asm.h revision 1.35
1 /* $NetBSD: asm.h,v 1.35 2017/01/14 16:15:10 martin Exp $ */ 2 3 /* 4 * Copyright (c) 1991,1990,1989,1994,1995,1996 Carnegie Mellon University 5 * All Rights Reserved. 6 * 7 * Permission to use, copy, modify and distribute this software and its 8 * documentation is hereby granted, provided that both the copyright 9 * notice and this permission notice appear in all copies of the 10 * software, derivative works or modified versions, and any portions 11 * thereof, and that both notices appear in supporting documentation. 12 * 13 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 14 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 15 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 16 * 17 * Carnegie Mellon requests users of this software to return to 18 * 19 * Software Distribution Coordinator or Software.Distribution (at) CS.CMU.EDU 20 * School of Computer Science 21 * Carnegie Mellon University 22 * Pittsburgh PA 15213-3890 23 * 24 * any improvements or extensions that they make and grant Carnegie Mellon 25 * the rights to redistribute these changes. 26 */ 27 28 /* 29 * Assembly coding style 30 * 31 * This file contains macros and register defines to 32 * aid in writing more readable assembly code. 33 * Some rules to make assembly code understandable by 34 * a debugger are also noted. 35 * 36 * The document 37 * 38 * "ALPHA Calling Standard", DEC 27-Apr-90 39 * 40 * defines (a superset of) the rules and conventions 41 * we use. While we make no promise of adhering to 42 * such standard and its evolution (esp where we 43 * can get faster code paths) it is certainly intended 44 * that we be interoperable with such standard. 45 * 46 * In this sense, this file is a proper part of the 47 * definition of the (software) Alpha architecture. 48 */ 49 50 /* 51 * Symbolic register names and register saving rules 52 * 53 * Legend: 54 * T Saved by caller (Temporaries) 55 * S Saved by callee (call-Safe registers) 56 */ 57 58 #define v0 $0 /* (T) return value */ 59 #define t0 $1 /* (T) temporary registers */ 60 #define t1 $2 61 #define t2 $3 62 #define t3 $4 63 #define t4 $5 64 #define t5 $6 65 #define t6 $7 66 #define t7 $8 67 68 #define s0 $9 /* (S) call-safe registers */ 69 #define s1 $10 70 #define s2 $11 71 #define s3 $12 72 #define s4 $13 73 #define s5 $14 74 #define s6 $15 75 #define a0 $16 /* (T) argument registers */ 76 #define a1 $17 77 #define a2 $18 78 #define a3 $19 79 #define a4 $20 80 #define a5 $21 81 #define t8 $22 /* (T) temporary registers */ 82 #define t9 $23 83 #define t10 $24 84 #define t11 $25 85 #define ra $26 /* (S) return address */ 86 #define t12 $27 /* (T) another temporary */ 87 #define at_reg $28 /* (T) assembler scratch */ 88 #define gp $29 /* (T) (local) data pointer */ 89 #define sp $30 /* (S) stack pointer */ 90 #define zero $31 /* wired zero */ 91 92 /* Floating point registers (XXXX VERIFY THIS) */ 93 #define fv0 $f0 /* (T) return value (real) */ 94 #define fv1 $f1 /* (T) return value (imaginary)*/ 95 #define ft0 fv1 96 #define fs0 $f2 /* (S) call-safe registers */ 97 #define fs1 $f3 98 #define fs2 $f4 99 #define fs3 $f5 