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real.h revision 1.1
      1 /* Definitions of floating-point access for GNU compiler.
      2    Copyright (C) 1989, 1991, 1994, 1996, 1997, 1998, 1999,
      3    2000, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
      4    Free Software Foundation, Inc.
      5 
      6    This file is part of GCC.
      7 
      8    GCC is free software; you can redistribute it and/or modify it under
      9    the terms of the GNU General Public License as published by the Free
     10    Software Foundation; either version 3, or (at your option) any later
     11    version.
     12 
     13    GCC is distributed in the hope that it will be useful, but WITHOUT ANY
     14    WARRANTY; without even the implied warranty of MERCHANTABILITY or
     15    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
     16    for more details.
     17 
     18    You should have received a copy of the GNU General Public License
     19    along with GCC; see the file COPYING3.  If not see
     20    <http://www.gnu.org/licenses/>.  */
     21 
     22 #ifndef GCC_REAL_H
     23 #define GCC_REAL_H
     24 
     25 #ifndef GENERATOR_FILE
     26 #include <gmp.h>
     27 #include <mpfr.h>
     28 #include <mpc.h>
     29 extern tree do_mpc_arg2 (tree, tree, tree, int, int (*)(mpc_ptr, mpc_srcptr, mpc_srcptr, mpc_rnd_t));
     30 #endif
     31 #include "machmode.h"
     32 
     33 /* An expanded form of the represented number.  */
     34 
     35 /* Enumerate the special cases of numbers that we encounter.  */
     36 enum real_value_class {
     37   rvc_zero,
     38   rvc_normal,
     39   rvc_inf,
     40   rvc_nan
     41 };
     42 
     43 #define SIGNIFICAND_BITS	(128 + HOST_BITS_PER_LONG)
     44 #define EXP_BITS		(32 - 6)
     45 #define MAX_EXP			((1 << (EXP_BITS - 1)) - 1)
     46 #define SIGSZ			(SIGNIFICAND_BITS / HOST_BITS_PER_LONG)
     47 #define SIG_MSB			((unsigned long)1 << (HOST_BITS_PER_LONG - 1))
     48 
     49 struct GTY(()) real_value {
     50   /* Use the same underlying type for all bit-fields, so as to make
     51      sure they're packed together, otherwise REAL_VALUE_TYPE_SIZE will
     52      be miscomputed.  */
     53   unsigned int /* ENUM_BITFIELD (real_value_class) */ cl : 2;
     54   unsigned int decimal : 1;
     55   unsigned int sign : 1;
     56   unsigned int signalling : 1;
     57   unsigned int canonical : 1;
     58   unsigned int uexp : EXP_BITS;
     59   unsigned long sig[SIGSZ];
     60 };
     61 
     62 #define REAL_EXP(REAL) \
     63   ((int)((REAL)->uexp ^ (unsigned int)(1 << (EXP_BITS - 1))) \
     64    - (1 << (EXP_BITS - 1)))
     65 #define SET_REAL_EXP(REAL, EXP) \
     66   ((REAL)->uexp = ((unsigned int)(EXP) & (unsigned int)((1 << EXP_BITS) - 1)))
     67 
     68 /* Various headers condition prototypes on #ifdef REAL_VALUE_TYPE, so it
     69    needs to be a macro.  We do need to continue to have a structure tag
     70    so that other headers can forward declare it.  */
     71 #define REAL_VALUE_TYPE struct real_value
     72 
     73 /* We store a REAL_VALUE_TYPE into an rtx, and we do this by putting it in
     74    consecutive "w" slots.  Moreover, we've got to compute the number of "w"
     75    slots at preprocessor time, which means we can't use sizeof.  Guess.  */
     76 
     77 #define REAL_VALUE_TYPE_SIZE (SIGNIFICAND_BITS + 32)
     78 #define REAL_WIDTH \
     79   (REAL_VALUE_TYPE_SIZE/HOST_BITS_PER_WIDE_INT \
     80    + (REAL_VALUE_TYPE_SIZE%HOST_BITS_PER_WIDE_INT ? 1 : 0)) /* round up */
     81 
     82 /* Verify the guess.  */
     83 extern char test_real_width
     84   [sizeof(REAL_VALUE_TYPE) <= REAL_WIDTH*sizeof(HOST_WIDE_INT) ? 1 : -1];
     85 
     86 /* Calculate the format for CONST_DOUBLE.  We need as many slots as
     87    are necessary to overlay a REAL_VALUE_TYPE on them.  This could be
     88    as many as four (32-bit HOST_WIDE_INT, 128-bit REAL_VALUE_TYPE).
