gcc/real.h

   1 /* Definitions of floating-point access for GNU compiler.
   2    Copyright (C) 1989-2022 Free Software Foundation, Inc.
   3
   4    This file is part of GCC.
   5
   6    GCC is free software; you can redistribute it and/or modify it under
   7    the terms of the GNU General Public License as published by the Free
   8    Software Foundation; either version 3, or (at your option) any later
   9    version.
  10
  11    GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12    WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14    for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GCC; see the file COPYING3.  If not see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef GCC_REAL_H
  21 #define GCC_REAL_H
  22
  23 /* An expanded form of the represented number.  */
  24
  25 /* Enumerate the special cases of numbers that we encounter.  */
  26 enum real_value_class {
  27   rvc_zero,
  28   rvc_normal,
  29   rvc_inf,
  30   rvc_nan
  31 };
  32
  33 #define SIGNIFICAND_BITS        (128 + HOST_BITS_PER_LONG)
  34 #define EXP_BITS                (32 - 6)
  35 #define MAX_EXP                 ((1 << (EXP_BITS - 1)) - 1)
  36 #define SIGSZ                   (SIGNIFICAND_BITS / HOST_BITS_PER_LONG)
  37 #define SIG_MSB                 ((unsigned long)1 << (HOST_BITS_PER_LONG - 1))
  38
  39 struct GTY(()) real_value {
  40   /* Use the same underlying type for all bit-fields, so as to make
  41      sure they're packed together, otherwise REAL_VALUE_TYPE_SIZE will
  42      be miscomputed.  */
  43   unsigned int /* ENUM_BITFIELD (real_value_class) */ cl : 2;
  44   /* 1 if number is decimal floating point.  */
  45   unsigned int decimal : 1;
  46   /* 1 if number is negative.  */
  47   unsigned int sign : 1;
  48   /* 1 if number is signalling.  */
  49   unsigned int signalling : 1;
  50   /* 1 if number is canonical
  51   All are generally used for handling cases in real.cc.  */
  52   unsigned int canonical : 1;
  53   /* unbiased exponent of the number.  */
  54   unsigned int uexp : EXP_BITS;
  55   /* significand of the number.  */
  56   unsigned long sig[SIGSZ];
  57 };
  58
  59 #define REAL_EXP(REAL) \
  60   ((int)((REAL)->uexp ^ (unsigned int)(1 << (EXP_BITS - 1))) \
  61    - (1 << (EXP_BITS - 1)))
  62 #define SET_REAL_EXP(REAL, EXP) \
  63   ((REAL)->uexp = ((unsigned int)(EXP) & (unsigned int)((1 << EXP_BITS) - 1)))
  64
  65 /* Various headers condition prototypes on #ifdef REAL_VALUE_TYPE, so it
  66    needs to be a macro.  We do need to continue to have a structure tag
  67    so that other headers can forward declare it.  */
  68 #define REAL_VALUE_TYPE struct real_value
  69
  70 /* We store a REAL_VALUE_TYPE into an rtx, and we do this by putting it in
  71    consecutive "w" slots.  Moreover, we've got to compute the number of "w"
  72    slots at preprocessor time, which means we can't use sizeof.  Guess.  */
  73
  74 #define REAL_VALUE_TYPE_SIZE (SIGNIFICAND_BITS + 32)
  75 #define REAL_WIDTH \
  76   (REAL_VALUE_TYPE_SIZE/HOST_BITS_PER_WIDE_INT \
  77    + (REAL_VALUE_TYPE_SIZE%HOST_BITS_PER_WIDE_INT ? 1 : 0)) /* round up */
  78
  79 /* Verify the guess.  */
  80 extern char test_real_width
  81   [sizeof (REAL_VALUE_TYPE) <= REAL_WIDTH * sizeof (HOST_WIDE_INT) ? 1 : -1];
  82
  83 /* Calculate the format for CONST_DOUBLE.  We need as many slots as
  84    are necessary to overlay a REAL_VALUE_TYPE on them.  This could be
  85    as many as four (32-bit HOST_WIDE_INT, 128-bit REAL_VALUE_TYPE).
