 family (which was already the fastest 12415 version to date). Upgrading from older versions might show even 12416 bigger improvements. 12417 * ELF visibility attributes can now be applied to a class type, so 12418 that it affects every member function of a class at once, without 12419 having to specify each individually: 12420 class __attribute__ ((visibility("hidden"))) Foo 12421 { 12422 int foo1(); 12423 void foo2(); 12424 }; 12425 The syntax is deliberately similar to the __declspec() system used 12426 by Microsoft Windows based compilers, allowing cross-platform 12427 projects to easily reuse their existing macro system for denoting 12428 exports and imports. By explicitly marking internal classes never 12429 used outside a binary as hidden, one can completely avoid PLT 12430 indirection overheads during their usage by the compiler. You can 12431 find out more about the advantages of this at 12432 [6]https://www.akkadia.org/drepper/dsohowto.pdf 12433 * The -fvisibility-inlines-hidden option has been added which marks 12434 all inlineable functions as having hidden ELF visibility, thus 12435 removing their symbol and typeinfo from the exported symbol table 12436 of the output ELF binary. Using this option can reduce the exported 12437 symbol count of template-heavy code by up to 40% with no code 12438 change at all, thus notably improving link and load times for the 12439 binary as well as a reduction in size of up to 10%. Also, check the 12440 new [7]-fvisibility option. 12441 * The compiler now uses the library interface specified by the [8]C++ 12442 ABI for thread-safe initialization of function-scope static 12443 variables. Most users should leave this alone, but embedded 12444 programmers may want to disable this by specifying 12445 -fno-threadsafe-statics for a small savings in code size. 12446 * Taking the address of an explicit register variable is no longer 12447 supported. Note that C++ allows taking the address of variables 12448 with register storage so this will continue to compile with a 12449 warning. For example, assuming that r0 is a machine register: 12450 register int foo asm ("r0"); 12451 register int bar; 12452 &foo; // error, no longer accepted 12453 &bar; // OK, with a warning 12454 * G++ has an undocumented extension to virtual function covariancy 12455 rules that allowed the overrider to return a type that was 12456 implicitly convertable to the overridden function's return type. 12457 For instance a function returning void * could be overridden by a 12458 function returning T *. This is now deprecated and will be removed 12459 in a future release. 12460 * The G++ minimum and maximum operators (<? and >?) and their 12461 compound forms (<?=) and >?=) have been deprecated and will be 12462 removed in a future version. Code using these operators should be 12463 modified to use std::min and std::max instead. 12464 * Declaration of nested classes of class templates as friends are 12465 supported: 12466 template <typename T> struct A { 12467 class B {}; 12468 }; 12469 class C { 12470 template <typename T> friend class A<T>::B; 12471 }; 12472 This complements the feature member functions of class templates as 12473 friends introduced in GCC 3.4.0. 12474 * When declaring a friend class using an unqualified name, classes 12475 outside the innermost non-class scope are not searched: 12476 class A; 12477 namespace N { 12478 class B { 12479 friend class A; // Refer to N::A which has not been declared yet 12480 // because name outside namespace N are not searched 12481 friend class ::A; // Refer to ::A 12482 }; 12483 } 12484 Hiding the friend name until declaration is still not implemented. 12485 * Friends of classes defined outside their namespace are correctly 12486 handled: 12487 namespace N { 12488 class A; 12489 } 12490 class N::A { 12491 friend class B; // Refer to N::B in GCC 4.0.0 12492 // but ::B in earlier versions of GCC 12493 }; 12494 12495 Runtime Library (libstdc++) 12496 12497 * Optimization work: 12498 + Added efficient specializations of istream functions for char 12499 and wchar_t. 12500 + Further performance tuning of strings, in particular wrt 12501 single-char append and getline. 12502 + iter_swap - and therefore most of the mutating algorithms - 12503 now makes an unqualified call to swap when the value_type of 12504 the two iterators is the same. 12505 * A large subset of the features in Technical Report 1 (TR1 for 12506 short) is experimentally delivered (i.e., no guarantees about the 12507 implementation are provided. In particular it is not promised that 12508 the library will remain link-compatible when code using TR1 is 12509 used): 12510 + General utilities such as reference_wrapper and shared_ptr. 12511 + Function objects, i.e., result_of, mem_fn, bind, function. 12512 + Support for metaprogramming. 12513 + New containers such as tuple, array, unordered_set, 12514 unordered_map, unordered_multiset, unordered_multimap. 12515 * As usual, many bugs have been fixed and LWG resolutions implemented 12516 for the first time (e.g., DR 409). 12517 12518 Java 12519 12520 * In order to prevent naming conflicts with other implementations of 12521 these tools, some GCJ binaries have been renamed: 12522 + rmic is now grmic, 12523 + rmiregistry is now grmiregistry, and 12524 + jar is now fastjar. 12525 In particular, these names were problematic for the jpackage.org 12526 packaging conventions which install symlinks in /usr/bin that point 12527 to the preferred versions of these tools. 12528 * The -findirect-dispatch argument to the compiler now works and 12529 generates code following a new "binary compatibility" ABI. Code 12530 compiled this way follows the binary compatibility rules of the 12531 Java Language Specification. 12532 * libgcj now has support for using GCJ as a JIT, using the 12533 gnu.gcj.jit family of system properties. 12534 * libgcj can now find a shared library corresponding to the bytecode 12535 representation of a class. See the documentation for the new 12536 gcj-dbtool program, and the new gnu.gcj.precompiled.db.path system 12537 property. 12538 * There have been many improvements to the class library. Here are 12539 some highlights: 12540 + Much more of AWT and Swing exist. 12541 + Many new packages and classes were added, including 12542 java.util.regex, java.net.URI, javax.crypto, 12543 javax.crypto.interfaces, javax.crypto.spec, javax.net, 12544 javax.net.ssl, javax.security.auth, 12545 javax.security.auth.callback, javax.security.auth.login, 12546 javax.security.auth.x500, javax.security.sasl, org.ietf.jgss, 12547 javax.imageio, javax.imageio.event, javax.imageio.spi, 12548 javax.print, javax.print.attribute, 12549 javax.print.attribute.standard, javax.print.event, and 12550 javax.xml 12551 + Updated SAX and DOM, and imported GNU JAXP 12552 12553 Fortran 12554 12555 * A new [9]Fortran front end has replaced the aging GNU Fortran 77 12556 front end. The new front end supports Fortran 90 and Fortran 95. It 12557 may not yet be as stable as the old Fortran front end. 12558 12559 Ada 12560 12561 * Ada (with tasking and Zero Cost Exceptions) is now available on 12562 many more targets, including but not limited to: alpha-linux, 12563 hppa-hpux, hppa-linux, powerpc-darwin, powerpc-linux, s390-linux, 12564 s390x-linux, sparc-linux. 12565 * Some of the new Ada 2005 features are now implemented like 12566 Wide_Wide_Character and Ada.Containers. 12567 * Many bugs have been fixed, tools and documentation improved. 12568 * To compile Ada from the sources, install an older working Ada 12569 compiler and then use --enable-languages=ada at configuration time, 12570 since the Ada front end is not currently activated by default. See 12571 the [10]Installing GCC for details. 12572 12573 New Targets and Target Specific Improvements 12574 12575 H8/300 12576 12577 * The frame layout has changed. In the new layout, the prologue of a 12578 function first saves registers and then allocate space for locals, 12579 resulting in an 1% improvement on code size. 12580 12581 IA-32/x86-64 (AMD64) 12582 12583 * The acos, asin, drem, exp10, exp2, expm1, fmod, ilogb, log10, 12584 log1p, log2, logb and tan mathematical builtins (and their float 12585 and long double variants) are now implemented as inline x87 12586 intrinsics when using -ffast-math. 12587 * The ceil, floor, nearbyint, rint and trunc mathematical builtins 12588 (and their float and long double variants) are now implemented as 12589 inline x87 intrinsics when using -ffast-math. 12590 * The x87's fsincos instruction is now used automatically with 12591 -ffast-math when calculating both the sin and cos of the same 12592 argument. 12593 * Instruction selection for multiplication and division by constants 12594 has been improved. 12595 12596 IA-64 12597 12598 * Floating point division, integer division and sqrt are now inlined, 12599 resulting in significant performance improvements on some codes. 12600 12601 MIPS 12602 12603 * Division by zero checks now use conditional traps if the target 12604 processor supports them. This decreases code size by one word per 12605 division operation. The old behavior (branch and break) can be 12606 obtained either at configure time by passing --with-divide=breaks 12607 to configure or at runtime by passing -mdivide-breaks to GCC. 12608 * Support for MIPS64 paired-single instructions has been added. It is 12609 enabled by -mpaired-single and can be accessed using both the 12610 target-independent vector extensions and new MIPS-specific built-in 12611 functions. 12612 * Support for the MIPS-3D ASE has been added. It is enabled by 12613 -mips3d and provides new MIPS-3D-specific built-in functions. 12614 * The -mexplicit-relocs option now supports static n64 code (as is 12615 used, for example, in 64-bit linux kernels). -mexplicit-relocs 12616 should now be feature-complete and is enabled by default when GCC 12617 is configured to use a compatible assembler. 12618 * Support for the NEC VR4130 series has been added. This support 12619 includes the use of VR-specific instructions and a new VR4130 12620 scheduler. Full VR4130 support can be selected with -march=vr4130 12621 while code for any ISA can be tuned for the VR4130 using 12622 -mtune=vr4130. There is also a new -mvr4130-align option that 12623 produces better schedules at the cost of increased code size. 12624 * Support for the Broadcom SB-1 has been extended. There is now an 12625 SB-1 scheduler as well as support for the SB-1-specific 12626 paired-single instructions. Full SB-1 support can be selected with 12627 -march=sb1 while code for any ISA can be optimized for the SB-1 12628 using -mtune=sb1. 12629 * The compiler can now work around errata in R4000, R4400, VR4120 and 12630 VR4130 processors. These workarounds are enabled by -mfix-r4000, 12631 -mfix-r4400, -mfix-vr4120 and -mfix-vr4130 respectively. The VR4120 12632 and VR4130 workarounds need binutils 2.16 or above. 12633 * IRIX shared libraries are now installed into the standard library 12634 directories: o32 libraries go into lib/, n32 libraries go into 12635 lib32/ and n64 libraries go into lib64/. 12636 * The compiler supports a new -msym32 option. It can be used to 12637 optimize n64 code in which all symbols are known to have 32-bit 12638 values. 12639 12640 S/390 and zSeries 12641 12642 * New command-line options help to generate code intended to run in 12643 an environment where stack space is restricted, e.g. Linux kernel 12644 code: 12645 + -mwarn-framesize and -mwarn-dynamicstack trigger compile-time 12646 warnings for single functions that require large or dynamic 12647 stack frames. 12648 + -mstack-size and -mstack-guard generate code that checks for 12649 stack overflow at run time. 12650 + -mpacked-stack generates code that reduces the stack frame 12651 size of many functions by reusing unneeded parts of the stack 12652 bias area. 12653 * The -msoft-float option now ensures that generated code never 12654 accesses floating point registers. 12655 * The s390x-ibm-tpf target now fully supports C++, including 12656 exceptions and threads. 12657 * Various changes to improve performance of the generated code have 12658 been implemented, including: 12659 + GCC now uses sibling calls where possible. 12660 + Condition code handling has been optimized, allowing GCC to 12661 omit redundant comparisons in certain cases. 12662 + The cost function guiding many optimizations has been refined 12663 to more accurately represent the z900 and z990 processors. 12664 + The ADD LOGICAL WITH CARRY and SUBTRACT LOGICAL WITH BORROW 12665 instructions are now used to avoid conditional branches in 12666 certain cases. 12667 + The back end now uses the LEGITIMIZE_RELOAD_ADDRESS feature to 12668 optimize address arithmetic required to access large stack 12669 frames. 12670 + GCC now makes more efficient use of memory-to-memory type 12671 instructions (MVC, CLC, ...). 12672 + More precise tracking of special register use allows better 12673 instruction scheduling, in particular of the function prologue 12674 and epilogue sequences. 12675 + The Java front end now generates inline code to implement 12676 integer division, instead of calling library routines. 12677 12678 SPARC 12679 12680 * The options -mv8, -msparclite, -mcypress, -msupersparc, -mf930 and 12681 -mf934 have been removed. They have been replaced with -mcpu=xxx. 12682 * The internal model used to estimate the relative cost of each 12683 instruction has been updated. It is expected to give better results 12684 on recent UltraSPARC processors. 12685 * Code generation for function prologues and epilogues has been 12686 improved, resulting in better scheduling and allowing multiple exit 12687 points in functions. 12688 * Support for Sun's Visual Instruction Set (VIS) has been enhanced. 12689 It is enabled by -mvis and provides new built-in functions for VIS 12690 instructions on UltraSPARC processors. 12691 * The option -mapp-regs has been turned on by default on Solaris too. 12692 12693 NetWare 12694 12695 * Novell NetWare (on ix86, no other hardware platform was ever really 12696 supported by this OS) has been re-enabled and the ABI supported by 12697 GCC has been brought into sync with that of MetroWerks CodeWarrior 12698 (the ABI previously supported was that of some Unix systems, which 12699 NetWare never tried to support). 12700 12701 Obsolete Systems 12702 12703 Support for a number of older systems has been declared obsolete in GCC 12704 4.0. Unless there is activity to revive them, the next release of GCC 12705 will have their sources permanently removed. 12706 12707 All GCC ports for the following processor architectures have been 12708 declared obsolete: 12709 * Intel i860 12710 * Ubicom IP2022 12711 * National Semiconductor NS32K (ns32k) 12712 * Texas Instruments TMS320C[34]x 12713 12714 Also, those for some individual systems have been obsoleted: 12715 * SPARC family 12716 + SPARClite-based systems (sparclite-*-coff, sparclite-*-elf, 12717 sparc86x-*-elf) 12718 + OpenBSD 32-bit (sparc-*-openbsd*) 12719 12720 Documentation improvements 12721 12722 Other significant improvements 12723 12724 * Location lists are now generated by default when compiling with 12725 debug info and optimization. Location lists provide more accurate 12726 debug info about locations of variables and they allow debugging 12727 code compiled with -fomit-frame-pointer. 12728 * The -fvisibility option has been added which allows the default ELF 12729 visibility of all symbols to be set per compilation and the new 12730 #pragma GCC visibility preprocessor command allows the setting of 12731 default ELF visibility for a region of code. Using 12732 -fvisibility=hidden especially in combination with the new 12733 -fvisibility-inlines-hidden can yield substantial improvements in 12734 output binary quality including avoiding PLT indirection overheads, 12735 reduction of the exported symbol count by up to 60% (with resultant 12736 improvements to link and load times), better scope for the 12737 optimizer to improve code and up to a 20% reduction in binary size. 12738 Using these options correctly yields a binary with a similar symbol 12739 count to a Windows DLL. 12740 Perhaps more importantly, this new feature finally allows (with 12741 careful planning) complete avoidance of symbol clashes when 12742 manually loading shared objects with RTLD_GLOBAL, thus finally 12743 solving problems many projects such as python were forced to use 12744 RTLD_LOCAL for (with its resulting issues for C++ correctness). You 12745 can find more information about using these options at 12746 [11]https://gcc.gnu.org/wiki/Visibility. 12747 __________________________________________________________________ 12748 12749 GCC 4.0.1 12750 12751 This is the [12]list of problem reports (PRs) from GCC's bug tracking 12752 system that are known to be fixed in the 4.0.1 release. This list might 12753 not be complete (that is, it is possible that some PRs that have been 12754 fixed are not listed here). 12755 12756 GCC 4.0.2 12757 12758 This is the [13]list of problem reports (PRs) from GCC's bug tracking 12759 system that are known to be fixed in the 4.0.2 release. This list might 12760 not be complete (that is, it is possible that some PRs that have been 12761 fixed are not listed here). 12762 12763 Unfortunately, due to a release engineering failure, this release has a 12764 regression on Solaris that will affect some C++ programs. We suggest 12765 that Solaris users apply a [14]patch that corrects the problem. Users 12766 who do not wish to apply the patch should explicitly link C++ programs 12767 with the -pthreads option, even if they do not use threads. This 12768 problem has been corrected in the current 4.0 branch sources and will 12769 not be present in GCC 4.0.3. 12770 12771 GCC 4.0.3 12772 12773 Starting with this release, the function getcontext is recognized by 12774 the compiler as having the same semantics as the setjmp function. In 12775 particular, the compiler will ensure that all registers are dead before 12776 calling such a function and will emit a warning about the variables 12777 that may be clobbered after the second return from the function. 12778 12779 GCC 4.0.4 12780 12781 This is the [15]list of problem reports (PRs) from GCC's bug tracking 12782 system that are known to be fixed in the 4.0.4 release. This list might 12783 not be complete (that is, it is possible that some PRs that have been 12784 fixed are not listed here). 12785 12786 The 4.0.4 release is provided for those that require a high degree of 12787 binary compatibility with previous 4.0.x releases. For most users, the 12788 GCC team recommends that version 4.1.1 or later be used instead." 12789 12790 12791 For questions related to the use of GCC, please consult these web 12792 pages and the [16]GCC manuals. If that fails, the 12793 [17]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 12794 web pages and the development of GCC are welcome on our developer 12795 list at [18]gcc (a] gcc.gnu.org. All of [19]our lists have public 12796 archives. 12797 12798 Copyright (C) [20]Free Software Foundation, Inc. Verbatim copying and 12799 distribution of this entire article is permitted in any medium, 12800 provided this notice is preserved. 12801 12802 These pages are [21]maintained by the GCC team. Last modified 12803 2019-11-28[22]. 12804 12805 References 12806 12807 1. http://gcc.gnu.org/gcc-4.0/changes.html#4.0.4 12808 2. https://www.cl.cam.ac.uk/~mgk25/ucs/quotes.html 12809 3. http://gcc.gnu.org/projects/tree-ssa/ 12810 4. http://gcc.gnu.org/projects/tree-ssa/vectorization.html 12811 5. http://gcc.gnu.org/news/sms.html 12812 6. https://www.akkadia.org/drepper/dsohowto.pdf 12813 7. http://gcc.gnu.org/gcc-4.0/changes.html#visibility 12814 8. https://itanium-cxx-abi.github.io/cxx-abi/ 12815 9. http://gcc.gnu.org/fortran/ 12816 10. https://gcc.gnu.org/install/ 12817 11. https://gcc.gnu.org/wiki/Visibility 12818 12. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.0.1 12819 13. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.0.2 12820 14. https://gcc.gnu.org/ml/gcc-cvs/2005-09/msg00984.html 12821 15. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=4.0.4 12822 16. https://gcc.gnu.org/onlinedocs/ 12823 17. mailto:gcc-help (a] gcc.gnu.org 12824 18. mailto:gcc (a] gcc.gnu.org 12825 19. https://gcc.gnu.org/lists.html 12826 20. https://www.fsf.org/ 12827 21. https://gcc.gnu.org/about.html 12828 22. http://validator.w3.org/check/referer 12829 ====================================================================== 12830 http://gcc.gnu.org/gcc-3.4/index.html 12831 GCC 3.4 Release Series 12832 12833 (This release series is no longer supported.) 12834 12835 May 26, 2006 12836 12837 The [1]GNU project and the GCC developers are pleased to announce the 12838 release of GCC 3.4.6. 12839 12840 This release is a bug-fix release, containing fixes for regressions in 12841 GCC 3.4.4 relative to previous releases of GCC. This is the last of the 12842 3.4.x series. 12843 12844 The GCC 3.4 release series includes numerous [2]new features, 12845 improvements, bug fixes, and other changes, thanks to an [3]amazing 12846 group of volunteers. 12847 12848 Release History 12849 12850 GCC 3.4.6 12851 March 6, 2006 ([4]changes) 12852 12853 GCC 3.4.5 12854 November 30, 2005 ([5]changes) 12855 12856 GCC 3.4.4 12857 May 18, 2005 ([6]changes) 12858 12859 GCC 3.4.3 12860 November 4, 2004 ([7]changes) 12861 12862 GCC 3.4.2 12863 September 6, 2004 ([8]changes) 12864 12865 GCC 3.4.1 12866 July 1, 2004 ([9]changes) 12867 12868 GCC 3.4.0 12869 April 18, 2004 ([10]changes) 12870 12871 References and Acknowledgements 12872 12873 GCC used to stand for the GNU C Compiler, but since the compiler 12874 supports several other languages aside from C, it now stands for the 12875 GNU Compiler Collection. 12876 12877 A list of [11]successful builds is updated as new information becomes 12878 available. 12879 12880 The GCC developers would like to thank the numerous people that have 12881 contributed new features, improvements, bug fixes, and other changes as 12882 well as test results to GCC. This [12]amazing group of volunteers is 12883 what makes GCC successful. 12884 12885 For additional information about GCC please refer to the [13]GCC 12886 project web site or contact the [14]GCC development mailing list. 12887 12888 To obtain GCC please use [15]our mirror sites, or [16]our version 12889 control system. 12890 12891 12892 For questions related to the use of GCC, please consult these web 12893 pages and the [17]GCC manuals. If that fails, the 12894 [18]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 12895 web pages and the development of GCC are welcome on our developer 12896 list at [19]gcc (a] gcc.gnu.org. All of [20]our lists have public 12897 archives. 12898 12899 Copyright (C) [21]Free Software Foundation, Inc. Verbatim copying and 12900 distribution of this entire article is permitted in any medium, 12901 provided this notice is preserved. 12902 12903 These pages are [22]maintained by the GCC team. Last modified 12904 2020-01-14[23]. 12905 12906 References 12907 12908 1. http://www.gnu.org/ 12909 2. http://gcc.gnu.org/gcc-3.4/changes.html 12910 3. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 12911 4. http://gcc.gnu.org/gcc-3.4/changes.html#3.4.6 12912 5. http://gcc.gnu.org/gcc-3.4/changes.html#3.4.5 12913 6. http://gcc.gnu.org/gcc-3.4/changes.html#3.4.4 12914 7. http://gcc.gnu.org/gcc-3.4/changes.html#3.4.3 12915 8. http://gcc.gnu.org/gcc-3.4/changes.html#3.4.2 12916 9. http://gcc.gnu.org/gcc-3.4/changes.html#3.4.1 12917 10. http://gcc.gnu.org/gcc-3.4/changes.html 12918 11. http://gcc.gnu.org/gcc-3.4/buildstat.html 12919 12. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 12920 13. http://gcc.gnu.org/index.html 12921 14. mailto:gcc (a] gcc.gnu.org 12922 15. http://gcc.gnu.org/mirrors.html 12923 16. http://gcc.gnu.org/git.html 12924 17. https://gcc.gnu.org/onlinedocs/ 12925 18. mailto:gcc-help (a] gcc.gnu.org 12926 19. mailto:gcc (a] gcc.gnu.org 12927 20. https://gcc.gnu.org/lists.html 12928 21. https://www.fsf.org/ 12929 22. https://gcc.gnu.org/about.html 12930 23. http://validator.w3.org/check/referer 12931 ====================================================================== 12932 http://gcc.gnu.org/gcc-3.4/changes.html 12933 GCC 3.4 Release Series 12934 Changes, New Features, and Fixes 12935 12936 The final release in the 3.4 release series is [1]GCC 3.4.6. The series 12937 is now closed. 12938 12939 GCC 3.4 has [2]many improvements in the C++ front end. Before reporting 12940 a bug, please make sure it's really GCC, and not your code, that is 12941 broken. 12942 12943 Caveats 12944 12945 * GNU Make is now required to build GCC. 12946 * With -nostdinc the preprocessor used to ignore both standard 12947 include paths and include paths contained in environment variables. 12948 It was neither documented nor intended that environment variable 12949 paths be ignored, so this has been corrected. 12950 * GCC no longer accepts the options -fvolatile, -fvolatile-global and 12951 -fvolatile-static. It is unlikely that they worked correctly in any 12952 3.x release. 12953 * GCC no longer ships <varargs.h>. Use <stdarg.h> instead. 12954 * Support for all the systems [3]obsoleted in GCC 3.3 has been 12955 removed from GCC 3.4. See below for a [4]list of systems which are 12956 obsoleted in this release. 12957 * GCC now requires an ISO C90 (ANSI C89) C compiler to build. K&R C 12958 compilers will not work. 12959 * The implementation of the [5]MIPS ABIs has changed. As a result, 12960 the code generated for certain MIPS targets will not be binary 12961 compatible with earlier releases. 12962 * In previous releases, the MIPS port had a fake "hilo" register with 12963 the user-visible name accum. This register has been removed. 12964 * The implementation of the [6]SPARC ABIs has changed. As a result, 12965 the code generated will not be binary compatible with earlier 12966 releases in certain cases. 12967 * The configure option --enable-threads=pthreads has been removed; 12968 use --enable-threads=posix instead, which should have the same 12969 effect. 12970 * Code size estimates used by inlining heuristics for C, Objective-C, 12971 C++ and Java have been redesigned significantly. As a result the 12972 parameters of -finline-insns, --param max-inline-insns-single and 12973 --param max-inline-insns-auto need to be reconsidered. 12974 * --param max-inline-slope and --param min-inline-insns have been 12975 removed; they are not needed for the new bottom-up inlining 12976 heuristics. 12977 * The new unit-at-a-time compilation scheme has several compatibility 12978 issues: 12979 + The order in which functions, variables, and top-level asm 12980 statements are emitted may have changed. Code relying on some 12981 particular ordering needs to be updated. The majority of such 12982 top-level asm statements can be replaced by section 12983 attributes. 12984 + Unreferenced static variables and functions are removed. This 12985 may result in undefined references when an asm statement 12986 refers to the variable/function directly. In that case either 12987 the variable/function shall be listed in asm statement operand 12988 or in the case of top-level asm statements the attribute used 12989 shall be used to force function/variable to be always output 12990 and considered as a possibly used by unknown code. 12991 For variables the attribute is accepted only by GCC 3.4 and 12992 newer, while for earlier versions it is sufficient to use 12993 unused to silence warnings about the variables not being 12994 referenced. To keep code portable across different GCC 12995 versions, you can use appropriate preprocessor conditionals. 12996 + Static functions now can use non-standard passing conventions 12997 that may break asm statements calling functions directly. 12998 Again the attribute used shall be used to prevent this 12999 behavior. 13000 As a temporary workaround, -fno-unit-at-a-time can be used, but 13001 this scheme may not be supported by future releases of GCC. 13002 * GCC 3.4 automatically places zero-initialized variables in the .bss 13003 section on some operating systems. Versions of GNU Emacs up to (and 13004 including) 21.3 will not work correctly when using this 13005 optimization; you can use -fno-zero-initialized-in-bss to disable 13006 it. 13007 * If GCC 3.4 is configured with --enable-threads=posix (the default 13008 on most targets that support pthreads) then _REENTRANT will be 13009 defined unconditionally by some libstdc++ headers. C++ code which 13010 relies on that macro to detect whether multi-threaded code is being 13011 compiled might change in meaning, possibly resulting in linker 13012 errors for single-threaded programs. Affected users of [7]Boost 13013 should compile single-threaded code with -DBOOST_DISABLE_THREADS. 13014 See Bugzilla for [8]more information. 13015 13016 General Optimizer Improvements 13017 13018 * Usability of the profile feedback and coverage testing has been 13019 improved. 13020 + Performance of profiled programs has been improved by faster 13021 profile merging code. 13022 + Better use of the profile feedback for optimization (loop 13023 unrolling and loop peeling). 13024 + File locking support allowing fork() calls and parallel runs 13025 of profiled programs. 13026 + Coverage file format has been redesigned. 13027 + gcov coverage tool has been improved. 13028 + make profiledbootstrap available to build a faster compiler. 13029 Experiments made on i386 hardware showed an 11% speedup on -O0 13030 and a 7.5% speedup on -O2 compilation of a [9]large C++ 13031 testcase. 13032 + New value profiling pass enabled via -fprofile-values 13033 + New value profile transformations pass enabled via -fvpt aims 13034 to optimize some code sequences by exploiting knowledge about 13035 value ranges or other properties of the operands. At the 13036 moment a conversion of expensive divisions into cheaper 13037 operations has been implemented. 13038 + New -fprofile-generate and -fprofile-use command-line options 13039 to simplify the use of profile feedback. 13040 * A new unit-at-a-time compilation scheme for C, Objective-C, C++ and 13041 Java which is enabled via -funit-at-a-time (and implied by -O2). In 13042 this scheme a whole file is parsed first and optimized later. The 13043 following basic inter-procedural optimizations are implemented: 13044 + Removal of unreachable functions and variables 13045 + Discovery of local functions (functions with static linkage 13046 whose address is never taken) 13047 + On i386, these local functions use register parameter passing 13048 conventions. 13049 + Reordering of functions in topological order of the call graph 13050 to enable better propagation of optimizing hints (such as the 13051 stack alignments needed by functions) in the back end. 13052 + Call graph based out-of-order inlining heuristics which allows 13053 to limit overall compilation unit growth (--param 13054 inline-unit-growth). 13055 Overall, the unit-at-a-time scheme produces a 1.3% improvement for 13056 the SPECint2000 benchmark on the i386 architecture (AMD Athlon 13057 CPU). 13058 * More realistic code size estimates used by inlining for C, 13059 Objective-C, C++ and Java. The growth of large functions can now be 13060 limited via --param large-function-insns and --param 13061 large-function-growth. 13062 * A new cfg-level loop optimizer pass replaces the old loop unrolling 13063 pass and adds two other loop transformations -- loop peeling and 13064 loop unswitching -- and also uses the profile feedback to limit 13065 code growth. (The three optimizations are enabled by 13066 -funroll-loops, -fpeel-loops and -funswitch-loops flags, 13067 respectively). 13068 The old loop unroller still can be enabled by -fold-unroll-loops 13069 and may produce better code in some cases, especially when the 13070 webizer optimization pass is not run. 13071 * A new web construction pass enabled via -fweb (and implied by -O3) 13072 improves the quality of register allocation, CSE, first scheduling 13073 pass and some other optimization passes by avoiding re-use of 13074 pseudo registers with non-overlapping live ranges. The pass almost 13075 always improves code quality but does make debugging difficult and 13076 thus is not enabled by default by -O2 13077 The pass is especially effective as cleanup after code duplication 13078 passes, such as the loop unroller or the tracer. 13079 * Experimental implementations of superblock or trace scheduling in 13080 the second scheduling pass can be enabled via 13081 -fsched2-use-superblocks and -fsched2-use-traces, respectively. 13082 13083 New Languages and Language specific improvements 13084 13085 Ada 13086 13087 * The Ada front end has been updated to include numerous bug fixes 13088 and enhancements. These include: 13089 + Improved project file support 13090 + Additional set of warnings about potential wrong code 13091 + Improved error messages 13092 + Improved code generation 13093 + Improved cross reference information 13094 + Improved inlining 13095 + Better run-time check elimination 13096 + Better error recovery 13097 + More efficient implementation of unbounded strings 13098 + Added features in GNAT.Sockets, GNAT.OS_Lib, GNAT.Debug_Pools, 13099 ... 13100 + New GNAT.xxxx packages (e.g. GNAT.Strings, 13101 GNAT.Exception_Action) 13102 + New pragmas 13103 + New -gnatS switch replacing gnatpsta 13104 + Implementation of new Ada features (in particular limited 13105 with, limited aggregates) 13106 13107 C/Objective-C/C++ 13108 13109 * Precompiled headers are now supported. Precompiled headers can 13110 dramatically speed up compilation of some projects. There are some 13111 known defects in the current precompiled header implementation that 13112 will result in compiler crashes in relatively rare situations. 13113 Therefore, precompiled headers should be considered a "technology 13114 preview" in this release. Read the manual for details about how to 13115 use precompiled headers. 13116 * File handling in the preprocessor has been rewritten. GCC no longer 13117 gets confused by symlinks and hardlinks, and now has a correct 13118 implementation of #import and #pragma once. These two directives 13119 have therefore been un-deprecated. 13120 * The undocumented extension that allowed C programs to have a label 13121 at the end of a compound statement, which has been deprecated since 13122 GCC 3.0, has been removed. 13123 * The cast-as-lvalue extension has been removed for C++ and 13124 deprecated for C and Objective-C. In particular, code like this: 13125 int i; 13126 (char) i = 5; 13127 13128 or this: 13129 char *p; 13130 ((int *) p)++; 13131 13132 is no longer accepted for C++ and will not be accepted for C and 13133 Objective-C in a future version. 13134 * The conditional-expression-as-lvalue extension has been deprecated 13135 for C and Objective-C. In particular, code like this: 13136 int a, b, c; 13137 (a ? b : c) = 2; 13138 13139 will not be accepted for C and Objective-C in a future version. 13140 * The compound-expression-as-lvalue extension has been deprecated for 13141 C and Objective-C. In particular, code like this: 13142 int a, b; 13143 (a, b) = 2; 13144 13145 will not be accepted for C and Objective-C in a future version. A 13146 possible non-intrusive workaround is the following: 13147 (*(a, &b)) = 2; 13148 13149 * Several [10]built-in functions such as __builtin_popcount for 13150 counting bits, finding the highest and lowest bit in a word, and 13151 parity have been added. 13152 * The -fwritable-strings option has been deprecated and will be 13153 removed. 13154 * Many C math library functions are now recognized as built-ins and 13155 optimized. 13156 * The C, C++, and Objective-C compilers can now handle source files 13157 written in any character encoding supported by the host C library. 13158 The default input character set is taken from the current locale, 13159 and may be overridden with the -finput-charset command line option. 13160 In the future we will add support for inline encoding markers. 13161 13162 C++ 13163 13164 * G++ is now much closer to full conformance to the ISO/ANSI C++ 13165 standard. This means, among other things, that a lot of invalid 13166 constructs which used to be accepted in previous versions will now 13167 be rejected. It is very likely that existing C++ code will need to 13168 be fixed. This document lists some of the most common issues. 13169 * A hand-written recursive-descent C++ parser has replaced the 13170 YACC-derived C++ parser from previous GCC releases. The new parser 13171 contains much improved infrastructure needed for better parsing of 13172 C++ source codes, handling of extensions, and clean separation 13173 (where possible) between proper semantics analysis and parsing. The 13174 new parser fixes many bugs that were found in the old parser. 13175 * You must now use the typename and template keywords to disambiguate 13176 dependent names, as required by the C++ standard. 13177 struct K { 13178 typedef int mytype_t; 13179 }; 13180 13181 template <class T1> struct A { 13182 template <class T2> struct B { 13183 void callme(void); 13184 }; 13185 13186 template <int N> void bar(void) 13187 { 13188 // Use 'typename' to tell the parser that T1::mytype_t names 13189 // a type. This is needed because the name is dependent (in 13190 // this case, on template parameter T1). 13191 typename T1::mytype_t x; 13192 x = 0; 13193 } 13194 }; 13195 13196 template <class T> void template_func(void) 13197 { 13198 // Use 'template' to prefix member templates within 13199 // dependent types (a has type A<T>, which depends on 13200 // the template parameter T). 