     89 
     90    A number of places assume that there are always at least two 'w'
     91    slots in a CONST_DOUBLE, so we provide them even if one would suffice.  */
     92 
     93 #if REAL_WIDTH == 1
     94 # define CONST_DOUBLE_FORMAT	 "ww"
     95 #else
     96 # if REAL_WIDTH == 2
     97 #  define CONST_DOUBLE_FORMAT	 "ww"
     98 # else
     99 #  if REAL_WIDTH == 3
    100 #   define CONST_DOUBLE_FORMAT	 "www"
    101 #  else
    102 #   if REAL_WIDTH == 4
    103 #    define CONST_DOUBLE_FORMAT	 "wwww"
    104 #   else
    105 #    if REAL_WIDTH == 5
    106 #     define CONST_DOUBLE_FORMAT "wwwww"
    107 #    else
    108 #     if REAL_WIDTH == 6
    109 #      define CONST_DOUBLE_FORMAT "wwwwww"
    110 #     else
    111        #error "REAL_WIDTH > 6 not supported"
    112 #     endif
    113 #    endif
    114 #   endif
    115 #  endif
    116 # endif
    117 #endif
    118 
    119 
    120 /* Describes the properties of the specific target format in use.  */
    121 struct real_format
    122 {
    123   /* Move to and from the target bytes.  */
    124   void (*encode) (const struct real_format *, long *,
    125 		  const REAL_VALUE_TYPE *);
    126   void (*decode) (const struct real_format *, REAL_VALUE_TYPE *,
    127 		  const long *);
    128 
    129   /* The radix of the exponent and digits of the significand.  */
    130   int b;
    131 
    132   /* Size of the significand in digits of radix B.  */
    133   int p;
    134 
    135   /* Size of the significant of a NaN, in digits of radix B.  */
    136   int pnan;
    137 
    138   /* The minimum negative integer, x, such that b**(x-1) is normalized.  */
    139   int emin;
    140 
    141   /* The maximum integer, x, such that b**(x-1) is representable.  */
    142   int emax;
    143 
    144   /* The bit position of the sign bit, for determining whether a value
    145      is positive/negative, or -1 for a complex encoding.  */
    146   int signbit_ro;
    147 
    148   /* The bit position of the sign bit, for changing the sign of a number,
    149      or -1 for a complex encoding.  */
    150   int signbit_rw;
    151 
    152   /* Default rounding mode for operations on this format.  */
    153   bool round_towards_zero;
    154   bool has_sign_dependent_rounding;
    155 
    156   /* Properties of the format.  */
    157   bool has_nans;
    158   bool has_inf;
    159   bool has_denorm;
    160   bool has_signed_zero;
    161   bool qnan_msb_set;
    162   bool canonical_nan_lsbs_set;
    163 };
    164 
    165 
    166 /* The target format used for each floating point mode.
    167    Float modes are followed by decimal float modes, with entries for
    168    float modes indexed by (MODE - first float mode), and entries for
    169    decimal float modes indexed by (MODE - first decimal float mode) +
    170    the number of float modes.  */
    171 extern const struct real_format *
    172   real_format_for_mode[MAX_MODE_FLOAT - MIN_MODE_FLOAT + 1
    173 		       + MAX_MODE_DECIMAL_FLOAT - MIN_MODE_DECIMAL_FLOAT + 1];
    174 
    175 #define REAL_MODE_FORMAT(MODE)						\
    176   (real_format_for_mode[DECIMAL_FLOAT_MODE_P (MODE)			\
    177 			? (((MODE) - MIN_MODE_DECIMAL_FLOAT)		\
    178 			   + (MAX_MODE_FLOAT - MIN_MODE_FLOAT + 1))	\
    179 			: ((MODE) - MIN_MODE_FLOAT)])
    180 
    181 #define FLOAT_MODE_FORMAT(MODE) \
    182   (REAL_MODE_FORMAT (SCALAR_FLOAT_MODE_P (MODE)? (MODE) \
    183 					       : GET_MODE_INNER (MODE)))
    184 
    185 /* The following macro determines whether the floating point format is
    186    composite, i.e. may contain non-consecutive mantissa bits, in which
    187    case compile-time FP overflow may not model run-time overflow.  */
    188 #define MODE_COMPOSITE_P(MODE) \
    189   (FLOAT_MODE_P (MODE) \
    190    && FLOAT_MODE_FORMAT (MODE)->pnan < FLOAT_MODE_FORMAT (MODE)->p)