  86
  87    A number of places assume that there are always at least two 'w'
  88    slots in a CONST_DOUBLE, so we provide them even if one would suffice.  */
  89
  90 #if REAL_WIDTH == 1
  91 # define CONST_DOUBLE_FORMAT     "ww"
  92 #else
  93 # if REAL_WIDTH == 2
  94 #  define CONST_DOUBLE_FORMAT    "ww"
  95 # else
  96 #  if REAL_WIDTH == 3
  97 #   define CONST_DOUBLE_FORMAT   "www"
  98 #  else
  99 #   if REAL_WIDTH == 4
 100 #    define CONST_DOUBLE_FORMAT  "wwww"
 101 #   else
 102 #    if REAL_WIDTH == 5
 103 #     define CONST_DOUBLE_FORMAT "wwwww"
 104 #    else
 105 #     if REAL_WIDTH == 6
 106 #      define CONST_DOUBLE_FORMAT "wwwwww"
 107 #     else
 108        #error "REAL_WIDTH > 6 not supported"
 109 #     endif
 110 #    endif
 111 #   endif
 112 #  endif
 113 # endif
 114 #endif
 115
 116
 117 /* Describes the properties of the specific target format in use.  */
 118 struct real_format
 119 {
 120   /* Move to and from the target bytes.  */
 121   void (*encode) (const struct real_format *, long *,
 122                   const REAL_VALUE_TYPE *);
 123   void (*decode) (const struct real_format *, REAL_VALUE_TYPE *,
 124                   const long *);
 125
 126   /* The radix of the exponent and digits of the significand.  */
 127   int b;
 128
 129   /* Size of the significand in digits of radix B.  */
 130   int p;
 131
 132   /* Size of the significant of a NaN, in digits of radix B.  */
 133   int pnan;
 134
 135   /* The minimum negative integer, x, such that b**(x-1) is normalized.  */
 136   int emin;
 137
 138   /* The maximum integer, x, such that b**(x-1) is representable.  */
 139   int emax;
 140
 141   /* The bit position of the sign bit, for determining whether a value
 142      is positive/negative, or -1 for a complex encoding.  */
 143   int signbit_ro;
 144
 145   /* The bit position of the sign bit, for changing the sign of a number,
 146      or -1 for a complex encoding.  */
 147   int signbit_rw;
 148
 149   /* If this is an IEEE interchange format, the number of bits in the
 150      format; otherwise, if it is an IEEE extended format, one more
 151      than the greatest number of bits in an interchange format it
 152      extends; otherwise 0.  Formats need not follow the IEEE 754-2008
 153      recommended practice regarding how signaling NaNs are identified,
 154      and may vary in the choice of default NaN, but must follow other
 155      IEEE practice regarding having NaNs, infinities and subnormal
 156      values, and the relation of minimum and maximum exponents, and,
 157      for interchange formats, the details of the encoding.  */
 158   int ieee_bits;
 159
 160   /* Default rounding mode for operations on this format.  */
 161   bool round_towards_zero;
 162   bool has_sign_dependent_rounding;
 163
 164   /* Properties of the format.  */
 165   bool has_nans;
 166   bool has_inf;
 167   bool has_denorm;
 168   bool has_signed_zero;
 169   bool qnan_msb_set;
 170   bool canonical_nan_lsbs_set;
 171   const char *name;
 172 };
 173
 174
 175 /* The target format used for each floating point mode.
 176    Float modes are followed by decimal float modes, with entries for
 177    float modes indexed by (MODE - first float mode), and entries for
 178    decimal float modes indexed by (MODE - first decimal float mode) +
 179    the number of float modes.  */
 180 extern const struct real_format *
 181   real_format_for_mode[NUM_MODE_FLOAT + NUM_MODE_DECIMAL_FLOAT];
 182
 183 #define REAL_MODE_FORMAT(MODE)                                          \
 184   (real_format_for_mode[DECIMAL_FLOAT_MODE_P (MODE)                     \
 185                         ? (((MODE) - MIN_MODE_DECIMAL_FLOAT)            \
 186                            + NUM_MODE_FLOAT)                            \
 187                         : GET_MODE_CLASS (MODE) == MODE_FLOAT           \
 188                         ? ((MODE) - MIN_MODE_FLOAT)                     \
 189                         : (gcc_unreachable (), 0)])
 190
 191 #define FLOAT_MODE_FORMAT(MODE) \