13201 A<T> a; 13202 a.template bar<0>(); 13203 13204 // Use 'template' to tell the parser that B is a nested 13205 // template class (dependent on template parameter T), and 13206 // 'typename' because the whole A<T>::B<int> is 13207 // the name of a type (again, dependent). 13208 typename A<T>::template B<int> b; 13209 b.callme(); 13210 } 13211 13212 void non_template_func(void) 13213 { 13214 // Outside of any template class or function, no names can be 13215 // dependent, so the use of the keyword 'typename' and 'template' 13216 // is not needed (and actually forbidden). 13217 A<K> a; 13218 a.bar<0>(); 13219 A<K>::B<float> b; 13220 b.callme(); 13221 } 13222 * In a template definition, unqualified names will no longer find 13223 members of a dependent base (as specified by [temp.dep]/3 in the 13224 C++ standard). For example, 13225 template <typename T> struct B { 13226 int m; 13227 int n; 13228 int f (); 13229 int g (); 13230 }; 13231 int n; 13232 int g (); 13233 template <typename T> struct C : B<T> { 13234 void h () 13235 { 13236 m = 0; // error 13237 f (); // error 13238 n = 0; // ::n is modified 13239 g (); // ::g is called 13240 } 13241 }; 13242 You must make the names dependent, e.g. by prefixing them with 13243 this->. Here is the corrected definition of C<T>::h, 13244 template <typename T> void C<T>::h () 13245 { 13246 this->m = 0; 13247 this->f (); 13248 this->n = 0 13249 this->g (); 13250 } 13251 As an alternative solution (unfortunately not backwards compatible 13252 with GCC 3.3), you may use using declarations instead of this->: 13253 template <typename T> struct C : B<T> { 13254 using B<T>::m; 13255 using B<T>::f; 13256 using B<T>::n; 13257 using B<T>::g; 13258 void h () 13259 { 13260 m = 0; 13261 f (); 13262 n = 0; 13263 g (); 13264 } 13265 }; 13266 * In templates, all non-dependent names are now looked up and bound 13267 at definition time (while parsing the code), instead of later when 13268 the template is instantiated. For instance: 13269 void foo(int); 13270 13271 template <int> struct A { 13272 static void bar(void){ 13273 foo('a'); 13274 } 13275 }; 13276 13277 void foo(char); 13278 13279 int main() 13280 { 13281 A<0>::bar(); // Calls foo(int), used to call foo(char). 13282 } 13283 13284 * In an explicit instantiation of a class template, you must use 13285 class or struct before the template-id: 13286 template <int N> 13287 class A {}; 13288 13289 template A<0>; // error, not accepted anymore 13290 template class A<0>; // OK 13291 * The "named return value" and "implicit typename" extensions have 13292 been removed. 13293 * Default arguments in function types have been deprecated and will 13294 be removed. 13295 * ARM-style name-injection of friend declarations has been deprecated 13296 and will be removed. For example: struct S { friend void f(); }; 13297 void g() { f(); } will not be accepted by future versions of G++; 13298 instead a declaration of "f" will need to be present outside of the 13299 scope of "S". 13300 * Covariant returns are implemented for all but varadic functions 13301 that require an adjustment. 13302 * When -pedantic is used, G++ now issues errors about spurious 13303 semicolons. For example, 13304 namespace N {}; // Invalid semicolon. 13305 void f() {}; // Invalid semicolon. 13306 * G++ no longer accepts attributes for a declarator after the 13307 initializer associated with that declarator. For example, 13308 X x(1) __attribute__((...)); 13309 is no longer accepted. Instead, use: 13310 X x __attribute__((...)) (1); 13311 * Inside the scope of a template class, the name of the class itself 13312 can be treated as either a class or a template. So GCC used to 13313 accept the class name as argument of type template, and template 13314 template parameter. However this is not C++ standard compliant. Now 13315 the name is not treated as a valid template template argument 13316 unless you qualify the name by its scope. For example, the code 13317 below no longer compiles. 13318 template <template <class> class TT> class X {}; 13319 template <class T> class Y { 13320 X<Y> x; // Invalid, Y is always a type template parameter. 13321 }; 13322 The valid code for the above example is 13323 X< ::Y> x; // Valid. 13324 (Notice the space between < and : to prevent GCC to interpret this 13325 as a digraph for [.) 13326 * Friend declarations that refer to template specializations are 13327 rejected if the template has not already been declared. For 13328 example, 13329 template <typename T> 13330 class C { 13331 friend void f<> (C&); 13332 }; 13333 is rejected. You must first declare f as a template, 13334 template <typename T> 13335 void f(T); 13336 * In case of friend declarations, every name used in the friend 13337 declaration must be accessible at the point of that declaration. 13338 Previous versions of G++ used to be less strict about this and 13339 allowed friend declarations for private class members, for example. 13340 See the ISO C++ Standard Committee's [11]defect report #209 for 13341 details. 13342 * Declaration of member functions of class templates as friends are 13343 supported. For example, 13344 template <typename T> struct A { 13345 void f(); 13346 }; 13347 class C { 13348 template <typename T> friend void A<T>::f(); 13349 }; 13350 * You must use template <> to introduce template specializations, as 13351 required by the standard. For example, 13352 template <typename T> 13353 struct S; 13354 13355 struct S<int> { }; 13356 is rejected. You must write, 13357 template <> struct S<int> {}; 13358 * G++ used to accept code like this, 13359 struct S { 13360 int h(); 13361 void f(int i = g()); 13362 int g(int i = h()); 13363 }; 13364 This behavior is not mandated by the standard. Now G++ issues an 13365 error about this code. To avoid the error, you must move the 13366 declaration of g before the declaration of f. The default arguments 13367 for g must be visible at the point where it is called. 13368 * The C++ ABI Section 3.3.3 specifications for the array construction 13369 routines __cxa_vec_new2 and __cxa_vec_new3 were changed to return 13370 NULL when the allocator argument returns NULL. These changes are 13371 incorporated into the libstdc++ runtime library. 13372 * Using a name introduced by a typedef in a friend declaration or in 13373 an explicit instantiation is now rejected, as specified by the ISO 13374 C++ standard. 13375 class A; 13376 typedef A B; 13377 class C { 13378 friend class B; // error, no typedef name here 13379 friend B; // error, friend always needs class/struct/enum 13380 friend class A; // OK 13381 }; 13382 13383 template <int> class Q {}; 13384 typedef Q<0> R; 13385 template class R; // error, no typedef name here 13386 template class Q<0>; // OK 13387 * When allocating an array with a new expression, GCC used to allow 13388 parentheses around the type name. This is actually ill-formed and 13389 it is now rejected: 13390 int* a = new (int)[10]; // error, not accepted anymore 13391 int* a = new int[10]; // OK 13392 * When binding an rvalue of class type to a reference, the copy 13393 constructor of the class must be accessible. For instance, consider 13394 the following code: 13395 class A 13396 { 13397 public: 13398 A(); 13399 13400 private: 13401 A(const A&); // private copy ctor 13402 }; 13403 13404 A makeA(void); 13405 void foo(const A&); 13406 13407 void bar(void) 13408 { 13409 foo(A()); // error, copy ctor is not accessible 13410 foo(makeA()); // error, copy ctor is not accessible 13411 13412 A a1; 13413 foo(a1); // OK, a1 is a lvalue 13414 } 13415 This might be surprising at first sight, especially since most 13416 popular compilers do not correctly implement this rule ([12]further 13417 details). 13418 * When forming a pointer to member or a pointer to member function, 13419 access checks for class visibility (public, protected, private) are 13420 now performed using the qualifying scope of the name itself. This 13421 is better explained with an example: 13422 class A 13423 { 13424 public: 13425 void pub_func(); 13426 protected: 13427 void prot_func(); 13428 private: 13429 void priv_func(); 13430 }; 13431 13432 class B : public A 13433 { 13434 public: 13435 void foo() 13436 { 13437 &A::pub_func; // OK, pub_func is accessible through A 13438 &A::prot_func; // error, cannot access prot_func through A 13439 &A::priv_func; // error, cannot access priv_func through A 13440 13441 &B::pub_func; // OK, pub_func is accessible through B 13442 &B::prot_func; // OK, can access prot_func through B (within B) 13443 &B::priv_func; // error, cannot access priv_func through B 13444 } 13445 }; 13446 13447 Runtime Library (libstdc++) 13448 13449 * Optimization work: 13450 + Streamlined streambuf, filebuf, separate synched with C 13451 Standard I/O streambuf. 13452 + All formatted I/O now uses cached locale information. 13453 + STL optimizations (memory/speed for list, red-black trees as 13454 used by sets and maps). 13455 + More use of GCC builtins. 13456 + String optimizations (avoid contention on 13457 increment/decrement-and-test of the reference count in the 13458 empty-string object, constructor from input_iterators 13459 speedup). 13460 * Static linkage size reductions. 13461 * Large File Support (files larger than 2 GB on 32-bit systems). 13462 * Wide character and variable encoding filebuf work (UTF-8, Unicode). 13463 * Generic character traits. 13464 * Also support wchar_t specializations on Mac OS 10.3.x, FreeBSD 5.x, 13465 Solaris 2.7 and above, AIX 5.x, Irix 6.5. 13466 * The allocator class is now standard-conformant, and two additional 13467 extension allocators have been added, mt_alloc and 13468 bitmap_allocator. 13469 * PCH support: -include bits/stdc++.h (2x compile speedup). 13470 * Rewrote __cxa_demangle with support for C++ style allocators. 13471 * New debug modes for STL containers and iterators. 13472 * Testsuite rewrite: five times as many tests, plus increasingly 13473 sophisticated tests, including I/O, MT, multi-locale, wide and 13474 narrow characters. 13475 * Use current versions of GNU "autotools" for build/configuration. 13476 13477 Objective-C 13478 13479 * The Objective-C front end has been updated to include the numerous 13480 bug fixes and enhancements previously available only in Apple's 13481 version of GCC. These include: 13482 + Structured exception (@try... @catch... @finally, @throw) and 13483 synchronization (@synchronized) support. These are accessible 13484 via the -fobjc-exceptions switch; as of this writing, they may 13485 only be used in conjunction with -fnext-runtime on Mac OS X 13486 10.3 and later. See [13]Options Controlling Objective-C 13487 Dialect for more information. 13488 + An overhaul of @encode logic. The C99 _Bool and C++ bool type 13489 may now be encoded as 'B'. In addition, the back-end/codegen 13490 dependencies have been removed. 13491 + An overhaul of message dispatch construction, ensuring that 13492 the various receiver types (and casts thereof) are handled 13493 properly, and that correct diagnostics are issued. 13494 + Support for "Zero-Link" (-fzero-link) and "Fix-and-Continue" 13495 (-freplace-objc-classes) debugging modes, currently available 13496 on Mac OS X 10.3 and later. See [14]Options Controlling 13497 Objective-C Dialect for more information. 13498 + Access to optimized runtime entry points (-fno-nil-receivers ) 13499 on the assumption that message receivers are never nil. This 13500 is currently available on Mac OS X 10.3 and later. See 13501 [15]Options Controlling Objective-C Dialect for more 13502 information. 13503 13504 Java 13505 13506 * Compiling a .jar file will now cause non-.class entries to be 13507 automatically compiled as resources. 13508 * libgcj has been ported to Darwin. 13509 * Jeff Sturm has adapted Jan Hubicka's call graph optimization code 13510 to gcj. 13511 * libgcj has a new gcjlib URL type; this lets URLClassLoader load 13512 code from shared libraries. 13513 * libgcj has been much more completely merged with [16]GNU Classpath. 13514 * Class loading is now much more correct; in particular the caller's 13515 class loader is now used when that is required. 13516 * [17]Eclipse 2.x will run out of the box using gij. 13517 * Parts of java.nio have been implemented. Direct and indirect 13518 buffers work, as do fundamental file and socket operations. 13519 * java.awt has been improved, though it is still not ready for 13520 general use. 13521 * The HTTP protocol handler now uses HTTP/1.1 and can handle the POST 13522 method. 13523 * The MinGW port has matured. Enhancements include socket timeout 13524 support, thread interruption, improved Runtime.exec() handling and 13525 support for accented characters in filenames. 13526 13527 Fortran 13528 13529 * Fortran improvements are listed in the [18]Fortran documentation. 13530 13531 New Targets and Target Specific Improvements 13532 13533 Alpha 13534 13535 * Several [19]built-in functions have been added such as 13536 __builtin_alpha_zap to allow utilizing the more obscure 13537 instructions of the CPU. 13538 * Parameter passing of complex arguments has changed to match the 13539 ABI. This change is incompatible with previous GCC versions, but 13540 does fix compatibility with the Tru64 compiler and several corner 13541 cases where GCC was incompatible with itself. 13542 13543 ARM 13544 13545 * Nicolas Pitre has contributed his hand-coded floating-point support 13546 code for ARM. It is both significantly smaller and faster than the 13547 existing C-based implementation, even when building applications 13548 for Thumb. The arm-elf configuration has been converted to use the 13549 new code. 13550 * Support for the Intel's iWMMXt architecture, a second generation 13551 XScale processor, has been added. Enabled at run time with the 13552 -mcpu=iwmmxt command line switch. 13553 * A new ARM target has been added: arm-wince-pe. This is similar to 13554 the arm-pe target, but it defaults to using the APCS32 ABI. 13555 * The existing ARM pipeline description has been converted to the use 13556 the [20]DFA processor pipeline model. There is not much change in 13557 code performance, but the description is now [21]easier to 13558 understand. 13559 * Support for the Cirrus EP9312 Maverick floating point co-processor 13560 added. Enabled at run time with the -mcpu=ep9312 command line 13561 switch. Note however that the multilibs to support this chip are 13562 currently disabled in gcc/config/arm/t-arm-elf, so if you want to 13563 enable their production you will have to uncomment the entries in 13564 that file. 13565 13566 H8/300 13567 13568 * Support for long long has been added. 13569 * Support for saveall attribute has been added. 13570 * Pavel Pisa contributed hand-written 32-bit-by-32-bit division code 13571 for H8/300H and H8S, which is much faster than the previous 13572 implementation. 13573 * A lot of small performance improvements. 13574 13575 IA-32/AMD64 (x86-64) 13576 13577 * Tuning for K8 (AMD Opteron/Athlon64) core is available via 13578 -march=k8 and -mcpu=k8. 13579 * Scalar SSE code generation carefully avoids reformatting penalties, 13580 hidden dependencies and minimizes the number of uops generated on 13581 both Intel and AMD CPUs. 13582 * Vector MMX and SSE operands are now passed in registers to improve 13583 performance and match the argument passing convention used by the 13584 Intel C++ Compiler. As a result it is not possible to call 13585 functions accepting vector arguments compiled by older GCC version. 13586 * Conditional jump elimination is now more aggressive on modern CPUs. 13587 * The Athlon ports has been converted to use the DFA processor 13588 pipeline description. 13589 * Optimization of indirect tail calls is now possible in a similar 13590 fashion as direct sibcall optimization. 13591 * Further small performance improvements. 13592 * -m128bit-long-double is now less buggy. 13593 * __float128 support in 64-bit compilation. 13594 * Support for data structures exceeding 2GB in 64-bit mode. 13595 * -mcpu has been renamed to -mtune. 13596 13597 IA-64 13598 13599 * Tuning code for the Itanium 2 processor has been added. The 13600 generation of code tuned for Itanium 2 (option -mtune=itanium2) is 13601 enabled by default now. To generate code tuned for Itanium 1 the 13602 option -mtune=itanium1 should be used. 13603 * [22]DFA processor pipeline descriptions for the IA-64 processors 13604 have been added. This resulted in about 3% improvement on the 13605 SPECInt2000 benchmark for Itanium 2. 13606 * Instruction bundling for the IA-64 processors has been rewritten 13607 using the DFA pipeline hazard recognizer. It resulted in about 60% 13608 compiler speedup on the SPECInt2000 C programs. 13609 13610 M32R 13611 13612 * Support for the M32R/2 processor has been added by Renesas. 13613 * Support for an M32R GNU/Linux target and PIC code generation has 13614 been added by Renesas. 13615 13616 M68000 13617 13618 * Bernardo Innocenti (Develer S.r.l.) has contributed the 13619 m68k-uclinux target, based on former work done by Paul Dale 13620 (SnapGear Inc.). Code generation for the ColdFire processors family 13621 has been enhanced and extended to support the MCF 53xx and MCF 54xx 13622 cores, integrating former work done by Peter Barada (Motorola). 13623 13624 MIPS 13625 13626 Processor-specific changes 13627 13628 * Support for the RM7000 and RM9000 processors has been added. It can 13629 be selected using the -march compiler option and should work with 13630 any MIPS I (mips-*) or MIPS III (mips64-*) configuration. 13631 * Support for revision 2 of the MIPS32 ISA has been added. It can be 13632 selected with the command-line option -march=mips32r2. 13633 * There is a new option, -mfix-sb1, to work around certain SB-1 13634 errata. 13635 13636 Configuration 13637 13638 * It is possible to customize GCC using the following configure-time 13639 options: 13640 + --with-arch, which specifies the default value of the -march 13641 option. 13642 + --with-tune, which specifies the default value of the -mtune 13643 option. 13644 + --with-abi, which specifies the default ABI. 13645 + --with-float=soft, which tells GCC to use software floating 13646 point by default. 13647 + --with-float=hard, which tells GCC to use hardware floating 13648 point by default. 13649 * A 64-bit GNU/Linux port has been added. The associated 13650 configurations are mips64-linux-gnu and mips64el-linux-gnu. 13651 * The 32-bit GNU/Linux port now supports Java. 13652 * The IRIX 6 configuration now supports the o32 ABI and will build 13653 o32 multilibs by default. This support is compatible with both 13654 binutils and the SGI tools, but note that several features, 13655 including debugging information and DWARF2 exception handling, are 13656 only available when using the GNU assembler. Use of the GNU 13657 assembler and linker (version 2.15 or above) is strongly 13658 recommended. 13659 * The IRIX 6 configuration now supports 128-bit long doubles. 13660 * There are two new RTEMS-specific configurations, mips-rtems and 13661 mipsel-rtems. 13662 * There are two new *-elf configurations, mipsisa32r2-elf and 13663 mipsisa32r2el-elf. 13664 13665 General 13666 13667 * Several [23]ABI bugs have been fixed. Unfortunately, these changes 13668 will break binary compatibility with earlier releases. 13669 * GCC can now use explicit relocation operators when generating 13670 -mabicalls code. This behavior is controlled by -mexplicit-relocs 13671 and can have several performance benefits. For example: 13672 + It allows for more optimization of GOT accesses, including 13673 better scheduling and redundancy elimination. 13674 + It allows sibling calls to be implemented as jumps. 13675 + n32 and n64 leaf functions can use a call-clobbered global 13676 pointer instead of $28. 13677 + The code to set up $gp can be removed from functions that 13678 don't need it. 13679 * A new option, -mxgot, allows the GOT to be bigger than 64k. This 13680 option is equivalent to the assembler's -xgot option and should be 13681 used instead of -Wa,-xgot. 13682 * Frame pointer elimination is now supported when generating 64-bit 13683 MIPS16 code. 13684 * Inline block moves have been optimized to take more account of 13685 alignment information. 13686 * Many internal changes have been made to the MIPS port, mostly aimed 13687 at reducing the reliance on assembler macros. 13688 13689 PowerPC 13690 13691 * GCC 3.4 releases have a number of fixes for PowerPC and PowerPC64 13692 [24]ABI incompatibilities regarding the way parameters are passed 13693 during functions calls. These changes may result in incompatibility 13694 between code compiled with GCC 3.3 and GCC 3.4. 13695 13696 PowerPC Darwin 13697 13698 * Support for shared/dylib gcc libraries has been added. It is 13699 enabled by default on powerpc-apple-darwin7.0.0 and up. 13700 * Libgcj is enabled by default. On systems older than 13701 powerpc-apple-darwin7.0.0 you need to install dlcompat. 13702 * 128-bit IBM extended precision format support added for long 13703 double. 13704 13705 PowerPC64 GNU/Linux 13706 13707 * By default, PowerPC64 GNU/Linux now uses natural alignment of 13708 structure elements. The old four byte alignment for double, with 13709 special rules for a struct starting with a double, can be chosen 13710 with -malign-power. This change may result in incompatibility 13711 between code compiled with GCC 3.3 and GCC 3.4. 13712 * -mabi=altivec is now the default rather than -mabi=no-altivec. 13713 * 128-bit IBM extended precision format support added for long 13714 double. 13715 13716 S/390 and zSeries 13717 13718 * New command-line options allow to specify the intended execution 13719 environment for generated code: 13720 + -mesa/-mzarch allows to specify whether to generate code 13721 running in ESA/390 mode or in z/Architecture mode (this is 13722 applicable to 31-bit code only). 13723 + -march allows to specify a minimum processor architecture 13724 level (g5, g6, z900, or z990). 13725 + -mtune allows to specify which processor to tune for. 13726 * It is possible to customize GCC using the following configure-time 13727 options: 13728 + --with-mode, which specifies whether to default to assuming 13729 ESA/390 or z/Architecture mode. 13730 + --with-arch, which specifies the default value of the -march 13731 option. 13732 + --with-tune, which specifies the default value of the -mtune 13733 option. 13734 * Support for the z990 processor has been added, and can be selected 13735 using -march=z990 or -mtune=z990. This includes instruction 13736 scheduling tuned for the superscalar instruction pipeline of the 13737 z990 processor as well as support for all new instructions provided 13738 by the long-displacement facility. 13739 * Support to generate 31-bit code optimized for zSeries processors 13740 (running in ESA/390 or in z/Architecture mode) has been added. This 13741 can be selected using -march=z900 and -mzarch respectively. 13742 * Instruction scheduling for the z900 and z990 processors now uses 13743 the DFA pipeline hazard recognizer. 13744 * GCC no longer generates code to maintain a stack backchain, 13745 previously used to generate stack backtraces for debugging 13746 purposes. As replacement that does not incur runtime overhead, 13747 DWARF-2 call frame information is provided by GCC; this is 13748 supported by GDB 6.1. The old behavior can be restored using the 13749 -mbackchain option. 13750 * The stack frame size of functions may now exceed 2 GB in 64-bit 13751 code. 13752 * A port for the 64-bit IBM TPF operating system has been added; the 13753 configuration is s390x-ibm-tpf. This configuration is supported as 13754 cross-compilation target only. 13755 * Various changes to improve the generated code have been 13756 implemented, including: 13757 + GCC now uses the MULTIPLY AND ADD and MULTIPLY AND SUBTRACT 13758 instructions to significantly speed up many floating-point 13759 applications. 13760 + GCC now uses the ADD LOGICAL WITH CARRY and SUBTRACT LOGICAL 13761 WITH BORROW instructions to speed up long long arithmetic. 13762 + GCC now uses the SEARCH STRING instruction to implement 13763 strlen(). 13764 + In many cases, function call overhead for 31-bit code has been 13765 reduced by placing the literal pool after the function code 13766 instead of after the function prolog. 13767 + Register 14 is no longer reserved in 64-bit code. 13768 + Handling of global register variables has been improved. 13769 13770 SPARC 13771 13772 * The option -mflat is deprecated. 13773 * Support for large (> 2GB) frames has been added to the 64-bit port. 13774 * Several [25]ABI bugs have been fixed. Unfortunately, these changes 13775 will break binary compatibility with earlier releases. 13776 * The default debugging format has been switched from STABS to 13777 DWARF-2 for 32-bit code on Solaris 7 and later. DWARF-2 is already 13778 the default debugging format for 64-bit code on Solaris. 13779 13780 SuperH 13781 13782 * Support for the SH2E processor has been added. Enabled at run time 13783 with the -m2e command line switch, or at configure time by 13784 specifying sh2e as the machine part of the target triple. 13785 13786 V850 13787 13788 * Support for the Mitsubishi V850E1 processor has been added. This is 13789 a variant of the V850E processor with some additional debugging 13790 instructions. 13791 13792 Xtensa 13793 13794 * Several ABI bugs have been fixed. Unfortunately, these changes 13795 break binary compatibility with earlier releases. 13796 + For big-endian processors, the padding of aggregate return 13797 values larger than a word has changed. If the size of an 13798 aggregate return value is not a multiple of 32 bits, previous 13799 versions of GCC inserted padding in the most-significant bytes 13800 of the first return value register. Aggregates larger than a 13801 word are now padded in the least-significant bytes of the last 13802 return value register used. Aggregates smaller than a word are 13803 still padded in the most-significant bytes. The return value 13804 padding has not changed for little-endian processors. 13805 + Function arguments with 16-byte alignment are now properly 13806 aligned. 13807 + The implementation of the va_list type has changed. A va_list 13808 value created by va_start from a previous release cannot be 13809 used with va_arg from this release, or vice versa. 13810 * More processor configuration options for Xtensa processors are 13811 supported: 13812 + the ABS instruction is now optional; 13813 + the ADDX* and SUBX* instructions are now optional; 13814 + an experimental CONST16 instruction can be used to synthesize 13815 constants instead of loading them from constant pools. 13816 These and other Xtensa processor configuration options can no 13817 longer be enabled or disabled by command-line options; the 13818 processor configuration must be specified by the xtensa-config.h 13819 header file when building GCC. Additionally, the 13820 -mno-serialize-volatile option is no longer supported. 13821 13822 Obsolete Systems 13823 13824 Support for a number of older systems has been declared obsolete in GCC 13825 3.4. Unless there is activity to revive them, the next release of GCC 13826 will have their sources permanently removed. 13827 13828 All configurations of the following processor architectures have been 13829 declared obsolete: 13830 * Mitsubishi D30V, d30v-* 13831 * AT&T DSP1600 and DSP1610, dsp16xx-* 13832 * Intel 80960, i960 13833 13834 Also, some individual systems have been obsoleted: 13835 * ARM Family 13836 + Support for generating code for operation in APCS/26 mode 13837 (-mapcs-26). 13838 * IBM ESA/390 13839 + "Bigfoot" port, i370-*. (The other port, s390-*, is actively 13840 maintained and supported.) 13841 * Intel 386 family 13842 + MOSS, i?86-moss-msdos and i?86-*-moss* 13843 + NCR 3000 running System V r.4, i?86-ncr-sysv4* 13844 + FreeBSD with a.out object format, i?86-*-freebsd*aout* and 13845 i?86-*-freebsd2* 13846 + GNU/Linux with a.out object format, i?86-linux*aout* 13847 + GNU/Linux with libc5, a.k.a. glibc1, i?86-linux*libc1* 13848 + Interix versions before Interix 3, i?86-*-interix 13849 + Mach microkernel, i?86-mach* 13850 + SCO UnixWare with UDK, i?86-*-udk* 13851 + Generic System V releases 1, 2, and 3, i?86-*-sysv[123]* 13852 + VSTa microkernel, i386-*-vsta 13853 * Motorola M68000 family 13854 + HPUX, m68k-hp-hpux* and m68000-hp-hpux* 13855 + NetBSD with a.out object format (before NetBSD 1.4), 13856 m68k-*-*-netbsd* except m68k-*-*-netbsdelf* 13857 + Generic System V r.4, m68k-*-sysv4* 13858 * VAX 13859 + Generic VAX, vax-*-* (This is generic VAX only; we have not 13860 obsoleted any VAX triples for specific operating systems.) 13861 13862 Documentation improvements 13863 13864 Other significant improvements 13865 13866 * The build system has undergone several significant cleanups. 13867 Subdirectories will only be configured if they are being built, and 13868 all subdirectory configures are run from the make command. The top 13869 level has been autoconfiscated. 13870 * Building GCC no longer writes to its source directory. This should 13871 help those wishing to share a read-only source directory over NFS 13872 or build from a CD. The exceptions to this feature are if you 13873 configure with either --enable-maintainer-mode or 13874 --enable-generated-files-in-srcdir. 13875 * The -W warning option has been renamed to -Wextra, which is more 13876 easily understood. The older spelling will be retained for 13877 backwards compatibility. 13878 * Substantial improvements in compile time have been made, 13879 particularly for non-optimizing compilations. 13880 __________________________________________________________________ 13881 13882 GCC 3.4.0 13883 13884 Bug Fixes 13885 13886 A vast number of bugs have been fixed in 3.4.0, too many to publish a 13887 complete list here. [26]Follow this link to query the Bugzilla database 13888 for the list of over 900 bugs fixed in 3.4.0. This is the list of all 13889 bugs marked as resolved and fixed in 3.4.0 that are not flagged as 3.4 13890 regressions. 13891 __________________________________________________________________ 13892 13893 GCC 3.4.1 13894 13895 Bug Fixes 13896 13897 This section lists the problem reports (PRs) from GCC's bug tracking 13898 system that are known to be fixed in the 3.4.1 release. This list might 13899 not be complete (that is, it is possible that some PRs that have been 13900 fixed are not listed here). 13901 13902 Bootstrap failures 13903 13904 * [27]10129 Ada bootstrap fails on PPC-Darwin - invalid assembler 13905 emitted - PIC related 13906 * [28]14576 [ARM] ICE in libiberty when building gcc-3.4 for arm-elf 13907 * [29]14760 A bug in configure.in prevents using both 13908 --program-suffix and --program-prefix 13909 * [30]14671 [hppa64] bootstrap fails: ICE in 13910 save_call_clobbered_regs, in caller_save.c 13911 * [31]15093 [alpha][Java] make bootstrap fails to configure libffi on 13912 Alpha 13913 * [32]15178 Solaris 9/x86 fails linking after stage 3 13914 13915 Multi-platform internal compiler errors (ICEs) 13916 13917 * [33]12753 (preprocessor) Memory corruption in preprocessor on bad 13918 input 13919 * [34]13985 ICE in gcc.c-torture/compile/930621-1.c 13920 * [35]14810 (c++) tree check failures with invalid code involving 13921 templates 13922 * [36]14883 (c++) ICE on invalid code, in cp_parser_lookup_name, in 13923 cp/parser.c 13924 * [37]15044 (c++) ICE on syntax error, template header 13925 * [38]15057 (c++) Compiling of conditional value throw constructs 13926 cause a segmentation violation 13927 * [39]15064 (c++) typeid of template parameter gives ICE 13928 * [40]15142 (c++) ICE when passing a string where a char* is expected 13929 in a throw statement 13930 * [41]15159 ICE in rtl_verify_flow_info_1 13931 * [42]15165 (c++) ICE in instantiate_template 13932 * [43]15193 Unary minus using pointer to V4SF vector causes 13933 -fforce-mem to exhaust all memory 13934 * [44]15209 (c++) Runs out of memory with packed structs 13935 * [45]15227 (c++) Trouble with invalid function definition 13936 * [46]15285 (c++) instantiate_type ICE when forming pointer to 13937 template function 13938 * [47]15299 (c++) ICE in resolve_overloaded_unification 13939 * [48]15329 (c++) ICE on constructor of member template 13940 * [49]15550 ICE in extract_insn, in recog.c 13941 * [50]15554 (c++) ICE in tsubst_copy, in cp/pt.c 13942 * [51]15640 (c++) ICE on invalid code in arg_assoc, in 13943 cp/name-lookup.c 13944 * [52]15666 [unit-at-a-time] Gcc abort on valid code 13945 * [53]15696 (c++) ICE with bad pointer-to-member code 13946 * [54]15701 (c++) ICE with friends and template template parameter 13947 * [55]15761 ICE in do_SUBST, in combine.c 13948 * [56]15829 (c++) ICE on Botan-1.3.13 due to -funroll-loops 13949 13950 Ada 13951 13952 * [57]14538 All RTEMS targets broken for gnat 13953 13954 C front end 13955 13956 * [58]12391 missing warning about assigning to an incomplete type 13957 * [59]14649 atan(1.0) should not be a constant expression 13958 * [60]15004 [unit-at-a-time] no warning for unused paramater in 13959 static function 13960 * [61]15749 --pedantic-errors behaves differently from --pedantic 13961 with C-compiler on GNU/Linux 13962 13963 C++ compiler and library 13964 13965 * [62]10646 non-const reference is incorrectly matched in a "const T" 13966 partial specialization 13967 * [63]12077 wcin.rdbuf()->in_avail() return value too high 13968 * [64]13598 enc_filebuf doesn't work 13969 * [65]14211 const_cast returns lvalue but should be rvalue 13970 * [66]14220 num_put::do_put() undesired float/double behavior 13971 * [67]14245 problem with user-defined allocators in std::basic_string 13972 * [68]14340 libstdc++ Debug mode: failure to convert iterator to 13973 const_iterator 13974 * [69]14600 __gnu_cxx::stdio_sync_filebuf should expose internal 13975 FILE* 13976 * [70]14668 no warning anymore for reevaluation of declaration 13977 * [71]14775 LFS (large file support) tests missing 13978 * [72]14821 Duplicate namespace alias declaration should not conflict 13979 * [73]14930 Friend declaration ignored 13980 * [74]14932 cannot use offsetof to get offsets of array elements in 13981 g++ 3.4.0 13982 * [75]14950 [non unit-at-a-time] always_inline does not mix with 13983 templates and -O0 13984 * [76]14962 g++ ignores #pragma redefine_extname 13985 * [77]14975 Segfault on low-level write error during imbue 13986 * [78]15002 Linewise stream input is unusably slow (std::string slow) 13987 * [79]15025 compiler accepts redeclaration of template as 13988 non-template 13989 * [80]15046 [arm] Math functions misdetected by cross configuration 13990 * [81]15069 a bit test on a variable of enum type is miscompiled 13991 * [82]15074 g++ -lsupc++ still links against libstdc++ 13992 * [83]15083 spurious "statement has no effect" warning 13993 * [84]15096 parse error with templates and pointer to const member 13994 * [85]15287 combination of operator[] and operator .* fails in 13995 templates 13996 * [86]15317 __attribute__ unused in first parameter of constructor 13997 gives error 13998 * [87]15337 sizeof on incomplete type diagnostic 13999 * [88]15361 bitset<>::_Find_next fails 14000 * [89]15412 _GLIBCXX_ symbols symbols defined and used in different 14001 namespaces 14002 * [90]15427 valid code results in incomplete type error 14003 * [91]15471 Incorrect member pointer offsets in anonymous 14004 structs/unions 14005 * [92]15503 nested template problem 14006 * [93]15507 compiler hangs while laying out union 14007 * [94]15542 operator & and template definitions 14008 * [95]15565 SLES9: leading + sign for unsigned int with showpos 14009 * [96]15625 friend defined inside a template fails to find static 14010 function 14011 * [97]15629 Function templates, overloads, and friend name injection 14012 * [98]15742 'noreturn' attribute ignored in method of template 14013 functions. 