    191 
    192 /* Accessor macros for format properties.  */
    193 #define MODE_HAS_NANS(MODE) \
    194   (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_nans)
    195 #define MODE_HAS_INFINITIES(MODE) \
    196   (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_inf)
    197 #define MODE_HAS_SIGNED_ZEROS(MODE) \
    198   (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_signed_zero)
    199 #define MODE_HAS_SIGN_DEPENDENT_ROUNDING(MODE) \
    200   (FLOAT_MODE_P (MODE) \
    201    && FLOAT_MODE_FORMAT (MODE)->has_sign_dependent_rounding)
    202 
    203 /* True if the given mode has a NaN representation and the treatment of
    204    NaN operands is important.  Certain optimizations, such as folding
    205    x * 0 into 0, are not correct for NaN operands, and are normally
    206    disabled for modes with NaNs.  The user can ask for them to be
    207    done anyway using the -funsafe-math-optimizations switch.  */
    208 #define HONOR_NANS(MODE) \
    209   (MODE_HAS_NANS (MODE) && !flag_finite_math_only)
    210 
    211 /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs).  */
    212 #define HONOR_SNANS(MODE) (flag_signaling_nans && HONOR_NANS (MODE))
    213 
    214 /* As for HONOR_NANS, but true if the mode can represent infinity and
    215    the treatment of infinite values is important.  */
    216 #define HONOR_INFINITIES(MODE) \
    217   (MODE_HAS_INFINITIES (MODE) && !flag_finite_math_only)
    218 
    219 /* Like HONOR_NANS, but true if the given mode distinguishes between
    220    positive and negative zero, and the sign of zero is important.  */
    221 #define HONOR_SIGNED_ZEROS(MODE) \
    222   (MODE_HAS_SIGNED_ZEROS (MODE) && flag_signed_zeros)
    223 
    224 /* Like HONOR_NANS, but true if given mode supports sign-dependent rounding,
    225    and the rounding mode is important.  */
    226 #define HONOR_SIGN_DEPENDENT_ROUNDING(MODE) \
    227   (MODE_HAS_SIGN_DEPENDENT_ROUNDING (MODE) && flag_rounding_math)
    228 
    229 /* Declare functions in real.c.  */
    230 
    231 /* Binary or unary arithmetic on tree_code.  */
    232 extern bool real_arithmetic (REAL_VALUE_TYPE *, int, const REAL_VALUE_TYPE *,
    233 			     const REAL_VALUE_TYPE *);
    234 
    235 /* Compare reals by tree_code.  */
    236 extern bool real_compare (int, const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
    237 
    238 /* Determine whether a floating-point value X is infinite.  */
    239 extern bool real_isinf (const REAL_VALUE_TYPE *);
    240 
    241 /* Determine whether a floating-point value X is a NaN.  */
    242 extern bool real_isnan (const REAL_VALUE_TYPE *);
    243 
    244 /* Determine whether a floating-point value X is finite.  */
    245 extern bool real_isfinite (const REAL_VALUE_TYPE *);
    246 
    247 /* Determine whether a floating-point value X is negative.  */
    248 extern bool real_isneg (const REAL_VALUE_TYPE *);
    249 
    250 /* Determine whether a floating-point value X is minus zero.  */
    251 extern bool real_isnegzero (const REAL_VALUE_TYPE *);
    252 
    253 /* Compare two floating-point objects for bitwise identity.  */
    254 extern bool real_identical (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
    255 
    256 /* Extend or truncate to a new mode.  */
    257 extern void real_convert (REAL_VALUE_TYPE *, enum machine_mode,
    258 			  const REAL_VALUE_TYPE *);
    259 
    260 /* Return true if truncating to NEW is exact.  */
    261 extern bool exact_real_truncate (enum machine_mode, const REAL_VALUE_TYPE *);
    262 
    263 /* Render R as a decimal floating point constant.  */
    264 extern void real_to_decimal (char *, const REAL_VALUE_TYPE *, size_t,
    265 			     size_t, int);
    266 
    267 /* Render R as a decimal floating point constant, rounded so as to be
    268    parsed back to the same value when interpreted in mode MODE.  */