 192   (REAL_MODE_FORMAT (as_a <scalar_float_mode> (GET_MODE_INNER (MODE))))
 193
 194 /* The following macro determines whether the floating point format is
 195    composite, i.e. may contain non-consecutive mantissa bits, in which
 196    case compile-time FP overflow may not model run-time overflow.  */
 197 #define MODE_COMPOSITE_P(MODE) \
 198   (FLOAT_MODE_P (MODE) \
 199    && FLOAT_MODE_FORMAT (MODE)->pnan < FLOAT_MODE_FORMAT (MODE)->p)
 200
 201 /* Accessor macros for format properties.  */
 202 #define MODE_HAS_NANS(MODE) \
 203   (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_nans)
 204 #define MODE_HAS_INFINITIES(MODE) \
 205   (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_inf)
 206 #define MODE_HAS_SIGNED_ZEROS(MODE) \
 207   (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_signed_zero)
 208 #define MODE_HAS_SIGN_DEPENDENT_ROUNDING(MODE) \
 209   (FLOAT_MODE_P (MODE) \
 210    && FLOAT_MODE_FORMAT (MODE)->has_sign_dependent_rounding)
 211
 212 /* This class allows functions in this file to accept a floating-point
 213    format as either a mode or an explicit real_format pointer.  In the
 214    former case the mode must be VOIDmode (which means "no particular
 215    format") or must satisfy SCALAR_FLOAT_MODE_P.  */
 216 class format_helper
 217 {
 218 public:
 219   format_helper (const real_format *format) : m_format (format) {}
 220   template<typename T> format_helper (const T &);
 221   const real_format *operator-> () const { return m_format; }
 222   operator const real_format *() const { return m_format; }
 223
 224   bool decimal_p () const { return m_format && m_format->b == 10; }
 225   bool can_represent_integral_type_p (tree type) const;
 226
 227 private:
 228   const real_format *m_format;
 229 };
 230
 231 template<typename T>
 232 inline format_helper::format_helper (const T &m)
 233   : m_format (m == VOIDmode ? 0 : REAL_MODE_FORMAT (m))
 234 {}
 235
 236 /* Declare functions in real.cc.  */
 237
 238 /* True if the given mode has a NaN representation and the treatment of
 239    NaN operands is important.  Certain optimizations, such as folding
 240    x * 0 into 0, are not correct for NaN operands, and are normally
 241    disabled for modes with NaNs.  The user can ask for them to be
 242    done anyway using the -funsafe-math-optimizations switch.  */
 243 extern bool HONOR_NANS (machine_mode);
 244 extern bool HONOR_NANS (const_tree);
 245 extern bool HONOR_NANS (const_rtx);
 246
 247 /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs).  */
 248 extern bool HONOR_SNANS (machine_mode);
 249 extern bool HONOR_SNANS (const_tree);
 250 extern bool HONOR_SNANS (const_rtx);
 251
 252 /* As for HONOR_NANS, but true if the mode can represent infinity and
 253    the treatment of infinite values is important.  */
 254 extern bool HONOR_INFINITIES (machine_mode);
 255 extern bool HONOR_INFINITIES (const_tree);
 256 extern bool HONOR_INFINITIES (const_rtx);
 257
 258 /* Like HONOR_NANS, but true if the given mode distinguishes between
 259    positive and negative zero, and the sign of zero is important.  */
 260 extern bool HONOR_SIGNED_ZEROS (machine_mode);
 261 extern bool HONOR_SIGNED_ZEROS (const_tree);
 262 extern bool HONOR_SIGNED_ZEROS (const_rtx);
 263
 264 /* Like HONOR_NANS, but true if given mode supports sign-dependent rounding,
 265    and the rounding mode is important.  */
 266 extern bool HONOR_SIGN_DEPENDENT_ROUNDING (machine_mode);
 267 extern bool HONOR_SIGN_DEPENDENT_ROUNDING (const_tree);
 268 extern bool HONOR_SIGN_DEPENDENT_ROUNDING (const_rtx);
 269
 270 /* Binary or unary arithmetic on tree_code.  */
 271 extern bool real_arithmetic (REAL_VALUE_TYPE *, int, const REAL_VALUE_TYPE *,
 272                              const REAL_VALUE_TYPE *);
 273
 274 /* Compare reals by tree_code.  */
 275 extern bool real_compare (int, const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
 276
 277 /* Determine whether a floating-point value X is infinite.  */
 278 extern bool real_isinf (const REAL_VALUE_TYPE *);
 279