14014 * [99]15775 Allocator::pointer consistently ignored 14015 * [100]15821 Duplicate namespace alias within namespace rejected 14016 * [101]15862 'enum yn' fails (confict with undeclared builtin) 14017 * [102]15875 rejects pointer to member in template 14018 * [103]15877 valid code using templates and anonymous enums is 14019 rejected 14020 * [104]15947 Puzzling error message for wrong destructor declaration 14021 in template class 14022 * [105]16020 cannot copy __gnu_debug::bitset 14023 * [106]16154 input iterator concept too restrictive 14024 * [107]16174 deducing top-level consts 14025 14026 Java 14027 14028 * [108]14315 Java compiler is not parallel make safe 14029 14030 Fortran 14031 14032 * [109]15151 [g77] incorrect logical i/o in 64-bit mode 14033 14034 Objective-C 14035 14036 * [110]7993 private variables cannot be shadowed in subclasses 14037 14038 Optimization bugs 14039 14040 * [111]15228 useless copies of floating point operands 14041 * [112]15345 [non-unit-at-a-time] unreferenced nested inline 14042 functions not optimized away 14043 * [113]15945 Incorrect floating point optimization 14044 * [114]15526 ftrapv aborts on 0 * (-1) 14045 * [115]14690 Miscompiled POOMA tests 14046 * [116]15112 GCC generates code to write to unchanging memory 14047 14048 Preprocessor 14049 14050 * [117]15067 Minor glitch in the source of cpp 14051 14052 Main driver program bugs 14053 14054 * [118]1963 collect2 interprets -oldstyle_liblookup as -o 14055 ldstyle_liblookup 14056 14057 x86-specific (Intel/AMD) 14058 14059 * [119]15717 Error: can't resolve `L0' {*ABS* section} - `xx' {*UND* 14060 section} 14061 14062 HPPA-specific 14063 14064 * [120]14782 GCC produces an unaligned data access at -O2 14065 * [121]14828 FAIL: gcc.c-torture/execute/20030408-1.c execution, -O2 14066 * [122]15202 ICE in reload_cse_simplify_operands, in postreload.c 14067 14068 IA64-specific 14069 14070 * [123]14610 __float80 constants incorrectly emitted 14071 * [124]14813 init_array sections are initialized in the wrong order 14072 * [125]14857 GCC segfault on duplicated asm statement 14073 * [126]15598 Gcc 3.4 ICE on valid code 14074 * [127]15653 Gcc 3.4 ICE on valid code 14075 14076 MIPS-specific 14077 14078 * [128]15189 wrong filling of delay slot with -march=mips1 -G0 14079 -mno-split-addresses -mno-explicit-relocs 14080 * [129]15331 Assembler error building gnatlib on IRIX 6.5 with GNU as 14081 2.14.91 14082 * [130]16144 Bogus reference to __divdf3 when -O1 14083 * [131]16176 Miscompilation of unaligned data in MIPS backend 14084 14085 PowerPC-specific 14086 14087 * [132]11591 ICE in gcc.dg/altivec-5.c 14088 * [133]12028 powerpc-eabispe produces bad sCOND operation 14089 * [134]14478 rs6000 geu/ltu patterns generate incorrect code 14090 * [135]14567 long double and va_arg complex args 14091 * [136]14715 Altivec stack layout may overlap gpr save with stack 14092 temps 14093 * [137]14902 (libstdc++) Stream checking functions fail when -pthread 14094 option is used. 14095 * [138]14924 Compiler ICE on valid code 14096 * [139]14960 -maltivec affects vector return with -mabi=no-altivec 14097 * [140]15106 vector varargs failure passing from altivec to 14098 non-altivec code for -m32 14099 * [141]16026 ICE in function.c:4804, assign_parms, when -mpowerpc64 & 14100 half-word operation 14101 * [142]15191 -maltivec -mabi=no-altivec results in mis-aligned lvx 14102 and stvx 14103 * [143]15662 Segmentation fault when an exception is thrown - even if 14104 try and catch are specified 14105 14106 s390-specific 14107 14108 * [144]15054 Bad code due to overlapping stack temporaries 14109 14110 SPARC-specific 14111 14112 * [145]15783 ICE with union assignment in 64-bit mode 14113 * [146]15626 GCC 3.4 emits "ld: warning: relocation error: 14114 R_SPARC_UA32" 14115 14116 x86-64-specific 14117 14118 * [147]14326 boehm-gc hardcodes to 3DNow! prefetch for x86_64 14119 * [148]14723 Backported -march=nocona from mainline 14120 * [149]15290 __float128 failed to pass to function properly 14121 14122 Cygwin/Mingw32-specific 14123 14124 * [150]15250 Option -mms-bitfields support on GCC 3.4 is not 14125 conformant to MS layout 14126 * [151]15551 -mtune=pentium4 -O2 with sjlj EH breaks stack probe 14127 worker on windows32 targets 14128 14129 Bugs specific to embedded processors 14130 14131 * [152]8309 [m68k] -m5200 produces erroneous SImode set of short 14132 varaible on stack 14133 * [153]13250 [SH] Gcc code for rotation clobbers the register, but 14134 gcc continues to use the register as if it was not clobbered 14135 * [154]13803 [coldfire] movqi operand constraints too restrictivefor 14136 TARGET_COLDFIRE 14137 * [155]14093 [SH] ICE for code when using -mhitachi option in SH 14138 * [156]14457 [m6811hc] ICE with simple c++ source 14139 * [157]14542 [m6811hc] ICE on simple source 14140 * [158]15100 [SH] cc1plus got hang-up on 14141 libstdc++-v3/testsuite/abi_check.cc 14142 * [159]15296 [CRIS] Delayed branch scheduling causing invalid code on 14143 cris-* 14144 * [160]15396 [SH] ICE with -O2 -fPIC 14145 * [161]15782 [coldfire] m68k_output_mi_thunk emits wrong code for 14146 ColdFire 14147 14148 Testsuite problems (compiler not affected) 14149 14150 * [162]11610 libstdc++ testcases 27_io/* don't work properly remotely 14151 * [163]15488 (libstdc++) possibly insufficient file permissions for 14152 executing test suite 14153 * [164]15489 (libstdc++) testsuite_files determined incorrectly 14154 14155 Documentation bugs 14156 14157 * [165]13928 (libstdc++) no whatis info in some man pages generated 14158 by doxygen 14159 * [166]14150 Ada documentation out of date 14160 * [167]14949 (c++) Need to document method visibility changes 14161 * [168]15123 libstdc++-doc: Allocators.3 manpage is empty 14162 __________________________________________________________________ 14163 14164 GCC 3.4.2 14165 14166 Bug Fixes 14167 14168 This section lists the problem reports (PRs) from GCC's bug tracking 14169 system that are known to be fixed in the 3.4.2 release. This list might 14170 not be complete (that is, it is possible that some PRs that have been 14171 fixed are not listed here). 14172 14173 Bootstrap failures and issues 14174 14175 * [169]16469 [mips-sgi-irix5.3] bootstrap fails in 14176 libstdc++-v3/testsuite 14177 * [170]16344 [hppa-linux-gnu] libstdc++'s PCH built by 14178 profiledbootstrap does not work with the built compiler 14179 * [171]16842 [Solaris/x86] mkheaders can not find mkheaders.conf 14180 14181 Multi-platform internal compiler errors (ICEs) 14182 14183 * [172]12608 (c++) ICE: expected class 't', have 'x' (error_mark) in 14184 cp_parser_class_specifier, in cp/parser.c 14185 * [173]14492 ICE in loc_descriptor_from_tree, in dwarf2out.c 14186 * [174]15461 (c++) ICE due to NRV and inlining 14187 * [175]15890 (c++) ICE in c_expand_expr, in c-common.c 14188 * [176]16180 ICE: segmentation fault in RTL optimization 14189 * [177]16224 (c++) ICE in write_unscoped_name (template/namespace) 14190 * [178]16408 ICE: in delete_insn, in cfgrtl.c 14191 * [179]16529 (c++) ICE for: namespace-alias shall not be declared as 14192 the name of any other entity 14193 * [180]16698 (c++) ICE with exceptions and declaration of __cxa_throw 14194 * [181]16706 (c++) ICE in finish_member_declaration, in 14195 cp/semantics.c 14196 * [182]16810 (c++) Legal C++ program with cast gives ICE in 14197 build_ptrmemfunc 14198 * [183]16851 (c++) ICE when throwing a comma expression 14199 * [184]16870 (c++) Boost.Spirit causes ICE in tsubst, in cp/pt.c 14200 * [185]16904 (c++) ICE in finish_class_member_access_expr, in 14201 cp/typeck.c 14202 * [186]16905 (c++) ICE (segfault) with exceptions 14203 * [187]16964 (c++) ICE in cp_parser_class_specifier due to 14204 redefinition 14205 * [188]17068 (c++) ICE: tree check: expected class 'd', have 'x' 14206 (identifier_node) in dependent_template_p, in cp/pt.c 14207 14208 Preprocessor bugs 14209 14210 * [189]16366 Preprocessor option -remap causes memory corruption 14211 14212 Optimization 14213 14214 * [190]15345 unreferenced nested inline functions not optimized away 14215 * [191]16590 Incorrect execution when compiling with -O2 14216 * [192]16693 Bitwise AND is lost when used within a cast to an enum 14217 of the same precision 14218 * [193]17078 Jump into if(0) substatement fails 14219 14220 Problems in generated debug information 14221 14222 * [194]13956 incorrect stabs for nested local variables 14223 14224 C front end bugs 14225 14226 * [195]16684 GCC should not warn about redundant redeclarations of 14227 built-ins 14228 14229 C++ compiler and library 14230 14231 * [196]12658 Thread safety problems in locale::global() and 14232 locale::locale() 14233 * [197]13092 g++ accepts invalid pointer-to-member conversion 14234 * [198]15320 Excessive memory consumption 14235 * [199]16246 Incorrect template argument deduction 14236 * [200]16273 Memory exhausted when using nested classes and virtual 14237 functions 14238 * [201]16401 ostringstream in gcc 3.4.x very slow for big data 14239 * [202]16411 undefined reference to 14240 __gnu_cxx::stdio_sync_filebuf<char, std::char_traits<char> 14241 >::file() 14242 * [203]16489 G++ incorrectly rejects use of a null constant integral 14243 expression as a null constant pointer 14244 * [204]16618 offsetof fails with constant member 14245 * [205]16637 syntax error reported for valid input code 14246 * [206]16717 __attribute__((constructor)) broken in C++ 14247 * [207]16813 compiler error in DEBUG version of range insertion 14248 std::map::insert 14249 * [208]16853 pointer-to-member initialization from incompatible one 14250 accepted 14251 * [209]16889 ambiguity is not detected 14252 * [210]16959 Segmentation fault in ios_base::sync_with_stdio 14253 14254 Java compiler and library 14255 14256 * [211]7587 direct threaded interpreter not thread-safe 14257 * [212]16473 ServerSocket accept() leaks file descriptors 14258 * [213]16478 Hash synchronization deadlock with finalizers 14259 14260 Alpha-specific 14261 14262 * [214]10695 ICE in dwarf2out_frame_debug_expr, in dwarf2out.c 14263 * [215]16974 could not split insn (ice in final_scan_insn, in 14264 final.c) 14265 14266 x86-specific 14267 14268 * [216]16298 ICE in output_operand 14269 * [217]17113 ICE with SSE2 intrinsics 14270 14271 x86-64 specific 14272 14273 * [218]14697 libstdc++ couldn't find 32bit libgcc_s 14274 14275 MIPS-specific 14276 14277 * [219]15869 [mips64] No NOP after LW (with -mips1 -O0) 14278 * [220]16325 [mips64] value profiling clobbers gp on mips 14279 * [221]16357 [mipsisa64-elf] ICE copying 7 bytes between extern 14280 char[]s 14281 * [222]16380 [mips64] Use of uninitialised register after dbra 14282 conversion 14283 * [223]16407 [mips64] Unaligned access to local variables 14284 * [224]16643 [mips64] verify_local_live_at_start ICE after 14285 crossjumping & cfgcleanup 14286 14287 ARM-specific 14288 14289 * [225]15927 THUMB -O2: strength-reduced iteration variable ends up 14290 off by 1 14291 * [226]15948 THUMB: ICE with non-commutative cbranch 14292 * [227]17019 THUMB: bad switch statement in md code for 14293 addsi3_cbranch_scratch 14294 14295 IA64-specific 14296 14297 * [228]16130 ICE on valid code: in bundling, in config/ia64/ia64.c 14298 (-mtune=merced) 14299 * [229]16142 ICE on valid code: in bundling, in config/ia64/ia64.c 14300 (-mtune=itanium) 14301 * [230]16278 Gcc failed to build Linux kernel with -mtune=merced 14302 * [231]16414 ICE on valid code: typo in comparison of asm_noperands 14303 result 14304 * [232]16445 ICE on valid code: don't count ignored insns 14305 * [233]16490 ICE (segfault) while compiling with -fprofile-use 14306 * [234]16683 ia64 does not honor SUBTARGET_EXTRA_SPECS 14307 14308 PowerPC-specific 14309 14310 * [235]16195 (ppc64): Miscompilation of GCC 3.3.x by 3.4.x 14311 * [236]16239 ICE on ppc64 (mozilla 1.7 compile, -O1 -fno-exceptions 14312 issue) 14313 14314 SPARC-specific 14315 14316 * [237]16199 ICE while compiling apache 2.0.49 14317 * [238]16416 -m64 doesn't imply -mcpu=v9 anymore 14318 * [239]16430 ICE when returning non-C aggregates larger than 16 bytes 14319 14320 Bugs specific to embedded processors 14321 14322 * [240]16379 [m32r] can't output large model function call of memcpy 14323 * [241]17093 [m32r] ICE with -msdata=use -O0 14324 * [242]17119 [m32r] ICE at switch case 0x8000 14325 14326 DJGPP-specific 14327 14328 * [243]15928 libstdc++ in 3.4.x doesn't cross-compile for djgpp 14329 14330 Alpha Tru64-specific 14331 14332 * [244]16210 libstdc++ gratuitously omits "long long" I/O 14333 14334 Testsuite, documentation issues (compiler is not affected): 14335 14336 * [245]15488 (libstdc++) possibly insufficient file permissions for 14337 executing test suite 14338 * [246]16250 ada/doctools runs makeinfo even in release tarball 14339 __________________________________________________________________ 14340 14341 GCC 3.4.3 14342 14343 This is the [247]list of problem reports (PRs) from GCC's bug tracking 14344 system that are known to be fixed in the 3.4.3 release. This list might 14345 not be complete (that is, it is possible that some PRs that have been 14346 fixed are not listed here). 14347 14348 Bootstrap failures 14349 14350 * [248]17369 [ia64] Bootstrap failure with binutils-2.15.90.0.1.1 14351 * [249]17850 [arm-elf] bootstrap failure - libstdc++ uses strtold 14352 when undeclared 14353 14354 Internal compiler errors (ICEs) affecting multiple platforms 14355 14356 * [250]13948 (java) GCJ segmentation fault while compiling GL4Java 14357 .class files 14358 * [251]14492 ICE in loc_descriptor_from_tree, in dwarf2out.c 14359 * [252]16301 (c++) ICE when "strong" attribute is attached to a using 14360 directive 14361 * [253]16566 ICE with flexible arrays 14362 * [254]17023 ICE with nested functions in parameter declaration 14363 * [255]17027 ICE with noreturn function in loop at -O2 14364 * [256]17524 ICE in grokdeclarator, in cp/decl.c 14365 * [257]17826 (c++) ICE in cp_tree_equal 14366 14367 C and optimization bugs 14368 14369 * [258]15526 -ftrapv aborts on 0 * (-1) 14370 * [259]16999 #ident stopped working 14371 * [260]17503 quadratic behaviour in invalid_mode_change_p 14372 * [261]17581 Long long arithmetic fails inside a switch/case 14373 statement when compiled with -O2 14374 * [262]18129 -fwritable-strings doesn't work 14375 14376 C++ compiler and library bugs 14377 14378 * [263]10975 incorrect initial ostringstream::tellp() 14379 * [264]11722 Unbuffered filebuf::sgetn is slow 14380 * [265]14534 Unrecognizing static function as a template parameter 14381 when its return value is also templated 14382 * [266]15172 Copy constructor optimization in aggregate 14383 initialization 14384 * [267]15786 Bad error message for frequently occuring error. 14385 * [268]16162 Rejects valid member-template-definition 14386 * [269]16612 empty basic_strings can't live in shared memory 14387 * [270]16715 std::basic_iostream is instantiated when used, even 14388 though instantiations are already contained in libstdc++ 14389 * [271]16848 code in /ext/demangle.h appears broken 14390 * [272]17132 GCC fails to eliminate function template specialization 14391 when argument deduction fails 14392 * [273]17259 One more _S_leaf incorrectly qualified with _RopeRep:: 14393 in ropeimpl.h 14394 * [274]17327 use of `enumeral_type' in template type unification 14395 * [275]17393 "unused variable '._0'" warning with -Wall 14396 * [276]17501 Confusion with member templates 14397 * [277]17537 g++ not passing -lstdc++ to linker when all command line 14398 arguments are libraries 14399 * [278]17585 usage of unqualified name of static member from within 14400 class not allowed 14401 * [279]17821 Poor diagnostic for using "." instead of "->" 14402 * [280]17829 wrong error: call of overloaded function is ambiguous 14403 * [281]17851 Misleading diagnostic for invalid function declarations 14404 with undeclared types 14405 * [282]17976 Destructor is called twice 14406 * [283]18020 rejects valid definition of enum value in template 14407 * [284]18093 bogus conflict in namespace aliasing 14408 * [285]18140 C++ parser bug when using >> in templates 14409 14410 Fortran 14411 14412 * [286]17541 data statements with double precision constants fail 14413 14414 x86-specific 14415 14416 * [287]17853 -O2 ICE for MMX testcase 14417 14418 SPARC-specific 14419 14420 * [288]17245 ICE compiling gsl-1.5 statistics/lag1.c 14421 14422 Darwin-specific 14423 14424 * [289]17167 FATAL:Symbol L_foo$stub already defined. 14425 14426 AIX-specific 14427 14428 * [290]17277 could not catch an exception when specified -maix64 14429 14430 Solaris-specific 14431 14432 * [291]17505 <cmath> calls acosf(), ceilf(), and other functions 14433 missing from system libraries 14434 14435 HP/UX specific: 14436 14437 * [292]17684 /usr/ccs/bin/ld: Can't create libgcc_s.sl 14438 14439 ARM-specific 14440 14441 * [293]17384 ICE with mode attribute on structures 14442 14443 MIPS-specific 14444 14445 * [294]17770 No NOP after LWL with -mips1 14446 14447 Other embedded target specific 14448 14449 * [295]11476 [arc-elf] gcc ICE on newlib's vfprintf.c 14450 * [296]14064 [avr-elf] -fdata-sections triggers ICE 14451 * [297]14678 [m68hc11-elf] gcc ICE 14452 * [298]15583 [powerpc-rtems] powerpc-rtems lacks __USE_INIT_FINI__ 14453 * [299]15790 [i686-coff] Alignment error building gcc with i686-coff 14454 target 14455 * [300]15886 [SH] Miscompilation with -O2 -fPIC 14456 * [301]16884 [avr-elf] [fweb related] bug while initializing 14457 variables 14458 14459 Bugs relating to debugger support 14460 14461 * [302]13841 missing debug info for _Complex function arguments 14462 * [303]15860 [big-endian targets] No DW_AT_location debug info is 14463 emitted for formal arguments to a function that uses "register" 14464 qualifiers 14465 14466 Testsuite issues (compiler not affected) 14467 14468 * [304]17465 Testsuite in libffi overrides LD_LIBRARY_PATH 14469 * [305]17469 Testsuite in libstdc++ overrides LD_LIBRARY_PATH 14470 * [306]18138 [mips-sgi-irix6.5] libgcc_s.so.1 not found by 64-bit 14471 testsuite 14472 14473 Documentation 14474 14475 * [307]15498 typo in gcc manual: non-existing locale example en_UK, 14476 should be en_GB 14477 * [308]15747 [mips-sgi-irix5.3] /bin/sh hangs during bootstrap: 14478 document broken shell 14479 * [309]16406 USE_LD_AS_NEEDED undocumented 14480 __________________________________________________________________ 14481 14482 GCC 3.4.4 14483 14484 This is the [310]list of problem reports (PRs) from GCC's bug tracking 14485 system that are known to be fixed in the 3.4.4 release. This list might 14486 not be complete (that is, it is possible that some PRs that have been 14487 fixed are not listed here). 14488 __________________________________________________________________ 14489 14490 GCC 3.4.5 14491 14492 This is the [311]list of problem reports (PRs) from GCC's bug tracking 14493 system that are known to be fixed in the 3.4.5 release. This list might 14494 not be complete (that is, it is possible that some PRs that have been 14495 fixed are not listed here). 14496 14497 Bootstrap issues 14498 14499 * [312]24688 sco_math fixincl breaks math.h 14500 14501 C compiler bugs 14502 14503 * [313]17188 struct Foo { } redefinition 14504 * [314]20187 wrong code for ((unsigned char)(unsigned long 14505 long)((a?a:1)&(a*b)))?0:1) 14506 * [315]21873 infinite warning loop on bad array initializer 14507 * [316]21899 enum definition accepts values to be overriden 14508 * [317]22061 ICE in find_function_data, in function.c 14509 * [318]22308 Failure to diagnose violation of constraint 6.516p2 14510 * [319]22458 ICE on missing brace 14511 * [320]22589 ICE casting to long long 14512 * [321]24101 Segfault with preprocessed source 14513 14514 C++ compiler and library bugs 14515 14516 * [322]10611 operations on vector mode not recognized in C++ 14517 * [323]13377 unexpected behavior of namespace usage directive 14518 * [324]16002 Strange error message with new parser 14519 * [325]17413 local classes as template argument 14520 * [326]17609 spurious error message after using keyword 14521 * [327]17618 ICE in cp_convert_to_pointer, in cp/cvt.c 14522 * [328]18124 ICE with invalid template template parameter 14523 * [329]18155 typedef in template declaration not rejected 14524 * [330]18177 ICE with const_cast for undeclared variable 14525 * [331]18368 C++ error message regression 14526 * [332]16378 ICE when returning a copy of a packed member 14527 * [333]18466 int ::i; accepted 14528 * [334]18512 ICE on invalid usage of template base class 14529 * [335]18454 ICE when returning undefined type 14530 * [336]18738 typename not allowed with non-dependent qualified name 14531 * [337]18803 rejects access to operator() in template 14532 * [338]19004 ICE in uses_template_parms, in cp/pt.c 14533 * [339]19208 Spurious error about variably modified type 14534 * [340]18253 bad error message / ICE for invalid template parameter 14535 * [341]19608 ICE after friend function definition in local class 14536 * [342]19884 ICE on explicit instantiation of a non-template 14537 constructor 14538 * [343]20153 ICE when C++ template function contains anonymous union 14539 * [344]20563 Infinite loop in diagnostic (and ice after error 14540 message) 14541 * [345]20789 ICE with incomplete type in template 14542 * [346]21336 Internal compiler error when using custom new operators 14543 * [347]21768 ICE in error message due to violation of coding 14544 conventions 14545 * [348]21853 constness of pointer to data member ignored 14546 * [349]21903 Default argument of template function causes a 14547 compile-time error 14548 * [350]21983 multiple diagnostics 14549 * [351]21987 New testsuite failure 14550 g++.dg/warn/conversion-function-1.C 14551 * [352]22153 ICE on invalid template specialization 14552 * [353]22172 Internal compiler error, seg fault. 14553 * [354]21286 filebuf::xsgetn vs pipes 14554 * [355]22233 ICE with wrong number of template parameters 14555 * [356]22508 ICE after invalid operator new 14556 * [357]22545 ICE with pointer to class member & user defined 14557 conversion operator 14558 * [358]23528 Wrong default allocator in ext/hash_map 14559 * [359]23550 char_traits requirements/1.cc test bad math 14560 * [360]23586 Bad diagnostic for invalid namespace-name 14561 * [361]23624 ICE in invert_truthvalue, in fold-const.c 14562 * [362]23639 Bad error message: not a member of '<declaration error>' 14563 * [363]23797 ICE on typename outside template 14564 * [364]23965 Bogus error message: no matching function for call to 14565 'foo(<type error>)' 14566 * [365]24052 &#`label_decl' not supported by dump_expr#<expression 14567 error> 14568 * [366]24580 virtual base class cause exception not to be caught 14569 14570 Problems in generated debug information 14571 14572 * [367]24267 Bad DWARF for altivec vectors 14573 14574 Optimizations issues 14575 14576 * [368]17810 ICE in verify_local_live_at_start 14577 * [369]17860 Wrong generated code for loop with varying bound 14578 * [370]21709 ICE on compile-time complex NaN 14579 * [371]21964 broken tail call at -O2 or more 14580 * [372]22167 Strange optimization bug when using -Os 14581 * [373]22619 Compilation failure for real_const_1.f and 14582 real_const_2.f90 14583 * [374]23241 Invalid code generated for comparison of uchar to 255 14584 * [375]23478 Miscompilation due to reloading of a var that is also 14585 used in EH pad 14586 * [376]24470 segmentation fault in cc1plus when compiling with -O 14587 * [377]24950 ICE in operand_subword_force 14588 14589 Precompiled headers problems 14590 14591 * [378]14400 Cannot compile qt-x11-free-3.3.0 14592 * [379]14940 PCH largefile test fails on various platforms 14593 14594 Preprocessor bugs 14595 14596 * [380]20239 ICE on empty preprocessed input 14597 * [381]15220 "gcc -E -MM -MG" reports missing system headers in 14598 source directory 14599 14600 Testsuite issues 14601 14602 * [382]19275 gcc.dg/20020919-1.c fails with -fpic/-fPIC on 14603 i686-pc-linux-gnu 14604 14605 Alpha specific 14606 14607 * [383]21888 bootstrap failure with linker relaxation enabled 14608 14609 ARM specific 14610 14611 * [384]15342 [arm-linux]: ICE in verify_local_live_at_start 14612 * [385]23985 Memory aliasing information incorrect in inlined memcpy 14613 14614 ColdFile specific 14615 14616 * [386]16719 Illegal move of byte into address register causes 14617 compiler to ICE 14618 14619 HPPA specific 14620 14621 * [387]21723 ICE while building libgfortran 14622 * [388]21841 -mhp-ld/-mgnu-ld documentation 14623 14624 IA-64 specific 14625 14626 * [389]23644 IA-64 hardware models and configuration options 14627 documentation error 14628 * [390]24718 Shared libgcc not used for linking by default 14629 14630 M68000 specific 14631 14632 * [391]18421 ICE in reload_cse_simplify_operands, in postreload.c 14633 14634 MIPS specific 14635 14636 * [392]20621 ICE in change_address_1, in emit-rtl.c 14637 14638 PowerPC and PowerPC64 specific 14639 14640 * [393]18583 error on valid code: const 14641 __attribute__((altivec(vector__))) doesn't work in arrays 14642 * [394]20191 ICE in reload_cse_simplify_operands 14643 * [395]22083 AIX: TARGET_C99_FUNCTIONS is wrongly defined 14644 * [396]23070 CALL_V4_CLEAR_FP_ARGS flag not properly set 14645 * [397]23404 gij trashes args of functions with more than 8 fp args 14646 * [398]23539 C & C++ compiler generating misaligned references 14647 regardless of compiler flags 14648 * [399]24102 floatdisf2_internal2 broken 14649 * [400]24465 -mminimal-toc miscompilation of __thread vars 14650 14651 Solaris specific 14652 14653 * [401]19933 Problem with define of HUGE_VAL in math_c99 14654 * [402]21889 Native Solaris assembler cannot grok DTP-relative debug 14655 symbols 14656 14657 SPARC specific 14658 14659 * [403]19300 PCH failures on sparc-linux 14660 * [404]20301 Assembler labels have a leading "-" 14661 * [405]20673 C PCH testsuite assembly comparison failure 14662 14663 x86 and x86_64 specific 14664 14665 * [406]18582 ICE with arrays of type V2DF 14666 * [407]19340 Compilation SEGFAULTs with -O1 -fschedule-insns2 14667 -fsched2-use-traces 14668 * [408]21716 ICE in reg-stack.c's swap_rtx_condition 14669 * [409]24315 amd64 fails -fpeephole2 14670 __________________________________________________________________ 14671 14672 GCC 3.4.6 14673 14674 This is the [410]list of problem reports (PRs) from GCC's bug tracking 14675 system that are known to be fixed in the 3.4.6 release. This list might 14676 not be complete (that is, it is possible that some PRs that have been 14677 fixed are not listed here). 14678 14679 14680 For questions related to the use of GCC, please consult these web 14681 pages and the [411]GCC manuals. If that fails, the 14682 [412]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 14683 web pages and the development of GCC are welcome on our developer 14684 list at [413]gcc (a] gcc.gnu.org. All of [414]our lists have public 14685 archives. 14686 14687 Copyright (C) [415]Free Software Foundation, Inc. Verbatim copying and 14688 distribution of this entire article is permitted in any medium, 14689 provided this notice is preserved. 14690 14691 These pages are [416]maintained by the GCC team. Last modified 14692 2019-11-28[417]. 14693 14694 References 14695 14696 1. http://gcc.gnu.org/gcc-3.4/changes.html#3.4.6 14697 2. http://gcc.gnu.org/gcc-3.4/changes.html#cplusplus 14698 3. http://gcc.gnu.org/gcc-3.3/changes.html#obsolete_systems 14699 4. http://gcc.gnu.org/gcc-3.4/changes.html#obsolete_systems 14700 5. http://gcc.gnu.org/gcc-3.4/mips-abi.html 14701 6. http://gcc.gnu.org/gcc-3.4/sparc-abi.html 14702 7. https://www.boost.org/ 14703 8. https://gcc.gnu.org/PR11953 14704 9. https://gcc.gnu.org/PR8361 14705 10. https://gcc.gnu.org/onlinedocs/gcc-3.4.3/gcc/Other-Builtins.html#Other Builtins 14706 11. http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_closed.html#209 14707 12. http://gcc.gnu.org/bugs/#cxx_rvalbind 14708 13. https://gcc.gnu.org/onlinedocs/gcc-3.4.3/gcc/Objective-C-Dialect-Options.html 14709 14. https://gcc.gnu.org/onlinedocs/gcc-3.4.3/gcc/Objective-C-Dialect-Options.html 14710 15. https://gcc.gnu.org/onlinedocs/gcc-3.4.3/gcc/Objective-C-Dialect-Options.html 14711 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https://gcc.gnu.org/PR15396 14856 161. https://gcc.gnu.org/PR15782 14857 162. https://gcc.gnu.org/PR11610 14858 163. https://gcc.gnu.org/PR15488 14859 164. https://gcc.gnu.org/PR15489 14860 165. https://gcc.gnu.org/PR13928 14861 166. https://gcc.gnu.org/PR14150 14862 167. https://gcc.gnu.org/PR14949 14863 168. https://gcc.gnu.org/PR15123 14864 169. https://gcc.gnu.org/PR16469 14865 170. https://gcc.gnu.org/PR16344 14866 171. https://gcc.gnu.org/PR16842 14867 172. https://gcc.gnu.org/PR12608 14868 173. https://gcc.gnu.org/PR14492 14869 174. https://gcc.gnu.org/PR15461 14870 175. https://gcc.gnu.org/PR15890 14871 176. https://gcc.gnu.org/PR16180 14872 177. https://gcc.gnu.org/PR16224 14873 178. https://gcc.gnu.org/PR16408 14874 179. https://gcc.gnu.org/PR16529 14875 180. https://gcc.gnu.org/PR16698 14876 181. https://gcc.gnu.org/PR16706 14877 182. https://gcc.gnu.org/PR16810 14878 183. https://gcc.gnu.org/PR16851 14879 184. https://gcc.gnu.org/PR16870 14880 185. https://gcc.gnu.org/PR16904 14881 186. https://gcc.gnu.org/PR16905 14882 187. https://gcc.gnu.org/PR16964 14883 188. https://gcc.gnu.org/PR17068 14884 189. https://gcc.gnu.org/PR16366 14885 190. https://gcc.gnu.org/PR15345 14886 191. https://gcc.gnu.org/PR16590 14887 192. https://gcc.gnu.org/PR16693 14888 193. https://gcc.gnu.org/PR17078 14889 194. https://gcc.gnu.org/PR13956 14890 195. https://gcc.gnu.org/PR16684 14891 196. https://gcc.gnu.org/PR12658 14892 197. https://gcc.gnu.org/PR13092 14893 198. https://gcc.gnu.org/PR15320 14894 199. https://gcc.gnu.org/PR16246 14895 200. https://gcc.gnu.org/PR16273 14896 201. https://gcc.gnu.org/PR16401 14897 202. https://gcc.gnu.org/PR16411 14898 203. https://gcc.gnu.org/PR16489 14899 204. https://gcc.gnu.org/PR16618 14900 205. https://gcc.gnu.org/PR16637 14901 206. https://gcc.gnu.org/PR16717 14902 207. https://gcc.gnu.org/PR16813 14903 208. https://gcc.gnu.org/PR16853 14904 209. https://gcc.gnu.org/PR16889 14905 210. 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https://gcc.gnu.org/PR18093 14980 285. https://gcc.gnu.org/PR18140 14981 286. https://gcc.gnu.org/PR17541 14982 287. https://gcc.gnu.org/PR17853 14983 288. https://gcc.gnu.org/PR17245 14984 289. https://gcc.gnu.org/PR17167 14985 290. https://gcc.gnu.org/PR17277 14986 291. https://gcc.gnu.org/PR17505 14987 292. https://gcc.gnu.org/PR17684 14988 293. https://gcc.gnu.org/PR17384 14989 294. https://gcc.gnu.org/PR17770 14990 295. https://gcc.gnu.org/PR11476 14991 296. https://gcc.gnu.org/PR14064 14992 297. https://gcc.gnu.org/PR14678 14993 298. https://gcc.gnu.org/PR15583 14994 299. https://gcc.gnu.org/PR15790 14995 300. https://gcc.gnu.org/PR15886 14996 301. https://gcc.gnu.org/PR16884 14997 302. https://gcc.gnu.org/PR13841 14998 303. https://gcc.gnu.org/PR15860 14999 304. https://gcc.gnu.org/PR17465 15000 305. https://gcc.gnu.org/PR17469 15001 306. https://gcc.gnu.org/PR18138 15002 307. https://gcc.gnu.org/PR15498 15003 308. https://gcc.gnu.org/PR15747 15004 309. https://gcc.gnu.org/PR16406 15005 310. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=3.4.4 15006 311. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=3.4.5 15007 312. https://gcc.gnu.org/PR24688 15008 313. https://gcc.gnu.org/PR17188 15009 314. https://gcc.gnu.org/PR20187 15010 315. https://gcc.gnu.org/PR21873 15011 316. https://gcc.gnu.org/PR21899 15012 317. https://gcc.gnu.org/PR22061 15013 318. https://gcc.gnu.org/PR22208 15014 319. https://gcc.gnu.org/PR22458 15015 320. https://gcc.gnu.org/PR22589 15016 321. https://gcc.gnu.org/PR24101 15017 322. https://gcc.gnu.org/PR10611 15018 323. https://gcc.gnu.org/PR13377 15019 324. https://gcc.gnu.org/PR16002 15020 325. https://gcc.gnu.org/PR17413 15021 326. https://gcc.gnu.org/PR17609 15022 327. https://gcc.gnu.org/PR17618 15023 328. https://gcc.gnu.org/PR18124 15024 329. https://gcc.gnu.org/PR18155 15025 330. https://gcc.gnu.org/PR18177 15026 331. https://gcc.gnu.org/PR18368 15027 332. https://gcc.gnu.org/PR18378 15028 333. https://gcc.gnu.org/PR18466 15029 334. https://gcc.gnu.org/PR18512 15030 335. https://gcc.gnu.org/PR18545 15031 336. https://gcc.gnu.org/PR18738 15032 337. https://gcc.gnu.org/PR18803 15033 338. https://gcc.gnu.org/PR19004 15034 339. https://gcc.gnu.org/PR19208 15035 340. https://gcc.gnu.org/PR19253 15036 341. https://gcc.gnu.org/PR19608 15037 342. https://gcc.gnu.org/PR19884 15038 343. https://gcc.gnu.org/PR20153 15039 344. https://gcc.gnu.org/PR20563 15040 345. https://gcc.gnu.org/PR20789 15041 346. https://gcc.gnu.org/PR21336 15042 347. https://gcc.gnu.org/PR21768 15043 348. https://gcc.gnu.org/PR21853 15044 349. https://gcc.gnu.org/PR21903 15045 350. https://gcc.gnu.org/PR21983 15046 351. https://gcc.gnu.org/PR21987 15047 352. https://gcc.gnu.org/PR22153 15048 353. https://gcc.gnu.org/PR22172 15049 354. https://gcc.gnu.org/PR21286 15050 355. https://gcc.gnu.org/PR22233 15051 356. https://gcc.gnu.org/PR22508 15052 357. https://gcc.gnu.org/PR22545 15053 358. https://gcc.gnu.org/PR23528 15054 359. https://gcc.gnu.org/PR23550 15055 360. https://gcc.gnu.org/PR23586 15056 361. https://gcc.gnu.org/PR23624 15057 362. https://gcc.gnu.org/PR23639 15058 363. https://gcc.gnu.org/PR23797 15059 364. https://gcc.gnu.org/PR23965 15060 365. https://gcc.gnu.org/PR24052 15061 366. https://gcc.gnu.org/PR24580 15062 367. https://gcc.gnu.org/PR24267 15063 368. https://gcc.gnu.org/PR17810 15064 369. https://gcc.gnu.org/PR17860 15065 370. https://gcc.gnu.org/PR21709 15066 371. https://gcc.gnu.org/PR21964 15067 372. https://gcc.gnu.org/PR22167 15068 373. https://gcc.gnu.org/PR22619 15069 374. https://gcc.gnu.org/PR23241 15070 375. https://gcc.gnu.org/PR23478 15071 376. https://gcc.gnu.org/PR24470 15072 377. https://gcc.gnu.org/PR24950 15073 378. https://gcc.gnu.org/PR14400 15074 379. https://gcc.gnu.org/PR14940 15075 380. https://gcc.gnu.org/PR20239 15076 381. https://gcc.gnu.org/PR15220 15077 382. https://gcc.gnu.org/PR19275 15078 383. https://gcc.gnu.org/PR21888 15079 384. https://gcc.gnu.org/PR15342 15080 385. https://gcc.gnu.org/PR23985 15081 386. https://gcc.gnu.org/PR16719 15082 387. https://gcc.gnu.org/PR21723 15083 388. https://gcc.gnu.org/PR21841 15084 389. https://gcc.gnu.org/PR23644 15085 390. https://gcc.gnu.org/PR24718 15086 391. https://gcc.gnu.org/PR18421 15087 392. https://gcc.gnu.org/PR20621 15088 393. https://gcc.gnu.org/PR18583 15089 394. https://gcc.gnu.org/PR20191 15090 395. https://gcc.gnu.org/PR22083 15091 396. https://gcc.gnu.org/PR23070 15092 397. https://gcc.gnu.org/PR23404 15093 398. https://gcc.gnu.org/PR23539 15094 399. https://gcc.gnu.org/PR24102 15095 400. https://gcc.gnu.org/PR24465 15096 401. https://gcc.gnu.org/PR19933 15097 402. https://gcc.gnu.org/PR21889 15098 403. https://gcc.gnu.org/PR19300 15099 404. https://gcc.gnu.org/PR20301 15100 405. https://gcc.gnu.org/PR20673 15101 406. https://gcc.gnu.org/PR18582 15102 407. https://gcc.gnu.org/PR19340 15103 408. https://gcc.gnu.org/PR21716 15104 409. https://gcc.gnu.org/PR24315 15105 410. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=3.4.6 15106 411. https://gcc.gnu.org/onlinedocs/ 15107 412. mailto:gcc-help (a] gcc.gnu.org 15108 413. mailto:gcc (a] gcc.gnu.org 15109 414. https://gcc.gnu.org/lists.html 15110 415. https://www.fsf.org/ 15111 416. https://gcc.gnu.org/about.html 15112 417. http://validator.w3.org/check/referer 15113 ====================================================================== 15114 http://gcc.gnu.org/gcc-3.3/index.html 15115 GCC 3.3 Release Series 15116 15117 (This release series is no longer supported.) 15118 15119 May 03, 2005 15120 15121 The [1]GNU project and the GCC developers are pleased to announce the 15122 release of GCC 3.3.6. 15123 15124 This release is a bug-fix release, containing fixes for regressions in 15125 GCC 3.3.5 relative to previous releases of GCC. 15126 15127 This release is the last of the series 3.3.x. 15128 15129 The GCC 3.3 release series includes numerous [2]new features, 15130 improvements, bug fixes, and other changes, thanks to an [3]amazing 15131 group of volunteers. 15132 15133 Release History 15134 15135 GCC 3.3.6 15136 May 3, 2005 ([4]changes) 15137 15138 GCC 3.3.5 15139 September 30, 2004 ([5]changes) 15140 15141 GCC 3.3.4 15142 May 31, 2004 ([6]changes) 15143 15144 GCC 3.3.3 15145 February 14, 2004 ([7]changes) 15146 15147 GCC 3.3.2 15148 October 16, 2003 ([8]changes) 15149 15150 GCC 3.3.1 15151 August 8, 2003 ([9]changes) 15152 15153 GCC 3.3 15154 May 14, 2003 ([10]changes) 15155 15156 References and Acknowledgements 15157 15158 GCC used to stand for the GNU C Compiler, but since the compiler 15159 supports several other languages aside from C, it now stands for the 15160 GNU Compiler Collection. 15161 15162 A list of [11]successful builds is updated as new information becomes 15163 available. 15164 15165 The GCC developers would like to thank the numerous people that have 15166 contributed new features, improvements, bug fixes, and other changes as 15167 well as test results to GCC. This [12]amazing group of volunteers is 15168 what makes GCC successful. 15169 15170 For additional information about GCC please refer to the [13]GCC 15171 project web site or contact the [14]GCC development mailing list. 15172 15173 To obtain GCC please use [15]our mirror sites, or our CVS server. 15174 15175 15176 For questions related to the use of GCC, please consult these web 15177 pages and the [16]GCC manuals. If that fails, the 15178 [17]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 15179 web pages and the development of GCC are welcome on our developer 15180 list at [18]gcc (a] gcc.gnu.org. All of [19]our lists have public 15181 archives. 15182 15183 Copyright (C) [20]Free Software Foundation, Inc. Verbatim copying and 15184 distribution of this entire article is permitted in any medium, 15185 provided this notice is preserved. 15186 15187 These pages are [21]maintained by the GCC team. Last modified 15188 2019-11-28[22]. 15189 15190 References 15191 15192 1. http://www.gnu.org/ 15193 2. http://gcc.gnu.org/gcc-3.3/changes.html 15194 3. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 15195 4. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.6 15196 5. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.5 15197 6. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.4 15198 7. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.3 15199 8. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.2 15200 9. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.1 15201 10. http://gcc.gnu.org/gcc-3.3/changes.html 15202 11. http://gcc.gnu.org/gcc-3.3/buildstat.html 15203 12. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 15204 13. http://gcc.gnu.org/index.html 15205 14. mailto:gcc (a] gcc.gnu.org 15206 15. http://gcc.gnu.org/mirrors.html 15207 16. https://gcc.gnu.org/onlinedocs/ 15208 17. mailto:gcc-help (a] gcc.gnu.org 15209 18. mailto:gcc (a] gcc.gnu.org 15210 19. https://gcc.gnu.org/lists.html 15211 20. https://www.fsf.org/ 15212 21. https://gcc.gnu.org/about.html 15213 22. http://validator.w3.org/check/referer 15214 ====================================================================== 15215 http://gcc.gnu.org/gcc-3.3/changes.html 15216 GCC 3.3 Release Series 15217 Changes, New Features, and Fixes 15218 15219 The latest release in the 3.3 release series is [1]GCC 3.3.6. 15220 15221 Caveats 15222 15223 * The preprocessor no longer accepts multi-line string literals. They 15224 were deprecated in 3.0, 3.1, and 3.2. 15225 * The preprocessor no longer supports the -A- switch when appearing 15226 alone. -A- followed by an assertion is still supported. 