    269 extern void real_to_decimal_for_mode (char *, const REAL_VALUE_TYPE *, size_t,
    270 				      size_t, int, enum machine_mode);
    271 
    272 /* Render R as a hexadecimal floating point constant.  */
    273 extern void real_to_hexadecimal (char *, const REAL_VALUE_TYPE *,
    274 				 size_t, size_t, int);
    275 
    276 /* Render R as an integer.  */
    277 extern HOST_WIDE_INT real_to_integer (const REAL_VALUE_TYPE *);
    278 extern void real_to_integer2 (HOST_WIDE_INT *, HOST_WIDE_INT *,
    279 			      const REAL_VALUE_TYPE *);
    280 
    281 /* Initialize R from a decimal or hexadecimal string.  Return -1 if
    282    the value underflows, +1 if overflows, and 0 otherwise.  */
    283 extern int real_from_string (REAL_VALUE_TYPE *, const char *);
    284 /* Wrapper to allow different internal representation for decimal floats. */
    285 extern void real_from_string3 (REAL_VALUE_TYPE *, const char *, enum machine_mode);
    286 
    287 /* Initialize R from an integer pair HIGH/LOW.  */
    288 extern void real_from_integer (REAL_VALUE_TYPE *, enum machine_mode,
    289 			       unsigned HOST_WIDE_INT, HOST_WIDE_INT, int);
    290 
    291 extern long real_to_target_fmt (long *, const REAL_VALUE_TYPE *,
    292 				const struct real_format *);
    293 extern long real_to_target (long *, const REAL_VALUE_TYPE *, enum machine_mode);
    294 
    295 extern void real_from_target_fmt (REAL_VALUE_TYPE *, const long *,
    296 				  const struct real_format *);
    297 extern void real_from_target (REAL_VALUE_TYPE *, const long *,
    298 			      enum machine_mode);
    299 
    300 extern void real_inf (REAL_VALUE_TYPE *);
    301 
    302 extern bool real_nan (REAL_VALUE_TYPE *, const char *, int, enum machine_mode);
    303 
    304 extern void real_maxval (REAL_VALUE_TYPE *, int, enum machine_mode);
    305 
    306 extern void real_2expN (REAL_VALUE_TYPE *, int, enum machine_mode);
    307 
    308 extern unsigned int real_hash (const REAL_VALUE_TYPE *);
    309 
    310 
    311 /* Target formats defined in real.c.  */
    312 extern const struct real_format ieee_single_format;
    313 extern const struct real_format mips_single_format;
    314 extern const struct real_format motorola_single_format;
    315 extern const struct real_format spu_single_format;
    316 extern const struct real_format ieee_double_format;
    317 extern const struct real_format mips_double_format;
    318 extern const struct real_format motorola_double_format;
    319 extern const struct real_format ieee_extended_motorola_format;
    320 extern const struct real_format ieee_extended_intel_96_format;
    321 extern const struct real_format ieee_extended_intel_96_round_53_format;
    322 extern const struct real_format ieee_extended_intel_128_format;
    323 extern const struct real_format ibm_extended_format;
    324 extern const struct real_format mips_extended_format;
    325 extern const struct real_format ieee_quad_format;
    326 extern const struct real_format mips_quad_format;
    327 extern const struct real_format vax_f_format;
    328 extern const struct real_format vax_d_format;
    329 extern const struct real_format vax_g_format;
    330 extern const struct real_format real_internal_format;
    331 extern const struct real_format decimal_single_format;
    332 extern const struct real_format decimal_double_format;
    333 extern const struct real_format decimal_quad_format;
    334 extern const struct real_format ieee_half_format;
    335 extern const struct real_format arm_half_format;
    336 
    337 
    338 /* ====================================================================== */
    339 /* Crap.  */
    340 
    341 #define REAL_ARITHMETIC(value, code, d1, d2) \
    342   real_arithmetic (&(value), code, &(d1), &(d2))
    343 
    344 #define REAL_VALUES_IDENTICAL(x, y)	real_identical (&(x), &(y))