 280 /* Determine whether a floating-point value X is a NaN.  */
 281 extern bool real_isnan (const REAL_VALUE_TYPE *);
 282
 283 /* Determine whether a floating-point value X is a signaling NaN.  */
 284 extern bool real_issignaling_nan (const REAL_VALUE_TYPE *);
 285
 286 /* Determine whether a floating-point value X is finite.  */
 287 extern bool real_isfinite (const REAL_VALUE_TYPE *);
 288
 289 /* Determine whether a floating-point value X is negative.  */
 290 extern bool real_isneg (const REAL_VALUE_TYPE *);
 291
 292 /* Determine whether a floating-point value X is minus zero.  */
 293 extern bool real_isnegzero (const REAL_VALUE_TYPE *);
 294
 295 /* Test relationships between reals.  */
 296 extern bool real_identical (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
 297 extern bool real_equal (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
 298 extern bool real_less (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
 299
 300 /* Extend or truncate to a new format.  */
 301 extern void real_convert (REAL_VALUE_TYPE *, format_helper,
 302                           const REAL_VALUE_TYPE *);
 303
 304 /* Return true if truncating to NEW is exact.  */
 305 extern bool exact_real_truncate (format_helper, const REAL_VALUE_TYPE *);
 306
 307 /* Render R as a decimal floating point constant.  */
 308 extern void real_to_decimal (char *, const REAL_VALUE_TYPE *, size_t,
 309                              size_t, int);
 310
 311 /* Render R as a decimal floating point constant, rounded so as to be
 312    parsed back to the same value when interpreted in mode MODE.  */
 313 extern void real_to_decimal_for_mode (char *, const REAL_VALUE_TYPE *, size_t,
 314                                       size_t, int, machine_mode);
 315
 316 /* Render R as a hexadecimal floating point constant.  */
 317 extern void real_to_hexadecimal (char *, const REAL_VALUE_TYPE *,
 318                                  size_t, size_t, int);
 319
 320 /* Render R as an integer.  */
 321 extern HOST_WIDE_INT real_to_integer (const REAL_VALUE_TYPE *);
 322
 323 /* Initialize R from a decimal or hexadecimal string.  Return -1 if
 324    the value underflows, +1 if overflows, and 0 otherwise.  */
 325 extern int real_from_string (REAL_VALUE_TYPE *, const char *);
 326 /* Wrapper to allow different internal representation for decimal floats. */
 327 extern void real_from_string3 (REAL_VALUE_TYPE *, const char *, format_helper);
 328
 329 extern long real_to_target (long *, const REAL_VALUE_TYPE *, format_helper);
 330
 331 extern void real_from_target (REAL_VALUE_TYPE *, const long *,
 332                               format_helper);
 333
 334 extern void real_inf (REAL_VALUE_TYPE *);
 335
 336 extern bool real_nan (REAL_VALUE_TYPE *, const char *, int, format_helper);
 337
 338 extern void real_maxval (REAL_VALUE_TYPE *, int, machine_mode);
 339
 340 extern void real_2expN (REAL_VALUE_TYPE *, int, format_helper);
 341
 342 extern unsigned int real_hash (const REAL_VALUE_TYPE *);
 343
 344
 345 /* Target formats defined in real.cc.  */
 346 extern const struct real_format ieee_single_format;
 347 extern const struct real_format mips_single_format;
 348 extern const struct real_format motorola_single_format;
 349 extern const struct real_format spu_single_format;
 350 extern const struct real_format ieee_double_format;
 351 extern const struct real_format mips_double_format;
 352 extern const struct real_format motorola_double_format;
 353 extern const struct real_format ieee_extended_motorola_format;
 354 extern const struct real_format ieee_extended_intel_96_format;
 355 extern const struct real_format ieee_extended_intel_96_round_53_format;
 356 extern const struct real_format ieee_extended_intel_128_format;
 357 extern const struct real_format ibm_extended_format;
 358 extern const struct real_format mips_extended_format;
 359 extern const struct real_format ieee_quad_format;
 360 extern const struct real_format mips_quad_format;
 361 extern const struct real_format vax_f_format;
 362 extern const struct real_format vax_d_format;