15227 * Support for all the systems [2]obsoleted in GCC 3.1 has been 15228 removed from GCC 3.3. See below for a [3]list of systems which are 15229 obsoleted in this release. 15230 * Checking for null format arguments has been decoupled from the rest 15231 of the format checking mechanism. Programs which use the format 15232 attribute may regain this functionality by using the new [4]nonnull 15233 function attribute. Note that all functions for which GCC has a 15234 built-in format attribute, an appropriate built-in nonnull 15235 attribute is also applied. 15236 * The DWARF (version 1) debugging format has been deprecated and will 15237 be removed in a future version of GCC. Version 2 of the DWARF 15238 debugging format will continue to be supported for the foreseeable 15239 future. 15240 * The C and Objective-C compilers no longer accept the "Naming Types" 15241 extension (typedef foo = bar); it was already unavailable in C++. 15242 Code which uses it will need to be changed to use the "typeof" 15243 extension instead: typedef typeof(bar) foo. (We have removed this 15244 extension without a period of deprecation because it has caused the 15245 compiler to crash since version 3.0 and no one noticed until very 15246 recently. Thus we conclude it is not in widespread use.) 15247 * The -traditional C compiler option has been removed. It was 15248 deprecated in 3.1 and 3.2. (Traditional preprocessing remains 15249 available.) The <varargs.h> header, used for writing variadic 15250 functions in traditional C, still exists but will produce an error 15251 message if used. 15252 * GCC 3.3.1 automatically places zero-initialized variables in the 15253 .bss section on some operating systems. Versions of GNU Emacs up to 15254 (and including) 21.3 will not work correctly when using this 15255 optimization; you can use -fno-zero-initialized-in-bss to disable 15256 it. 15257 15258 General Optimizer Improvements 15259 15260 * A new scheme for accurately describing processor pipelines, the 15261 [5]DFA scheduler, has been added. 15262 * Pavel Nejedly, Charles University Prague, has contributed new file 15263 format used by the edge coverage profiler (-fprofile-arcs). 15264 The new format is robust and diagnoses common mistakes where 15265 profiles from different versions (or compilations) of the program 15266 are combined resulting in nonsensical profiles and slow code to 15267 produced with profile feedback. Additionally this format allows 15268 extra data to be gathered. Currently, overall statistics are 15269 produced helping optimizers to identify hot spots of a program 15270 globally replacing the old intra-procedural scheme and resulting in 15271 better code. Note that the gcov tool from older GCC versions will 15272 not be able to parse the profiles generated by GCC 3.3 and vice 15273 versa. 15274 * Jan Hubicka, SuSE Labs, has contributed a new superblock formation 15275 pass enabled using -ftracer. This pass simplifies the control flow 15276 of functions allowing other optimizations to do better job. 15277 He also contributed the function reordering pass 15278 (-freorder-functions) to optimize function placement using profile 15279 feedback. 15280 15281 New Languages and Language specific improvements 15282 15283 C/ObjC/C++ 15284 15285 * The preprocessor now accepts directives within macro arguments. It 15286 processes them just as if they had not been within macro arguments. 15287 * The separate ISO and traditional preprocessors have been completely 15288 removed. The front end handles either type of preprocessed output 15289 if necessary. 15290 * In C99 mode preprocessor arithmetic is done in the precision of the 15291 target's intmax_t, as required by that standard. 15292 * The preprocessor can now copy comments inside macros to the output 15293 file when the macro is expanded. This feature, enabled using the 15294 -CC option, is intended for use by applications which place 15295 metadata or directives inside comments, such as lint. 15296 * The method of constructing the list of directories to be searched 15297 for header files has been revised. If a directory named by a -I 15298 option is a standard system include directory, the option is 15299 ignored to ensure that the default search order for system 15300 directories and the special treatment of system header files are 15301 not defeated. 15302 * A few more [6]ISO C99 features now work correctly. 15303 * A new function attribute, nonnull, has been added which allows 15304 pointer arguments to functions to be specified as requiring a 15305 non-null value. The compiler currently uses this information to 15306 issue a warning when it detects a null value passed in such an 15307 argument slot. 15308 * A new type attribute, may_alias, has been added. Accesses to 15309 objects with types with this attribute are not subjected to 15310 type-based alias analysis, but are instead assumed to be able to 15311 alias any other type of objects, just like the char type. 15312 15313 C++ 15314 15315 * Type based alias analysis has been implemented for C++ aggregate 15316 types. 15317 15318 Objective-C 15319 15320 * Generate an error if Objective-C objects are passed by value in 15321 function and method calls. 15322 * When -Wselector is used, check the whole list of selectors at the 15323 end of compilation, and emit a warning if a @selector() is not 15324 known. 15325 * Define __NEXT_RUNTIME__ when compiling for the NeXT runtime. 15326 * No longer need to include objc/objc-class.h to compile self calls 15327 in class methods (NeXT runtime only). 15328 * New -Wundeclared-selector option. 15329 * Removed selector bloating which was causing object files to be 10% 15330 bigger on average (GNU runtime only). 15331 * Using at run time @protocol() objects has been fixed in certain 15332 situations (GNU runtime only). 15333 * Type checking has been fixed and improved in many situations 15334 involving protocols. 15335 15336 Java 15337 15338 * The java.sql and javax.sql packages now implement the JDBC 3.0 (JDK 15339 1.4) API. 15340 * The JDK 1.4 assert facility has been implemented. 15341 * The bytecode interpreter is now direct threaded and thus faster. 15342 15343 Fortran 15344 15345 * Fortran improvements are listed in [7]the Fortran documentation. 15346 15347 Ada 15348 15349 * Ada tasking now works with glibc 2.3.x threading libraries. 15350 15351 New Targets and Target Specific Improvements 15352 15353 * The following changes have been made to the HP-PA port: 15354 + The port now defaults to scheduling for the PA8000 series of 15355 processors. 15356 + Scheduling support for the PA7300 processor has been added. 15357 + The 32-bit port now supports weak symbols under HP-UX 11. 15358 + The handling of initializers and finalizers has been improved 15359 under HP-UX 11. The 64-bit port no longer uses collect2. 15360 + Dwarf2 EH support has been added to the 32-bit GNU/Linux port. 15361 + ABI fixes to correct the passing of small structures by value. 15362 * The SPARC, HP-PA, SH4, and x86/pentium ports have been converted to 15363 use the DFA processor pipeline description. 15364 * The following NetBSD configurations for the SuperH processor family 15365 have been added: 15366 + SH3, big-endian, sh-*-netbsdelf* 15367 + SH3, little-endian, shle-*-netbsdelf* 15368 + SH5, SHmedia, big-endian, 32-bit default, sh5-*-netbsd* 15369 + SH5, SHmedia, little-endian, 32-bit default, sh5le-*-netbsd* 15370 + SH5, SHmedia, big-endian, 64-bit default, sh64-*-netbsd* 15371 + SH5, SHmedia, little-endian, 64-bit default, sh64le-*-netbsd* 15372 * The following changes have been made to the IA-32/x86-64 port: 15373 + SSE2 and 3dNOW! intrinsics are now supported. 15374 + Support for thread local storage has been added to the IA-32 15375 and x86-64 ports. 15376 + The x86-64 port has been significantly improved. 15377 * The following changes have been made to the MIPS port: 15378 + All configurations now accept the -mabi switch. Note that you 15379 will need appropriate multilibs for this option to work 15380 properly. 15381 + ELF configurations will always pass an ABI flag to the 15382 assembler, except when the MIPS EABI is selected. 15383 + -mabi=64 no longer selects MIPS IV code. 15384 + The -mcpu option, which was deprecated in 3.1 and 3.2, has 15385 been removed from this release. 15386 + -march now changes the core ISA level. In previous releases, 15387 it would change the use of processor-specific extensions, but 15388 would leave the core ISA unchanged. For example, mips64-elf 15389 -march=r8000 will now generate MIPS IV code. 15390 + Under most configurations, -mipsN now acts as a synonym for 15391 -march. 15392 + There are some new preprocessor macros to describe the -march 15393 and -mtune settings. See the documentation of those options 15394 for details. 15395 + Support for the NEC VR-Series processors has been added. This 15396 includes the 54xx, 5500, and 41xx series. 15397 + Support for the Sandcraft sr71k processor has been added. 15398 * The following changes have been made to the S/390 port: 15399 + Support to build the Java runtime libraries has been added. 15400 Java is now enabled by default on s390-*-linux* and 15401 s390x-*-linux* targets. 15402 + Multilib support for the s390x-*-linux* target has been added; 15403 this allows to build 31-bit binaries using the -m31 option. 15404 + Support for thread local storage has been added. 15405 + Inline assembler code may now use the 'Q' constraint to 15406 specify memory operands without index register. 15407 + Various platform-specific performance improvements have been 15408 implemented; in particular, the compiler now uses the BRANCH 15409 ON COUNT family of instructions and makes more frequent use of 15410 the TEST UNDER MASK family of instructions. 15411 * The following changes have been made to the PowerPC port: 15412 + Support for IBM Power4 processor added. 15413 + Support for Motorola e500 SPE added. 15414 + Support for AIX 5.2 added. 15415 + Function and Data sections now supported on AIX. 15416 + Sibcall optimizations added. 15417 * The support for H8 Tiny is added to the H8/300 port with -mn. 15418 15419 Obsolete Systems 15420 15421 Support for a number of older systems has been declared obsolete in GCC 15422 3.3. Unless there is activity to revive them, the next release of GCC 15423 will have their sources permanently removed. 15424 15425 All configurations of the following processor architectures have been 15426 declared obsolete: 15427 * Matsushita MN10200, mn10200-*-* 15428 * Motorola 88000, m88k-*-* 15429 * IBM ROMP, romp-*-* 15430 15431 Also, some individual systems have been obsoleted: 15432 * Alpha 15433 + Interix, alpha*-*-interix* 15434 + Linux libc1, alpha*-*-linux*libc1* 15435 + Linux ECOFF, alpha*-*-linux*ecoff* 15436 * ARM 15437 + Generic a.out, arm*-*-aout* 15438 + Conix, arm*-*-conix* 15439 + "Old ABI," arm*-*-oabi 15440 + StrongARM/COFF, strongarm-*-coff* 15441 * HPPA (PA-RISC) 15442 + Generic OSF, hppa1.0-*-osf* 15443 + Generic BSD, hppa1.0-*-bsd* 15444 + HP/UX versions 7, 8, and 9, hppa1.[01]-*-hpux[789]* 15445 + HiUX, hppa*-*-hiux* 15446 + Mach Lites, hppa*-*-lites* 15447 * Intel 386 family 15448 + Windows NT 3.x, i?86-*-win32 15449 * MC68000 family 15450 + HP systems, m68000-hp-bsd* and m68k-hp-bsd* 15451 + Sun systems, m68000-sun-sunos*, m68k-sun-sunos*, and 15452 m68k-sun-mach* 15453 + AT&T systems, m68000-att-sysv* 15454 + Atari systems, m68k-atari-sysv* 15455 + Motorola systems, m68k-motorola-sysv* 15456 + NCR systems, m68k-ncr-sysv* 15457 + Plexus systems, m68k-plexus-sysv* 15458 + Commodore systems, m68k-cbm-sysv* 15459 + Citicorp TTI, m68k-tti-* 15460 + Unos, m68k-crds-unos* 15461 + Concurrent RTU, m68k-ccur-rtu* 15462 + Linux a.out, m68k-*-linux*aout* 15463 + Linux libc1, m68k-*-linux*libc1* 15464 + pSOS, m68k-*-psos* 15465 * MIPS 15466 + Generic ECOFF, mips*-*-ecoff* 15467 + SINIX, mips-sni-sysv4 15468 + Orion RTEMS, mips64orion-*-rtems* 15469 * National Semiconductor 32000 15470 + OpenBSD, ns32k-*-openbsd* 15471 * POWER (aka RS/6000) and PowerPC 15472 + AIX versions 1, 2, and 3, rs6000-ibm-aix[123]* 15473 + Bull BOSX, rs6000-bull-bosx 15474 + Generic Mach, rs6000-*-mach* 15475 + Generic SysV, powerpc*-*-sysv* 15476 + Linux libc1, powerpc*-*-linux*libc1* 15477 * Sun SPARC 15478 + Generic a.out, sparc-*-aout*, sparclet-*-aout*, 15479 sparclite-*-aout*, and sparc86x-*-aout* 15480 + NetBSD a.out, sparc-*-netbsd*aout* 15481 + Generic BSD, sparc-*-bsd* 15482 + ChorusOS, sparc-*-chorusos* 15483 + Linux a.out, sparc-*-linux*aout* 15484 + Linux libc1, sparc-*-linux*libc1* 15485 + LynxOS, sparc-*-lynxos* 15486 + Solaris on HAL hardware, sparc-hal-solaris2* 15487 + SunOS versions 3 and 4, sparc-*-sunos[34]* 15488 * NEC V850 15489 + RTEMS, v850-*-rtems* 15490 * VAX 15491 + VMS, vax-*-vms* 15492 15493 Documentation improvements 15494 15495 Other significant improvements 15496 15497 * Almost all front-end dependencies in the compiler have been 15498 separated out into a set of language hooks. This should make adding 15499 a new front end clearer and easier. 15500 * One effect of removing the separate preprocessor is a small 15501 increase in the robustness of the compiler in general, and the 15502 maintainability of target descriptions. Previously target-specific 15503 built-in macros and others, such as __FAST_MATH__, had to be 15504 handled with so-called specs that were hard to maintain. Often they 15505 would fail to behave properly when conflicting options were 15506 supplied on the command line, and define macros in the user's 15507 namespace even when strict ISO compliance was requested. 15508 Integrating the preprocessor has cleanly solved these issues. 15509 * The Makefile suite now supports redirection of make install by 15510 means of the variable DESTDIR. 15511 __________________________________________________________________ 15512 15513 GCC 3.3 15514 15515 Detailed release notes for the GCC 3.3 release follow. 15516 15517 Bug Fixes 15518 15519 bootstrap failures 15520 15521 * [8]10140 cross compiler build failures: missing __mempcpy (DUP: 15522 [9]10198,[10]10338) 15523 15524 Internal compiler errors (multi-platform) 15525 15526 * [11]3581 large string causes segmentation fault in cc1 15527 * [12]4382 __builtin_{set,long}jmp with -O3 can crash the compiler 15528 * [13]5533 (c++) ICE when processing std::accumulate(begin, end, 15529 init, invalid_op) 15530 * [14]6387 -fpic -gdwarf-2 -g1 combination gives ICE in dwarf2out 15531 * [15]6412 (c++) ICE in retrieve_specialization 15532 * [16]6620 (c++) partial template specialization causes an ICE 15533 (segmentation fault) 15534 * [17]6663 (c++) ICE with attribute aligned 15535 * [18]7068 ICE with incomplete types 15536 * [19]7083 (c++) ICE using -gstabs with dodgy class derivation 15537 * [20]7647 (c++) ICE when data member has the name of the enclosing 15538 class 15539 * [21]7675 ICE in fixup_var_refs_1 15540 * [22]7718 'complex' template instantiation causes ICE 15541 * [23]8116 (c++) ICE in member template function 15542 * [24]8358 (ada) Ada compiler accesses freed memory, crashes 15543 * [25]8511 (c++) ICE: (hopefully) reproducible cc1plus segmentation 15544 fault 15545 * [26]8564 (c++) ICE in find_function_data, in function.c 15546 * [27]8660 (c++) template overloading ICE in tsubst_expr, in cp/pt.c 15547 * [28]8766 (c++) ICE after failed initialization of static template 15548 variable 15549 * [29]8803 ICE in instantiate_virtual_regs_1, in function.c 15550 * [30]8846 (c++) ICE after diagnostic if fr_FR@euro locale is set 15551 * [31]8906 (c++) ICE (Segmentation fault) when parsing nested-class 15552 definition 15553 * [32]9216 (c++) ICE on missing template parameter 15554 * [33]9261 (c++) ICE in arg_assoc, in cp/decl2.c 15555 * [34]9263 (fortran) ICE caused by invalid PARAMETER in implied DO 15556 loop 15557 * [35]9429 (c++) ICE in template instantiation with a pointered new 15558 operator 15559 * [36]9516 Internal error when using a big array 15560 * [37]9600 (c++) ICE with typedefs in template class 15561 * [38]9629 (c++) virtual inheritance segfault 15562 * [39]9672 (c++) ICE: Error reporting routines re-entered 15563 * [40]9749 (c++) ICE in write_expression on invalid function 15564 prototype 15565 * [41]9794 (fortran) ICE: floating point exception during constant 15566 folding 15567 * [42]9829 (c++) Missing colon in nested namespace usage causes ICE 15568 * [43]9916 (c++) ICE with noreturn function in ?: statement 15569 * [44]9936 ICE with local function and variable-length 2d array 15570 * [45]10262 (c++) cc1plus crashes with large generated code 15571 * [46]10278 (c++) ICE in parser for invalid code 15572 * [47]10446 (c++) ICE on definition of nonexistent member function of 15573 nested class in a class template 15574 * [48]10451 (c++) ICE in grokdeclarator on spurious mutable 15575 declaration 15576 * [49]10506 (c++) ICE in build_new at cp/init.c with 15577 -fkeep-inline-functions and multiple inheritance 15578 * [50]10549 (c++) ICE in store_bit_field on bitfields that exceed the 15579 precision of the declared type 15580 15581 Optimization bugs 15582 15583 * [51]2001 Inordinately long compile times in reload CSE regs 15584 * [52]2391 Exponential compilation time explosion in combine 15585 * [53]2960 Duplicate loop conditions even with -Os 15586 * [54]4046 redundant conditional branch 15587 * [55]6405 Loop-unrolling related performance regressions 15588 * [56]6798 very long compile time with large case-statement 15589 * [57]6871 const objects shouldn't be moved to .bss 15590 * [58]6909 problem w/ -Os on modified loop-2c.c test case 15591 * [59]7189 gcc -O2 -Wall does not print ``control reaches end of 15592 non-void function'' warning 15593 * [60]7642 optimization problem with signbit() 15594 * [61]8634 incorrect code for inlining of memcpy under -O2 15595 * [62]8750 Cygwin prolog generation erroneously emitting __alloca as 15596 regular function call 15597 15598 C front end 15599 15600 * [63]2161 long if-else cascade overflows parser stack 15601 * [64]4319 short accepted on typedef'd char 15602 * [65]8602 incorrect line numbers in warning messages when using 15603 inline functions 15604 * [66]9177 -fdump-translation-unit: C front end deletes function_decl 15605 AST nodes and breaks debugging dumps 15606 * [67]9853 miscompilation of non-constant structure initializer 15607 15608 c++ compiler and library 15609 15610 * [68]45 legal template specialization code is rejected (DUP: 15611 [69]3784) 15612 * [70]764 lookup failure: friend operator and dereferencing a pointer 15613 and templates (DUP: [71]5116) 15614 * [72]2862 gcc accepts invalid explicit instantiation syntax (DUP: 15615 2863) 15616 * [73]3663 G++ doesn't check access control during template 15617 instantiation 15618 * [74]3797 gcc fails to emit explicit specialization of a template 15619 member 15620 * [75]3948 Two destructors are called when no copy destructor is 15621 defined (ABI change) 15622 * [76]4137 Conversion operator within template is not accepted 15623 * [77]4361 bogus ambiguity taking the address of a member template 15624 * [78]4802 g++ accepts illegal template code (access to private 15625 member; DUP: [79]5837) 15626 * [80]4803 inline function is used but never defined, and g++ does 15627 not object 15628 * [81]5094 Partial specialization cannot be friend? 15629 * [82]5730 complex<double>::norm() -- huge slowdown from egcs-2.91.66 15630 * [83]6713 Regression wrt 3.0.4: g++ -O2 leads to seg fault at run 15631 time 15632 * [84]7015 certain __asm__ constructs rejected 15633 * [85]7086 compile time regression (quadratic behavior in 15634 fixup_var_refs) 15635 * [86]7099 G++ doesn't set the noreturn attribute on std::exit and 15636 std::abort 15637 * [87]7247 copy constructor missing when inlining enabled (invalid 15638 optimization?) 15639 * [88]7441 string array initialization compilation time regression 15640 from seconds to minutes 15641 * [89]7768 __PRETTY_FUNCTION__ for template destructor is wrong 15642 * [90]7804 bad printing of floating point constant in warning message 15643 * [91]8099 Friend classes and template specializations 15644 * [92]8117 member function pointers and multiple inheritance 15645 * [93]8205 using declaration and multiple inheritance 15646 * [94]8645 unnecessary non-zero checks in stl_tree.h 15647 * [95]8724 explicit destructor call for incomplete class allowed 15648 * [96]8805 compile time regression with many member variables 15649 * [97]8691 -O3 and -fno-implicit-templates are incompatible 15650 * [98]8700 unhelpful error message for binding temp to reference 15651 * [99]8724 explicit destructor call for incomplete class allowed 15652 * [100]8949 numeric_limits<>::denorm_min() and is_iec559 problems 15653 * [101]9016 Failure to consistently constant fold "constant" C++ 15654 objects 15655 * [102]9053 g++ confused about ambiguity of overloaded function 15656 templates 15657 * [103]9152 undefined virtual thunks 15658 * [104]9182 basic_filebuf<> does not report errors in codecvt<>::out 15659 * [105]9297 data corruption due to codegen bug (when copying.) 15660 * [106]9318 i/ostream::operator>>/<<(streambuf*) broken 15661 * [107]9320 Incorrect usage of traits_type::int_type in stdio_filebuf 15662 * [108]9400 bogus -Wshadow warning: shadowed declaration of this in 15663 local classes 15664 * [109]9424 i/ostream::operator>>/<<(streambuf*) drops characters 15665 * [110]9425 filebuf::pbackfail broken (DUP: [111]9439) 15666 * [112]9474 GCC freezes in compiling a weird code mixing <iostream> 15667 and <iostream.h> 15668 * [113]9548 Incorrect results from setf(ios::fixed) and precision(-1) 15669 [114][DR 231] 15670 * [115]9555 ostream inserters fail to set badbit on exception 15671 * [116]9561 ostream inserters rethrow exception of wrong type 15672 * [117]9563 ostream::sentry returns true after a failed preparation 15673 * [118]9582 one-definition rule violation in std::allocator 15674 * [119]9622 __PRETTY_FUNCTION__ incorrect in template destructors 15675 * [120]9683 bug in initialization chains for static const variables 15676 from template classes 15677 * [121]9791 -Woverloaded-virtual reports hiding of destructor 15678 * [122]9817 collate::compare doesn't handle nul characters 15679 * [123]9825 filebuf::sputbackc breaks sbumpc 15680 * [124]9826 operator>>(basic_istream, basic_string) fails to compile 15681 with custom traits 15682 * [125]9924 Multiple using statements for builtin functions not 15683 allowed 15684 * [126]9946 destructor is not called for temporary object 15685 * [127]9964 filebuf::close() sometimes fails to close file 15686 * [128]9988 filebuf::overflow writes EOF to file 15687 * [129]10033 optimization breaks polymorphic references w/ typeid 15688 operator 15689 * [130]10097 filebuf::underflow drops characters 15690 * [131]10132 filebuf destructor can throw exceptions 15691 * [132]10180 gcc fails to warn about non-inlined function 15692 * [133]10199 method parametrized by template does not work everywhere 15693 * [134]10300 use of array-new (nothrow) in segfaults on NULL return 15694 * [135]10427 Stack corruption with variable-length automatic arrays 15695 and virtual destructors 15696 * [136]10503 Compilation never stops in fixed_type_or_null 15697 15698 Objective-C 15699 15700 * [137]5956 selectors aren't matched properly when added to the 15701 selector table 15702 15703 Fortran compiler and library 15704 15705 * [138]1832 list directed i/o overflow hangs, -fbounds-check doesn't 15706 detect 15707 * [139]3924 g77 generates code that is rejected by GAS if COFF debug 15708 info requested 15709 * [140]5634 doc: explain that configure --prefix=~/... does not work 15710 * [141]6367 multiple repeat counts confuse namelist read into array 15711 * [142]6491 Logical operations error on logicals when using 15712 -fugly-logint 15713 * [143]6742 Generation of C++ Prototype for FORTRAN and extern "C" 15714 * [144]7113 Failure of g77.f-torture/execute/f90-intrinsic-bit.f -Os 15715 on irix6.5 15716 * [145]7236 OPEN(...,RECL=nnn,...) without ACCESS='DIRECT' should 15717 assume a direct access file 15718 * [146]7278 g77 "bug"; the executable misbehaves (with -O2 15719 -fno-automatic) 15720 * [147]7384 DATE_AND_TIME milliseconds field inactive on Windows 15721 * [148]7388 Incorrect output with 0-based array of characters 15722 * [149]8587 Double complex zero ** double precision number -> NaN 15723 instead of zero 15724 * [150]9038 -ffixed-line-length-none -x f77-cpp-input gives: Warning: 15725 unknown register name line-length-none 15726 * [151]10197 Direct access files not unformatted by default 15727 15728 Java compiler and library 15729 15730 * [152]6005 gcj fails to build rhug on alpha 15731 * [153]6389 System.getProperty("") should always throw an 15732 IllegalArgumentException 15733 * [154]6576 java.util.ResourceBundle.getResource ignores locale 15734 * [155]6652 new java.io.File("").getCanonicalFile() throws exception 15735 * [156]7060 getMethod() doesn't search super interface 15736 * [157]7073 bytecode interpreter gives wrong answer for interface 15737 getSuperclass() 15738 * [158]7180 possible bug in 15739 javax.naming.spi.NamingManager.getPlusPath() 15740 * [159]7416 java.security startup refs "GNU libgcj.security" 15741 * [160]7570 Runtime.exec with null envp: child doesn't inherit parent 15742 env (DUP: [161]7578) 15743 * [162]7611 Internal error while compiling libjava with -O 15744 * [163]7709 NullPointerException in _Jv_ResolvePoolEntry 15745 * [164]7766 ZipInputStream.available returns 0 immediately after 15746 construction 15747 * [165]7785 Calendar.getTimeInMillis/setTimeInMillis should be public 15748 * [166]7786 TimeZone.getDSTSavings() from JDK1.4 not implemented 15749 * [167]8142 '$' in class names vs. dlopen 'dynamic string tokens' 15750 * [168]8234 ZipInputStream chokes when InputStream.read() returns 15751 small chunks 15752 * [169]8415 reflection bug: exception info for Method 15753 * [170]8481 java.Random.nextInt(int) may return negative 15754 * [171]8593 Error reading GZIPped files with BufferedReader 15755 * [172]8759 java.beans.Introspector has no flushCaches() or 15756 flushFromCaches() methods 15757 * [173]8997 spin() calls Thread.sleep 15758 * [174]9253 on win32, java.io.File.listFiles("C:\\") returns pwd 15759 instead of the root content of C: 15760 * [175]9254 java::lang::Object::wait(), threads-win32.cc returns 15761 wrong return codes 15762 * [176]9271 Severe bias in java.security.SecureRandom 15763 15764 Ada compiler and library 15765 15766 * [177]6767 make gnatlib-shared fails on -laddr2line 15767 * [178]9911 gnatmake fails to link when GCC configured with 15768 --with-sjlj-exceptions=yes 15769 * [179]10020 Can't bootstrap gcc on AIX with Ada enabled 15770 * [180]10546 Ada tasking not working on Red Hat 9 15771 15772 preprocessor 15773 15774 * [181]7029 preprocessor should ignore #warning with -M 15775 15776 ARM-specific 15777 15778 * [182]2903 [arm] Optimization bug with long long arithmetic 15779 * [183]7873 arm-linux-gcc fails when assigning address to a bit field 15780 15781 FreeBSD-specific 15782 15783 * [184]7680 float functions undefined in math.h/cmath with #define 15784 _XOPEN_SOURCE 15785 15786 HP-UX or HP-PA-specific 15787 15788 * [185]8705 [HP-PA] ICE in emit_move_insn_1, in expr.c 15789 * [186]9986 [HP-UX] Incorrect transformation of fputs_unlocked to 15790 fputc_unlocked 15791 * [187]10056 [HP-PA] ICE at -O2 when building c++ code from doxygen 15792 15793 m68hc11-specific 15794 15795 * [188]6744 Bad assembler code generated: reference to pseudo 15796 register z 15797 * [189]7361 Internal compiler error in reload_cse_simplify_operands, 15798 in reload1.c 15799 15800 MIPS-specific 15801 15802 * [190]9496 [mips-linux] bug in optimizer? 15803 15804 PowerPC-specific 15805 15806 * [191]7067 -Os with -mcpu=powerpc optimizes for speed (?) instead of 15807 space 15808 * [192]8480 reload ICEs for LAPACK code on powerpc64-linux 15809 * [193]8784 [AIX] Internal compiler error in simplify_gen_subreg 15810 * [194]10315 [powerpc] ICE: in extract_insn, in recog.c 15811 15812 SPARC-specific 15813 15814 * [195]10267 (documentation) Wrong build instructions for 15815 *-*-solaris2* 15816 15817 x86-specific (Intel/AMD) 15818 15819 * [196]7916 ICE in instantiate_virtual_register_1 15820 * [197]7926 (c++) i486 instructions in header files make c++ programs 15821 crash on i386 15822 * [198]8555 ICE in gen_split_1231 15823 * [199]8994 ICE with -O -march=pentium4 15824 * [200]9426 ICE with -fssa -funroll-loops -fprofile-arcs 15825 * [201]9806 ICE in inline assembly with -fPIC flag 15826 * [202]10077 gcc -msse2 generates movd to move dwords between xmm 15827 regs 15828 * [203]10233 64-bit comparison only comparing bottom 32-bits 15829 * [204]10286 type-punning doesn't work with __m64 and -O 15830 * [205]10308 [x86] ICE with -O -fgcse or -O2 15831 __________________________________________________________________ 15832 15833 GCC 3.3.1 15834 15835 Bug Fixes 15836 15837 This section lists the problem reports (PRs) from GCC's bug tracking 15838 system that are known to be fixed in the 3.3.1 release. This list might 15839 not be complete (that is, it is possible that some PRs that have been 15840 fixed are not listed here). 15841 15842 Bootstrap failures 15843 15844 * [206]11272 [Solaris] make bootstrap fails while building libstdc++ 15845 15846 Internal compiler errors (multi-platform) 15847 15848 * [207]5754 ICE on invalid nested template class 15849 * [208]6597 ICE in set_mem_alias_set compiling Qt with -O2 on ia64 15850 and --enable-checking 15851 * [209]6949 (c++) ICE in tsubst_decl, in cp/pt.c 15852 * [210]7053 (c++) ICE when declaring a function already defined as a 15853 friend method of a template class 15854 * [211]8164 (c++) ICE when using different const expressions as 15855 template parameter 15856 * [212]8384 (c++) ICE in is_base_type, in dwarf2out.c 15857 * [213]9559 (c++) ICE with invalid initialization of a static const 15858 * [214]9649 (c++) ICE in finish_member_declaration, in cp/semantics.c 15859 when redeclaring a static member variable 15860 * [215]9864 (fortran) ICE in add_abstract_origin_attribute, in 15861 dwarfout.c with -g -O -finline-functions 15862 * [216]10432 (c++) ICE in poplevel, in cp/decl.c 15863 * [217]10475 ICE in subreg_highpart_offset for code with long long 15864 * [218]10635 (c++) ICE when dereferencing an incomplete type casted 15865 from a void pointer 15866 * [219]10661 (c++) ICE in instantiate_decl, in cp/pt.c while 15867 instantiating static member variables 15868 * [220]10700 ICE in copy_to_mode_reg on 64-bit targets 15869 * [221]10712 (c++) ICE in constructor_name_full, in cp/decl2.c 15870 * [222]10796 (c++) ICE when defining an enum with two values: -1 and 15871 MAX_INT_64BIT 15872 * [223]10890 ICE in merge_assigned_reloads building Linux 2.4.2x 15873 sched.c 15874 * [224]10939 (c++) ICE with template code 15875 * [225]10956 (c++) ICE when specializing a template member function 15876 of a template class, in tsubst, in cp/pt.c 15877 * [226]11041 (c++) ICE: const myclass &x = *x; (when operator*() 15878 defined) 15879 * [227]11059 (c++) ICE with empty union 15880 * [228]11083 (c++) ICE in commit_one_edge_insertion, in cfgrtl.c with 15881 -O2 -fnon-call-exceptions 15882 * [229]11105 (c++) ICE in mangle_conv_op_name_for_type 15883 * [230]11149 (c++) ICE on error when instantiation with call function 15884 of a base type 15885 * [231]11228 (c++) ICE on new-expression using array operator new and 15886 default-initialization 15887 * [232]11282 (c++) Infinite memory usage after syntax error 15888 * [233]11301 (fortran) ICE with -fno-globals 15889 * [234]11308 (c++) ICE when using an enum type name as if it were a 15890 class or namespace 15891 * [235]11473 (c++) ICE with -gstabs when empty struct inherits from 15892 an empty struct 15893 * [236]11503 (c++) ICE when instantiating template with ADDR_EXPR 15894 * [237]11513 (c++) ICE in push_template_decl_real, in cp/pt.c: 15895 template member functions 15896 15897 Optimization bugs 15898 15899 * [238]11198 -O2 -frename-registers generates wrong code (aliasing 15900 problem) 15901 * [239]11304 Wrong code production with -fomit-frame-pointer 15902 * [240]11381 volatile memory access optimized away 15903 * [241]11536 [strength-reduce] -O2 optimization produces wrong code 15904 * [242]11557 constant folding bug generates wrong code 15905 15906 C front end 15907 15908 * [243]5897 No warning for statement after return 15909 * [244]11279 DWARF-2 output mishandles large enums 15910 15911 Preprocessor bugs 15912 15913 * [245]11022 no warning for non-compatible macro redefinition 15914 15915 C++ compiler and library 15916 15917 * [246]2330 static_cast<>() to a private base is allowed 15918 * [247]5388 Incorrect message "operands to ?: have different types" 15919 * [248]5390 Libiberty fails to demangle multi-digit template 15920 parameters 15921 * [249]7877 Incorrect parameter passing to specializations of member 15922 function templates 15923 * [250]9393 Anonymous namespaces and compiling the same file twice 15924 * [251]10032 -pedantic converts some errors to warnings 15925 * [252]10468 const typeof(x) is non-const, but only in templates 15926 * [253]10527 confused error message with "new int()" parameter 15927 initializer 15928 * [254]10679 parameter MIN_INLINE_INSNS is not honored 15929 * [255]10682 gcc chokes on a typedef for an enum inside a class 15930 template 15931 * [256]10689 pow(std::complex(0),1/3) returns (nan, nan) instead of 15932 0. 15933 * [257]10845 template member function (with nested template as 15934 parameter) cannot be called anymore if another unrelated template 15935 member function is defined 15936 * [258]10849 Cannot define an out-of-class specialization of a 15937 private nested template class 15938 * [259]10888 Suppress -Winline warnings for system headers 15939 * [260]10929 -Winline warns about functions for which no definition 15940 is visible 15941 * [261]10931 valid conversion static_cast<const unsigned 15942 int&>(lvalue-of-type-int) is rejected 15943 * [262]10940 Bad code with explicit specialization 15944 * [263]10968 If member function implicitly instantiated, explicit 15945 instantiation of class fails to instantiate it 15946 * [264]10990 Cannot convert with dynamic_cast<> to a private base 15947 class from within a member function 15948 * [265]11039 Bad interaction between implicit typename deprecation 15949 and friendship 15950 * [266]11062 (libstdc++) avoid __attribute__ ((unused)); say 15951 "__unused__" instead 15952 * [267]11095 C++ iostream manipulator causes segfault when called 15953 with negative argument 15954 * [268]11098 g++ doesn't emit complete debugging information for 15955 local variables in destructors 15956 * [269]11137 GNU/Linux shared library constructors not called unless 15957 there's one global object 15958 * [270]11154 spurious ambiguity report for template class 15959 specialization 15960 * [271]11329 Compiler cannot find user defined implicit typecast 15961 * [272]11332 Spurious error with casts in ?: expression 15962 * [273]11431 static_cast behavior with subclasses when default 15963 constructor available 15964 * [274]11528 money_get facet does not accept "$.00" as valid 15965 * [275]11546 Type lookup problems in out-of-line definition of a 15966 class doubly nested from a template class 15967 * [276]11567 C++ code containing templated member function with same 15968 name as pure virtual member function results in linking failure 15969 * [277]11645 Failure to deal with using and private inheritance 15970 15971 Java compiler and library 15972 15973 * [278]5179 Qualified static field access doesn't initialize its 15974 class 15975 * [279]8204 gcj -O2 to native reorders certain instructions 15976 improperly 15977 * [280]10838 java.io.ObjectInputStream syntax error 15978 * [281]10886 The RMI registry that comes with GCJ does not work 15979 correctly 15980 * [282]11349 JNDI URL context factories not located correctly 15981 15982 x86-specific (Intel/AMD) 15983 15984 * [283]4823 ICE on inline assembly code 15985 * [284]8878 miscompilation with -O and SSE 15986 * [285]9815 (c++ library) atomicity.h - fails to compile with -O3 15987 -masm=intel 15988 * [286]10402 (inline assembly) [x86] ICE in merge_assigned_reloads, 15989 in reload1.c 15990 * [287]10504 ICE with SSE2 code and -O3 -mcpu=pentium4 -msse2 15991 * [288]10673 ICE for x86-64 on freebsd libc vfprintf.c source 15992 * [289]11044 [x86] out of range loop instructions for FP code on K6 15993 * [290]11089 ICE: instantiate_virtual_regs_lossage while using SSE 15994 built-ins 15995 * [291]11420 [x86_64] gcc generates invalid asm code when "-O -fPIC" 15996 is used 15997 15998 SPARC- or Solaris- specific 15999 16000 * [292]9362 solaris 'as' dies when fed .s and "-gstabs" 16001 * [293]10142 [SPARC64] gcc produces wrong code when passing 16002 structures by value 16003 * [294]10663 New configure check aborts with Sun tools. 