gcc/real.h

   1 /* Definitions of floating-point access for GNU compiler.
   2    Copyright (C) 1989-2018 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   unsigned int decimal : 1;
  45   unsigned int sign : 1;
  46   unsigned int signalling : 1;
  47   unsigned int canonical : 1;
  48   unsigned int uexp : EXP_BITS;
  49   unsigned long sig[SIGSZ];
  50 };
  51
  52 #define REAL_EXP(REAL) \
  53   ((int)((REAL)->uexp ^ (unsigned int)(1 << (EXP_BITS - 1))) \
  54    - (1 << (EXP_BITS - 1)))
  55 #define SET_REAL_EXP(REAL, EXP) \
  56   ((REAL)->uexp = ((unsigned int)(EXP) & (unsigned int)((1 << EXP_BITS) - 1)))
  57
  58 /* Various headers condition prototypes on #ifdef REAL_VALUE_TYPE, so it
  59    needs to be a macro.  We do need to continue to have a structure tag
  60    so that other headers can forward declare it.  */
  61 #define REAL_VALUE_TYPE struct real_value
  62
  63 /* We store a REAL_VALUE_TYPE into an rtx, and we do this by putting it in
  64    consecutive "w" slots.  Moreover, we've got to compute the number of "w"
  65    slots at preprocessor time, which means we can't use sizeof.  Guess.  */
  66
  67 #define REAL_VALUE_TYPE_SIZE (SIGNIFICAND_BITS + 32)
  68 #define REAL_WIDTH \
  69   (REAL_VALUE_TYPE_SIZE/HOST_BITS_PER_WIDE_INT \
  70    + (REAL_VALUE_TYPE_SIZE%HOST_BITS_PER_WIDE_INT ? 1 : 0)) /* round up */
  71
  72 /* Verify the guess.  */
  73 extern char test_real_width
  74   [sizeof (REAL_VALUE_TYPE) <= REAL_WIDTH * sizeof (HOST_WIDE_INT) ? 1 : -1];
  75
  76 /* Calculate the format for CONST_DOUBLE.  We need as many slots as
  77    are necessary to overlay a REAL_VALUE_TYPE on them.  This could be
  78    as many as four (32-bit HOST_WIDE_INT, 128-bit REAL_VALUE_TYPE).
  79
  80    A number of places assume that there are always at least two 'w'
  81    slots in a CONST_DOUBLE, so we provide them even if one would suffice.  */
  82
  83 #if REAL_WIDTH == 1
  84 # define CONST_DOUBLE_FORMAT     "ww"
  85 #else
  86 # if REAL_WIDTH == 2
  87 #  define CONST_DOUBLE_FORMAT    "ww"
  88 # else
  89 #  if REAL_WIDTH == 3
  90 #   define CONST_DOUBLE_FORMAT   "www"
  91 #  else
  92 #   if REAL_WIDTH == 4
  93 #    define CONST_DOUBLE_FORMAT  "wwww"
  94 #   else
  95 #    if REAL_WIDTH == 5
  96 #     define CONST_DOUBLE_FORMAT "wwwww"
  97 #    else
  98 #     if REAL_WIDTH == 6
  99 #      define CONST_DOUBLE_FORMAT "wwwwww"
 100 #     else
 101        #error "REAL_WIDTH > 6 not supported"
 102 #     endif
 103 #    endif
 104 #   endif
 105 #  endif
 106 # endif
 107 #endif
 108
 109
 110 /* Describes the properties of the specific target format in use.  */
 111 struct real_format
 112 {
 113   /* Move to and from the target bytes.  */
 114   void (*encode) (const struct real_format *, long *,
 115                   const REAL_VALUE_TYPE *);
 116   void (*decode) (const struct real_format *, REAL_VALUE_TYPE *,
 117                   const long *);
 118
 119   /* The radix of the exponent and digits of the significand.  */
 120   int b;
 121
 122   /* Size of the significand in digits of radix B.  */
 123   int p;
 124
 125   /* Size of the significant of a NaN, in digits of radix B.  */
 126   int pnan;
 127
 128   /* The minimum negative integer, x, such that b**(x-1) is normalized.  */
 129   int emin;
 130
 131   /* The maximum integer, x, such that b**(x-1) is representable.  */
 132   int emax;
 133
 134   /* The bit position of the sign bit, for determining whether a value
 135      is positive/negative, or -1 for a complex encoding.  */
 136   int signbit_ro;
 137
 138   /* The bit position of the sign bit, for changing the sign of a number,
 139      or -1 for a complex encoding.  */
 140   int signbit_rw;
 141
 142   /* If this is an IEEE interchange format, the number of bits in the
 143      format; otherwise, if it is an IEEE extended format, one more
 144      than the greatest number of bits in an interchange format it
 145      extends; otherwise 0.  Formats need not follow the IEEE 754-2008
 146      recommended practice regarding how signaling NaNs are identified,
 147      and may vary in the choice of default NaN, but must follow other
 148      IEEE practice regarding having NaNs, infinities and subnormal
 149      values, and the relation of minimum and maximum exponents, and,
 150      for interchange formats, the details of the encoding.  */
 151   int ieee_bits;
 152
 153   /* Default rounding mode for operations on this format.  */
 154   bool round_towards_zero;
 155   bool has_sign_dependent_rounding;
 156
 157   /* Properties of the format.  */
 158   bool has_nans;
 159   bool has_inf;
 160   bool has_denorm;
 161   bool has_signed_zero;
 162   bool qnan_msb_set;
 163   bool canonical_nan_lsbs_set;
 164   const char *name;
 165 };
 166
 167
 168 /* The target format used for each floating point mode.