 363 extern const struct real_format vax_g_format;
 364 extern const struct real_format real_internal_format;
 365 extern const struct real_format decimal_single_format;
 366 extern const struct real_format decimal_double_format;
 367 extern const struct real_format decimal_quad_format;
 368 extern const struct real_format ieee_half_format;
 369 extern const struct real_format arm_half_format;
 370 extern const struct real_format arm_bfloat_half_format;
 371
 372
 373 /* ====================================================================== */
 374 /* Crap.  */
 375
 376 /* Determine whether a floating-point value X is infinite.  */
 377 #define REAL_VALUE_ISINF(x)             real_isinf (&(x))
 378
 379 /* Determine whether a floating-point value X is a NaN.  */
 380 #define REAL_VALUE_ISNAN(x)             real_isnan (&(x))
 381
 382 /* Determine whether a floating-point value X is a signaling NaN.  */
 383 #define REAL_VALUE_ISSIGNALING_NAN(x)  real_issignaling_nan (&(x))
 384
 385 /* Determine whether a floating-point value X is negative.  */
 386 #define REAL_VALUE_NEGATIVE(x)          real_isneg (&(x))
 387
 388 /* Determine whether a floating-point value X is minus zero.  */
 389 #define REAL_VALUE_MINUS_ZERO(x)        real_isnegzero (&(x))
 390
 391 /* IN is a REAL_VALUE_TYPE.  OUT is an array of longs.  */
 392 #define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT)                       \
 393   real_to_target (OUT, &(IN),                                           \
 394                   float_mode_for_size (LONG_DOUBLE_TYPE_SIZE).require ())
 395
 396 #define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT) \
 397   real_to_target (OUT, &(IN), float_mode_for_size (64).require ())
 398
 399 /* IN is a REAL_VALUE_TYPE.  OUT is a long.  */
 400 #define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT) \
 401   ((OUT) = real_to_target (NULL, &(IN), float_mode_for_size (32).require ()))
 402
 403 /* Real values to IEEE 754 decimal floats.  */
 404
 405 /* IN is a REAL_VALUE_TYPE.  OUT is an array of longs.  */
 406 #define REAL_VALUE_TO_TARGET_DECIMAL128(IN, OUT) \
 407   real_to_target (OUT, &(IN), decimal_float_mode_for_size (128).require ())
 408
 409 #define REAL_VALUE_TO_TARGET_DECIMAL64(IN, OUT) \
 410   real_to_target (OUT, &(IN), decimal_float_mode_for_size (64).require ())
 411
 412 /* IN is a REAL_VALUE_TYPE.  OUT is a long.  */
 413 #define REAL_VALUE_TO_TARGET_DECIMAL32(IN, OUT) \
 414   ((OUT) = real_to_target (NULL, &(IN), \
 415                            decimal_float_mode_for_size (32).require ()))
 416
 417 extern REAL_VALUE_TYPE real_value_truncate (format_helper, REAL_VALUE_TYPE);
 418
 419 extern REAL_VALUE_TYPE real_value_negate (const REAL_VALUE_TYPE *);
 420 extern REAL_VALUE_TYPE real_value_abs (const REAL_VALUE_TYPE *);
 421
 422 extern int significand_size (format_helper);
 423
 424 extern REAL_VALUE_TYPE real_from_string2 (const char *, format_helper);
 425
 426 #define REAL_VALUE_ATOF(s, m) \
 427   real_from_string2 (s, m)
 428
 429 #define CONST_DOUBLE_ATOF(s, m) \
 430   const_double_from_real_value (real_from_string2 (s, m), m)
 431
 432 #define REAL_VALUE_FIX(r) \
 433   real_to_integer (&(r))
 434
 435 /* ??? Not quite right.  */
 436 #define REAL_VALUE_UNSIGNED_FIX(r) \
 437   real_to_integer (&(r))
 438
 439 /* ??? These were added for Paranoia support.  */
 440
 441 /* Return floor log2(R).  */
 442 extern int real_exponent (const REAL_VALUE_TYPE *);
 443
 444 /* R = A * 2**EXP.  */
 445 extern void real_ldexp (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *, int);
 446
 447 /* **** End of software floating point emulator interface macros **** */
 448 \f
 449 /* Constant real values 0, 1, 2, -1 and 0.5.  */
 450
 451 extern REAL_VALUE_TYPE dconst0;
 452 extern REAL_VALUE_TYPE dconst1;
 453 extern REAL_VALUE_TYPE dconst2;
 454 extern REAL_VALUE_TYPE dconstm1;
 455 extern REAL_VALUE_TYPE dconsthalf;
 456
 457 #define dconst_e() (*dconst_e_ptr ())
 458 #define dconst_third() (*dconst_third_ptr ())