16004 * [295]10835 combinatorial explosion in scheduler on HyperSPARC 16005 * [296]10876 ICE in calculate_giv_inc when building KDE 16006 * [297]10955 wrong code at -O3 for structure argument in context of 16007 structure return 16008 * [298]11018 -mcpu=ultrasparc busts tar-1.13.25 16009 * [299]11556 [sparc64] ICE in gen_reg_rtx() while compiling 2.6.x 16010 Linux kernel 16011 16012 ia64 specific 16013 16014 * [300]10907 gcc violates the ia64 ABI (GP must be preserved) 16015 * [301]11320 scheduler bug (in machine depended reorganization pass) 16016 * [302]11599 bug with conditional and __builtin_prefetch 16017 16018 PowerPC specific 16019 16020 * [303]9745 [powerpc] gcc mis-compiles libmcrypt (alias problem 16021 during loop) 16022 * [304]10871 error in rs6000_stack_info save_size computation 16023 * [305]11440 gcc mis-compiles c++ code (libkhtml) with -O2, -fno-gcse 16024 cures it 16025 16026 m68k-specific 16027 16028 * [306]7594 [m68k] ICE on legal code associated with simplify-rtx 16029 * [307]10557 [m68k] ICE in subreg_offset_representable_p 16030 * [308]11054 [m68k] ICE in reg_overlap_mentioned_p 16031 16032 ARM-specific 16033 16034 * [309]10834 [arm] GCC 3.3 still generates incorrect instructions for 16035 functions with __attribute__ ((interrupt ("IRQ"))) 16036 * [310]10842 [arm] Clobbered link register is copied to pc under 16037 certain circumstances 16038 * [311]11052 [arm] noce_process_if_block() can lose REG_INC notes 16039 * [312]11183 [arm] ICE in change_address_1 (3.3) / subreg_hard_regno 16040 (3.4) 16041 16042 MIPS-specific 16043 16044 * [313]11084 ICE in propagate_one_insn, in flow.c 16045 16046 SH-specific 16047 16048 * [314]10331 can't compile c++ part of gcc cross compiler for sh-elf 16049 * [315]10413 [SH] ICE in reload_cse_simplify_operands, in reload1.c 16050 * [316]11096 i686-linux to sh-linux cross compiler fails to compile 16051 C++ files 16052 16053 GNU/Linux (or Hurd?) specific 16054 16055 * [317]2873 Bogus fixinclude of stdio.h from glibc 2.2.3 16056 16057 UnixWare specific 16058 16059 * [318]3163 configure bug: gcc/aclocal.m4 mmap test fails on UnixWare 16060 7.1.1 16061 16062 Cygwin (or mingw) specific 16063 16064 * [319]5287 ICE with dllimport attribute 16065 * [320]10148 [MingW/CygWin] Compiler dumps core 16066 16067 DJGPP specific 16068 16069 * [321]8787 GCC fails to emit .intel_syntax when invoked with 16070 -masm=intel on DJGPP 16071 16072 Darwin (and MacOS X) specific 16073 16074 * [322]10900 trampolines crash 16075 16076 Documentation 16077 16078 * [323]1607 (c++) Format attributes on methods undocumented 16079 * [324]4252 Invalid option `-fdump-translation-unit' 16080 * [325]4490 Clarify restrictions on -m96bit-long-double, 16081 -m128bit-long-double 16082 * [326]10355 document an issue with regparm attribute on some systems 16083 (e.g. Solaris) 16084 * [327]10726 (fortran) Documentation for function "IDate Intrinsic 16085 (Unix)" is wrong 16086 * [328]10805 document bug in old version of Sun assembler 16087 * [329]10815 warn against GNU binutils on AIX 16088 * [330]10877 document need for newer binutils on i?86-*-linux-gnu 16089 * [331]11280 Manual incorrect with respect to -freorder-blocks 16090 * [332]11466 Document -mlittle-endian and its restrictions for the 16091 sparc64 port 16092 16093 Testsuite bugs (compiler itself is not affected) 16094 16095 * [333]10737 newer bison causes g++.dg/parse/crash2.C to incorrectly 16096 report failure 16097 * [334]10810 gcc-3.3 fails make check: buffer overrun in 16098 test_demangle.c 16099 __________________________________________________________________ 16100 16101 GCC 3.3.2 16102 16103 Bug Fixes 16104 16105 This section lists the problem reports (PRs) from GCC's bug tracker 16106 that are known to be fixed in the 3.3.2 release. This list might not be 16107 complete (that is, it is possible that some PRs that have been fixed 16108 are not listed here). 16109 16110 Bootstrap failures and problems 16111 16112 * [335]8336 [SCO5] bootstrap config still tries to use COFF options 16113 * [336]9330 [alpha-osf] Bootstrap failure on Compaq Tru64 with 16114 --enable-threads=posix 16115 * [337]9631 [hppa64-linux] gcc-3.3 fails to bootstrap 16116 * [338]9877 fixincludes makes a bad sys/byteorder.h on svr5 (UnixWare 16117 7.1.1) 16118 * [339]11687 xstormy16-elf build fails in libf2c 16119 * [340]12263 [SGI IRIX] bootstrap fails during compile of 16120 libf2c/libI77/backspace.c 16121 * [341]12490 buffer overflow in scan-decls.c (during Solaris 9 16122 fix-header processing) 16123 16124 Internal compiler errors (multi-platform) 16125 16126 * [342]7277 Casting integers to vector types causes ICE 16127 * [343]7939 (c++) ICE on invalid function template specialization 16128 * [344]11063 (c++) ICE on parsing initialization list of const array 16129 member 16130 * [345]11207 ICE with negative index in array element designator 16131 * [346]11522 (fortran) g77 dwarf-2 ICE in 16132 add_abstract_origin_attribute 16133 * [347]11595 (c++) ICE on duplicate label definition 16134 * [348]11646 (c++) ICE in commit_one_edge_insertion with 16135 -fnon-call-exceptions -fgcse -O 16136 * [349]11665 ICE in struct initializer when taking address 16137 * [350]11852 (c++) ICE with bad struct initializer. 16138 * [351]11878 (c++) ICE in cp_expr_size 16139 * [352]11883 ICE with any -O on mercury-generated C code 16140 * [353]11991 (c++) ICE in cxx_incomplete_type_diagnostic, in 16141 cp/typeck2.c when applying typeid operator to template template 16142 parameter 16143 * [354]12146 ICE in lookup_template_function, in cp/pt.c 16144 * [355]12215 ICE in make_label_edge with -fnon-call-exceptions 16145 -fno-gcse -O2 16146 * [356]12369 (c++) ICE with templates and friends 16147 * [357]12446 ICE in emit_move_insn on complicated array reference 16148 * [358]12510 ICE in final_scan_insn 16149 * [359]12544 ICE with large parameters used in nested functions 16150 16151 C and optimization bugs 16152 16153 * [360]9862 spurious warnings with -W -finline-functions 16154 * [361]10962 lookup_field is a linear search on a linked list (can be 16155 slow if large struct) 16156 * [362]11370 -Wunreachable-code gives false complaints 16157 * [363]11637 invalid assembly with -fnon-call-exceptions 16158 * [364]11885 Problem with bitfields in packed structs 16159 * [365]12082 Inappropriate unreachable code warnings 16160 * [366]12180 Inline optimization fails for variadic function 16161 * [367]12340 loop unroller + gcse produces wrong code 16162 16163 C++ compiler and library 16164 16165 * [368]3907 nested template parameter collides with member name 16166 * [369]5293 confusing message when binding a temporary to a reference 16167 * [370]5296 [DR115] Pointers to functions and to template functions 16168 behave differently in deduction 16169 * [371]7939 ICE on function template specialization 16170 * [372]8656 Unable to assign function with __attribute__ and pointer 16171 return type to an appropriate variable 16172 * [373]10147 Confusing error message for invalid template function 16173 argument 16174 * [374]11400 std::search_n() makes assumptions about Size parameter 16175 * [375]11409 issues with using declarations, overloading, and 16176 built-in functions 16177 * [376]11740 ctype<wchar_t>::do_is(mask, wchar_t) doesn't handle 16178 multiple bits in mask 16179 * [377]11786 operator() call on variable in other namespace not 16180 recognized 16181 * [378]11867 static_cast ignores ambiguity 16182 * [379]11928 bug with conversion operators that are typedefs 16183 * [380]12114 Uninitialized memory accessed in dtor 16184 * [381]12163 static_cast + explicit constructor regression 16185 * [382]12181 Wrong code with comma operator and c++ 16186 * [383]12236 regparm and fastcall messes up parameters 16187 * [384]12266 incorrect instantiation of unneeded template during 16188 overload resolution 16189 * [385]12296 istream::peek() doesn't set eofbit 16190 * [386]12298 [sjlj exceptions] Stack unwind destroys 16191 not-yet-constructed object 16192 * [387]12369 ICE with templates and friends 16193 * [388]12337 apparently infinite loop in g++ 16194 * [389]12344 stdcall attribute ignored if function returns a pointer 16195 * [390]12451 missing(late) class forward declaration in cxxabi.h 16196 * [391]12486 g++ accepts invalid use of a qualified name 16197 16198 x86 specific (Intel/AMD) 16199 16200 * [392]8869 [x86 MMX] ICE with const variable optimization and MMX 16201 builtins 16202 * [393]9786 ICE in fixup_abnormal_edges with -fnon-call-exceptions 16203 -O2 16204 * [394]11689 g++3.3 emits un-assembleable code for k6 architecture 16205 * [395]12116 [k6] Invalid assembly output values with X-MAME code 16206 * [396]12070 ICE converting between double and long double with 16207 -msoft-float 16208 16209 ia64-specific 16210 16211 * [397]11184 [ia64 hpux] ICE on __builtin_apply building libobjc 16212 * [398]11535 __builtin_return_address may not work on ia64 16213 * [399]11693 [ia64] ICE in gen_nop_type 16214 * [400]12224 [ia64] Thread-local storage doesn't work 16215 16216 PowerPC-specific 16217 16218 * [401]11087 [powerpc64-linux] GCC miscompiles raid1.c from linux 16219 kernel 16220 * [402]11319 loop miscompiled on ppc32 16221 * [403]11949 ICE Compiler segfault with ffmpeg -maltivec code 16222 16223 SPARC-specific 16224 16225 * [404]11662 wrong code for expr. with cast to long long and 16226 exclusive or 16227 * [405]11965 invalid assembler code for a shift < 32 operation 16228 * [406]12301 (c++) stack corruption when a returned expression throws 16229 an exception 16230 16231 Alpha-specific 16232 16233 * [407]11717 [alpha-linux] unrecognizable insn compiling for.c of 16234 kernel 2.4.22-pre8 16235 16236 HPUX-specific 16237 16238 * [408]11313 problem with #pragma weak and static inline functions 16239 * [409]11712 __STDC_EXT__ not defined for C++ by default anymore? 16240 16241 Solaris specific 16242 16243 * [410]12166 Profiled programs crash if PROFDIR is set 16244 16245 Solaris-x86 specific 16246 16247 * [411]12101 i386 Solaris no longer works with GNU as? 16248 16249 Miscellaneous embedded target-specific bugs 16250 16251 * [412]10988 [m32r-elf] wrong blockmove code with -O3 16252 * [413]11805 [h8300-unknown-coff] [H8300] ICE for simple code with 16253 -O2 16254 * [414]11902 [sh4] spec file improperly inserts rpath even when none 16255 needed 16256 * [415]11903 [sh4] -pthread fails to link due to error in spec file 16257 on sh4 16258 __________________________________________________________________ 16259 16260 GCC 3.3.3 16261 16262 Minor features 16263 16264 In addition to the bug fixes documented below, this release contains 16265 few minor features such as: 16266 * Support for --with-sysroot 16267 * Support for automatic detection of executable stacks 16268 * Support for SSE3 instructions 16269 * Support for thread local storage debugging under GDB on S390 16270 16271 Bug Fixes 16272 16273 This section lists the problem reports (PRs) from GCC's bug tracker 16274 that are known to be fixed in the 3.3.3 release. This list might not be 16275 complete (that is, it is possible that some PRs that have been fixed 16276 are not listed here). 16277 16278 Bootstrap failures and issues 16279 16280 * [416]11890 Building cross gcc-3.3.1 for sparc-sun-solaris2.6 fails 16281 * [417]12399 boehm-gc fails (when building a cross compiler): libtool 16282 unable to infer tagged configuration 16283 * [418]13068 mklibgcc.in doesn't handle multi-level multilib 16284 subdirectories properly 16285 16286 Internal compiler errors (multi-platform) 16287 16288 * [419]10060 ICE (stack overflow) on huge file (300k lines) due to 16289 recursive behaviour of copy_rtx_if_shared, in emit_rtl.c 16290 * [420]10555 (c++) ICE on undefined template argument 16291 * [421]10706 (c++) ICE in mangle_class_name_for_template 16292 * [422]11496 (fortran) error in flow_loops_find when -funroll-loops 16293 active 16294 * [423]11741 ICE in pre_insert_copy_insn, in gcse.c 16295 * [424]12440 GCC crashes during compilation of quicktime4linux 2.0.0 16296 * [425]12632 (fortran) -fbounds-check ICE 16297 * [426]12712 (c++) ICE on short legit C++ code fragment with gcc 16298 3.3.2 16299 * [427]12726 (c++) ICE (segfault) on trivial code 16300 * [428]12890 (c++) ICE on compilation of class with throwing method 16301 * [429]12900 (c++) ICE in rtl_verify_flow_info_1 16302 * [430]13060 (fortran) ICE in fixup_var_refs_1, in function.c on 16303 correct code with -O2 -fno-force-mem 16304 * [431]13289 (c++) ICE in regenerate_decl_from_template on recursive 16305 template 16306 * [432]13318 ICE: floating point exception in the loop optimizer 16307 * [433]13392 (c++) ICE in convert_from_eh_region_ranges_1, in 16308 except.c 16309 * [434]13574 (c++) invalid array default initializer in class lets 16310 gcc consume all memory and die 16311 * [435]13475 ICE on SIMD variables with partial value initialization 16312 * [436]13797 (c++) ICE on invalid template parameter 16313 * [437]13824 (java) gcj SEGV with simple .java program 16314 16315 C and optimization bugs 16316 16317 * [438]8776 loop invariants are not removed (most likely) 16318 * [439]10339 [sparc,ppc,ppc64] Invalid optimization: replacing 16319 strncmp by memcmp 16320 * [440]11350 undefined labels with -Os -fPIC 16321 * [441]12826 Optimizer removes reference through volatile pointer 16322 * [442]12500 stabs debug info: void no longer a predefined / builtin 16323 type 16324 * [443]12941 builtin-bitops-1.c miscompilation (latent bug) 16325 * [444]12953 tree inliner bug (in inline_forbidden_p) and fix 16326 * [445]13041 linux-2.6/sound/core/oss/rate.c miscompiled 16327 * [446]13507 spurious printf format warning 16328 * [447]13382 Type information for const pointer disappears during 16329 optimization. 16330 * [448]13394 noreturn attribute ignored on recursive invokation 16331 * [449]13400 Compiled code crashes storing to read-only location 16332 * [450]13521 Endless loop in calculate_global_regs_live 16333 16334 C++ compiler and library 16335 16336 Some of the bug fixes in this list were made to implement decisions 16337 that the ISO C++ standards committee has made concerning several defect 16338 reports (DRs). Links in the list below point to detailed discussion of 16339 the relevant defect report. 16340 * [451]2094 unimplemented: use of `ptrmem_cst' in template type 16341 unification 16342 * [452]2294 using declaration confusion 16343 * [453]5050 template instantiation depth exceeds limit: recursion 16344 problem? 16345 * [454]9371 Bad exception handling in 16346 i/ostream::operator>>/<<(streambuf*) 16347 * [455]9546 bad exception handling in ostream members 16348 * [456]10081 basic_ios::_M_cache_locale leaves NULL members in the 16349 face of unknown locales 16350 * [457]10093 [458][DR 61] Setting failbit in exceptions doesn't work 16351 * [459]10095 istream::operator>>(int&) sets ios::badbit when 16352 ios::failbit is set. 16353 * [460]11554 Warning about reordering of initializers doesn't mention 16354 location of constructor 16355 * [461]12297 istream::sentry::sentry() handles eof() incorrectly. 16356 * [462]12352 Exception safety problems in src/localename.cc 16357 * [463]12438 Memory leak in locale::combine() 16358 * [464]12540 Memory leak in locale::locale(const char*) 16359 * [465]12594 DRs [466]60 [TC] and [467]63 [TC] not implemented 16360 * [468]12657 Resolution of [469]DR 292 (WP) still unimplemented 16361 * [470]12696 memory eating infinite loop in diagnostics (error 16362 recovery problem) 16363 * [471]12815 Code compiled with optimization behaves unexpectedly 16364 * [472]12862 Conflicts between typedefs/enums and namespace member 16365 declarations 16366 * [473]12926 Wrong value after assignment in initialize list using 16367 bit-fields 16368 * [474]12967 Resolution of [475]DR 300 [WP] still unimplemented 16369 * [476]12971 Resolution of [477]DR 328 [WP] still unimplemented 16370 * [478]13007 basic_streambuf::pubimbue, imbue wrong 16371 * [479]13009 Implicitly-defined assignment operator writes to wrong 16372 memory 16373 * [480]13057 regparm attribute not applied to destructor 16374 * [481]13070 -Wformat option ignored in g++ 16375 * [482]13081 forward template declarations in <complex> let inlining 16376 fail 16377 * [483]13239 Assertion does not seem to work correctly anymore 16378 * [484]13262 "xxx is private within this context" when initializing a 16379 self-contained template class 16380 * [485]13290 simple typo in concept checking for std::generate_n 16381 * [486]13323 Template code does not compile in presence of typedef 16382 * [487]13369 __verify_grouping (and __add_grouping?) not correct 16383 * [488]13371 infinite loop with packed struct and inlining 16384 * [489]13445 Template argument replacement "dereferences" a typedef 16385 * [490]13461 Fails to access protected-ctor from public constant 16386 * [491]13462 Non-standard-conforming type set::pointer 16387 * [492]13478 gcc uses wrong constructor to initialize a const 16388 reference 16389 * [493]13544 "conflicting types" for enums in different scopes 16390 * [494]13650 string::compare should not (always) use 16391 traits_type::length() 16392 * [495]13683 bogus warning about passing non-PODs through ellipsis 16393 * [496]13688 Derived class is denied access to protected base class 16394 member class 16395 * [497]13774 Member variable cleared in virtual multiple inheritance 16396 class 16397 * [498]13884 Protect sstream.tcc from extern template use 16398 16399 Java compiler and library 16400 16401 * [499]10746 [win32] garbage collection crash in GCJ 16402 16403 Objective-C compiler and library 16404 16405 * [500]11433 Crash due to dereferencing null pointer when querying 16406 protocol 16407 16408 Fortran compiler and library 16409 16410 * [501]12633 logical expression gives incorrect result with 16411 -fugly-logint option 16412 * [502]13037 [gcse-lm] g77 generates incorrect code 16413 * [503]13213 Hex constant problem when compiling with -fugly-logint 16414 and -ftypeless-boz 16415 16416 x86-specific (Intel/AMD) 16417 16418 * [504]4490 ICE with -m128bit-long-double 16419 * [505]12292 [x86_64] ICE: RTL check: expected code `const_int', have 16420 `reg' in make_field_assignment, in combine.c 16421 * [506]12441 ICE: can't find a register to spill 16422 * [507]12943 array static-init failure under -fpic, -fPIC 16423 * [508]13608 Incorrect code with -O3 -ffast-math 16424 16425 PowerPC-specific 16426 16427 * [509]11598 testcase gcc.dg/20020118-1.c fails runtime check of 16428 __attribute__((aligned(16))) 16429 * [510]11793 ICE in extract_insn, in recog.c (const_vector's) 16430 * [511]12467 vmsumubm emitted when vmsummbm appropriate (typo in 16431 altivec.md) 16432 * [512]12537 g++ generates writeable text sections 16433 16434 SPARC-specific 16435 16436 * [513]12496 wrong result for __atomic_add(&value, -1) when using -O0 16437 -m64 16438 * [514]12865 mprotect call to make trampoline executable may fail 16439 * [515]13354 ICE in sparc_emit_set_const32 16440 16441 ARM-specific 16442 16443 * [516]10467 [arm] ICE in pre_insert_copy_insn, 16444 16445 ia64-specific 16446 16447 * [517]11226 ICE passing struct arg with two floats 16448 * [518]11227 ICE for _Complex float, _Complex long double args 16449 * [519]12644 GCC 3.3.2 fails to compile glibc on ia64 16450 * [520]13149 build gcc-3.3.2 1305 error:unrecognizable insn 16451 * Various fixes for libunwind 16452 16453 Alpha-specific 16454 16455 * [521]12654 Incorrect comparison code generated for Alpha 16456 * [522]12965 SEGV+ICE in cc1plus on alpha-linux with -O2 16457 * [523]13031 ICE (unrecognizable insn) when building gnome-libs-1.4.2 16458 16459 HPPA-specific 16460 16461 * [524]11634 [hppa] ICE in verify_local_live_at_start, in flow.c 16462 * [525]12158 [hppa] compilation does not terminate at -O1 16463 16464 S390-specific 16465 16466 * [526]11992 Wrong built-in code for memcmp with length 1<<24: only 16467 (1<<24)-1 possible for CLCL-Instruction 16468 16469 SH-specific 16470 16471 * [527]9365 segfault in gen_far_branch (config/sh/sh.c) 16472 * [528]10392 optimizer generates faulty array indexing 16473 * [529]11322 SH profiler outputs multiple definitions of symbol 16474 * [530]13069 gcc/config/sh/rtems.h broken 16475 * [531]13302 Putting a va_list in a struct causes seg fault 16476 * [532]13585 Incorrect optimization of call to sfunc 16477 * Fix inappropriately exported libgcc functions from the shared 16478 library 16479 16480 Other embedded target specific 16481 16482 * [533]8916 [mcore] unsigned char assign gets hosed. 16483 * [534]11576 [h8300] ICE in change_address_1, in emit-rtl.c 16484 * [535]13122 [h8300] local variable gets corrupted by function call 16485 when -fomit-frame-pointer is given 16486 * [536]13256 [cris] strict_low_part mistreated in delay slots 16487 * [537]13373 [mcore] optimization with -frerun-cse-after-loop 16488 -fexpensive-optimizations produces wrong code on mcore 16489 16490 GNU HURD-specific 16491 16492 * [538]12561 gcc/config/t-gnu needs updating to work with 16493 --with-sysroot 16494 16495 Tru64 Unix specific 16496 16497 * [539]6243 testsuite fails almost all tests due to no libintl in 16498 LD_LIBRARY_PATH during test. 16499 * [540]11397 weak aliases broken on Tru64 UNIX 16500 16501 AIX-specific 16502 16503 * [541]12505 build failure due to defines of uchar in cpphash.h and 16504 sys/types.h 16505 * [542]13150 WEAK symbols not exported by collect2 16506 16507 IRIX-specific 16508 16509 * [543]12666 fixincludes problem on IRIX 6.5.19m 16510 16511 Solaris-specific 16512 16513 * [544]12969 Including sys/byteorder.h breaks configure checks 16514 16515 Testsuite problems (compiler is not affected) 16516 16517 * [545]10819 testsuite creates CR+LF on compiler version lines in 16518 test summary files 16519 * [546]11612 abi_check not finding correct libgcc_s.so.1 16520 16521 Miscellaneous 16522 16523 * [547]13211 using -###, incorrect warnings about unused linker file 16524 are produced 16525 __________________________________________________________________ 16526 16527 GCC 3.3.4 16528 16529 This is the [548]list of problem reports (PRs) from GCC's bug tracking 16530 system that are known to be fixed in the 3.3.4 release. This list might 16531 not be complete (that is, it is possible that some PRs that have been 16532 fixed are not listed here). 16533 __________________________________________________________________ 16534 16535 GCC 3.3.5 16536 16537 This is the [549]list of problem reports (PRs) from GCC's bug tracking 16538 system that are known to be fixed in the 3.3.5 release. This list might 16539 not be complete (that is, it is possible that some PRs that have been 16540 fixed are not listed here). 16541 __________________________________________________________________ 16542 16543 GCC 3.3.6 16544 16545 This is the [550]list of problem reports (PRs) from GCC's bug tracking 16546 system that are known to be fixed in the 3.3.6 release. This list might 16547 not be complete (that is, it is possible that some PRs that have been 16548 fixed are not listed here). 16549 16550 16551 For questions related to the use of GCC, please consult these web 16552 pages and the [551]GCC manuals. If that fails, the 16553 [552]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 16554 web pages and the development of GCC are welcome on our developer 16555 list at [553]gcc (a] gcc.gnu.org. All of [554]our lists have public 16556 archives. 16557 16558 Copyright (C) [555]Free Software Foundation, Inc. Verbatim copying and 16559 distribution of this entire article is permitted in any medium, 16560 provided this notice is preserved. 16561 16562 These pages are [556]maintained by the GCC team. Last modified 16563 2019-11-28[557]. 16564 16565 References 16566 16567 1. http://gcc.gnu.org/gcc-3.3/changes.html#3.3.6 16568 2. http://gcc.gnu.org/gcc-3.1/changes.html#obsolete_systems 16569 3. http://gcc.gnu.org/gcc-3.3/changes.html#obsolete_systems 16570 4. http://gcc.gnu.org/gcc-3.3/changes.html#nonnull_attribute 16571 5. http://gcc.gnu.org/news/dfa.html 16572 6. http://gcc.gnu.org/c99status.html 16573 7. https://gcc.gnu.org/onlinedocs/gcc-3.3.6/g77/News.html 16574 8. https://gcc.gnu.org/PR10140 16575 9. https://gcc.gnu.org/PR10198 16576 10. https://gcc.gnu.org/PR10338 16577 11. https://gcc.gnu.org/PR3581 16578 12. https://gcc.gnu.org/PR4382 16579 13. https://gcc.gnu.org/PR5533 16580 14. https://gcc.gnu.org/PR6387 16581 15. https://gcc.gnu.org/PR6412 16582 16. https://gcc.gnu.org/PR6620 16583 17. https://gcc.gnu.org/PR6663 16584 18. https://gcc.gnu.org/PR7068 16585 19. https://gcc.gnu.org/PR7083 16586 20. https://gcc.gnu.org/PR7647 16587 21. https://gcc.gnu.org/PR7675 16588 22. 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https://gcc.gnu.org/PR12441 17073 507. https://gcc.gnu.org/PR12943 17074 508. https://gcc.gnu.org/PR13608 17075 509. https://gcc.gnu.org/PR11598 17076 510. https://gcc.gnu.org/PR11793 17077 511. https://gcc.gnu.org/PR12467 17078 512. https://gcc.gnu.org/PR12537 17079 513. https://gcc.gnu.org/PR12496 17080 514. https://gcc.gnu.org/PR12865 17081 515. https://gcc.gnu.org/PR13354 17082 516. https://gcc.gnu.org/PR10467 17083 517. https://gcc.gnu.org/PR11226 17084 518. https://gcc.gnu.org/PR11227 17085 519. https://gcc.gnu.org/PR12644 17086 520. https://gcc.gnu.org/PR13149 17087 521. https://gcc.gnu.org/PR12654 17088 522. https://gcc.gnu.org/PR12965 17089 523. https://gcc.gnu.org/PR13031 17090 524. https://gcc.gnu.org/PR11634 17091 525. https://gcc.gnu.org/PR12158 17092 526. https://gcc.gnu.org/PR11992 17093 527. https://gcc.gnu.org/PR9365 17094 528. https://gcc.gnu.org/PR10392 17095 529. https://gcc.gnu.org/PR11322 17096 530. https://gcc.gnu.org/PR13069 17097 531. https://gcc.gnu.org/PR13302 17098 532. https://gcc.gnu.org/PR13585 17099 533. https://gcc.gnu.org/PR8916 17100 534. https://gcc.gnu.org/PR11576 17101 535. https://gcc.gnu.org/PR13122 17102 536. https://gcc.gnu.org/PR13256 17103 537. https://gcc.gnu.org/PR13373 17104 538. https://gcc.gnu.org/PR12561 17105 539. https://gcc.gnu.org/PR6243 17106 540. https://gcc.gnu.org/PR11397 17107 541. https://gcc.gnu.org/PR12505 17108 542. https://gcc.gnu.org/PR13150 17109 543. https://gcc.gnu.org/PR12666 17110 544. https://gcc.gnu.org/PR12969 17111 545. https://gcc.gnu.org/PR10819 17112 546. https://gcc.gnu.org/PR11612 17113 547. https://gcc.gnu.org/PR13211 17114 548. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=3.3.4 17115 549. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=3.3.5 17116 550. https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=3.3.6 17117 551. https://gcc.gnu.org/onlinedocs/ 17118 552. mailto:gcc-help (a] gcc.gnu.org 17119 553. mailto:gcc (a] gcc.gnu.org 17120 554. https://gcc.gnu.org/lists.html 17121 555. https://www.fsf.org/ 17122 556. https://gcc.gnu.org/about.html 17123 557. http://validator.w3.org/check/referer 17124 ====================================================================== 17125 http://gcc.gnu.org/gcc-3.2/index.html 17126 GCC 3.2 Release Series 17127 17128 (This release series is no longer supported.) 17129 17130 April 25, 2003 17131 17132 The [1]GNU project and the GCC developers are pleased to announce the 17133 release of GCC 3.2.3. 17134 17135 The purpose of the GCC 3.2 release series is to provide a stable 17136 platform for OS distributors to use building their next releases. A 17137 primary objective was to stabilize the C++ ABI; we believe that the 17138 interface to the compiler and the C++ standard library are now 17139 relatively stable. 17140 17141 Be aware that C++ code compiled by GCC 3.2.x will (in general) not 17142 interoperate with code compiled by GCC 3.1.1 or earlier. 17143 17144 Please refer to our [2]detailed list of news, caveats, and bug-fixes 17145 for further information. 17146 17147 Release History 17148 17149 GCC 3.2.3 17150 April 25, 2003 ([3]changes) 17151 17152 GCC 3.2.2 17153 February 5, 2003 ([4]changes) 17154 17155 GCC 3.2.1 17156 November 19, 2002 ([5]changes) 17157 17158 GCC 3.2 17159 August 14, 2002 ([6]changes) 17160 17161 References and Acknowledgements 17162 17163 GCC used to stand for the GNU C Compiler, but since the compiler 17164 supports several other languages aside from C, it now stands for the 17165 GNU Compiler Collection. 17166 17167 A list of [7]successful builds is updated as new information becomes 17168 available. 17169 17170 The GCC developers would like to thank the numerous people that have 17171 contributed new features, improvements, bug fixes, and other changes as 17172 well as test results to GCC. This [8]amazing group of volunteers is 17173 what makes GCC successful. 17174 17175 For additional information about GCC please refer to the [9]GCC project 17176 web site or contact the [10]GCC development mailing list. 17177 17178 To obtain GCC please use [11]our mirror sites, or our CVS server. 17179 17180 17181 For questions related to the use of GCC, please consult these web 17182 pages and the [12]GCC manuals. If that fails, the 17183 [13]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 17184 web pages and the development of GCC are welcome on our developer 17185 list at [14]gcc (a] gcc.gnu.org. All of [15]our lists have public 17186 archives. 17187 17188 Copyright (C) [16]Free Software Foundation, Inc. Verbatim copying and 17189 distribution of this entire article is permitted in any medium, 17190 provided this notice is preserved. 17191 17192 These pages are [17]maintained by the GCC team. Last modified 17193 2019-11-28[18]. 17194 17195 References 17196 17197 1. http://www.gnu.org/ 17198 2. http://gcc.gnu.org/gcc-3.2/changes.html 17199 3. http://gcc.gnu.org/gcc-3.2/changes.html#3.2.3 17200 4. http://gcc.gnu.org/gcc-3.2/changes.html#3.2.2 17201 5. http://gcc.gnu.org/gcc-3.2/changes.html#3.2.1 17202 6. http://gcc.gnu.org/gcc-3.2/changes.html#3.2 17203 7. http://gcc.gnu.org/gcc-3.2/buildstat.html 17204 8. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 17205 9. http://gcc.gnu.org/index.html 17206 10. mailto:gcc (a] gcc.gnu.org 17207 11. http://gcc.gnu.org/mirrors.html 17208 12. https://gcc.gnu.org/onlinedocs/ 17209 13. mailto:gcc-help (a] gcc.gnu.org 17210 14. mailto:gcc (a] gcc.gnu.org 17211 15. https://gcc.gnu.org/lists.html 17212 16. https://www.fsf.org/ 17213 17. https://gcc.gnu.org/about.html 17214 18. http://validator.w3.org/check/referer 17215 ====================================================================== 17216 http://gcc.gnu.org/gcc-3.2/changes.html 17217 GCC 3.2 Release Series 17218 Changes, New Features, and Fixes 17219 17220 The latest release in the 3.2 release series is [1]GCC 3.2.3. 17221 17222 Caveats and New Features 17223 17224 Caveats 17225 17226 * The C++ compiler does not correctly zero-initialize 17227 pointers-to-data members. You must explicitly initialize them. For 17228 example: int S::*m(0); will work, but depending on 17229 default-initialization to zero will not work. This bug cannot be 17230 fixed in GCC 3.2 without inducing unacceptable risks. It will be 17231 fixed in GCC 3.3. 17232 * This GCC release is based on the GCC 3.1 sourcebase, and thus has 17233 all the [2]changes in the GCC 3.1 series. In addition, GCC 3.2 has 17234 a number of C++ ABI fixes which make its C++ compiler generate 17235 binary code which is incompatible with the C++ compilers found in 17236 earlier GCC releases, including GCC 3.1 and GCC 3.1.1. 17237 17238 Frontend Enhancements 17239 17240 C/C++/Objective-C 17241 17242 * The method of constructing the list of directories to be searched 17243 for header files has been revised. If a directory named by a -I 17244 option is a standard system include directory, the option is 17245 ignored to ensure that the default search order for system 17246 directories and the special treatment of system header files are 17247 not defeated. 17248 * The C and Objective-C compilers no longer accept the "Naming Types" 17249 extension (typedef foo = bar); it was already unavailable in C++. 17250 Code which uses it will need to be changed to use the "typeof" 17251 extension instead: typedef typeof(bar) foo. (We have removed this 17252 extension without a period of deprecation because it has caused the 17253 compiler to crash since version 3.0 and no one noticed until very 17254 recently. Thus we conclude it is not in widespread use.) 17255 17256 C++ 17257 17258 * GCC 3.2 fixed serveral differences between the C++ ABI implemented 17259 in GCC and the multi-vendor standard, but more have been found 17260 since the release. 3.2.1 adds a new warning, -Wabi, to warn about 17261 code which is affected by these bugs. We will fix these bugs in 17262 some future release, once we are confident that all have been 17263 found; until then, it is our intention to make changes to the ABI 17264 only if they are necessary for correct compilation of C++, as 17265 opposed to conformance to the ABI documents. 17266 * For details on how to build an ABI compliant compiler for GNU/Linux 17267 systems, check the [3]common C++ ABI page. 17268 17269 New Targets and Target Specific Improvements 17270 17271 IA-32 17272 17273 * Fixed a number of bugs in SSE and MMX intrinsics. 17274 * Fixed common compiler crashes with SSE instruction set enabled 17275 (implied by -march=pentium3, pentium4, athlon-xp) 17276 * __m128 and __m128i is not 128bit aligned when used in structures. 17277 17278 x86-64 17279 17280 * A bug whereby the compiler could generate bad code for bzero has 17281 been fixed. 17282 * ABI fixes (implying ABI incompatibilities with previous version in 17283 some corner cases) 17284 * Fixed prefetch code generation 17285 __________________________________________________________________ 17286 17287 GCC 3.2.3 17288 17289 3.2.3 is a bug fix release only; there are no new features that were 17290 not present in GCC 3.2.2. 17291 17292 Bug Fixes 17293 17294 This section lists the problem reports (PRs) from GCC's bug tracking 17295 system that are known to be fixed in the 3.2.3 release. This list might 17296 not be complete (that is, it is possible that some PRs that have been 17297 fixed are not listed here), and some of the titles have been changed to 17298 make them more clear. 17299 17300 Internal Compiler Errors (multi-platform) 17301 17302 * [4]3782: (c++) -quiet -fstats produces a segmentation fault in 17303 cc1plus 17304 * [5]6440: (c++) template specializations cause ICE 17305 * [6]7050: (c++) ICE on: (i ? get_string() : throw) 17306 * [7]7741: ICE on conflicting types (make_decl_rtl in varasm.c) 17307 * [8]7982: (c++) ICE due to infinite recursion (using STL set) 17308 * [9]8068: exceedingly high (infinite) memory usage 17309 * [10]8178: ICE with __builtin_ffs 17310 * [11]8396: ICE in copy_to_mode_reg, in explow.c 17311 * [12]8674: (c++) ICE in cp_expr_size, in cp/cp-lang.c 17312 * [13]9768: ICE when optimizing inline code at -O2 17313 * [14]9798: (c++) Infinite recursion (segfault) in 17314 cp/decl.c:push_using_directive with recursive using directives 17315 * [15]9799: mismatching structure initializer with nested flexible 17316 array member: ICE 17317 * [16]9928: ICE on duplicate enum declaration 17318 * [17]10114: ICE in mem_loc_descriptor, in dwarf2out.c (affects 17319 sparc, alpha) 17320 * [18]10352: ICE in find_reloads_toplev 17321 * [19]10336: ICE with -Wunreachable-code 17322 17323 C/optimizer bugs: 17324 17325 * [20]8224: Incorrect joining of signed and unsigned division 17326 * [21]8613: -O2 produces wrong code with builtin strlen and 17327 postincrements 17328 * [22]8828: gcc reports some code is unreachable when it is not 17329 * [23]9226: GCSE breaking argument passing 17330 * [24]9853: miscompilation of non-constant structure initializer 17331 * [25]9797: C99-style struct initializers are miscompiled 17332 * [26]9967: Some standard C function calls should not be replaced 17333 when optimizing for size 17334 * [27]10116: ce2: invalid merge of join_bb in the context of switch 17335 statements 17336 * [28]10171: wrong code for inlined function 17337 * [29]10175: -Wunreachable-code doesn't work for single lines 17338 17339 C++ compiler and library: 17340 17341 * [30]8316: Confusing diagnostic for code that misuses conversion 17342 operators 17343 * [31]9169: filebuf output fails if codecvt<>::out returns noconv 17344 * [32]9420: incomplete type incorrectly reported 17345 * [33]9459: typeof in return type specification of template not 17346 supported 17347 * [34]9507: filebuf::open handles ios_base::ate incorrectly 17348 * [35]9538: Out-of-bounds memory access in streambuf::sputbackc 17349 * [36]9602: Total confusion about template/friend/virtual/abstract 17350 * [37]9993: destructor not called for local object created within and 17351 returned from infinite loop 17352 * [38]10167: ieee_1003.1-2001 locale specialisations on a glibc-2.3.2 17353 system 17354 17355 Java compiler and library: 17356 17357 * [39]9652: libgcj build fails on irix6.5.1[78] 17358 * [40]10144: gas on solaris complains about bad .stabs lines for 17359 java, native as unaffected 17360 17361 x86-specific (Intel/AMD): 17362 17363 * [41]8746: gcc miscompiles Linux kernel ppa driver on x86 17364 * [42]9888: -mcpu=k6 -Os produces out of range loop instructions 17365 * [43]9638: Cross-build for target i386-elf and i586-pc-linux-gnu 17366 failed 17367 * [44]9954: Cross-build for target i586-pc-linux-gnu (--with-newlib) 17368 failed 17369 17370 SPARC-specific: 17371 17372 * [45]7784: [Sparc] ICE in extract_insn, in recog.c 17373 * [46]7796: sparc extra failure with -m64 on execute/930921-1.c in 17374 unroll.c 17375 * [47]8281: ICE when compiling with -O2 -fPIC for Ultrasparc 17376 * [48]8366: [Sparc] C testsuite failure with -m64 -fpic -O in 17377 execute/loop-2d.c 17378 * [49]8726: gcc -O2 miscompiles Samba 2.2.7 on 32-bit sparc 17379 * [50]9414: Scheduling bug on Ultrasparc 17380 * [51]10067: GCC-3.2.2 outputs invalid asm on sparc64 17381 17382 m68k-specific: 17383 17384 * [52]7248: broken "inclusive or" code 17385 * [53]8343: m68k-elf/rtems ICE at instantiate_virtual_regs_1 17386 17387 PowerPC-specific: 17388 17389 * [54]9732: Wrong code with -O2 -fPIC 17390 * [55]10073: ICE: powerpc cannot split insn 17391 17392 Alpha-specific: 17393 17394 * [56]7702: optimization problem on a DEC alpha under OSF1 17395 * [57]9671: gcc.3.2.2 does not build on a HP Tru64 Unix v5.1B system 17396 17397 HP-specific: 17398 17399 * [58]8694: <string> breaks <ctype.h> on HP-UX 10.20 (DUP: 9275) 17400 * [59]9953: (ada) gcc 3.2.x can't build 3.3-branch ada on HP-UX 10 17401 (missing symbol) 17402 * [60]10271: Floating point args don't get reloaded across function 17403 calls with -O2 17404 17405 MIPS specific: 17406 17407 * [61]6362: mips-irix6 gcc-3.1 C testsuite failure with -mips4 in 17408 compile/920501-4.c 17409 17410 CRIS specific: 17411 17412 * [62]10377: gcc-3.2.2 creates bad assembler code for cris 17413 17414 Miscellaneous and minor bugs: 17415 17416 * [63]6955: collect2 says "core dumped" when there is no core 17417 __________________________________________________________________ 17418 17419 GCC 3.2.2 17420 17421 Beginning with 3.2.2, GCC's Makefile suite supports redirection of make 17422 install by means of the DESTDIR variable. Parts of the GCC tree have 17423 featured that support long before, but now it is available even from 17424 the top level. 