100 #define fs4 $f6 101 #define fs5 $f7 102 #define fs6 $f8 103 #define fs7 $f9 104 #define ft1 $f10 /* (T) temporary registers */ 105 #define ft2 $f11 106 #define ft3 $f12 107 #define ft4 $f13 108 #define ft5 $f14 109 #define ft6 $f15 110 #define fa0 $f16 /* (T) argument registers */ 111 #define fa1 $f17 112 #define fa2 $f18 113 #define fa3 $f19 114 #define fa4 $f20 115 #define fa5 $f21 116 #define ft7 $f22 /* (T) more temporaries */ 117 #define ft8 $f23 118 #define ft9 $f24 119 #define ft10 $f25 120 #define ft11 $f26 121 #define ft12 $f27 122 #define ft13 $f28 123 #define ft14 $f29 124 #define ft15 $f30 125 #define fzero $f31 /* wired zero */ 126 127 128 /* Other DEC standard names */ 129 #define ai $25 /* (T) argument information */ 130 #define pv $27 /* (T) procedure value */ 131 132 133 /* 134 * Useful stuff. 135 */ 136 #undef __CONCAT 137 #ifdef __STDC__ 138 #define __CONCAT(a,b) a ## b 139 #else 140 #define __CONCAT(a,b) a/**/b 141 #endif 142 #define ___CONCAT(a,b) __CONCAT(a,b) 143 144 /* 145 * Macro to make a local label name. 146 */ 147 #define LLABEL(name,num) ___CONCAT(___CONCAT(L,name),num) 148 149 /* 150 * 151 * Debuggers need symbol table information to be able to properly 152 * decode a stack trace. The minimum that should be provided is: 153 * 154 * name: 155 * .proc name,numargs 156 * 157 * where "name" is the function's name; 158 * "numargs" how many arguments it expects. For varargs 159 * procedures this should be a negative number, 160 * indicating the minimum required number of 161 * arguments (which is at least 1); 162 * 163 * NESTED functions (functions that call other functions) should define 164 * how they handle their stack frame in a .frame directive: 165 * 166 * .frame framesize, pc_reg, i_mask, f_mask 167 * 168 * where "framesize" is the size of the frame for this function, in bytes. 169 * That is: 170 * new_sp + framesize == old_sp 171 * Framesizes should be rounded to a cacheline size. 172 * Note that old_sp plays the role of a conventional 173 * "frame pointer"; 174 * "pc_reg" is either a register which preserves the caller's PC 175 * or 'std', if std the saved PC should be stored at 176 * old_sp-8 177 * "i_mask" is a bitmask that indicates which of the integer 178 * registers are saved. See the M_xx defines at the 179 * end for the encoding of this 32bit value. 180 * "f_mask" is the same, for floating point registers. 181 * 182 * Note, 10/31/97: This is interesting but it isn't the way gcc outputs 183 * frame directives and it isn't the way the macros below output them 184 * either. Frame directives look like this: 185 * 186 * .frame $15,framesize,$26,0 187 * 188 * If no fp is set up then $30 should be used instead of $15. 189 * Also, gdb expects to find a <lda sp,-framesize(sp)> at the beginning 190 * of a procedure. Don't use things like sub sp,framesize,sp for this 191 * reason. End Note 10/31/97. ross (at) NetBSD.org 192 * 193 * Note that registers should be saved starting at "old_sp-8", where the 194 * return address should be stored. Other registers follow at -16-24-32.. 195 * starting from register 0 (if saved) and up. Then float registers (ifany) 196 * are saved. 