 459 #define dconst_quarter() (*dconst_quarter_ptr ())
 460 #define dconst_sixth() (*dconst_sixth_ptr ())
 461 #define dconst_ninth() (*dconst_ninth_ptr ())
 462 #define dconst_sqrt2() (*dconst_sqrt2_ptr ())
 463
 464 /* Function to return the real value special constant 'e'.  */
 465 extern const REAL_VALUE_TYPE * dconst_e_ptr (void);
 466
 467 /* Returns a cached REAL_VALUE_TYPE corresponding to 1/n, for various n.  */
 468 extern const REAL_VALUE_TYPE *dconst_third_ptr (void);
 469 extern const REAL_VALUE_TYPE *dconst_quarter_ptr (void);
 470 extern const REAL_VALUE_TYPE *dconst_sixth_ptr (void);
 471 extern const REAL_VALUE_TYPE *dconst_ninth_ptr (void);
 472
 473 /* Returns the special REAL_VALUE_TYPE corresponding to sqrt(2).  */
 474 extern const REAL_VALUE_TYPE * dconst_sqrt2_ptr (void);
 475
 476 /* Function to return a real value (not a tree node)
 477    from a given integer constant.  */
 478 REAL_VALUE_TYPE real_value_from_int_cst (const_tree, const_tree);
 479
 480 /* Return a CONST_DOUBLE with value R and mode M.  */
 481 extern rtx const_double_from_real_value (REAL_VALUE_TYPE, machine_mode);
 482
 483 /* Replace R by 1/R in the given format, if the result is exact.  */
 484 extern bool exact_real_inverse (format_helper, REAL_VALUE_TYPE *);
 485
 486 /* Return true if arithmetic on values in IMODE that were promoted
 487    from values in TMODE is equivalent to direct arithmetic on values
 488    in TMODE.  */
 489 bool real_can_shorten_arithmetic (machine_mode, machine_mode);
 490
 491 /* In tree.cc: wrap up a REAL_VALUE_TYPE in a tree node.  */
 492 extern tree build_real (tree, REAL_VALUE_TYPE);
 493
 494 /* Likewise, but first truncate the value to the type.  */
 495 extern tree build_real_truncate (tree, REAL_VALUE_TYPE);
 496
 497 /* Calculate R as X raised to the integer exponent N in format FMT.  */
 498 extern bool real_powi (REAL_VALUE_TYPE *, format_helper,
 499                        const REAL_VALUE_TYPE *, HOST_WIDE_INT);
 500
 501 /* Standard round to integer value functions.  */
 502 extern void real_trunc (REAL_VALUE_TYPE *, format_helper,
 503                         const REAL_VALUE_TYPE *);
 504 extern void real_floor (REAL_VALUE_TYPE *, format_helper,
 505                         const REAL_VALUE_TYPE *);
 506 extern void real_ceil (REAL_VALUE_TYPE *, format_helper,
 507                        const REAL_VALUE_TYPE *);
 508 extern void real_round (REAL_VALUE_TYPE *, format_helper,
 509                         const REAL_VALUE_TYPE *);
 510 extern void real_roundeven (REAL_VALUE_TYPE *, format_helper,
 511                             const REAL_VALUE_TYPE *);
 512
 513 /* Set the sign of R to the sign of X.  */
 514 extern void real_copysign (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
 515
 516 /* Check whether the real constant value given is an integer.  */
 517 extern bool real_isinteger (const REAL_VALUE_TYPE *, format_helper);
 518 extern bool real_isinteger (const REAL_VALUE_TYPE *, HOST_WIDE_INT *);
 519
 520 /* Calculate nextafter (X, Y) in format FMT.  */
 521 extern bool real_nextafter (REAL_VALUE_TYPE *, format_helper,
 522                             const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
 523
 524 /* Write into BUF the maximum representable finite floating-point
 525    number, (1 - b**-p) * b**emax for a given FP format FMT as a hex
 526    float string.  BUF must be large enough to contain the result.  */
 527 extern void get_max_float (const struct real_format *, char *, size_t, bool);
 528
 529 #ifndef GENERATOR_FILE
 530 /* real related routines.  */
 531 extern wide_int real_to_integer (const REAL_VALUE_TYPE *, bool *, int);
 532 extern void real_from_integer (REAL_VALUE_TYPE *, format_helper,
 533                                const wide_int_ref &, signop);
 534 #endif
 535
 536 /* Fills r with the largest value such that 1 + r*r won't overflow.
 537    This is used in both sin (atan (x)) and cos (atan(x)) optimizations. */
 538 extern void build_sinatan_real (REAL_VALUE_TYPE *, tree);
 539
 540 #endif /* ! GCC_REAL_H */