    345 #define REAL_VALUES_EQUAL(x, y)		real_compare (EQ_EXPR, &(x), &(y))
    346 #define REAL_VALUES_LESS(x, y)		real_compare (LT_EXPR, &(x), &(y))
    347 
    348 /* Determine whether a floating-point value X is infinite.  */
    349 #define REAL_VALUE_ISINF(x)		real_isinf (&(x))
    350 
    351 /* Determine whether a floating-point value X is a NaN.  */
    352 #define REAL_VALUE_ISNAN(x)		real_isnan (&(x))
    353 
    354 /* Determine whether a floating-point value X is negative.  */
    355 #define REAL_VALUE_NEGATIVE(x)		real_isneg (&(x))
    356 
    357 /* Determine whether a floating-point value X is minus zero.  */
    358 #define REAL_VALUE_MINUS_ZERO(x)	real_isnegzero (&(x))
    359 
    360 /* IN is a REAL_VALUE_TYPE.  OUT is an array of longs.  */
    361 #define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT)			\
    362   real_to_target (OUT, &(IN),						\
    363 		  mode_for_size (LONG_DOUBLE_TYPE_SIZE, MODE_FLOAT, 0))
    364 
    365 #define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT) \
    366   real_to_target (OUT, &(IN), mode_for_size (64, MODE_FLOAT, 0))
    367 
    368 /* IN is a REAL_VALUE_TYPE.  OUT is a long.  */
    369 #define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT) \
    370   ((OUT) = real_to_target (NULL, &(IN), mode_for_size (32, MODE_FLOAT, 0)))
    371 
    372 #define REAL_VALUE_FROM_INT(r, lo, hi, mode) \
    373   real_from_integer (&(r), mode, lo, hi, 0)
    374 
    375 #define REAL_VALUE_FROM_UNSIGNED_INT(r, lo, hi, mode) \
    376   real_from_integer (&(r), mode, lo, hi, 1)
    377 
    378 /* Real values to IEEE 754 decimal floats.  */
    379 
    380 /* IN is a REAL_VALUE_TYPE.  OUT is an array of longs.  */
    381 #define REAL_VALUE_TO_TARGET_DECIMAL128(IN, OUT) \
    382   real_to_target (OUT, &(IN), mode_for_size (128, MODE_DECIMAL_FLOAT, 0))
    383 
    384 #define REAL_VALUE_TO_TARGET_DECIMAL64(IN, OUT) \
    385   real_to_target (OUT, &(IN), mode_for_size (64, MODE_DECIMAL_FLOAT, 0))
    386 
    387 /* IN is a REAL_VALUE_TYPE.  OUT is a long.  */
    388 #define REAL_VALUE_TO_TARGET_DECIMAL32(IN, OUT) \
    389   ((OUT) = real_to_target (NULL, &(IN), mode_for_size (32, MODE_DECIMAL_FLOAT, 0)))
    390 
    391 extern REAL_VALUE_TYPE real_value_truncate (enum machine_mode,
    392 					    REAL_VALUE_TYPE);
    393 
    394 #define REAL_VALUE_TO_INT(plow, phigh, r) \
    395   real_to_integer2 (plow, phigh, &(r))
    396 
    397 extern REAL_VALUE_TYPE real_arithmetic2 (int, const REAL_VALUE_TYPE *,
    398 					 const REAL_VALUE_TYPE *);
    399 
    400 #define REAL_VALUE_NEGATE(X) \
    401   real_arithmetic2 (NEGATE_EXPR, &(X), NULL)
    402 
    403 #define REAL_VALUE_ABS(X) \
    404   real_arithmetic2 (ABS_EXPR, &(X), NULL)
    405 
    406 extern int significand_size (enum machine_mode);
    407 
    408 extern REAL_VALUE_TYPE real_from_string2 (const char *, enum machine_mode);
    409 
    410 #define REAL_VALUE_ATOF(s, m) \
    411   real_from_string2 (s, m)
    412 
    413 #define CONST_DOUBLE_ATOF(s, m) \
    414   CONST_DOUBLE_FROM_REAL_VALUE (real_from_string2 (s, m), m)
    415 
    416 #define REAL_VALUE_FIX(r) \
    417   real_to_integer (&(r))
    418 
    419 /* ??? Not quite right.  */
    420 #define REAL_VALUE_UNSIGNED_FIX(r) \
    421   real_to_integer (&(r))
    422 
    423 /* ??? These were added for Paranoia support.  */
    424 
    425 /* Return floor log2(R).  */
    426 extern int real_exponent (const REAL_VALUE_TYPE *);
    427 
    428 /* R = A * 2**EXP.  */
    429 extern void real_ldexp (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *, int);
    430 
    431 /* **** End of software floating point emulator interface macros **** */
    432 
    433 /* Constant real values 0, 1, 2, -1 and 0.5.  */
    435 
    436 extern REAL_VALUE_TYPE dconst0;
    437 extern REAL_VALUE_TYPE dconst1;