197 * 198 * If you need to alias a leaf function, or to provide multiple entry points 199 * use the LEAF() macro for the main entry point and XLEAF() for the other 200 * additional/alternate entry points. 201 * "XLEAF"s must be nested within a "LEAF" and a ".end". 202 * Similar rules for nested routines, e.g. use NESTED/XNESTED 203 * Symbols that should not be exported can be declared with the STATIC_xxx 204 * macros. 205 * 206 * All functions must be terminated by the END macro 207 * 208 * It is conceivable, although currently at the limits of compiler 209 * technology, that while performing inter-procedural optimizations 210 * the compiler/linker be able to avoid unnecessary register spills 211 * if told about the register usage of LEAF procedures (and by transitive 212 * closure of NESTED procedures as well). Assembly code can help 213 * this process using the .reguse directive: 214 * 215 * .reguse i_mask, f_mask 216 * 217 * where the register masks are built as above or-ing M_xx defines. 218 * 219 * 220 * All symbols are internal unless EXPORTed. Symbols that are IMPORTed 221 * must be appropriately described to the debugger. 222 * 223 */ 224 225 /* 226 * MCOUNT 227 */ 228 229 #ifndef GPROF 230 #define MCOUNT /* nothing */ 231 #else 232 #define MCOUNT \ 233 .set noat; \ 234 jsr at_reg,_mcount; \ 235 .set at 236 #endif 237 /* 238 * PALVECT, ESETUP, and ERSAVE 239 * Declare a palcode transfer point, and carefully construct 240 * gdb symbols with an unusual _negative_ register-save offset 241 * so that gdb can find the otherwise lost PC and then 242 * invert the vector for traceback. Also, fix up framesize, 243 * allowing for the palframe for the same reason. 244 */ 245 246 #define PALVECT(_name_) \ 247 ESETUP(_name_); \ 248 ERSAVE() 249 250 #define ESETUP(_name_) \ 251 /* .loc 1 __LINE__; */ \ 252 .globl _name_; \ 253 .ent _name_ 0; \ 254 _name_:; \ 255 .set noat; \ 256 lda sp,-(FRAME_SW_SIZE*8)(sp); \ 257 .frame $30,(FRAME_SW_SIZE+6)*8,$26,0; /* give gdb the real size */\ 258 .mask 0x4000000,-0x28; \ 259 .set at 260 261 #define ERSAVE() \ 262 .set noat; \ 263 stq at_reg,(FRAME_AT*8)(sp); \ 264 .set at; \ 265 stq ra,(FRAME_RA*8)(sp); \ 266 /* .loc 1 __LINE__; */ \ 267 bsr ra,exception_save_regs /* jmp/CALL trashes pv/t12 */ 268 269 270 /* 271 * LEAF 272 * Declare a global leaf function. 273 * A leaf function does not call other functions AND does not 274 * use any register that is callee-saved AND does not modify 275 * the stack pointer. 276 */ 277 #define LEAF(_name_,_n_args_) \ 278 .globl _name_; \ 279 .ent _name_ 0; \ 280 _name_:; \ 281 .frame sp,0,ra; \ 282 MCOUNT 283 /* should have been 284 .proc _name_,_n_args_; \ 285 .frame 0,ra,0,0 286 */ 287 288 #define LEAF_NOPROFILE(_name_,_n_args_) \ 289 .globl _name_; \ 290 .ent _name_ 0; \ 291 _name_:; \ 292 .frame sp,0,ra 293 /* should have been 294 .proc _name_,_n_args_; \ 295 .frame 0,ra,0,0 296 */ 297 298 /* 299 * STATIC_LEAF 300 * Declare a local leaf function. 