17425 17426 Other than that, GCC 3.2.2 is a bug fix release only; there are no new 17427 features that were not present in GCC 3.2.1. 17428 17429 Bug Fixes 17430 17431 On the following i386-based systems GCC 3.2.1 broke the C ABI wrt. 17432 functions returning structures: Cygwin, FreeBSD (GCC 3.2.1 as shipped 17433 with FreeBSD 5.0 does not have this problem), Interix, a.out-based 17434 GNU/Linux and NetBSD, OpenBSD, and Darwin. GCC 3.2.2 reverts this ABI 17435 change, and thus restores ABI-compatibility with previous releases 17436 (except GCC 3.2.1) on these platforms. 17437 17438 This section lists the problem reports (PRs) from GCC's bug tracking 17439 system that are known to be fixed in the 3.2.2 release. This list might 17440 not be complete (that is, it is possible that some PRs that have been 17441 fixed are not listed here) and some of the titles have been changed to 17442 make them more clear. 17443 17444 Internal Compiler Errors (multi-platform) 17445 17446 * [64]5919: (c++) ICE when passing variable array to template 17447 function 17448 * [65]7129: (c++) ICE with min/max assignment operators (<?= and >?=) 17449 * [66]7507: ICE with -O2 when address of called function is a 17450 complicated expression 17451 * [67]7622: ICE with nested inline functions if function's address is 17452 taken 17453 * [68]7681: (fortran) ICE in compensate_edge, in reg-stack.c (also PR 17454 [69]9258) 17455 * [70]8031: (c++) ICE in code comparing typeids and casting from 17456 virtual base 17457 * [71]8275: ICE in simplify_subreg 17458 * [72]8332: (c++) builtin strlen/template interaction causes ICE 17459 * [73]8372: (c++) ICE on explicit call of destructor 17460 * [74]8439: (c, not c++) empty struct causes ICE 17461 * [75]8442: (c++) ICE with nested template classes 17462 * [76]8518: ICE when compiling mplayer ("extern inline" issue) 17463 * [77]8615: (c++) ICE with out-of-range character constant template 17464 argument 17465 * [78]8663: (c++) ICE in cp_expr_size, at cp-lang.c:307 17466 * [79]8799: (c++) ICE: error reporting routines re-entered 17467 * [80]9328: (c++) ICE with typeof(X) for overloaded X 17468 * [81]9465: (preprocessor) cpp -traditional ICE on null bytes 17469 17470 C++ (compiler and library) bugs 17471 17472 * [82]47: scoping in nested classes is broken 17473 * [83]6745: problems with iostream rdbuf() member function 17474 * [84]8214: conversion from const char* const to char* sometimes 17475 accepted illegally 17476 * [85]8493: builtin strlen and overload resolution (same bug as 17477 [86]8332) 17478 * [87]8503: strange behaviour of function types 17479 * [88]8727: compiler confused by inheritance from an anonymous struct 17480 * [89]7445: poor performance of std::locale::classic() in 17481 multi-threaded applications 17482 * [90]8230: mishandling of overflow in vector<T>::resize 17483 * [91]8399: sync_with_stdio(false) breaks unformatted input 17484 * [92]8662: illegal access of private member of unnamed class is 17485 accepted 17486 * [93]8707: "make distclean" fails in libstdc++-v3 directory 17487 * [94]8708: __USE_MALLOC doesn't work 17488 * [95]8790: Use of non-thread-safe strtok in src/localename.cc 17489 * [96]8887: Bug in date formats with --enable-clocale=generic 17490 * [97]9076: Call Frame Instructions are not handled correctly during 17491 unwind operation 17492 * [98]9151: std::setprecision limited to 16 digits when outputting a 17493 double to a stream 17494 * [99]9168: codecvt<char, char, mbstate_t> overwrites output buffers 17495 * [100]9269: libstdc++ headers: explicit specialization of function 17496 must precede its first use 17497 * [101]9322: return value of basic_streambuf<>::getloc affected by 17498 locale::global 17499 * [102]9433: segfault in runtime support for dynamic_cast 17500 17501 C and optimizer bugs 17502 17503 * [103]8032: GCC incorrectly initializes static structs that have 17504 flexible arrays 17505 * [104]8639: simple arithmetic expression broken 17506 * [105]8794: optimization improperly eliminates certain expressions 17507 * [106]8832: traditional "asm volatile" code is illegally optimized 17508 * [107]8988: loop optimizer bug: with -O2, code is generated that 17509 segfaults (found on i386, bug present for all platforms) 17510 * [108]9492: structure copy clobbers subsequent stores to structure 17511 17512 Objective-C bugs 17513 17514 * [109]9267: Objective-C parser won't build with newer bison versions 17515 (e.g. 1.875) 17516 17517 Ada bugs 17518 17519 * [110]8344: Ada build problem due to conflict between gcc/final.o, 17520 gcc/ada/final.o 17521 17522 Preprocessor bugs 17523 17524 * [111]8524: _Pragma within macros is improperly expanded 17525 * [112]8880: __WCHAR_TYPE__ macro incorrectly set to "long int" with 17526 -fshort-wchar 17527 17528 ARM-specific 17529 17530 * [113]9090: arm ICE with >= -O2; regression from gcc-2.95 17531 17532 x86-specific (Intel/AMD) 17533 17534 * [114]8588: ICE in extract_insn, at recog.c:NNNN (shift instruction) 17535 * [115]8599: loop unroll bug with -march=k6-3 17536 * [116]9506: ABI breakage in structure return (affects BSD and 17537 Cygwin, but not GNU/Linux) 17538 17539 FreeBSD 5.0 specific 17540 17541 * [117]9484: GCC 3.2.1 Bootstrap failure on FreeBSD 5.0 17542 17543 RTEMS-specific 17544 17545 * [118]9292: hppa1.1-rtems configurery problems 17546 * [119]9293: [m68k-elf/rtems] config/m68k/t-crtstuff bug 17547 * [120]9295: [mips-rtems] config/mips/rtems.h init/fini issue 17548 * [121]9296: gthr-rtems regression 17549 * [122]9316: powerpc-rtems: extending multilibs 17550 17551 HP-PA specific 17552 17553 * [123]9493: ICE with -O2 when building a simple function 17554 17555 Documentation 17556 17557 * [124]7341: hyperlink to gcov in GCC documentation doesn't work 17558 * [125]8947: Please add a warning about "-malign-double" in docs 17559 * [126]7448, [127]8882: typo cleanups 17560 __________________________________________________________________ 17561 17562 GCC 3.2.1 17563 17564 3.2.1 adds a new warning, -Wabi. This option warns when GNU C++ 17565 generates code that is known not to be binary-compatible with the 17566 vendor-neutral ia32/ia64 ABI. Please consult the GCC manual, included 17567 in the distribution, for details. 17568 17569 This release also removes an old GCC extension, "naming types", and the 17570 documentation now directs users to use a different GCC extension, 17571 __typeof__, instead. The feature had evidently been broken for a while. 17572 17573 Otherwise, 3.2.1 is a bug fix release only; other than bug fixes and 17574 the new warning there are no new features that were not present in GCC 17575 3.2. 17576 17577 In addition, the previous fix for [128]PR 7445 (poor performance of 17578 std::locale::classic() in multi-threaded applications) was reverted 17579 ("unfixed"), because the "fix" was not thread-safe. 17580 17581 Bug Fixes 17582 17583 This section lists the problem reports (PRs) from GCC's bug tracking 17584 system that are known to be fixed in the 3.2.1 release. This list might 17585 not be complete (that is, it is possible that some PRs that have been 17586 fixed are not listed here). As you can see, the number of bug fixes is 17587 quite large, so it is strongly recommended that users of earlier GCC 17588 3.x releases upgrade to GCC 3.2.1. 17589 17590 Internal Compiler Errors (multi-platform) 17591 17592 * [129]2521: (c++) ICE in build_ptrmemfunc, in cp/typeck.c 17593 * [130]5661: (c++) ICE instantiating template on array of unknown 17594 size (bad code) 17595 * [131]6419: (c++) ICE in make_decl_rtl for "longest" attribute on 17596 64-bit platforms 17597 * [132]6994: (c++) ICE in find_function_data 17598 * [133]7150: preprocessor: GCC -dM -E gives an ICE 17599 * [134]7160: ICE when optimizing branches without a return value 17600 * [135]7228: (c++) ICE when using member template and template 17601 function 17602 * [136]7266: (c++) ICE with -pedantic on missing typename 17603 * [137]7353: ICE from use of "Naming Types" extension, see above 17604 * [138]7411: ICE in instantiate_virtual_regs_1, in function.c 17605 * [139]7478: (c++) ICE on static_cast inside template 17606 * [140]7526: preprocessor core dump when _Pragma implies #pragma 17607 dependency 17608 * [141]7721: (c++) ICE on simple (but incorrect) template ([142]7803 17609 is a duplicate) 17610 * [143]7754: (c++) ICE on union with template parameter 17611 * [144]7788: (c++) redeclaring a definition as an incomplete class 17612 causes ICE 17613 * [145]8031: (c++) ICE in comptypes, in cp/typeck.c 17614 * [146]8055: preprocessor dies with SIG11 when building FreeBSD 17615 kernel 17616 * [147]8067: (c++) ICE due to mishandling of __FUNCTION__ and related 17617 variables 17618 * [148]8134: (c++) ICE in force_store_init_value on legal code 17619 * [149]8149: (c++) ICE on incomplete type 17620 * [150]8160: (c++) ICE in build_modify_expr, in cp/typeck.c: array 17621 initialization 17622 17623 C++ (compiler and library) bugs 17624 17625 * [151]5607: No pointer adjustment in covariant return types 17626 * [152]6579: Infinite loop with statement expressions in member 17627 initialization 17628 * [153]6803: Default copy constructor bug in GCC 3.1 17629 * [154]7176: g++ confused by friend and static member with same name 17630 * [155]7188: Segfault with template class and recursive (incorrect) 17631 initializer list 17632 * [156]7306: Regression: GCC 3.x fails to compile code with virtual 17633 inheritance if a method has a variable number of arguments 17634 * [157]7461: ctype<char>::classic_table() returns offset array on 17635 Cygwin 17636 * [158]7524: f(const float arg[3]) fails 17637 * [159]7584: Erroneous ambiguous base error on using declaration 17638 * [160]7676: Member template overloading problem 17639 * [161]7679: infinite loop when a right parenthesis is missing 17640 * [162]7811: default locale not taken from environment 17641 * [163]7961: compare( char *) implemented incorrectly in 17642 basic_string<> 17643 * [164]8071: basic_ostream::operator<<(streambuf*) loops forever if 17644 streambuf::underflow() leaves gptr() NULL (dups: [165]8127, 17645 [166]6745) 17646 * [167]8096: deque::at() throws std::range_error instead of 17647 std::out_of_range 17648 * [168]8127: cout << cin.rdbuf() infinite loop 17649 * [169]8218: Excessively large memory consumed for classes with large 17650 array members 17651 * [170]8287: GCC 3.2: Destructor called for non-constructed local 17652 object 17653 * [171]8347: empty vector range used in string construction causes 17654 core dump 17655 * [172]8348: fail() flag is set in istringstream when eof() flag is 17656 set 17657 * [173]8391: regression: infinite loop in cp/decl2.c(finish_file) 17658 17659 C and optimizer bugs 17660 17661 * [174]6627: -fno-align-functions doesn't seem to disable function 17662 alignment 17663 * [175]6631: life_analysis misoptimizes code to initialize fields of 17664 a structure 17665 * [176]7102: unsigned char division results in floating exception 17666 * [177]7120: Run once loop should *always* be unrolled 17667 (pessimization) 17668 * [178]7209: Bug involving array referencing and ?: operator 17669 * [179]7515: invalid inlining of global function with -O3 17670 * [180]7814: incorrect scheduling for glibc-2.2.92 strcpy test 17671 * [181]8467: bug in sibling call optimization 17672 17673 Preprocessor bugs 17674 17675 * [182]4890: incorrect line markers from the traditional preprocessor 17676 * [183]7357: -M option omits system headers files (making it the same 17677 as -MM) 17678 * [184]7358: Changes to Sun's make Dependencies 17679 * [185]7602: C++ header files found in CPLUS_INCLUDE_PATH treated as 17680 C headers 17681 * [186]7862: Interrupting GCC -MD removes .d file but not .o 17682 * [187]8190: Failed compilation deletes -MD dependency file 17683 * [188]8524: _Pragma within macro is improperly expanded 17684 17685 x86 specific (Intel/AMD) 17686 17687 * [189]5351: (i686-only) function pass-by-value structure copy 17688 corrupts stack ([190]7591 is a duplicate) 17689 * [191]6845, [192]7034, [193]7124, [194]7174: ICE's with 17690 -march=pentium3/pentium2/athlon (these are all the same underlying 17691 bug, in MMX register use) 17692 * [195]7134, [196]7375, [197]7390: ICE with -march=athlon (maybe same 17693 as above?) 17694 * [198]6890: xmmintrin.h, _MM_TRANSPOSE4_PS is broken 17695 * [199]6981: wrong code in 64-bit manipulation on x86 17696 * [200]7242: GCC -mcpu=pentium[23] doesn't define __tune_pentiumpro__ 17697 macro 17698 * [201]7396: ix86: cmpgt_ss, cmpge_ss, cmpngt_ss, and cmpnge_ss SSE 17699 intrinsics are broken 17700 * [202]7630: GCC 3.2 breaks on Mozilla 1.0's JS sources with 17701 -march=pentium4 17702 * [203]7693: Typo in i386 mmintrin.h header 17703 * [204]7723: ICE - Pentium3 sse - GCC 3.2 17704 * [205]7951: ICE on -march=pentium4 -O2 -mfpmath=sse 17705 * [206]8146: (i686 only) gcc 3.2 miscompiles gcc 2.95.3 17706 17707 PowerPC specific 17708 17709 * [207]5967: GCC bug when profiling nested functions on powerpc 17710 * [208]6984: wrong code generated with -O2, -O3, -Os for do-while 17711 loop on PowerPC 17712 * [209]7114: PowerPC: ICE building strcoll.op from glibc-2.2.5 17713 * [210]7130: miscompiled code for GCC-3.1 on 17714 powerpc-unknown-linux-gnu with -funroll-all-loops 17715 * [211]7133: PowerPC ICE: unrecognizable insn 17716 * [212]7380: ICE in extract_insn, at recog.c:2148 17717 * [213]8252: ICE on Altivec code with optimization turned on 17718 * [214]8451: Altivec ICE in GCC 3.2 17719 17720 HP/PA specific 17721 17722 * [215]7250: __ashrdi3 returns wrong value on 32 bit hppa 17723 17724 SPARC specific 17725 17726 * [216]6668: when using --disable-multilib, libgcc_s.so is installed 17727 in the wrong place on sparc-solaris 17728 * [217]7151: ICE when compiling for UltraSPARC 17729 * [218]7335: SPARC: ICE in verify_wide_reg (flow.c:557) with long 17730 double and -O1 17731 * [219]7842: [REGRESSION] SPARC code gen bug 17732 17733 ARM specific 17734 17735 * [220]7856: [arm] invalid offset in constant pool reference 17736 * [221]7967: optimization produces wrong code (ARM) 17737 17738 Alpha specific 17739 17740 * [222]7374: __builtin_fabsl broken on alpha 17741 17742 IBM s390 specific 17743 17744 * [223]7370: ICE in fixup_var_refs_1 on s390x 17745 * [224]7409: loop optimization bug on s390x-linux-gnu 17746 * [225]8232: s390x: ICE when using bcmp with int length argument 17747 17748 SCO specific 17749 17750 * [226]7623: SCO OpenServer build fails with machmode.def: undefined 17751 symbol: BITS_PER_UNIT 17752 17753 m68k/Coldfire specific 17754 17755 * [227]8314: crtbegin, crtend need to be multilib'ed for this 17756 platform 17757 17758 Documentation 17759 17760 * [228]761: Document some undocumented options 17761 * [229]5610: Fix documentation about invoking SSE instructions 17762 (-mfpmath=sse) 17763 * [230]7484: List -Wmissing-declarations as C-only option 17764 * [231]7531: -mcmodel not documented for x86-64 17765 * [232]8120: Update documentation of bad use of ## 17766 __________________________________________________________________ 17767 17768 GCC 3.2 17769 17770 3.2 is a small bug fix release, but there is a change to the 17771 application binary interface (ABI), hence the change to the second part 17772 of the version number. 17773 17774 The main purpose of the 3.2 release is to correct a couple of problems 17775 in the C++ ABI, with the intention of providing a stable interface 17776 going forward. Accordingly, 3.2 is only a small change to 3.1.1. 17777 17778 Bug Fixes 17779 17780 C++ 17781 17782 * [233]7320: g++ 3.2 relocation problem 17783 * [234]7470: vtable: virtual function pointers not in declaration 17784 order 17785 17786 libstdc++ 17787 17788 * [235]6410: Trouble with non-ASCII monetary symbols and wchar_t 17789 * [236]6503, [237]6642, [238]7186: Problems with comparing or 17790 subtracting various types of const and non-const iterators 17791 * [239]7216: ambiguity with basic_iostream::traits_type 17792 * [240]7220: problem with basic_istream::ignore(0,delimiter) 17793 * [241]7222: locale::operator==() doesn't work on std::locale("") 17794 * [242]7286: placement operator delete issue 17795 * [243]7442: cxxabi.h does not match the C++ ABI 17796 * [244]7445: poor performance of std::locale::classic() in 17797 multi-threaded applications 17798 17799 x86-64 specific 17800 17801 * [245]7291: off-by-one in generated inline bzero code for x86-64 17802 17803 17804 For questions related to the use of GCC, please consult these web 17805 pages and the [246]GCC manuals. If that fails, the 17806 [247]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 17807 web pages and the development of GCC are welcome on our developer 17808 list at [248]gcc (a] gcc.gnu.org. All of [249]our lists have public 17809 archives. 17810 17811 Copyright (C) [250]Free Software Foundation, Inc. Verbatim copying and 17812 distribution of this entire article is permitted in any medium, 17813 provided this notice is preserved. 17814 17815 These pages are [251]maintained by the GCC team. Last modified 17816 2019-11-28[252]. 17817 17818 References 17819 17820 1. http://gcc.gnu.org/gcc-3.2/changes.html#3.2.3 17821 2. http://gcc.gnu.org/gcc-3.1/changes.html 17822 3. http://gcc.gnu.org/gcc-3.2/c++-abi.html 17823 4. https://gcc.gnu.org/PR3782 17824 5. https://gcc.gnu.org/PR6440 17825 6. https://gcc.gnu.org/PR7050 17826 7. https://gcc.gnu.org/PR7741 17827 8. https://gcc.gnu.org/PR7982 17828 9. https://gcc.gnu.org/PR8068 17829 10. https://gcc.gnu.org/PR8178 17830 11. https://gcc.gnu.org/PR8396 17831 12. https://gcc.gnu.org/PR8674 17832 13. https://gcc.gnu.org/PR9768 17833 14. https://gcc.gnu.org/PR9798 17834 15. https://gcc.gnu.org/PR9799 17835 16. https://gcc.gnu.org/PR9928 17836 17. https://gcc.gnu.org/PR10114 17837 18. https://gcc.gnu.org/PR10352 17838 19. https://gcc.gnu.org/PR10336 17839 20. https://gcc.gnu.org/PR8224 17840 21. https://gcc.gnu.org/PR8613 17841 22. https://gcc.gnu.org/PR8828 17842 23. https://gcc.gnu.org/PR9226 17843 24. https://gcc.gnu.org/PR9853 17844 25. https://gcc.gnu.org/PR9797 17845 26. https://gcc.gnu.org/PR9967 17846 27. https://gcc.gnu.org/PR10116 17847 28. https://gcc.gnu.org/PR10171 17848 29. https://gcc.gnu.org/PR10175 17849 30. https://gcc.gnu.org/PR8316 17850 31. https://gcc.gnu.org/PR9169 17851 32. https://gcc.gnu.org/PR9420 17852 33. https://gcc.gnu.org/PR9459 17853 34. https://gcc.gnu.org/PR9507 17854 35. https://gcc.gnu.org/PR9538 17855 36. https://gcc.gnu.org/PR9602 17856 37. https://gcc.gnu.org/PR9993 17857 38. https://gcc.gnu.org/PR10167 17858 39. https://gcc.gnu.org/PR9652 17859 40. https://gcc.gnu.org/PR10144 17860 41. https://gcc.gnu.org/PR8746 17861 42. https://gcc.gnu.org/PR9888 17862 43. https://gcc.gnu.org/PR9638 17863 44. https://gcc.gnu.org/PR9954 17864 45. https://gcc.gnu.org/PR7784 17865 46. https://gcc.gnu.org/PR7796 17866 47. https://gcc.gnu.org/PR8281 17867 48. https://gcc.gnu.org/PR8366 17868 49. https://gcc.gnu.org/PR8726 17869 50. https://gcc.gnu.org/PR9414 17870 51. https://gcc.gnu.org/PR10067 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https://gcc.gnu.org/PR8663 17898 79. https://gcc.gnu.org/PR8799 17899 80. https://gcc.gnu.org/PR9328 17900 81. https://gcc.gnu.org/PR9465 17901 82. https://gcc.gnu.org/PR47 17902 83. https://gcc.gnu.org/PR6745 17903 84. https://gcc.gnu.org/PR8214 17904 85. https://gcc.gnu.org/PR8493 17905 86. https://gcc.gnu.org/PR8332 17906 87. https://gcc.gnu.org/PR8503 17907 88. https://gcc.gnu.org/PR8727 17908 89. https://gcc.gnu.org/PR7445 17909 90. https://gcc.gnu.org/PR8230 17910 91. https://gcc.gnu.org/PR8399 17911 92. https://gcc.gnu.org/PR8662 17912 93. https://gcc.gnu.org/PR8707 17913 94. https://gcc.gnu.org/PR8708 17914 95. https://gcc.gnu.org/PR8790 17915 96. https://gcc.gnu.org/PR8887 17916 97. https://gcc.gnu.org/PR9076 17917 98. https://gcc.gnu.org/PR9151 17918 99. https://gcc.gnu.org/PR9168 17919 100. https://gcc.gnu.org/PR9269 17920 101. https://gcc.gnu.org/PR9322 17921 102. https://gcc.gnu.org/PR9433 17922 103. https://gcc.gnu.org/PR8032 17923 104. https://gcc.gnu.org/PR8639 17924 105. https://gcc.gnu.org/PR8794 17925 106. https://gcc.gnu.org/PR8832 17926 107. https://gcc.gnu.org/PR8988 17927 108. https://gcc.gnu.org/PR9492 17928 109. https://gcc.gnu.org/PR9267 17929 110. https://gcc.gnu.org/PR8344 17930 111. https://gcc.gnu.org/PR8524 17931 112. https://gcc.gnu.org/PR8880 17932 113. https://gcc.gnu.org/PR9090 17933 114. https://gcc.gnu.org/PR8588 17934 115. https://gcc.gnu.org/PR8599 17935 116. https://gcc.gnu.org/PR9506 17936 117. https://gcc.gnu.org/PR9484 17937 118. https://gcc.gnu.org/PR9292 17938 119. https://gcc.gnu.org/PR9293 17939 120. https://gcc.gnu.org/PR9295 17940 121. https://gcc.gnu.org/PR9296 17941 122. https://gcc.gnu.org/PR9316 17942 123. https://gcc.gnu.org/PR9493 17943 124. https://gcc.gnu.org/PR7341 17944 125. https://gcc.gnu.org/PR8947 17945 126. https://gcc.gnu.org/PR7448 17946 127. https://gcc.gnu.org/PR8882 17947 128. https://gcc.gnu.org/PR7445 17948 129. https://gcc.gnu.org/PR2521 17949 130. https://gcc.gnu.org/PR5661 17950 131. https://gcc.gnu.org/PR6419 17951 132. https://gcc.gnu.org/PR6994 17952 133. https://gcc.gnu.org/PR7150 17953 134. https://gcc.gnu.org/PR7160 17954 135. https://gcc.gnu.org/PR7228 17955 136. https://gcc.gnu.org/PR7266 17956 137. https://gcc.gnu.org/PR7353 17957 138. https://gcc.gnu.org/PR7411 17958 139. https://gcc.gnu.org/PR7478 17959 140. https://gcc.gnu.org/PR7526 17960 141. https://gcc.gnu.org/PR7721 17961 142. https://gcc.gnu.org/PR7803 17962 143. https://gcc.gnu.org/PR7754 17963 144. https://gcc.gnu.org/PR7788 17964 145. https://gcc.gnu.org/PR8031 17965 146. https://gcc.gnu.org/PR8055 17966 147. https://gcc.gnu.org/PR8067 17967 148. https://gcc.gnu.org/PR8134 17968 149. https://gcc.gnu.org/PR8149 17969 150. https://gcc.gnu.org/PR8160 17970 151. https://gcc.gnu.org/PR5607 17971 152. https://gcc.gnu.org/PR6579 17972 153. https://gcc.gnu.org/PR6803 17973 154. https://gcc.gnu.org/PR7176 17974 155. https://gcc.gnu.org/PR7188 17975 156. https://gcc.gnu.org/PR7306 17976 157. 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https://gcc.gnu.org/PR7357 18003 184. https://gcc.gnu.org/PR7358 18004 185. https://gcc.gnu.org/PR7602 18005 186. https://gcc.gnu.org/PR7862 18006 187. https://gcc.gnu.org/PR8190 18007 188. https://gcc.gnu.org/PR8524 18008 189. https://gcc.gnu.org/PR5351 18009 190. https://gcc.gnu.org/PR7591 18010 191. https://gcc.gnu.org/PR6845 18011 192. https://gcc.gnu.org/PR7034 18012 193. https://gcc.gnu.org/PR7124 18013 194. https://gcc.gnu.org/PR7174 18014 195. https://gcc.gnu.org/PR7134 18015 196. https://gcc.gnu.org/PR7375 18016 197. https://gcc.gnu.org/PR7390 18017 198. https://gcc.gnu.org/PR6890 18018 199. https://gcc.gnu.org/PR6981 18019 200. https://gcc.gnu.org/PR7242 18020 201. https://gcc.gnu.org/PR7396 18021 202. https://gcc.gnu.org/PR7630 18022 203. https://gcc.gnu.org/PR7693 18023 204. https://gcc.gnu.org/PR7723 18024 205. https://gcc.gnu.org/PR7951 18025 206. https://gcc.gnu.org/PR8146 18026 207. https://gcc.gnu.org/PR5967 18027 208. https://gcc.gnu.org/PR6984 18028 209. 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https://gcc.gnu.org/PR6410 18055 236. https://gcc.gnu.org/PR6503 18056 237. https://gcc.gnu.org/PR6642 18057 238. https://gcc.gnu.org/PR7186 18058 239. https://gcc.gnu.org/PR7216 18059 240. https://gcc.gnu.org/PR7220 18060 241. https://gcc.gnu.org/PR7222 18061 242. https://gcc.gnu.org/PR7286 18062 243. https://gcc.gnu.org/PR7442 18063 244. https://gcc.gnu.org/PR7445 18064 245. https://gcc.gnu.org/PR7291 18065 246. https://gcc.gnu.org/onlinedocs/ 18066 247. mailto:gcc-help (a] gcc.gnu.org 18067 248. mailto:gcc (a] gcc.gnu.org 18068 249. https://gcc.gnu.org/lists.html 18069 250. https://www.fsf.org/ 18070 251. https://gcc.gnu.org/about.html 18071 252. http://validator.w3.org/check/referer 18072 ====================================================================== 18073 http://gcc.gnu.org/gcc-3.1/index.html 18074 GCC 3.1 18075 18076 (This release series is no longer supported.) 18077 18078 July 27, 2002 18079 18080 The [1]GNU project and the GCC developers are pleased to announce the 18081 release of GCC 3.1.1. 18082 18083 The links below still apply to GCC 3.1.1. 18084 18085 May 15, 2002 18086 18087 The [2]GNU project and the GCC developers are pleased to announce the 18088 release of GCC 3.1. 18089 18090 GCC used to stand for the GNU C Compiler, but since the compiler 18091 supports several other languages aside from C, it now stands for the 18092 GNU Compiler Collection. 18093 18094 A list of [3]successful builds is updated as new information becomes 18095 available. 18096 18097 The GCC developers would like to thank the numerous people that have 18098 contributed [4]new features, improvements, bug fixes, and other changes 18099 as well as test results to GCC. This [5]amazing group of volunteers is 18100 what makes GCC successful. 18101 18102 For additional information about GCC please refer to the [6]GCC project 18103 web site or contact the [7]GCC development mailing list. 18104 18105 To obtain GCC please use [8]our mirror sites, or our CVS server. 18106 __________________________________________________________________ 18107 18108 18109 For questions related to the use of GCC, please consult these web 18110 pages and the [9]GCC manuals. If that fails, the 18111 [10]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 18112 web pages and the development of GCC are welcome on our developer 18113 list at [11]gcc (a] gcc.gnu.org. All of [12]our lists have public 18114 archives. 18115 18116 Copyright (C) [13]Free Software Foundation, Inc. Verbatim copying and 18117 distribution of this entire article is permitted in any medium, 18118 provided this notice is preserved. 18119 18120 These pages are [14]maintained by the GCC team. Last modified 18121 2019-11-28[15]. 18122 18123 References 18124 18125 1. http://www.gnu.org/ 18126 2. http://www.gnu.org/ 18127 3. http://gcc.gnu.org/gcc-3.1/buildstat.html 18128 4. http://gcc.gnu.org/gcc-3.1/changes.html 18129 5. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 18130 6. http://gcc.gnu.org/index.html 18131 7. mailto:gcc (a] gcc.gnu.org 18132 8. http://gcc.gnu.org/mirrors.html 18133 9. https://gcc.gnu.org/onlinedocs/ 18134 10. mailto:gcc-help (a] gcc.gnu.org 18135 11. mailto:gcc (a] gcc.gnu.org 18136 12. https://gcc.gnu.org/lists.html 18137 13. https://www.fsf.org/ 18138 14. https://gcc.gnu.org/about.html 18139 15. http://validator.w3.org/check/referer 18140 ====================================================================== 18141 http://gcc.gnu.org/gcc-3.1/changes.html 18142 GCC 3.1 Release Series 18143 Changes, New Features, and Fixes 18144 18145 Additional changes in GCC 3.1.1 18146 18147 * A bug related to how structures and unions are returned has been 18148 fixed for powerpc-*-netbsd*. 18149 * An important bug in the implementation of -fprefetch-loop-arrays 18150 has been fixed. Previously the optimization prefetched random 18151 blocks of memory for most targets except for i386. 18152 * The Java compiler now compiles Java programs much faster and also 18153 works with parallel make. 18154 * Nested functions have been fixed for mips*-*-netbsd*. 18155 * Some missing floating point support routines have beed added for 18156 mips*-*-netbsd*. 18157 * This [1]message gives additional information about the bugs fixed 18158 in this release. 18159 18160 Caveats 18161 18162 * The -traditional C compiler option has been deprecated and will be 18163 removed in GCC 3.3. (It remains possible to preprocess non-C code 18164 with the traditional preprocessor.) 18165 * The default debugging format for most ELF platforms (including 18166 GNU/Linux and FreeBSD; notable exception is Solaris) has changed 18167 from stabs to DWARF2. This requires GDB 5.1.1 or later. 18168 18169 General Optimizer Improvements 18170 18171 * Jan Hubicka, SuSE Labs, together with Richard Henderson, Red Hat, 18172 and Andreas Jaeger, SuSE Labs, has contributed [2]infrastructure 18173 for profile driven optimizations. 18174 Options -fprofile-arcs and -fbranch-probabilities can now be used 18175 to improve speed of the generated code by profiling the actual 18176 program behaviour on typical runs. In the absence of profile info 18177 the compiler attempts to guess the profile statically. 18178 * [3]SPEC2000 and SPEC95 benchmark suites are now used daily to 18179 monitor performance of the generated code. 18180 According to the SPECInt2000 results on an AMD Athlon CPU, the code 18181 generated by GCC 3.1 is 6% faster on the average (8.2% faster with 18182 profile feedback) compared to GCC 3.0. The code produced by GCC 3.0 18183 is about 2.1% faster compared to 2.95.3. Tests were done using the 18184 -O2 -march=athlon command-line options. 18185 * Alexandre Oliva, of Red Hat, has generalized the tree inlining 18186 infrastructure developed by CodeSourcery, LLC for the C++ front 18187 end, so that it is now used in the C front end too. Inlining 18188 functions as trees exposes them earlier to the compiler, giving it 18189 more opportunities for optimization. 18190 * Support for data prefetching instructions has been added to the GCC 18191 back end and several targets. A new __builtin_prefetch intrinsic is 18192 available to explicitly insert prefetch instructions and 18193 experimental support for loop array prefetching has been added (see 18194 -fprefetch-loop-array documentation). 18195 * Support for emitting debugging information for macros has been 18196 added for DWARF2. It is activated using -g3. 18197 18198 New Languages and Language specific improvements 18199 18200 C/C++ 18201 18202 * A few more [4]ISO C99 features. 18203 * The preprocessor is 10-50% faster than the preprocessor in GCC 3.0. 18204 * The preprocessor's symbol table has been merged with the symbol 18205 table of the C, C++ and Objective-C front ends. 18206 * The preprocessor consumes less memory than the preprocessor in GCC 18207 3.0, often significantly so. On normal input files, it typically 18208 consumes less memory than pre-3.0 cccp-based GCC, too. 18209 18210 C++ 18211 18212 * -fhonor-std and -fno-honor-std have been removed. -fno-honor-std 18213 was a workaround to allow std compliant code to work with the 18214 non-std compliant libstdc++-v2. libstdc++-v3 is std compliant. 18215 * The C++ ABI has been fixed so that void (A::*)() const is mangled 18216 as "M1AKFvvE", rather than "MK1AFvvE" as before. This change only 18217 affects pointer to cv-qualified member function types. 18218 * The C++ ABI has been changed to correctly handle this code: 18219 struct A { 18220 void operator delete[] (void *, size_t); 18221 }; 18222 18223 struct B : public A { 18224 }; 18225 18226 new B[10]; 18227 18228 The amount of storage allocated for the array will be greater than 18229 it was in 3.0, in order to store the number of elements in the 18230 array, so that the correct size can be passed to operator delete[] 18231 when the array is deleted. Previously, the value passed to operator 18232 delete[] was unpredictable. 18233 This change will only affect code that declares a two-argument 18234 operator delete[] with a second parameter of type size_t in a base 18235 class, and does not override that definition in a derived class. 18236 * The C++ ABI has been changed so that: 18237 struct A { 18238 void operator delete[] (void *, size_t); 18239 void operator delete[] (void *); 18240 }; 18241 18242 does not cause unnecessary storage to be allocated when an array of 18243 A objects is allocated. 18244 This change will only affect code that declares both of these forms 18245 of operator delete[], and declared the two-argument form before the 18246 one-argument form. 18247 * The C++ ABI has been changed so that when a parameter is passed by 18248 value, any cleanup for that parameter is performed in the caller, 18249 as specified by the ia64 C++ ABI, rather than the called function 18250 as before. As a result, classes with a non-trivial destructor but a 18251 trivial copy constructor will be passed and returned by invisible 18252 reference, rather than by bitwise copy as before. 18253 * G++ now supports the "named return value optimization": for code 18254 like 18255 A f () { 18256 A a; 18257 ... 18258 return a; 18259 } 18260 18261 G++ will allocate a in the return value slot, so that the return 18262 becomes a no-op. For this to work, all return statements in the 18263 function must return the same variable. 18264 * Improvements to the C++ library are listed in [5]the libstdc++-v3 18265 FAQ. 18266 18267 Objective-C 18268 18269 * Annoying linker warnings (due to incorrect code being generated) 18270 have been fixed. 18271 * If a class method cannot be found, the compiler no longer issues a 18272 warning if a corresponding instance method exists in the root 18273 class. 18274 * Forward @protocol declarations have been fixed. 18275 * Loading of categories has been fixed in certain situations (GNU run 18276 time only). 18277 * The class lookup in the run-time library has been rewritten so that 18278 class method dispatch is more than twice as fast as it used to be 18279 (GNU run time only). 18280 18281 Java 18282 18283 * libgcj now includes RMI, java.lang.ref.*, javax.naming, and 18284 javax.transaction. 18285 * Property files and other system resources can be compiled into 18286 executables which use libgcj using the new gcj --resource feature. 18287 * libgcj has been ported to more platforms. In particular there is 18288 now a mostly-functional mingw32 (Windows) target port. 18289 * JNI and CNI invocation interfaces were implemented, so gcj-compiled 18290 Java code can now be called from a C/C++ application. 18291 * gcj can now use builtin functions for certain known methods, for 18292 instance Math.cos. 18293 * gcj can now automatically remove redundant array-store checks in 18294 some common cases. 18295 * The --no-store-checks optimization option was added. This can be 18296 used to omit runtime store checks for code which is known not to 18297 throw ArrayStoreException 18298 * The following third party interface standards were added to libgcj: 18299 org.w3c.dom and org.xml.sax. 18300 * java.security has been merged with GNU Classpath. The new package 18301 is now JDK 1.2 compliant, and much more complete. 18302 * A bytecode verifier was added to the libgcj interpreter. 18303 * java.lang.Character was rewritten to comply with the Unicode 3.0 18304 standard, and improve performance. 18305 * Partial support for many more locales was added to libgcj. 18306 * Socket timeouts have been implemented. 18307 * libgcj has been merged into a single shared library. There are no 18308 longer separate shared libraries for the garbage collector and 18309 zlib. 18310 * Several performance improvements were made to gcj and libgcj: 18311 + Hash synchronization (thin locks) 18312 + A special allocation path for finalizer-free objects 18313 + Thread-local allocation 18314 + Parallel GC, and other GC tweaks 18315 18316 Fortran 18317 18318 Fortran improvements are listed in [6]the Fortran documentation. 18319 18320 Ada 18321 18322 [7]AdaCore, has contributed its GNAT Ada 95 front end and associated 18323 tools. The GNAT compiler fully implements the Ada language as defined 18324 by the ISO/IEC 8652 standard. 18325 18326 Please note that the integration of the Ada front end is still work in 18327 progress. 18328 18329 New Targets and Target Specific Improvements 18330 18331 * Hans-Peter Nilsson has contributed a port to MMIX, the CPU 18332 architecture used in new editions of Donald E. Knuth's The Art of 18333 Computer Programming. 18334 * Axis Communications has contributed its port to the CRIS CPU 18335 architecture, used in the ETRAX system-on-a-chip series. 18336 * Alexandre Oliva, of Red Hat, has contributed a port to the SuperH 18337 SH5 64-bit RISC microprocessor architecture, extending the existing 18338 SH port. 18339 * UltraSPARC is fully supported in 64-bit mode. The option -m64 18340 enables it. 18341 * For compatibility with the Sun compiler #pragma redefine_extname 18342 has been implemented on Solaris. 18343 * The x86 back end has had some noticeable work done to it. 18344 + SuSE Labs developers Jan Hubicka, Bo Thorsen and Andreas 18345 Jaeger have contributed a port to the AMD x86-64 architecture. 18346 For more information on x86-64 see http://www.x86-64.org. 18347 + The compiler now supports MMX, 3DNow!, SSE, and SSE2 18348 instructions. Options -mmmx, -m3dnow, -msse, and -msse2 will 18349 enable the respective instruction sets. Intel C++ compatible 18350 MMX/3DNow!/SSE intrinsics are implemented. SSE2 intrinsics 18351 will be added in next major release. 18352 + Following those improvements, targets for Pentium MMX, K6-2, 18353 K6-3, Pentium III, Pentium 4, and Athlon 4 Mobile/XP/MP were 18354 added. Refer to the documentation on -march= and -mcpu= 18355 options for details. 18356 + For those targets that support it, -mfpmath=sse will cause the 18357 compiler to generate SSE/SSE2 instructions for floating point 18358 math instead of x87 instructions. Usually, this will lead to 18359 quicker code especially on the Pentium 4. Note that only 18360 scalar floating point instructions are used and GCC does not 18361 exploit SIMD features yet. 18362 + Prefetch support has been added to the Pentium III, Pentium 4, 18363 K6-2, K6-3, and Athlon series. 