    438 extern REAL_VALUE_TYPE dconst2;
    439 extern REAL_VALUE_TYPE dconstm1;
    440 extern REAL_VALUE_TYPE dconsthalf;
    441 
    442 #define dconst_e()  (*dconst_e_ptr ())
    443 #define dconst_third()  (*dconst_third_ptr ())
    444 #define dconst_sqrt2()  (*dconst_sqrt2_ptr ())
    445 
    446 /* Function to return the real value special constant 'e'.  */
    447 extern const REAL_VALUE_TYPE * dconst_e_ptr (void);
    448 
    449 /* Returns the special REAL_VALUE_TYPE corresponding to 1/3.  */
    450 extern const REAL_VALUE_TYPE * dconst_third_ptr (void);
    451 
    452 /* Returns the special REAL_VALUE_TYPE corresponding to sqrt(2).  */
    453 extern const REAL_VALUE_TYPE * dconst_sqrt2_ptr (void);
    454 
    455 /* Function to return a real value (not a tree node)
    456    from a given integer constant.  */
    457 REAL_VALUE_TYPE real_value_from_int_cst (const_tree, const_tree);
    458 
    459 /* Given a CONST_DOUBLE in FROM, store into TO the value it represents.  */
    460 #define REAL_VALUE_FROM_CONST_DOUBLE(to, from) \
    461   ((to) = *CONST_DOUBLE_REAL_VALUE (from))
    462 
    463 /* Return a CONST_DOUBLE with value R and mode M.  */
    464 #define CONST_DOUBLE_FROM_REAL_VALUE(r, m) \
    465   const_double_from_real_value (r, m)
    466 extern rtx const_double_from_real_value (REAL_VALUE_TYPE, enum machine_mode);
    467 
    468 /* Replace R by 1/R in the given machine mode, if the result is exact.  */
    469 extern bool exact_real_inverse (enum machine_mode, REAL_VALUE_TYPE *);
    470 
    471 /* Return true if arithmetic on values in IMODE that were promoted
    472    from values in TMODE is equivalent to direct arithmetic on values
    473    in TMODE.  */
    474 bool real_can_shorten_arithmetic (enum machine_mode, enum machine_mode);
    475 
    476 /* In tree.c: wrap up a REAL_VALUE_TYPE in a tree node.  */
    477 extern tree build_real (tree, REAL_VALUE_TYPE);
    478 
    479 /* Calculate R as the square root of X in the given machine mode.  */
    480 extern bool real_sqrt (REAL_VALUE_TYPE *, enum machine_mode,
    481 		       const REAL_VALUE_TYPE *);
    482 
    483 /* Calculate R as X raised to the integer exponent N in mode MODE.  */
    484 extern bool real_powi (REAL_VALUE_TYPE *, enum machine_mode,
    485 		       const REAL_VALUE_TYPE *, HOST_WIDE_INT);
    486 
    487 /* Standard round to integer value functions.  */
    488 extern void real_trunc (REAL_VALUE_TYPE *, enum machine_mode,
    489 			const REAL_VALUE_TYPE *);
    490 extern void real_floor (REAL_VALUE_TYPE *, enum machine_mode,
    491 			const REAL_VALUE_TYPE *);
    492 extern void real_ceil (REAL_VALUE_TYPE *, enum machine_mode,
    493 		       const REAL_VALUE_TYPE *);
    494 extern void real_round (REAL_VALUE_TYPE *, enum machine_mode,
    495 			const REAL_VALUE_TYPE *);
    496 
    497 /* Set the sign of R to the sign of X.  */
    498 extern void real_copysign (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
    499 
    500 #ifndef GENERATOR_FILE
    501 /* Convert between MPFR and REAL_VALUE_TYPE.  The caller is
    502    responsible for initializing and clearing the MPFR parameter.  */
    503 
    504 extern void real_from_mpfr (REAL_VALUE_TYPE *, mpfr_srcptr, tree, mp_rnd_t);
    505 extern void mpfr_from_real (mpfr_ptr, const REAL_VALUE_TYPE *, mp_rnd_t);
    506 #endif
    507 
    508 /* Check whether the real constant value given is an integer.  */
    509 extern bool real_isinteger (const REAL_VALUE_TYPE *c, enum machine_mode mode);
    510 
    511 /* Write into BUF the maximum representable finite floating-point
    512    number, (1 - b**-p) * b**emax for a given FP format FMT as a hex
    513    float string.  BUF must be large enough to contain the result.  */
    514 extern void get_max_float (const struct real_format *, char *, size_t);
    515 #endif /* ! GCC_REAL_H */
    516