301 */ 302 #define STATIC_LEAF(_name_,_n_args_) \ 303 .ent _name_ 0; \ 304 _name_:; \ 305 .frame sp,0,ra; \ 306 MCOUNT 307 /* should have been 308 .proc _name_,_n_args_; \ 309 .frame 0,ra,0,0 310 */ 311 /* 312 * XLEAF 313 * Global alias for a leaf function, or alternate entry point 314 */ 315 #define XLEAF(_name_,_n_args_) \ 316 .globl _name_; \ 317 .aent _name_ 0; \ 318 _name_: 319 /* should have been 320 .aproc _name_,_n_args_; 321 */ 322 323 /* 324 * STATIC_XLEAF 325 * Local alias for a leaf function, or alternate entry point 326 */ 327 #define STATIC_XLEAF(_name_,_n_args_) \ 328 .aent _name_ 0; \ 329 _name_: 330 /* should have been 331 .aproc _name_,_n_args_; 332 */ 333 334 /* 335 * NESTED 336 * Declare a (global) nested function 337 * A nested function calls other functions and needs 338 * therefore stack space to save/restore registers. 339 */ 340 #define NESTED(_name_, _n_args_, _framesize_, _pc_reg_, _i_mask_, _f_mask_ ) \ 341 .globl _name_; \ 342 .ent _name_ 0; \ 343 _name_:; \ 344 .frame sp,_framesize_,_pc_reg_; \ 345 .livereg _i_mask_,_f_mask_; \ 346 MCOUNT 347 /* should have been 348 .proc _name_,_n_args_; \ 349 .frame _framesize_, _pc_reg_, _i_mask_, _f_mask_ 350 */ 351 352 #define NESTED_NOPROFILE(_name_, _n_args_, _framesize_, _pc_reg_, _i_mask_, _f_mask_ ) \ 353 .globl _name_; \ 354 .ent _name_ 0; \ 355 _name_:; \ 356 .frame sp,_framesize_,_pc_reg_; \ 357 .livereg _i_mask_,_f_mask_ 358 /* should have been 359 .proc _name_,_n_args_; \ 360 .frame _framesize_, _pc_reg_, _i_mask_, _f_mask_ 361 */ 362 363 /* 364 * STATIC_NESTED 365 * Declare a local nested function. 366 */ 367 #define STATIC_NESTED(_name_, _n_args_, _framesize_, _pc_reg_, _i_mask_, _f_mask_ ) \ 368 .ent _name_ 0; \ 369 _name_:; \ 370 .frame sp,_framesize_,_pc_reg_; \ 371 .livereg _i_mask_,_f_mask_; \ 372 MCOUNT 373 /* should have been 374 .proc _name_,_n_args_; \ 375 .frame _framesize_, _pc_reg_, _i_mask_, _f_mask_ 376 */ 377 378 /* 379 * XNESTED 380 * Same as XLEAF, for a nested function. 381 */ 382 #define XNESTED(_name_,_n_args_) \ 383 .globl _name_; \ 384 .aent _name_ 0; \ 385 _name_: 386 /* should have been 387 .aproc _name_,_n_args_; 388 */ 389 390 391 /* 392 * STATIC_XNESTED 393 * Same as STATIC_XLEAF, for a nested function. 394 */ 395 #define STATIC_XNESTED(_name_,_n_args_) \ 396 .aent _name_ 0; \ 397 _name_: 398 /* should have been 399 .aproc _name_,_n_args_; 400 */ 401 402 403 /* 404 * END 405 * Function delimiter 406 */ 407 #define END(_name_) \ 408 .end _name_ 409 410 411 /* 412 * CALL 413 * Function invocation 414 */ 415 #define CALL(_name_) \ 416 /* .loc 1 __LINE__; */ \ 417 jsr ra,_name_; \ 418 ldgp gp,0(ra) 419 /* but this would cover longer jumps 420 br ra,.+4; \ 421 bsr ra,_name_ 422 */ 423 424 425 /* 426 * RET 427 * Return from function 428 */ 429 #define RET \ 430 ret zero,(ra),1 431 432 433 /* 434 * EXPORT 435 * Export a symbol 436 */ 437 #define EXPORT(_name_) \ 438 .globl _name_; \ 439 _name_: 440 441 442 /* 443 * IMPORT 444 * Make an external name visible, typecheck the size 445 */ 446 #define IMPORT(_name_, _size_) \ 447 .extern _name_,_size_ 448 449 450 /* 451 * ABS 452 * Define an absolute symbol 453 */ 454 #define ABS(_name_, _value_) \ 455 .globl _name_; \ 456 _name_ = _value_ 457 458 459 /* 460 * BSS 