18364 + Code generated for floating point to integer conversions has 18365 been improved leading to better performance of many 3D 18366 applications. 18367 * The PowerPC back end has added 64-bit PowerPC GNU/Linux support. 18368 * C++ support for AIX has been improved. 18369 * Aldy Hernandez, of Red Hat, Inc, has contributed extensions to the 18370 PowerPC port supporting the AltiVec programming model (SIMD). The 18371 support, though presently useful, is experimental and is expected 18372 to stabilize for 3.2. The support is written to conform to 18373 Motorola's AltiVec specs. See -maltivec. 18374 18375 Obsolete Systems 18376 18377 Support for a number of older systems has been declared obsolete in GCC 18378 3.1. Unless there is activity to revive them, the next release of GCC 18379 will have their sources permanently removed. 18380 18381 All configurations of the following processor architectures have been 18382 declared obsolete: 18383 * MIL-STD-1750A, 1750a-*-* 18384 * AMD A29k, a29k-*-* 18385 * Convex, c*-convex-* 18386 * Clipper, clipper-*-* 18387 * Elxsi, elxsi-*-* 18388 * Intel i860, i860-*-* 18389 * Sun picoJava, pj-*-* and pjl-*-* 18390 * Western Electric 32000, we32k-*-* 18391 18392 Most configurations of the following processor architectures have been 18393 declared obsolete, but we are preserving a few systems which may have 18394 active developers. It is unlikely that the remaining systems will 18395 survive much longer unless we see definite signs of port activity. 18396 * Motorola 88000 except 18397 + Generic a.out, m88k-*-aout* 18398 + Generic SVR4, m88k-*-sysv4 18399 + OpenBSD, m88k-*-openbsd* 18400 * NS32k except 18401 + NetBSD, ns32k-*-netbsd* 18402 + OpenBSD, ns32k-*-openbsd*. 18403 * ROMP except 18404 + OpenBSD, romp-*-openbsd*. 18405 18406 Finally, only some configurations of these processor architectures are 18407 being obsoleted. 18408 * Alpha: 18409 + OSF/1, alpha*-*-osf[123]*. (Digital Unix and Tru64 Unix, aka 18410 alpha*-*-osf[45], are still supported.) 18411 * ARM: 18412 + RISCiX, arm-*-riscix*. 18413 * i386: 18414 + 386BSD, i?86-*-bsd* 18415 + Chorus, i?86-*-chorusos* 18416 + DG/UX, i?86-*-dgux* 18417 + FreeBSD 1.x, i?86-*-freebsd1.* 18418 + IBM AIX, i?86-*-aix* 18419 + ISC UNIX, i?86-*-isc* 18420 + GNU/Linux with pre-BFD linker, i?86-*-linux*oldld* 18421 + NEXTstep, i?86-next-* 18422 + OSF UNIX, i?86-*-osf1* and i?86-*-osfrose* 18423 + RTEMS/coff, i?86-*-rtemscoff* 18424 + RTEMS/go32, i?86-go32-rtems* 18425 + Sequent/BSD, i?86-sequent-bsd* 18426 + Sequent/ptx before version 3, i?86-sequent-ptx[12]* and 18427 i?86-sequent-sysv3* 18428 + SunOS, i?86-*-sunos* 18429 * Motorola 68000: 18430 + Altos, m68[k0]*-altos-* 18431 + Apollo, m68[k0]*-apollo-* 18432 + Apple A/UX, m68[k0]*-apple-* 18433 + Bull, m68[k0]*-bull-* 18434 + Convergent, m68[k0]*-convergent-* 18435 + Generic SVR3, m68[k0]*-*-sysv3* 18436 + ISI, m68[k0]*-isi-* 18437 + LynxOS, m68[k0]*-*-lynxos* 18438 + NEXT, m68[k0]*-next-* 18439 + RTEMS/coff, m68[k0]*-*-rtemscoff* 18440 + Sony, m68[k0]*-sony-* 18441 * MIPS: 18442 + DEC Ultrix, mips-*-ultrix* and mips-dec-* 18443 + Generic BSD, mips-*-bsd* 18444 + Generic System V, mips-*-sysv* 18445 + IRIX before version 5, mips-sgi-irix[1234]* 18446 + RiscOS, mips-*-riscos* 18447 + Sony, mips-sony-* 18448 + Tandem, mips-tandem-* 18449 * SPARC: 18450 + RTEMS/a.out, sparc-*-rtemsaout*. 18451 18452 Documentation improvements 18453 18454 * The old manual ("Using and Porting the GNU Compiler Collection") 18455 has been replaced by a users manual ("Using the GNU Compiler 18456 Collection") and a separate internals reference manual ("GNU 18457 Compiler Collection Internals"). 18458 * More complete and much improved documentation about GCC's internal 18459 representation used by the C and C++ front ends. 18460 * Many cleanups and improvements in general. 18461 18462 18463 For questions related to the use of GCC, please consult these web 18464 pages and the [8]GCC manuals. If that fails, the 18465 [9]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 18466 web pages and the development of GCC are welcome on our developer 18467 list at [10]gcc (a] gcc.gnu.org. All of [11]our lists have public 18468 archives. 18469 18470 Copyright (C) [12]Free Software Foundation, Inc. Verbatim copying and 18471 distribution of this entire article is permitted in any medium, 18472 provided this notice is preserved. 18473 18474 These pages are [13]maintained by the GCC team. Last modified 18475 2019-11-28[14]. 18476 18477 References 18478 18479 1. https://gcc.gnu.org/ml/gcc/2002-07/msg01208.html 18480 2. http://gcc.gnu.org/news/profiledriven.html 18481 3. http://gcc.gnu.org/benchmarks/ 18482 4. http://gcc.gnu.org/c99status.html 18483 5. https://gcc.gnu.org/onlinedocs/libstdc++/faq.html 18484 6. https://gcc.gnu.org/onlinedocs/gcc-3.1.1/g77/News.html 18485 7. https://www.adacore.com/ 18486 8. https://gcc.gnu.org/onlinedocs/ 18487 9. mailto:gcc-help (a] gcc.gnu.org 18488 10. mailto:gcc (a] gcc.gnu.org 18489 11. https://gcc.gnu.org/lists.html 18490 12. https://www.fsf.org/ 18491 13. https://gcc.gnu.org/about.html 18492 14. http://validator.w3.org/check/referer 18493 ====================================================================== 18494 http://gcc.gnu.org/gcc-3.0/index.html 18495 GCC 3.0.4 18496 18497 (This release series is no longer supported.) 18498 18499 February 20, 2002 18500 18501 The [1]GNU project and the GCC developers are pleased to announce the 18502 release of GCC 3.0.4, which is a bug-fix release for the GCC 3.0 18503 series. 18504 18505 GCC used to stand for the GNU C Compiler, but since the compiler 18506 supports several other languages aside from C, it now stands for the 18507 GNU Compiler Collection. 18508 18509 GCC 3.0.x has several new optimizations, new targets, new languages and 18510 many other new features, relative to GCC 2.95.x. See the [2]new 18511 features page for a more complete list. 18512 18513 A list of [3]successful builds is updated as new information becomes 18514 available. 18515 18516 The GCC developers would like to thank the numerous people that have 18517 contributed new features, test results, bug fixes, etc to GCC. This 18518 [4]amazing group of volunteers is what makes GCC successful. 18519 18520 And finally, we can't in good conscience fail to mention some 18521 [5]caveats to using GCC 3.0.x. 18522 18523 For additional information about GCC please refer to the [6]GCC project 18524 web site or contact the [7]GCC development mailing list. 18525 18526 To obtain GCC please use [8]our mirror sites, or our CVS server. 18527 __________________________________________________________________ 18528 18529 Previous 3.0.x Releases 18530 18531 December 20, 2001: GCC 3.0.3 has been released. 18532 October 25, 2001: GCC 3.0.2 has been released. 18533 August 20, 2001: GCC 3.0.1 has been released. 18534 June 18, 2001: GCC 3.0 has been released. 18535 18536 18537 For questions related to the use of GCC, please consult these web 18538 pages and the [9]GCC manuals. If that fails, the 18539 [10]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 18540 web pages and the development of GCC are welcome on our developer 18541 list at [11]gcc (a] gcc.gnu.org. All of [12]our lists have public 18542 archives. 18543 18544 Copyright (C) [13]Free Software Foundation, Inc. Verbatim copying and 18545 distribution of this entire article is permitted in any medium, 18546 provided this notice is preserved. 18547 18548 These pages are [14]maintained by the GCC team. Last modified 18549 2019-11-28[15]. 18550 18551 References 18552 18553 1. http://www.gnu.org/ 18554 2. http://gcc.gnu.org/gcc-3.0/features.html 18555 3. http://gcc.gnu.org/gcc-3.0/buildstat.html 18556 4. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 18557 5. http://gcc.gnu.org/gcc-3.0/caveats.html 18558 6. http://gcc.gnu.org/index.html 18559 7. mailto:gcc (a] gcc.gnu.org 18560 8. http://gcc.gnu.org/mirrors.html 18561 9. https://gcc.gnu.org/onlinedocs/ 18562 10. mailto:gcc-help (a] gcc.gnu.org 18563 11. mailto:gcc (a] gcc.gnu.org 18564 12. https://gcc.gnu.org/lists.html 18565 13. https://www.fsf.org/ 18566 14. https://gcc.gnu.org/about.html 18567 15. http://validator.w3.org/check/referer 18568 ====================================================================== 18569 http://gcc.gnu.org/gcc-3.0/features.html 18570 GCC 3.0 New Features 18571 18572 Additional changes in GCC 3.0.4 18573 18574 * GCC 3.0 now supports newer versions of the [1]NetBSD operating 18575 system, which use the ELF object file format, on x86 processors. 18576 * Correct debugging information is generated from functions that have 18577 lines from multiple files (e.g. yacc output). 18578 * A fix for whitespace handling in the -traditional preprocessor, 18579 which can affect Fortran. 18580 * Fixes to the exception handling runtime. 18581 * More fixes for bad code generation in C++. 18582 * A fix for shared library generation under AIX 4.3. 18583 * Documentation updates. 18584 * Port of GCC to Tensilica's Xtensa processor contributed. 18585 * A fix for compiling the PPC Linux kernel (FAT fs wouldn't link). 18586 18587 Additional changes in GCC 3.0.3 18588 18589 * A fix to correct an accidental change to the PowerPC ABI. 18590 * Fixes for bad code generation on a variety of architectures. 18591 * Improvements to the debugging information generated for C++ 18592 classes. 18593 * Fixes for bad code generation in C++. 18594 * A fix to avoid crashes in the C++ demangler. 18595 * A fix to the C++ standard library to avoid buffer overflows. 18596 * Miscellaneous improvements for a variety of architectures. 18597 18598 Additional changes in GCC 3.0.2 18599 18600 * Fixes for bad code generation during loop unrolling. 18601 * Fixes for bad code generation by the sibling call optimization. 18602 * Minor improvements to x86 code generation. 18603 * Implementation of function descriptors in C++ vtables for IA64. 18604 * Numerous minor bug-fixes. 18605 18606 Additional changes in GCC 3.0.1 18607 18608 * C++ fixes for incorrect code-generation. 18609 * Improved cross-compiling support for the C++ standard library. 18610 * Fixes for some embedded targets that worked in GCC 2.95.3, but not 18611 in GCC 3.0. 18612 * Fixes for various exception-handling bugs. 18613 * A port to the S/390 architecture. 18614 18615 General Optimizer Improvements 18616 18617 * [2]Basic block reordering pass. 18618 * New if-conversion pass with support for conditional (predicated) 18619 execution. 18620 * New tail call and sibling call elimination optimizations. 18621 * New register renaming pass. 18622 * New (experimental) [3]static single assignment (SSA) representation 18623 support. 18624 * New dead-code elimination pass implemented using the SSA 18625 representation. 18626 * [4]Global null pointer test elimination. 18627 * [5]Global code hoisting/unification. 18628 * More builtins and optimizations for stdio.h, string.h and old BSD 18629 functions, as well as for ISO C99 functions. 18630 * New builtin __builtin_expect for giving hints to the branch 18631 predictor. 18632 18633 New Languages and Language specific improvements 18634 18635 * The GNU Compiler for the Java(TM) language (GCJ) is now integrated 18636 and supported, including the run-time library containing most 18637 common non-GUI Java classes, a bytecode interpreter, and the Boehm 18638 conservative garbage collector. Many bugs have been fixed. GCJ can 18639 compile Java source or Java bytecodes to either native code or Java 18640 class files, and supports native methods written in either the 18641 standard JNI or the more efficient and convenient CNI. 18642 * Here is a [6]partial list of C++ improvements, both new features 18643 and those no longer supported. 18644 * New C++ ABI. On the IA-64 platform GCC is capable of 18645 inter-operating with other IA-64 compilers. 18646 * The new ABI also significantly reduces the size of symbol and debug 18647 information. 18648 * New C++ support library and many C++ bug fixes, vastly improving 18649 our conformance to the ISO C++ standard. 18650 * New [7]inliner for C++. 18651 * Rewritten C preprocessor, integrated into the C, C++ and Objective 18652 C compilers, with very many improvements including ISO C99 support 18653 and [8]improvements to dependency generation. 18654 * Support for more [9]ISO C99 features. 18655 * Many improvements to support for checking calls to format functions 18656 such as printf and scanf, including support for ISO C99 format 18657 features, extensions from the Single Unix Specification and GNU 18658 libc 2.2, checking of strfmon formats and features to assist in 18659 auditing for format string security bugs. 18660 * New warnings for C code that may have undefined semantics because 18661 of violations of sequence point rules in the C standard (such as a 18662 = a++;, a[n] = b[n++]; and a[i++] = i;), included in -Wall. 18663 * Additional warning option -Wfloat-equal. 18664 * Improvements to -Wtraditional. 18665 * Fortran improvements are listed in [10]the Fortran documentation. 18666 18667 New Targets and Target Specific Improvements 18668 18669 * New x86 back end, generating much improved code. 18670 * Support for a generic i386-elf target contributed. 18671 * New option to emit x86 assembly code using Intel style syntax 18672 (-mintel-syntax). 18673 * HPUX 11 support contributed. 18674 * Improved PowerPC code generation, including scheduled prologue and 18675 epilogue. 18676 * Port of GCC to Intel's IA-64 processor contributed. 18677 * Port of GCC to Motorola's MCore 210 and 340 contributed. 18678 * New unified back-end for Arm, Thumb and StrongArm contributed. 18679 * Port of GCC to Intel's XScale processor contributed. 18680 * Port of GCC to Atmel's AVR microcontrollers contributed. 18681 * Port of GCC to Mitsubishi's D30V processor contributed. 18682 * Port of GCC to Matsushita's AM33 processor (a member of the MN10300 18683 processor family) contributed. 18684 * Port of GCC to Fujitsu's FR30 processor contributed. 18685 * Port of GCC to Motorola's 68HC11 and 68HC12 processors contributed. 18686 * Port of GCC to Sun's picoJava processor core contributed. 18687 18688 Documentation improvements 18689 18690 * Substantially rewritten and improved C preprocessor manual. 18691 * Many improvements to other documentation. 18692 * Manpages for gcc, cpp and gcov are now generated automatically from 18693 the master Texinfo manual, eliminating the problem of manpages 18694 being out of date. (The generated manpages are only extracts from 18695 the full manual, which is provided in Texinfo form, from which 18696 info, HTML, other formats and a printed manual can be generated.) 18697 * Generated info files are included in the release tarballs alongside 18698 their Texinfo sources, avoiding problems on some platforms with 18699 building makeinfo as part of the GCC distribution. 18700 18701 Other significant improvements 18702 18703 * Garbage collection used internally by the compiler for most memory 18704 allocation instead of obstacks. 18705 * Lengauer and Tarjan algorithm used for computing dominators in the 18706 CFG. This algorithm can be significantly faster and more space 18707 efficient than our older algorithm. 18708 * gccbug script provided to assist in submitting bug reports to our 18709 bug tracking system. (Bug reports previously submitted directly to 18710 our mailing lists, for which you received no bug tracking number, 18711 should be submitted again using gccbug if you can reproduce the 18712 problem with GCC 3.0.) 18713 * The internal libgcc library is [11]built as a shared library on 18714 systems that support it. 18715 * Extensive testsuite included with GCC, with many new tests. In 18716 addition to tests for GCC bugs that have been fixed, many tests 18717 have been added for language features, compiler warnings and 18718 builtin functions. 18719 * Additional language-independent warning options -Wpacked, -Wpadded, 18720 -Wunreachable-code and -Wdisabled-optimization. 18721 * Target-independent options -falign-functions, -falign-loops and 18722 -falign-jumps. 18723 18724 Plus a great many bug fixes and almost all the [12]features found in 18725 GCC 2.95. 18726 18727 18728 For questions related to the use of GCC, please consult these web 18729 pages and the [13]GCC manuals. If that fails, the 18730 [14]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 18731 web pages and the development of GCC are welcome on our developer 18732 list at [15]gcc (a] gcc.gnu.org. All of [16]our lists have public 18733 archives. 18734 18735 Copyright (C) [17]Free Software Foundation, Inc. Verbatim copying and 18736 distribution of this entire article is permitted in any medium, 18737 provided this notice is preserved. 18738 18739 These pages are [18]maintained by the GCC team. Last modified 18740 2019-11-28[19]. 18741 18742 References 18743 18744 1. http://www.netbsd.org/ 18745 2. http://gcc.gnu.org/news/reorder.html 18746 3. http://gcc.gnu.org/news/ssa.html 18747 4. http://gcc.gnu.org/news/null.html 18748 5. http://gcc.gnu.org/news/unify.html 18749 6. http://gcc.gnu.org/gcc-3.0/c++features.html 18750 7. http://gcc.gnu.org/news/inlining.html 18751 8. http://gcc.gnu.org/news/dependencies.html 18752 9. http://gcc.gnu.org/c99status.html 18753 10. https://gcc.gnu.org/onlinedocs/gcc-3.4.6/g77/News.html 18754 11. http://gcc.gnu.org/gcc-3.0/libgcc.html 18755 12. http://gcc.gnu.org/gcc-2.95/features.html 18756 13. https://gcc.gnu.org/onlinedocs/ 18757 14. mailto:gcc-help (a] gcc.gnu.org 18758 15. mailto:gcc (a] gcc.gnu.org 18759 16. https://gcc.gnu.org/lists.html 18760 17. https://www.fsf.org/ 18761 18. https://gcc.gnu.org/about.html 18762 19. http://validator.w3.org/check/referer 18763 ====================================================================== 18764 http://gcc.gnu.org/gcc-3.0/caveats.html 18765 GCC 3.0 Caveats 18766 18767 * -fstrict-aliasing is now part of -O2 and higher optimization 18768 levels. This allows the compiler to assume the strictest aliasing 18769 rules applicable to the language being compiled. For C and C++, 18770 this activates optimizations based on the type of expressions. This 18771 optimization may thus break old, non-compliant code. 18772 * Enumerations are now properly promoted to int in function 18773 parameters and function returns. Normally this change is not 18774 visible, but when using -fshort-enums this is an ABI change. 18775 * The undocumented extension that allowed C programs to have a label 18776 at the end of a compound statement has been deprecated and may be 18777 removed in a future version. Programs that now generate a warning 18778 about this may be fixed by adding a null statement (a single 18779 semicolon) after the label. 18780 * The poorly documented extension that allowed string constants in C, 18781 C++ and Objective C to contain unescaped newlines has been 18782 deprecated and may be removed in a future version. Programs using 18783 this extension may be fixed in several ways: the bare newline may 18784 be replaced by \n, or preceded by \n\, or string concatenation may 18785 be used with the bare newline preceded by \n" and " placed at the 18786 start of the next line. 18787 * The Chill compiler is not included in GCC 3.0, because of the lack 18788 of a volunteer to convert it to use garbage collection. 18789 * Certain non-standard iostream methods from earlier versions of 18790 libstdc++ are not included in libstdc++ v3, i.e. filebuf::attach, 18791 ostream::form, and istream::gets. 18792 * The new C++ ABI is not yet fully supported by current (as of 18793 2001-07-01) releases and development versions of GDB, or any 18794 earlier versions. There is a problem setting breakpoints by line 18795 number, and other related issues that have been fixed in GCC 3.0 18796 but not yet handled in GDB: 18797 [1]https://gcc.gnu.org/ml/gcc-bugs/2001-06/msg00421.html 18798 18799 18800 For questions related to the use of GCC, please consult these web 18801 pages and the [2]GCC manuals. If that fails, the 18802 [3]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 18803 web pages and the development of GCC are welcome on our developer 18804 list at [4]gcc (a] gcc.gnu.org. All of [5]our lists have public archives. 18805 18806 Copyright (C) [6]Free Software Foundation, Inc. Verbatim copying and 18807 distribution of this entire article is permitted in any medium, 18808 provided this notice is preserved. 18809 18810 These pages are [7]maintained by the GCC team. Last modified 18811 2019-11-28[8]. 18812 18813 References 18814 18815 1. https://gcc.gnu.org/ml/gcc-bugs/2001-06/msg00421.html 18816 2. https://gcc.gnu.org/onlinedocs/ 18817 3. mailto:gcc-help (a] gcc.gnu.org 18818 4. mailto:gcc (a] gcc.gnu.org 18819 5. https://gcc.gnu.org/lists.html 18820 6. https://www.fsf.org/ 18821 7. https://gcc.gnu.org/about.html 18822 8. http://validator.w3.org/check/referer 18823 ====================================================================== 18824 http://gcc.gnu.org/gcc-2.95/index.html 18825 GCC 2.95 18826 18827 (This release series is no longer supported.) 18828 18829 March 16, 2001: The GNU project and the GCC developers are pleased to 18830 announce the release of GCC version 2.95.3. 18831 18832 Release History 18833 18834 GCC 2.95.3 18835 March 16, 2001 18836 18837 GCC 2.95.2 18838 October 27, 1999 18839 18840 GCC 2.95.1 18841 August 19, 1999 18842 18843 GCC 2.95 18844 July 31, 1999. This is the first release of GCC since the April 18845 1999 GCC/EGCS reunification and includes nearly a year's worth 18846 of new development and bugfixes. 18847 18848 References and Acknowledgements 18849 18850 GCC used to stand for the GNU C Compiler, but since the compiler 18851 supports several other languages aside from C, it now stands for the 18852 GNU Compiler Collection. 18853 18854 The whole suite has been extensively [1]regression tested and 18855 [2]package tested. It should be reliable and suitable for widespread 18856 use. 18857 18858 The compiler has several new optimizations, new targets, new languages 18859 and other new features. See the [3]new features page for a more 18860 complete list of new features found in the GCC 2.95 releases. 18861 18862 The sources include installation instructions in both HTML and 18863 plaintext forms in the install directory in the distribution. However, 18864 the most up to date installation instructions and [4]build/test status 18865 are on the web pages. We will update those pages as new information 18866 becomes available. 18867 18868 The GCC developers would like to thank the numerous people that have 18869 contributed new features, test results, bugfixes, etc to GCC. This 18870 [5]amazing group of volunteers is what makes GCC successful. 18871 18872 And finally, we can't in good conscience fail to mention some 18873 [6]caveats to using GCC 2.95. 18874 18875 Download GCC 2.95 from one of our many [7]mirror sites. 18876 18877 For additional information about GCC please see the [8]GCC project web 18878 server or contact the [9]GCC development mailing list. 18879 18880 18881 For questions related to the use of GCC, please consult these web 18882 pages and the [10]GCC manuals. If that fails, the 18883 [11]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 18884 web pages and the development of GCC are welcome on our developer 18885 list at [12]gcc (a] gcc.gnu.org. All of [13]our lists have public 18886 archives. 18887 18888 Copyright (C) [14]Free Software Foundation, Inc. Verbatim copying and 18889 distribution of this entire article is permitted in any medium, 18890 provided this notice is preserved. 18891 18892 These pages are [15]maintained by the GCC team. Last modified 18893 2019-11-28[16]. 18894 18895 References 18896 18897 1. http://gcc.gnu.org/gcc-2.95/regress.html 18898 2. http://gcc.gnu.org/gcc-2.95/othertest.html 18899 3. http://gcc.gnu.org/gcc-2.95/features.html 18900 4. http://gcc.gnu.org/gcc-2.95/buildstat.html 18901 5. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 18902 6. http://gcc.gnu.org/gcc-2.95/caveats.html 18903 7. http://gcc.gnu.org/mirrors.html 18904 8. http://gcc.gnu.org/index.html 18905 9. mailto:gcc (a] gcc.gnu.org 18906 10. https://gcc.gnu.org/onlinedocs/ 18907 11. mailto:gcc-help (a] gcc.gnu.org 18908 12. mailto:gcc (a] gcc.gnu.org 18909 13. https://gcc.gnu.org/lists.html 18910 14. https://www.fsf.org/ 18911 15. https://gcc.gnu.org/about.html 18912 16. http://validator.w3.org/check/referer 18913 ====================================================================== 18914 http://gcc.gnu.org/gcc-2.95/features.html 18915 GCC 2.95 New Features 18916 18917 * General Optimizer Improvements: 18918 + [1]Localized register spilling to improve speed and code 18919 density especially on small register class machines. 18920 + [2]Global CSE using lazy code motion algorithms. 18921 + [3]Improved global constant/copy propagation. 18922 + [4]Improved control flow graph analysis and manipulation. 18923 + [5]Local dead store elimination. 18924 + [6]Memory Load hoisting/store sinking in loops. 18925 + [7]Type based alias analysis is enabled by default. Note this 18926 feature will expose bugs in the Linux kernel. Please refer to 18927 the FAQ (as shipped with GCC 2.95) for additional information 18928 on this issue. 18929 + Major revamp of GIV detection, combination and simplification 18930 to improve loop performance. 18931 + Major improvements to register allocation and reloading. 18932 * New Languages and Language specific improvements 18933 + [8]Many C++ improvements. 18934 + [9]Many Fortran improvements. 18935 + [10]Java front-end has been integrated. A [11]runtime library 18936 is available separately. 18937 + [12]ISO C99 support 18938 + [13]Chill front-end and runtime has been integrated. 18939 + Boehm garbage collector support in libobjc. 18940 + More support for various pragmas which appear in vendor 18941 include files 18942 * New Targets and Target Specific Improvements 18943 + [14]SPARC backend rewrite. 18944 + -mschedule=8000 will optimize code for PA8000 class 18945 processors; -mpa-risc-2-0 will generate code for PA2.0 18946 processors 18947 + Various micro-optimizations for the ia32 port. K6 18948 optimizations 18949 + Compiler will attempt to align doubles in the stack on the 18950 ia32 port 18951 + Alpha EV6 support 18952 + PowerPC 750 18953 + RS6000/PowerPC: -mcpu=401 was added as an alias for -mcpu=403. 18954 -mcpu=e603e was added to do -mcpu=603e and -msoft-float. 18955 + c3x, c4x 18956 + HyperSPARC 18957 + SparcLite86x 18958 + sh4 18959 + Support for new systems (OpenBSD, FreeBSD, UWIN, Interix, 18960 arm-linux) 18961 + vxWorks targets include support for vxWorks threads 18962 + StrongARM 110 and ARM9 support added. ARM Scheduling 18963 parameters rewritten. 18964 + Various changes to the MIPS port to avoid assembler macros, 18965 which in turn improves performance 18966 + Various performance improvements to the i960 port. 18967 + Major rewrite of ns32k port 18968 * Other significant improvements 18969 + [15]Ability to dump cfg information and display it using vcg. 18970 + The new faster scheme for fixing vendor header files is 18971 enabled by default. 18972 + Experimental internationalization support. 18973 + multibyte character support 18974 + Some compile-time speedups for pathological problems 18975 + Better support for complex types 18976 * Plus the usual mountain of bugfixes 18977 * Core compiler is based on the gcc2 development tree from Sept 30, 18978 1998, so we have all of the [16]features found in GCC 2.8. 18979 18980 Additional Changes in GCC 2.95.1 18981 18982 * Generic bugfixes and improvements 18983 + Various documentation fixes related to the GCC/EGCS merger. 18984 + Fix memory management bug which could lead to spurious aborts, 18985 core dumps or random parsing errors in the compiler. 18986 + Fix a couple bugs in the dwarf1 and dwarf2 debug record 18987 support. 18988 + Fix infinite loop in the CSE optimizer. 18989 + Avoid undefined behavior in compiler FP emulation code 18990 + Fix install problem when prefix is overridden on the make 18991 install command. 18992 + Fix problem with unwanted installation of assert.h on some 18993 systems. 18994 + Fix problem with finding the wrong assembler in a single tree 18995 build. 18996 + Avoid increasing the known alignment of a register that is 18997 already known to be a pointer. 18998 * Platform specific bugfixes and improvements 18999 + Codegen bugfix for prologue/epilogue for cpu32 target. 19000 + Fix long long code generation bug for the Coldfire target. 19001 + Fix various aborts in the SH compiler. 19002 + Fix bugs in libgcc support library for the SH. 19003 + Fix alpha ev6 code generation bug. 19004 + Fix problems with EXIT_SUCCESS/EXIT_FAILURE redefinitions on 19005 AIX platforms. 19006 + Fix -fpic code generation bug for rs6000/ppc svr4 targets. 19007 + Fix varargs/stdarg code generation bug for rs6000/ppc svr4 19008 targets. 19009 + Fix weak symbol handling for rs6000/ppc svr4 targets. 19010 + Fix various problems with 64bit code generation for the 19011 rs6000/ppc port. 19012 + Fix codegen bug which caused tetex to be mis-compiled on the 19013 x86. 19014 + Fix compiler abort in new cfg code exposed by x86 port. 19015 + Fix out of range array reference in code convert flat 19016 registers to the x87 stacked FP register file. 19017 + Fix minor vxworks configuration bug. 19018 + Fix return type of bsearch for SunOS 4.x. 19019 * Language & Runtime specific fixes. 19020 + The G++ signature extension has been deprecated. It will be 19021 removed in the next major release of G++. Use of signatures 19022 will result in a warning from the compiler. 19023 + Several bugs relating to templates and namespaces were fixed. 19024 + A bug that caused crashes when combining templates with -g on 19025 DWARF1 platforms was fixed. 19026 + Pointers-to-members, virtual functions, and multiple 19027 inheritance should now work together correctly. 19028 + Some code-generation bugs relating to function try blocks were 19029 fixed. 19030 + G++ is a little bit more lenient with certain archaic 19031 constructs than in GCC 2.95. 19032 + Fix to prevent shared library version #s from bring truncated 19033 to 1 digit 19034 + Fix missing std:: in the libstdc++ library. 19035 + Fix stream locking problems in libio. 19036 + Fix problem in java compiler driver. 19037 19038 Additional Changes in GCC 2.95.2 19039 19040 The -fstrict-aliasing is not enabled by default for GCC 2.95.2. While 19041 the optimizations performed by -fstrict-aliasing are valid according to 19042 the C and C++ standards, the optimization have caused some problems, 19043 particularly with old non-conforming code. 19044 19045 The GCC developers are experimenting with ways to warn users about code 19046 which violates the C/C++ standards, but those warnings are not ready 19047 for widespread use at this time. Rather than wait for those warnings 19048 the GCC developers have chosen to disable -fstrict-aliasing by default 19049 for the GCC 2.95.2 release. 19050 19051 We strongly encourage developers to find and fix code which violates 19052 the C/C++ standards as -fstrict-aliasing may be enabled by default in 19053 future releases. Use the option -fstrict-aliasing to re-enable these 19054 optimizations. 19055 * Generic bugfixes and improvements 19056 + Fix incorrectly optimized memory reference in global common 19057 subexpression elimination (GCSE) optimization pass. 19058 + Fix code generation bug in regmove.c in which it could 19059 incorrectly change a "const" value. 19060 + Fix bug in optimization of conditionals involving volatile 19061 memory references. 19062 + Avoid over-allocation of stack space for some procedures. 19063 + Fixed bug in the compiler which caused incorrect optimization 19064 of an obscure series of bit manipulations, shifts and 19065 arithmetic. 19066 + Fixed register allocator bug which caused teTeX to be 19067 mis-compiled on SPARC targets. 19068 + Avoid incorrect optimization of degenerate case statements for 19069 certain targets such as the ARM. 19070 + Fix out of range memory reference in the jump optimizer. 19071 + Avoid dereferencing null pointer in fix-header. 19072 + Fix test for GCC specific features so that it is possible to 19073 bootstrap with gcc-2.6.2 and older versions of GCC. 19074 + Fix typo in scheduler which could potentially cause out of 19075 range memory accesses. 19076 + Avoid incorrect loop reversal which caused incorrect code for 19077 certain loops on PowerPC targets. 19078 + Avoid incorrect optimization of switch statements on certain 19079 targets (for example the ARM). 19080 * Platform specific bugfixes and improvements 19081 + Work around bug in Sun V5.0 compilers which caused bootstrap 19082 comparison failures on SPARC targets. 19083 + Fix SPARC backend bug which caused aborts in final.c. 19084 + Fix sparc-hal-solaris2* configuration fragments. 19085 + Fix bug in sparc block profiling. 19086 + Fix obscure code generation bug for the PARISC targets. 19087 + Define __STDC_EXT__ for HPUX configurations. 19088 + Various POWERPC64 code generation bugfixes. 19089 + Fix abort for PPC targets using ELF (ex GNU/Linux). 19090 + Fix collect2 problems for AIX targets. 19091 + Correct handling of .file directive for PPC targets. 19092 + Fix bug in fix_trunc x86 patterns. 19093 + Fix x86 port to correctly pop the FP stack for functions that 19094 return structures in memory. 19095 + Fix minor bug in strlen x86 pattern. 19096 + Use stabs debugging instead of dwarf1 for x86-solaris targets. 19097 + Fix template repository code to handle leading underscore in 19098 mangled names. 19099 + Fix weak/weak alias support for OpenBSD. 19100 + GNU/Linux for the ARM has C++ compatible include files. 19101 * Language & Runtime specific fixes. 19102 + Fix handling of constructor attribute in the C front-end which 19103 caused problems building the Chill runtime library on some 19104 targets. 19105 + Fix minor problem merging type qualifiers in the C front-end. 19106 + Fix aliasing bug for pointers and references (C/C++). 19107 + Fix incorrect "non-constant initializer bug" when -traditional 19108 or -fwritable-strings is enabled. 19109 + Fix build error for Chill front-end on SunOS. 19110 + Do not complain about duplicate instantiations when using 19111 -frepo (C++). 19112 + Fix array bounds handling in C++ front-end which caused 19113 problems with dwarf debugging information in some 19114 circumstances. 19115 + Fix minor namespace problem. 19116 + Fix problem linking java programs. 19117 19118 Additional Changes in GCC 2.95.3 19119 19120 * Generic bugfixes and improvements 19121 + Fix numerous problems that caused incorrect optimization in 19122 the register reloading code. 19123 + Fix numerous problems that caused incorrect optimization in 19124 the loop optimizer. 19125 + Fix aborts in the functions build_insn_chain and scan_loops 19126 under some circumstances. 19127 + Fix an alias analysis bug. 19128 + Fix an infinite compilation bug in the combiner. 19129 + A few problems with complex number support have been fixed. 19130 + It is no longer possible for gcc to act as a fork bomb when 19131 installed incorrectly. 19132 + The -fpack-struct option should be recognized now. 19133 + Fixed a bug that caused incorrect code to be generated due to 19134 a lost stack adjustment. 19135 * Platform specific bugfixes and improvements 19136 + Support building ARM toolchains hosted on Windows. 19137 + Fix attribute calculations in ARM toolchains. 19138 + arm-linux support has been improved. 19139 + Fix a PIC failure on sparc targets. 19140 + On ix86 targets, the regparm attribute should now work 19141 reliably. 19142 + Several updates for the h8300 port. 19143 + Fix problem building libio with glibc 2.2. 19144 19145 19146 For questions related to the use of GCC, please consult these web 19147 pages and the [17]GCC manuals. If that fails, the 19148 [18]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 19149 web pages and the development of GCC are welcome on our developer 19150 list at [19]gcc (a] gcc.gnu.org. All of [20]our lists have public 19151 archives. 19152 19153 Copyright (C) [21]Free Software Foundation, Inc. Verbatim copying and 19154 distribution of this entire article is permitted in any medium, 19155 provided this notice is preserved. 19156 19157 These pages are [22]maintained by the GCC team. Last modified 19158 2019-11-28[23]. 19159 19160 References 19161 19162 1. http://gcc.gnu.org/news/spill.html 19163 2. http://gcc.gnu.org/news/lcm.html 19164 3. http://gcc.gnu.org/news/cprop.html 19165 4. http://gcc.gnu.org/news/cfg.html 19166 5. http://gcc.gnu.org/news/dse.html 19167 6. http://gcc.gnu.org/news/hoist.html 19168 7. http://gcc.gnu.org/news/alias.html 19169 8. http://gcc.gnu.org/gcc-2.95/c++features.html 19170 9. https://gcc.gnu.org/onlinedocs/gcc-3.4.6/g77/News.html 19171 10. http://gcc.gnu.org/news/gcj-announce.txt 19172 11. http://gcc.gnu.org/news/javaannounce.html 19173 12. http://gcc.gnu.org/c99status.html 19174 13. http://gcc.gnu.org/news/chill.html 19175 14. http://gcc.gnu.org/news/sparc.html 19176 15. http://gcc.gnu.org/news/egcs-vcg.html 19177 16. http://gcc.gnu.org/egcs-1.0/features-2.8.html 19178 17. https://gcc.gnu.org/onlinedocs/ 19179 18. mailto:gcc-help (a] gcc.gnu.org 19180 19. mailto:gcc (a] gcc.gnu.org 19181 20. https://gcc.gnu.org/lists.html 19182 21. https://www.fsf.org/ 19183 22. https://gcc.gnu.org/about.html 19184 23. http://validator.w3.org/check/referer 19185 ====================================================================== 19186 http://gcc.gnu.org/gcc-2.95/caveats.html 19187 GCC 2.95 Caveats 19188 19189 * GCC 2.95 will issue an error for invalid asm statements that had 19190 been silently accepted by earlier versions of the compiler. This is 19191 particularly noticeable when compiling older versions of the Linux 19192 kernel (2.0.xx). Please refer to the FAQ (as shipped with GCC 2.95) 19193 for more information on this issue. 