461 * Allocate un-initialized space for a global symbol 462 */ 463 #define BSS(_name_,_numbytes_) \ 464 .comm _name_,_numbytes_ 465 466 /* 467 * VECTOR 468 * Make an exception entry point look like a called function, 469 * to make it digestible to the debugger (KERNEL only) 470 */ 471 #define VECTOR(_name_, _i_mask_) \ 472 .globl _name_; \ 473 .ent _name_ 0; \ 474 _name_:; \ 475 .mask _i_mask_|IM_EXC,0; \ 476 .frame sp,MSS_SIZE,ra; 477 /* .livereg _i_mask_|IM_EXC,0 */ 478 /* should have been 479 .proc _name_,1; \ 480 .frame MSS_SIZE,$31,_i_mask_,0; \ 481 */ 482 483 /* 484 * MSG 485 * Allocate space for a message (a read-only ascii string) 486 */ 487 #define ASCIZ .asciz 488 #define MSG(msg,reg,label) \ 489 lda reg, label; \ 490 .data; \ 491 label: ASCIZ msg; \ 492 .text; 493 494 /* 495 * PRINTF 496 * Print a message 497 */ 498 #define PRINTF(msg,label) \ 499 MSG(msg,a0,label); \ 500 CALL(printf) 501 502 /* 503 * PANIC 504 * Fatal error (KERNEL) 505 */ 506 #define PANIC(msg,label) \ 507 MSG(msg,a0,label); \ 508 CALL(panic) 509 510 /* 511 * Register mask defines, used to define both save 512 * and use register sets. 513 * 514 * NOTE: The bit order should HAVE BEEN maintained when saving 515 * registers on the stack: sp goes at the highest 516 * address, gp lower on the stack, etc etc 517 * BUT NOONE CARES ABOUT DEBUGGERS AT MIPS 518 */ 519 520 #define IM_EXC 0x80000000 521 #define IM_SP 0x40000000 522 #define IM_GP 0x20000000 523 #define IM_AT 0x10000000 524 #define IM_T12 0x08000000 525 # define IM_PV IM_T4 526 #define IM_RA 0x04000000 527 #define IM_T11 0x02000000 528 # define IM_AI IM_T3 529 #define IM_T10 0x01000000 530 #define IM_T9 0x00800000 531 #define IM_T8 0x00400000 532 #define IM_A5 0x00200000 533 #define IM_A4 0x00100000 534 #define IM_A3 0x00080000 535 #define IM_A2 0x00040000 536 #define IM_A1 0x00020000 537 #define IM_A0 0x00010000 538 #define IM_S6 0x00008000 539 #define IM_S5 0x00004000 540 #define IM_S4 0x00002000 541 #define IM_S3 0x00001000 542 #define IM_S2 0x00000800 543 #define IM_S1 0x00000400 544 #define IM_S0 0x00000200 545 #define IM_T7 0x00000100 546 #define IM_T6 0x00000080 547 #define IM_T5 0x00000040 548 #define IM_T4 0x00000020 549 #define IM_T3 0x00000010 550 #define IM_T2 0x00000008 551 #define IM_T1 0x00000004 552 #define IM_T0 0x00000002 553 #define IM_V0 0x00000001 554 555 #define FM_T15 0x40000000 556 #define FM_T14 0x20000000 557 #define FM_T13 0x10000000 558 #define FM_T12 0x08000000 559 #define FM_T11 0x04000000 560 #define FM_T10 0x02000000 561 #define FM_T9 0x01000000 562 #define FM_T8 0x00800000 563 #define FM_T7 0x00400000 564 #define FM_A5 0x00200000 565 #define FM_A4 0x00100000 566 #define FM_A3 0x00080000 567 #define FM_A2 0x00040000 568 #define FM_A1 0x00020000 569 #define FM_A0 0x00010000 570 #define FM_T6 0x00008000 571 #define FM_T5 0x00004000 572 #define FM_T4 0x00002000 573 #define FM_T3 0x00001000 574 #define FM_T2 0x00000800 575 #define FM_T1 0x00000400 576 #define FM_S7 0x00000200 577 #define FM_S6 0x00000100 578 #define FM_S5 0x00000080 579 #define FM_S4 0x00000040 580 #define FM_S3 0x00000020 581 #define FM_S2 0x00000010 582 #define FM_S1 0x00000008 583 #define FM_S0 0x00000004 584 #define FM_T0 0x00000002 585 #define FM_V1 FM_T0 586 #define FM_V0 0x00000001 587 588 /* Pull in PAL "function" codes. */ 589 #include <machine/pal.h> 590 591 /* 592 * System call glue. 593 */ 594 #define SYSCALLNUM(name) \ 595 ___CONCAT(SYS_,name) 596 597 #define CALLSYS_NOERROR(name) \ 598 ldiq v0, SYSCALLNUM(name); \ 599 call_pal PAL_OSF1_callsys 600 601 #define LINUX_SYSCALLNUM(name) \ 602 ___CONCAT(LINUX_SYS_,name) 603 604 #define LINUX_CALLSYS_NOERROR(name) \ 605 ldiq v0, LINUX_SYSCALLNUM(name); \ 606 call_pal PAL_OSF1_callsys 607 608 /* 609 * Load the global pointer. 610 */ 611 #define LDGP(reg) \ 612 ldgp gp, 0(reg) 613 614 /* 615 * WEAK_ALIAS: create a weak alias. 616 */ 617 #define WEAK_ALIAS(alias,sym) \ 618 .weak alias; \ 619 alias = sym 620 621 /* 622 * STRONG_ALIAS: create a strong alias. 623 */ 624 #define STRONG_ALIAS(alias,sym) \ 625 .globl alias; \ 626 alias = sym 627 628 /* 629 * WARN_REFERENCES: create a warning if the specified symbol is referenced. 630 */ 631 #ifdef __STDC__ 632 #define WARN_REFERENCES(sym,msg) \ 633 .pushsection .gnu.warning. ## sym; \ 634 .ascii msg; \ 635 .popsection 636 #else 637 #define WARN_REFERENCES(sym,msg) \ 638 .pushsection .gnu.warning./**/sym; \ 639 .ascii msg; \ 640 .popsection 641 #endif /* __STDC__ */ 642 643 /* 644 * Kernel RCS ID tag and copyright macros 645 */ 646 #undef __SECTIONSTRING 647 #define __SECTIONSTRING(_sec, _str) \ 648 .pushsection _sec ; .asciz _str ; .popsection 649 650 #ifdef _KERNEL 651 652 #define __KERNEL_RCSID(_n, _s) __SECTIONSTRING(.ident, _s) 653 #define __KERNEL_COPYRIGHT(_n, _s) __SECTIONSTRING(.copyright, _s) 654 655 #ifdef NO_KERNEL_RCSIDS 656 #undef __KERNEL_RCSID 657 #define __KERNEL_RCSID(_n, _s) /* nothing */ 658 #endif 659 660 #if defined(MULTIPROCESSOR) 661 662 /* 663 * Get various per-cpu values. A pointer to our cpu_info structure 664 * is stored in SysValue. These macros clobber v0, t0, t8..t11. 665 * 666 * All return values are in v0. 667 */ 668 #define GET_CPUINFO call_pal PAL_OSF1_rdval 669 670 #define GET_CURLWP \ 671 call_pal PAL_OSF1_rdval ; \ 672 addq v0, CPU_INFO_CURLWP, v0 673 674 #define GET_FPCURLWP \ 675 call_pal PAL_OSF1_rdval ; \ 676 addq v0, CPU_INFO_FPCURLWP, v0 677 678 #define GET_CURPCB \ 679 call_pal PAL_OSF1_rdval ; \ 680 addq v0, CPU_INFO_CURPCB, v0 681 682 #define GET_IDLE_PCB(reg) \ 683 call_pal PAL_OSF1_rdval ; \ 684 ldq reg, CPU_INFO_IDLE_PCB_PADDR(v0) 685 686 #else /* if not MULTIPROCESSOR... */ 687 688 IMPORT(cpu_info_primary, CPU_INFO_SIZEOF) 689 690 #define GET_CPUINFO lda v0, cpu_info_primary 691 692 #define GET_CURLWP lda v0, cpu_info_primary + CPU_INFO_CURLWP 693 694 #define GET_FPCURLWP lda v0, cpu_info_primary + CPU_INFO_FPCURLWP 695 696 #define GET_CURPCB lda v0, cpu_info_primary + CPU_INFO_CURPCB 697 698 #define GET_IDLE_PCB(reg) \ 699 lda reg, cpu_info_primary ; \ 700 ldq reg, CPU_INFO_IDLE_PCB_PADDR(reg) 701 #endif /* MULTIPROCESSOR */ 702 #else 703 #define RCSID(_s) __SECTIONSTRING(.ident, _s) 704 705 #endif /* _KERNEL */ 706
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