19194 * GCC 2.95 implements type based alias analysis to disambiguate 19195 memory references. Some programs, particularly the Linux kernel 19196 violate ANSI/ISO aliasing rules and therefore may not operate 19197 correctly when compiled with GCC 2.95. Please refer to the FAQ (as 19198 shipped with GCC 2.95) for more information on this issue. 19199 * GCC 2.95 has a known bug in its handling of complex variables for 19200 64bit targets. Instead of silently generating incorrect code, GCC 19201 2.95 will issue a fatal error for situations it can not handle. 19202 This primarily affects the Fortran community as Fortran makes more 19203 use of complex variables than C or C++. 19204 * GCC 2.95 has an integrated libstdc++, but does not have an 19205 integrated libg++. Furthermore old libg++ releases will not work 19206 with GCC 2.95. You can retrieve a recent copy of libg++ from the 19207 [1]GCC ftp server. 19208 Note most C++ programs only need libstdc++. 19209 * Exception handling may not work with shared libraries, particularly 19210 on alphas, hppas, rs6000/powerpc and mips based platforms. 19211 Exception handling is known to work on x86 GNU/Linux platforms with 19212 shared libraries. 19213 * In general, GCC 2.95 is more rigorous about rejecting invalid C++ 19214 code or deprecated C++ constructs than G++ 2.7, G++ 2.8, EGCS 1.0, 19215 or EGCS 1.1. As a result it may be necessary to fix C++ code before 19216 it will compile with GCC 2.95. 19217 * G++ is also converting toward the ISO C++ standard; as a result 19218 code which was previously valid (and thus accepted by other 19219 compilers and older versions of g++) may no longer be accepted. The 19220 flag -fpermissive may allow some non-conforming code to compile 19221 with GCC 2.95. 19222 * GCC 2.95 compiled C++ code is not binary compatible with EGCS 19223 1.1.x, EGCS 1.0.x or GCC 2.8.x. 19224 * GCC 2.95 does not have changes from the GCC 2.8 tree that were made 19225 between Sept 30, 1998 and April 30, 1999 (the official end of the 19226 GCC 2.8 project). Future GCC releases will include all the changes 19227 from the defunct GCC 2.8 sources. 19228 19229 19230 For questions related to the use of GCC, please consult these web 19231 pages and the [2]GCC manuals. If that fails, the 19232 [3]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 19233 web pages and the development of GCC are welcome on our developer 19234 list at [4]gcc (a] gcc.gnu.org. All of [5]our lists have public archives. 19235 19236 Copyright (C) [6]Free Software Foundation, Inc. Verbatim copying and 19237 distribution of this entire article is permitted in any medium, 19238 provided this notice is preserved. 19239 19240 These pages are [7]maintained by the GCC team. Last modified 19241 2019-11-28[8]. 19242 19243 References 19244 19245 1. ftp://gcc.gnu.org/pub/gcc/infrastructure/libg++-2.8.1.3.tar.gz 19246 2. https://gcc.gnu.org/onlinedocs/ 19247 3. mailto:gcc-help (a] gcc.gnu.org 19248 4. mailto:gcc (a] gcc.gnu.org 19249 5. https://gcc.gnu.org/lists.html 19250 6. https://www.fsf.org/ 19251 7. https://gcc.gnu.org/about.html 19252 8. http://validator.w3.org/check/referer 19253 ====================================================================== 19254 http://gcc.gnu.org/egcs-1.1/index.html 19255 EGCS 1.1 19256 19257 September 3, 1998: We are pleased to announce the release of EGCS 1.1. 19258 December 1, 1998: We are pleased to announce the release of EGCS 1.1.1. 19259 March 15, 1999: We are pleased to announce the release of EGCS 1.1.2. 19260 19261 EGCS is a free software project to further the development of the GNU 19262 compilers using an open development environment. 19263 19264 EGCS 1.1 is a major new release of the EGCS compiler system. It has 19265 been [1]extensively tested and is believed to be stable and suitable 19266 for widespread use. 19267 19268 EGCS 1.1 is based on an June 6, 1998 snapshot of the GCC 2.8 19269 development sources; it contains all of the new features found in GCC 19270 2.8.1 as well as all new development from GCC up to June 6, 1998. 19271 19272 EGCS 1.1 also contains many improvements and features not found in GCC 19273 or in older versions of EGCS: 19274 * Global common subexpression elimination and global constant/copy 19275 propagation (aka [2]gcse) 19276 * Ongoing improvements to the [3]alias analysis support to allow for 19277 better optimizations throughout the compiler. 19278 * Vastly improved [4]C++ compiler and integrated C++ runtime 19279 libraries. 19280 * Fixes for the /tmp symlink race security problems. 19281 * New targets including mips16, arm-thumb and 64 bit PowerPC. 19282 * Improvements to GNU Fortran (g77) compiler and runtime library made 19283 since g77 version 0.5.23. 19284 19285 See the [5]new features page for a more complete list of new features 19286 found in EGCS 1.1 releases. 19287 19288 EGCS 1.1.1 is a minor update to fix several serious problems in EGCS 19289 1.1: 19290 * General improvements and fixes 19291 + Avoid some stack overflows when compiling large functions. 19292 + Avoid incorrect loop invariant code motions. 19293 + Fix some core dumps on Linux kernel code. 19294 + Bring back the imake -Di386 and friends fix from EGCS 1.0.2. 19295 + Fix code generation problem in gcse. 19296 + Various documentation related fixes. 19297 * g++/libstdc++ improvements and fixes 19298 + MT safe EH fix for setjmp/longjmp based exception handling. 19299 + Fix a few bad interactions between optimization and exception 19300 handling. 19301 + Fixes for demangling of template names starting with "__". 19302 + Fix a bug that would fail to run destructors in some cases 19303 with -O2. 19304 + Fix 'new' of classes with virtual bases. 19305 + Fix crash building Qt on the Alpha. 19306 + Fix failure compiling WIFEXITED macro on GNU/Linux. 19307 + Fix some -frepo failures. 19308 * g77 and libf2c improvements and fixes 19309 + Various documentation fixes. 19310 + Avoid compiler crash on RAND intrinsic. 19311 + Fix minor bugs in makefiles exposed by BSD make programs. 19312 + Define _XOPEN_SOURCE for libI77 build to avoid potential 19313 problems on some 64-bit systems. 19314 + Fix problem with implicit endfile on rewind. 19315 + Fix spurious recursive I/O errors. 19316 * platform specific improvements and fixes 19317 + Match all versions of UnixWare7. 19318 + Do not assume x86 SVR4 or UnixWare targets can handle stabs. 19319 + Fix PPC/RS6000 LEGITIMIZE_ADDRESS macro and bug in conversion 19320 from unsigned ints to double precision floats. 19321 + Fix ARM ABI issue with NetBSD. 19322 + Fix a few arm code generation bugs. 19323 + Fixincludes will fix additional broken SCO OpenServer header 19324 files. 19325 + Fix a m68k backend bug which caused invalid offsets in reg+d 19326 addresses. 19327 + Fix problems with 64bit AIX 4.3 support. 19328 + Fix handling of long longs for varargs/stdarg functions on the 19329 ppc. 19330 + Minor fixes to CPP predefines for Windows. 19331 + Fix code generation problems with gpr<->fpr copies for 64bit 19332 ppc. 19333 + Fix a few coldfire code generation bugs. 19334 + Fix some more header file problems on SunOS 4.x. 19335 + Fix assert.h handling for RTEMS. 19336 + Fix Windows handling of TREE_SYMBOL_REFERENCED. 19337 + Fix x86 compiler abort in reg-stack pass. 19338 + Fix cygwin/windows problem with section attributes. 19339 + Fix Alpha code generation problem exposed by SMP Linux 19340 kernels. 19341 + Fix typo in m68k 32->64bit integer conversion. 19342 + Make sure target libraries build with -fPIC for PPC & Alpha 19343 targets. 19344 19345 EGCS 1.1.2 is a minor update to fix several serious problems in EGCS 19346 1.1.1: 19347 * General improvements and fixes 19348 + Fix bug in loop optimizer which caused the SPARC (and 19349 potentially other) ports to segfault. 19350 + Fix infinite recursion in alias analysis and combiner code. 19351 + Fix bug in regclass preferencing. 19352 + Fix incorrect loop reversal which caused incorrect code to be 19353 generated for several targets. 19354 + Fix return value for builtin memcpy. 19355 + Reduce compile time for certain loops which exposed quadratic 19356 behavior in the loop optimizer. 19357 + Fix bug which caused volatile memory to be written multiple 19358 times when only one write was needed/desired. 19359 + Fix compiler abort in caller-save.c 19360 + Fix combiner bug which caused incorrect code generation for 19361 certain division by constant operations. 19362 + Fix incorrect code generation due to a bug in range check 19363 optimizations. 19364 + Fix incorrect code generation due to mis-handling of clobbered 19365 values in CSE. 19366 + Fix compiler abort/segfault due to incorrect register 19367 splitting when unrolling loops. 19368 + Fix code generation involving autoincremented addresses with 19369 ternary operators. 19370 + Work around bug in the scheduler which caused qt to be 19371 mis-compiled on some platforms. 19372 + Fix code generation problems with -fshort-enums. 19373 + Tighten security for temporary files. 19374 + Improve compile time for codes which make heavy use of 19375 overloaded functions. 19376 + Fix multiply defined constructor/destructor symbol problems. 19377 + Avoid setting bogus RPATH environment variable during 19378 bootstrap. 19379 + Avoid GNU-make dependencies in the texinfo subdir. 19380 + Install CPP wrapper script in $(prefix)/bin if --enable-cpp. 19381 --enable-cpp=<dirname> can be used to specify an additional 19382 install directory for the cpp wrapper script. 19383 + Fix CSE bug which caused incorrect label-label refs to appear 19384 on some platforms. 19385 + Avoid linking in EH routines from libgcc if they are not 19386 needed. 19387 + Avoid obscure bug in aliasing code. 19388 + Fix bug in weak symbol handling. 19389 * Platform-specific improvements and fixes 19390 + Fix detection of PPro/PII on Unixware 7. 19391 + Fix compiler segfault when building spec99 and other programs 19392 for SPARC targets. 19393 + Fix code-generation bugs for integer and floating point 19394 conditional move instructions on the PPro/PII. 19395 + Use fixincludes to fix byteorder problems on i?86-*-sysv. 19396 + Fix build failure for the arc port. 19397 + Fix floating point format configuration for i?86-gnu port. 19398 + Fix problems with hppa1.0-hp-hpux10.20 configuration when 19399 threads are enabled. 19400 + Fix coldfire code generation bugs. 19401 + Fix "unrecognized insn" problems for Alpha and PPC ports. 19402 + Fix h8/300 code generation problem with floating point values 19403 in memory. 19404 + Fix unrecognized insn problems for the m68k port. 19405 + Fix namespace-pollution problem for the x86 port. 19406 + Fix problems with old assembler on x86 NeXT systems. 19407 + Fix PIC code-generation problems for the SPARC port. 19408 + Fix minor bug with LONG_CALLS in PowerPC SVR4 support. 19409 + Fix minor ISO namespace violation in Alpha varargs/stdarg 19410 support. 19411 + Fix incorrect "braf" instruction usage for the SH port. 19412 + Fix minor bug in va-sh which prevented its use with -ansi. 19413 + Fix problems recognizing and supporting FreeBSD. 19414 + Handle OpenBSD systems correctly. 19415 + Minor fixincludes fix for Digital UNIX 4.0B. 19416 + Fix problems with ctors/dtors in SCO shared libraries. 19417 + Abort instead of generating incorrect code for PPro/PII 19418 floating point conditional moves. 19419 + Avoid multiply defined symbols on GNU/Linux systems using 19420 libc-5.4.xx. 19421 + Fix abort in alpha compiler. 19422 * Fortran-specific fixes 19423 + Fix the IDate intrinsic (VXT) (in libg2c) so the returned year 19424 is in the documented, non-Y2K-compliant range of 0-99, instead 19425 of being returned as 100 in the year 2000. 19426 + Fix the `Date_and_Time' intrinsic (in libg2c) to return the 19427 milliseconds value properly in Values(8). 19428 + Fix the `LStat' intrinsic (in libg2c) to return device-ID 19429 information properly in SArray(7). 19430 19431 Each release includes installation instructions in both HTML and 19432 plaintext forms (see the INSTALL directory in the toplevel directory of 19433 the distribution). However, we also keep the most up to date 19434 installation instructions and [6]build/test status on our web page. We 19435 will update those pages as new information becomes available. 19436 19437 The EGCS project would like to thank the numerous people that have 19438 contributed new features, test results, bugfixes, etc. This [7]amazing 19439 group of volunteers is what makes EGCS successful. 19440 19441 And finally, we can't in good conscience fail to mention some 19442 [8]caveats to using EGCS 1.1. 19443 19444 Download EGCS from egcs.cygnus.com (USA California). 19445 19446 The EGCS 1.1 release is also available on many mirror sites. 19447 [9]Goto mirror list to find a closer site. 19448 19449 19450 For questions related to the use of GCC, please consult these web 19451 pages and the [10]GCC manuals. If that fails, the 19452 [11]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 19453 web pages and the development of GCC are welcome on our developer 19454 list at [12]gcc (a] gcc.gnu.org. All of [13]our lists have public 19455 archives. 19456 19457 Copyright (C) [14]Free Software Foundation, Inc. Verbatim copying and 19458 distribution of this entire article is permitted in any medium, 19459 provided this notice is preserved. 19460 19461 These pages are [15]maintained by the GCC team. Last modified 19462 2019-11-28[16]. 19463 19464 References 19465 19466 1. http://gcc.gnu.org/egcs-1.1/egcs-1.1-test.html 19467 2. http://gcc.gnu.org/news/gcse.html 19468 3. http://gcc.gnu.org/news/alias.html 19469 4. http://gcc.gnu.org/egcs-1.1/c++features.html 19470 5. http://gcc.gnu.org/egcs-1.1/features.html 19471 6. http://gcc.gnu.org/egcs-1.1/buildstat.html 19472 7. https://gcc.gnu.org/onlinedocs/gcc/Contributors.html 19473 8. http://gcc.gnu.org/egcs-1.1/caveats.html 19474 9. http://gcc.gnu.org/mirrors.html 19475 10. https://gcc.gnu.org/onlinedocs/ 19476 11. mailto:gcc-help (a] gcc.gnu.org 19477 12. mailto:gcc (a] gcc.gnu.org 19478 13. https://gcc.gnu.org/lists.html 19479 14. https://www.fsf.org/ 19480 15. https://gcc.gnu.org/about.html 19481 16. http://validator.w3.org/check/referer 19482 ====================================================================== 19483 http://gcc.gnu.org/egcs-1.1/features.html 19484 EGCS 1.1 new features 19485 19486 * Integrated GNU Fortran (g77) compiler and runtime library with 19487 improvements, based on g77 version 0.5.23. 19488 * Vast improvements in the C++ compiler; so many they have [1]page of 19489 their own! 19490 * Compiler implements [2]global common subexpression elimination and 19491 global copy/constant propagation. 19492 * More major improvements in the [3]alias analysis code. 19493 * More major improvements in the exception handling code to improve 19494 performance, lower static overhead and provide the infrastructure 19495 for future improvements. 19496 * The infamous /tmp symlink race security problems have been fixed. 19497 * The regmove optimization pass has been nearly completely rewritten 19498 to improve performance of generated code. 19499 * The compiler now recomputes register usage information before local 19500 register allocation. By providing more accurate information to the 19501 priority based allocator, we get better register allocation. 19502 * The register reloading phase of the compiler optimizes spill code 19503 much better than in previous releases. 19504 * Some bad interactions between the register allocator and 19505 instruction scheduler have been fixed, resulting in much better 19506 code for certain programs. Additionally, we have tuned the 19507 scheduler in various ways to improve performance of generated code 19508 for some architectures. 19509 * The compiler's branch shortening algorithms have been significantly 19510 improved to work better on targets which align jump targets. 19511 * The compiler now supports -Os to prefer optimizing for code space 19512 over optimizing for code speed. 19513 * The compiler will now totally eliminate library calls which compute 19514 constant values. This primarily helps targets with no integer 19515 div/mul support and targets without floating point support. 19516 * The compiler now supports an extensive "--help" option. 19517 * cpplib has been greatly improved and may be suitable for limited 19518 use. 19519 * Memory footprint for the compiler has been significantly reduced 19520 for some pathological cases. 19521 * The time to build EGCS has been improved for certain targets 19522 (particularly the alpha and mips platforms). 19523 * Many infrastructure improvements throughout the compiler, plus the 19524 usual mountain of bugfixes and minor improvements. 19525 * Target dependent improvements: 19526 + SPARC port now includes V8 plus and V9 support as well as 19527 performance tuning for Ultra class machines. The SPARC port 19528 now uses the Haifa scheduler. 19529 + Alpha port has been tuned for the EV6 processor and has an 19530 optimized expansion of memcpy/bzero. The Alpha port now uses 19531 the Haifa scheduler. 19532 + RS6000/PowerPC: support for the Power64 architecture and AIX 19533 4.3. The RS6000/PowerPC port now uses the Haifa scheduler. 19534 + x86: Alignment of static store data and jump targets is per 19535 Intel recommendations now. Various improvements throughout the 19536 x86 port to improve performance on Pentium processors 19537 (including improved epilogue sequences for Pentium chips and 19538 backend improvements which should help register allocation on 19539 all x86 variants. Conditional move support has been fixed and 19540 enabled for PPro processors. The x86 port also better supports 19541 64bit operations now. Unixware 7, a System V Release 5 target, 19542 is now supported and SCO OpenServer targets can support GAS. 19543 + MIPS has improved multiply/multiply-add support and now 19544 includes mips16 ISA support. 19545 + M68k has many micro-optimizations and Coldfire fixes. 19546 * Core compiler is based on the GCC development tree from June 9, 19547 1998, so we have all of the [4]features found in GCC 2.8. 19548 19549 19550 For questions related to the use of GCC, please consult these web 19551 pages and the [5]GCC manuals. If that fails, the 19552 [6]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 19553 web pages and the development of GCC are welcome on our developer 19554 list at [7]gcc (a] gcc.gnu.org. All of [8]our lists have public archives. 19555 19556 Copyright (C) [9]Free Software Foundation, Inc. Verbatim copying and 19557 distribution of this entire article is permitted in any medium, 19558 provided this notice is preserved. 19559 19560 These pages are [10]maintained by the GCC team. Last modified 19561 2019-11-28[11]. 19562 19563 References 19564 19565 1. http://gcc.gnu.org/egcs-1.1/c++features.html 19566 2. http://gcc.gnu.org/news/gcse.html 19567 3. http://gcc.gnu.org/news/alias.html 19568 4. http://gcc.gnu.org/egcs-1.0/features-2.8.html 19569 5. https://gcc.gnu.org/onlinedocs/ 19570 6. mailto:gcc-help (a] gcc.gnu.org 19571 7. mailto:gcc (a] gcc.gnu.org 19572 8. https://gcc.gnu.org/lists.html 19573 9. https://www.fsf.org/ 19574 10. https://gcc.gnu.org/about.html 19575 11. http://validator.w3.org/check/referer 19576 ====================================================================== 19577 http://gcc.gnu.org/egcs-1.1/caveats.html 19578 EGCS 1.1 Caveats 19579 19580 * EGCS has an integrated libstdc++, but does not have an integrated 19581 libg++. Furthermore old libg++ releases will not work with EGCS; HJ 19582 Lu has made a libg++-2.8.1.2 snapshot available which may work with 19583 EGCS. 19584 Note most C++ programs only need libstdc++. 19585 * Exception handling may not work with shared libraries, particularly 19586 on alphas, hppas, rs6000/powerpc and mips based platforms. 19587 Exception handling is known to work on x86-linux platforms with 19588 shared libraries. 19589 * Some versions of the Linux kernel have bugs which prevent them from 19590 being compiled or from running when compiled by EGCS. See the FAQ 19591 (as shipped with EGCS 1.1) for additional information. 19592 * In general, EGCS is more rigorous about rejecting invalid C++ code 19593 or deprecated C++ constructs than g++-2.7, g++-2.8 or EGCS 1.0. As 19594 a result it may be necessary to fix C++ code before it will compile 19595 with EGCS. 19596 * G++ is also converting toward the ISO C++ standard; as a result 19597 code which was previously valid (and thus accepted by other 19598 compilers and older versions of g++) may no longer be accepted. 19599 * EGCS 1.1 compiled C++ code is not binary compatible with EGCS 1.0.x 19600 or GCC 2.8.x due to changes necessary to support thread safe 19601 exception handling. 19602 19603 19604 For questions related to the use of GCC, please consult these web 19605 pages and the [1]GCC manuals. If that fails, the 19606 [2]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 19607 web pages and the development of GCC are welcome on our developer 19608 list at [3]gcc (a] gcc.gnu.org. All of [4]our lists have public archives. 19609 19610 Copyright (C) [5]Free Software Foundation, Inc. Verbatim copying and 19611 distribution of this entire article is permitted in any medium, 19612 provided this notice is preserved. 19613 19614 These pages are [6]maintained by the GCC team. Last modified 19615 2019-11-28[7]. 19616 19617 References 19618 19619 1. https://gcc.gnu.org/onlinedocs/ 19620 2. mailto:gcc-help (a] gcc.gnu.org 19621 3. mailto:gcc (a] gcc.gnu.org 19622 4. https://gcc.gnu.org/lists.html 19623 5. https://www.fsf.org/ 19624 6. https://gcc.gnu.org/about.html 19625 7. http://validator.w3.org/check/referer 19626 ====================================================================== 19627 http://gcc.gnu.org/egcs-1.0/index.html 19628 EGCS 1.0 19629 19630 December 3, 1997: We are pleased to announce the release of EGCS 1.0. 19631 January 6, 1998: We are pleased to announce the release of EGCS 1.0.1. 19632 March 16, 1998: We are pleased to announce the release of EGCS 1.0.2. 19633 May 15, 1998 We are pleased to announce the release of EGCS 1.0.3. 19634 19635 EGCS is a collaborative effort involving several groups of hackers 19636 using an open development model to accelerate development and testing 19637 of GNU compilers and runtime libraries. 19638 19639 An important goal of EGCS is to allow wide scale testing of 19640 experimental features and optimizations; therefore, EGCS contains some 19641 features and optimizations which are still under development. However, 19642 EGCS has been carefully tested and should be comparable in quality to 19643 most GCC releases. 19644 19645 EGCS 1.0 is based on an August 2, 1997 snapshot of the GCC 2.8 19646 development sources; it contains nearly all of the new features found 19647 in GCC 2.8. 19648 19649 EGCS 1.0 also contains many improvements and features not found in GCC 19650 2.7 and even the GCC 2.8 series (which was released after the original 19651 EGCS 1.0 release). 19652 * Integrated C++ runtime libraries, including support for most major 19653 GNU/Linux systems! 19654 * The integrated libstdc++ library includes a verbatim copy of SGI's 19655 STL release. 19656 * Integrated GNU Fortran compiler. 19657 * New instruction scheduler. 19658 * New alias analysis code. 19659 19660 See the [1]new features page for a more complete list of new features. 19661 19662 EGCS 1.0.1 is a minor update to the EGCS 1.0 compiler to fix a few 19663 critical bugs and add support for Red Hat 5.0 Linux. Changes since the 19664 EGCS 1.0 release: 19665 * Add support for Red Hat 5.0 Linux and better support for Linux 19666 systems using glibc2. 19667 Many programs failed to link when compiled with EGCS 1.0 on Red Hat 19668 5.0 or on systems with newer versions of glibc2. EGCS 1.0.1 should 19669 fix these problems. 19670 * Compatibility with both EGCS 1.0 and GCC 2.8 libgcc exception 19671 handling interfaces. 19672 To avoid future compatibility problems, we strongly urge anyone who 19673 is planning on distributing shared libraries that contain C++ code 19674 to upgrade to EGCS 1.0.1 first. 19675 Soon after EGCS 1.0 was released, the GCC developers made some 19676 incompatible changes in libgcc's exception handling interfaces. 19677 These changes were needed to solve problems on some platforms. This 19678 means that GCC 2.8.0, when released, will not be seamlessly 19679 compatible with shared libraries built by EGCS 1.0. The reason is 19680 that the libgcc.a in GCC 2.8.0 will not contain a function needed 19681 by the old interface. 19682 The result of this is that there may be compatibility problems with 19683 shared libraries built by EGCS 1.0 when used with GCC 2.8.0. 19684 With EGCS 1.0.1, generated code uses the new (GCC 2.8.0) interface, 19685 and libgcc.a has the support routines for both the old and the new 19686 interfaces (so EGCS 1.0.1 and EGCS 1.0 code can be freely mixed, 19687 and EGCS 1.0.1 and GCC 2.8.0 code can be freely mixed). 19688 The maintainers of GCC 2.x have decided against including seamless 19689 support for the old interface in 2.8.0, since it was never 19690 "official", so to avoid future compatibility problems we recommend 19691 against distributing any shared libraries built by EGCS 1.0 that 19692 contain C++ code (upgrade to 1.0.1 and use that). 19693 * Various bugfixes in the x86, hppa, mips, and rs6000/ppc back ends. 19694 The x86 changes fix code generation errors exposed when building 19695 glibc2 and the usual GNU/Linux dynamic linker (ld.so). 19696 The hppa change fixes a compiler abort when configured for use with 19697 RTEMS. 19698 The MIPS changes fix problems with the definition of LONG_MAX on 19699 newer systems, allow for command line selection of the target ABI, 19700 and fix one code generation problem. 19701 The rs6000/ppc change fixes some problems with passing structures 19702 to varargs/stdarg functions. 19703 * A few machine independent bugfixes, mostly to fix code generation 19704 errors when building Linux kernels or glibc. 19705 * Fix a few critical exception handling and template bugs in the C++ 19706 compiler. 19707 * Fix Fortran namelist bug on alphas. 19708 * Fix build problems on x86-solaris systems. 19709 19710 EGCS 1.0.2 is a minor update to the EGCS 1.0.1 compiler to fix several 19711 serious problems in EGCS 1.0.1. 19712 * General improvements and fixes 19713 + Memory consumption significantly reduced, especially for 19714 templates and inline functions. 19715 + Fix various problems with glibc2.1. 19716 + Fix loop optimization bug exposed by rs6000/ppc port. 19717 + Fix to avoid potential code generation problems in jump.c. 19718 + Fix some undefined symbol problems in dwarf1 debug support. 19719 * g++/libstdc++ improvements and fixes 19720 + libstdc++ in the EGCS release has been updated and should be 19721 link compatible with libstdc++-2.8. 19722 + Various fixes in libio/libstdc++ to work better on GNU/Linux 19723 systems. 19724 + Fix problems with duplicate symbols on systems that do not 19725 support weak symbols. 19726 + Memory corruption bug and undefined symbols in bastring have 19727 been fixed. 19728 + Various exception handling fixes. 19729 + Fix compiler abort for very long thunk names. 19730 * g77 improvements and fixes 19731 + Fix compiler crash for omitted bound in Fortran CASE 19732 statement. 19733 + Add missing entries to g77 lang-options. 19734 + Fix problem with -fpedantic in the g77 compiler. 19735 + Fix "backspace" problem with g77 on alphas. 19736 + Fix x86 backend problem with Fortran literals and -fpic. 19737 + Fix some of the problems with negative subscripts for g77 on 19738 alphas. 19739 + Fixes for Fortran builds on cygwin32/mingw32. 19740 * platform specific improvements and fixes 19741 + Fix long double problems on x86 (exposed by glibc). 19742 + x86 ports define i386 again to keep imake happy. 19743 + Fix exception handling support on NetBSD ports. 19744 + Several changes to collect2 to fix many problems with AIX. 19745 + Define __ELF__ for GNU/Linux on rs6000. 19746 + Fix -mcall-linux problem on GNU/Linux on rs6000. 19747 + Fix stdarg/vararg problem for GNU/Linux on rs6000. 19748 + Allow autoconf to select a proper install problem on AIX 3.1. 19749 + m68k port support includes -mcpu32 option as well as cpu32 19750 multilibs. 19751 + Fix stdarg bug for irix6. 19752 + Allow EGCS to build on irix5 without the gnu assembler. 19753 + Fix problem with static linking on sco5. 19754 + Fix bootstrap on sco5 with native compiler. 19755 + Fix for abort building newlib on H8 target. 19756 + Fix fixincludes handling of math.h on SunOS. 19757 + Minor fix for Motorola 3300 m68k systems. 19758 19759 EGCS 1.0.3 is a minor update to the EGCS 1.0.2 compiler to fix a few 19760 problems reported by Red Hat for builds of Red Hat 5.1. 19761 * Generic bugfixes: 19762 + Fix a typo in the libio library which resulted in incorrect 19763 behavior of istream::get. 19764 + Fix the Fortran negative array index problem. 19765 + Fix a major problem with the ObjC runtime thread support 19766 exposed by glibc2. 19767 + Reduce memory consumption of the Haifa scheduler. 19768 * Target specific bugfixes: 19769 + Fix one x86 floating point code generation bug exposed by 19770 glibc2 builds. 19771 + Fix one x86 internal compiler error exposed by glibc2 builds. 19772 + Fix profiling bugs on the Alpha. 19773 + Fix ImageMagick & emacs 20.2 build problems on the Alpha. 19774 + Fix rs6000/ppc bug when converting values from integer types 19775 to floating point types. 19776 19777 The EGCS 1.0 releases include installation instructions in both HTML 19778 and plaintext forms (see the INSTALL directory in the toplevel 19779 directory of the distribution). However, we also keep the most up to 19780 date installation instructions and [2]build/test status on our web 19781 page. We will update those pages as new information becomes available. 19782 19783 And, we can't in good conscience fail to mention some [3]caveats to 19784 using EGCS. 19785 19786 Update: Big thanks to Stanford for providing a high speed link for 19787 downloading EGCS (go.cygnus.com)! 19788 19789 Download EGCS from ftp.cygnus.com (USA California) or go.cygnus.com 19790 (USA California -- High speed link provided by Stanford). 19791 19792 The EGCS 1.0 release is also available many mirror sites. 19793 [4]Goto mirror list to find a closer site 19794 19795 We'd like to thank the numerous people that have contributed new 19796 features, test results, bugfixes, etc. Unfortunately, they're far too 19797 numerous to mention by name. 19798 19799 19800 For questions related to the use of GCC, please consult these web 19801 pages and the [5]GCC manuals. If that fails, the 19802 [6]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 19803 web pages and the development of GCC are welcome on our developer 19804 list at [7]gcc (a] gcc.gnu.org. All of [8]our lists have public archives. 19805 19806 Copyright (C) [9]Free Software Foundation, Inc. Verbatim copying and 19807 distribution of this entire article is permitted in any medium, 19808 provided this notice is preserved. 19809 19810 These pages are [10]maintained by the GCC team. Last modified 19811 2019-11-28[11]. 19812 19813 References 19814 19815 1. http://gcc.gnu.org/egcs-1.0/features.html 19816 2. http://gcc.gnu.org/egcs-1.0/buildstat.html 19817 3. http://gcc.gnu.org/egcs-1.0/caveats.html 19818 4. http://gcc.gnu.org/mirrors.html 19819 5. https://gcc.gnu.org/onlinedocs/ 19820 6. mailto:gcc-help (a] gcc.gnu.org 19821 7. mailto:gcc (a] gcc.gnu.org 19822 8. https://gcc.gnu.org/lists.html 19823 9. https://www.fsf.org/ 19824 10. https://gcc.gnu.org/about.html 19825 11. http://validator.w3.org/check/referer 19826 ====================================================================== 19827 http://gcc.gnu.org/egcs-1.0/features.html 19828 EGCS 1.0 features 19829 19830 * Core compiler is based on the gcc2 development tree from Aug 2, 19831 1997, so we have most of the [1]features found in GCC 2.8. 19832 * Integrated GNU Fortran compiler based on g77-0.5.22-19970929. 19833 * Vast improvements in the C++ compiler; so many they have [2]page of 19834 their own! 19835 * Integrated C++ runtime libraries, including support for most major 19836 GNU/Linux systems! 19837 * New instruction scheduler from IBM Haifa which includes support for 19838 function wide instruction scheduling as well as superscalar 19839 scheduling. 19840 * Significantly improved alias analysis code. 19841 * Improved register allocation for two address machines. 19842 * Significant code generation improvements for Fortran code on 19843 Alphas. 19844 * Various optimizations from the g77 project as well as improved loop 19845 optimizations. 19846 * Dwarf2 debug format support for some targets. 19847 * egcs libstdc++ includes the SGI STL implementation without changes. 19848 * As a result of these and other changes, egcs libstc++ is not binary 19849 compatible with previous releases of libstdc++. 19850 * Various new ports -- UltraSPARC, Irix6.2 & Irix6.3 support, The SCO 19851 Openserver 5 family (5.0.{0,2,4} and Internet FastStart 1.0 and 19852 1.1), Support for RTEMS on several embedded targets, Support for 19853 arm-linux, Mitsubishi M32R, Hitachi H8/S, Matsushita MN102 and 19854 MN103, NEC V850, Sparclet, Solaris & GNU/Linux on PowerPCs, etc. 19855 * Integrated testsuites for gcc, g++, g77, libstdc++ and libio. 19856 * RS6000/PowerPC ports generate code which can run on all 19857 RS6000/PowerPC variants by default. 19858 * -mcpu= and -march= switches for the x86 port to allow better 19859 control over how the x86 port generates code. 19860 * Includes the template repository patch (aka repo patch); note the 19861 new template code makes repo obsolete for ELF systems using gnu-ld 19862 such as GNU/Linux. 19863 * Plus the usual assortment of bugfixes and improvements. 19864 19865 19866 For questions related to the use of GCC, please consult these web 19867 pages and the [3]GCC manuals. If that fails, the 19868 [4]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 19869 web pages and the development of GCC are welcome on our developer 19870 list at [5]gcc (a] gcc.gnu.org. All of [6]our lists have public archives. 19871 19872 Copyright (C) [7]Free Software Foundation, Inc. Verbatim copying and 19873 distribution of this entire article is permitted in any medium, 19874 provided this notice is preserved. 19875 19876 These pages are [8]maintained by the GCC team. Last modified 19877 2019-11-28[9]. 19878 19879 References 19880 19881 1. http://gcc.gnu.org/egcs-1.0/features-2.8.html 19882 2. http://gcc.gnu.org/egcs-1.0/c++features.html 19883 3. https://gcc.gnu.org/onlinedocs/ 19884 4. mailto:gcc-help (a] gcc.gnu.org 19885 5. mailto:gcc (a] gcc.gnu.org 19886 6. https://gcc.gnu.org/lists.html 19887 7. https://www.fsf.org/ 19888 8. https://gcc.gnu.org/about.html 19889 9. http://validator.w3.org/check/referer 19890 ====================================================================== 19891 http://gcc.gnu.org/egcs-1.0/caveats.html 19892 EGCS 1.0 Caveats 19893 19894 * EGCS has an integrated libstdc++, but does not have an integrated 19895 libg++. Furthermore old libg++ releases will not work with egc; HJ 19896 Lu has made a libg++-2.8.1.2 available which may work with EGCS. 19897 Note most C++ programs only need libstdc++. 19898 * Note that using -pedantic or -Wreturn-type can cause an explosion 19899 in the amount of memory needed for template-heavy C++ code, such as 19900 code that uses STL. Also note that -Wall includes -Wreturn-type, so 19901 if you use -Wall you will need to specify -Wno-return-type to turn 19902 it off. 19903 * Exception handling may not work with shared libraries, particularly 19904 on alphas, hppas, and mips based platforms. Exception handling is 19905 known to work on x86-linux platforms with shared libraries. 19906 * Some versions of the Linux kernel have bugs which prevent them from 19907 being compiled or from running when compiled by EGCS. See the FAQ 19908 (as shipped with EGCS 1.0) for additional information. 19909 * In general, EGCS is more rigorous about rejecting invalid C++ code 19910 or deprecated C++ constructs than G++ 2.7. As a result it may be 19911 necessary to fix C++ code before it will compile with EGCS. 19912 * G++ is also aggressively tracking the C++ standard; as a result 19913 code which was previously valid (and thus accepted by other 19914 compilers and older versions of G++) may no longer be accepted. 19915 * EGCS 1.0 may not work with Red Hat Linux 5.0 on all targets. EGCS 19916 1.0.x and later releases should work with Red Hat Linux 5.0. 19917 19918 19919 For questions related to the use of GCC, please consult these web 19920 pages and the [1]GCC manuals. If that fails, the 19921 [2]gcc-help (a] gcc.gnu.org mailing list might help. Comments on these 19922 web pages and the development of GCC are welcome on our developer 19923 list at [3]gcc (a] gcc.gnu.org. All of [4]our lists have public archives. 19924 19925 Copyright (C) [5]Free Software Foundation, Inc. Verbatim copying and 19926 distribution of this entire article is permitted in any medium, 19927 provided this notice is preserved. 19928 19929 These pages are [6]maintained by the GCC team. Last modified 19930 2019-11-28[7]. 19931 19932 References 19933 19934 1. https://gcc.gnu.org/onlinedocs/ 19935 2. mailto:gcc-help (a] gcc.gnu.org 19936 3. mailto:gcc (a] gcc.gnu.org 19937 4. https://gcc.gnu.org/lists.html 19938 5. https://www.fsf.org/ 19939 6. https://gcc.gnu.org/about.html 19940 7. http://validator.w3.org/check/referer 19941 ====================================================================== 19942
Indexes created Tue Oct 27 00:25:24 UTC 2026