 169    Float modes are followed by decimal float modes, with entries for
 170    float modes indexed by (MODE - first float mode), and entries for
 171    decimal float modes indexed by (MODE - first decimal float mode) +
 172    the number of float modes.  */
 173 extern const struct real_format *
 174   real_format_for_mode[MAX_MODE_FLOAT - MIN_MODE_FLOAT + 1
 175                        + MAX_MODE_DECIMAL_FLOAT - MIN_MODE_DECIMAL_FLOAT + 1];
 176
 177 #define REAL_MODE_FORMAT(MODE)                                          \
 178   (real_format_for_mode[DECIMAL_FLOAT_MODE_P (MODE)                     \
 179                         ? (((MODE) - MIN_MODE_DECIMAL_FLOAT)            \
 180                            + (MAX_MODE_FLOAT - MIN_MODE_FLOAT + 1))     \
 181                         : GET_MODE_CLASS (MODE) == MODE_FLOAT           \
 182                         ? ((MODE) - MIN_MODE_FLOAT)                     \
 183                         : (gcc_unreachable (), 0)])
 184
 185 #define FLOAT_MODE_FORMAT(MODE) \
 186   (REAL_MODE_FORMAT (as_a <scalar_float_mode> (GET_MODE_INNER (MODE))))
 187
 188 /* The following macro determines whether the floating point format is
 189    composite, i.e. may contain non-consecutive mantissa bits, in which
 190    case compile-time FP overflow may not model run-time overflow.  */
 191 #define MODE_COMPOSITE_P(MODE) \
 192   (FLOAT_MODE_P (MODE) \
 193    && FLOAT_MODE_FORMAT (MODE)->pnan < FLOAT_MODE_FORMAT (MODE)->p)
 194
 195 /* Accessor macros for format properties.  */
 196 #define MODE_HAS_NANS(MODE) \
 197   (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_nans)
 198 #define MODE_HAS_INFINITIES(MODE) \
 199   (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_inf)
 200 #define MODE_HAS_SIGNED_ZEROS(MODE) \
 201   (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_signed_zero)
 202 #define MODE_HAS_SIGN_DEPENDENT_ROUNDING(MODE) \
 203   (FLOAT_MODE_P (MODE) \
 204    && FLOAT_MODE_FORMAT (MODE)->has_sign_dependent_rounding)
 205
 206 /* This class allows functions in this file to accept a floating-point
 207    format as either a mode or an explicit real_format pointer.  In the
 208    former case the mode must be VOIDmode (which means "no particular
 209    format") or must satisfy SCALAR_FLOAT_MODE_P.  */
 210 class format_helper
 211 {
 212 public:
 213   format_helper (const real_format *format) : m_format (format) {}
 214   template<typename T> format_helper (const T &);
 215   const real_format *operator-> () const { return m_format; }
 216   operator const real_format *() const { return m_format; }
 217
 218   bool decimal_p () const { return m_format && m_format->b == 10; }
 219   bool can_represent_integral_type_p (tree type) const;
 220
 221 private:
 222   const real_format *m_format;
 223 };
 224
 225 template<typename T>
 226 inline format_helper::format_helper (const T &m)
 227   : m_format (m == VOIDmode ? 0 : REAL_MODE_FORMAT (m))
 228 {}
 229
 230 /* Declare functions in real.c.  */
 231
 232 /* True if the given mode has a NaN representation and the treatment of
 233    NaN operands is important.  Certain optimizations, such as folding
 234    x * 0 into 0, are not correct for NaN operands, and are normally
 235    disabled for modes with NaNs.  The user can ask for them to be
 236    done anyway using the -funsafe-math-optimizations switch.  */
 237 extern bool HONOR_NANS (machine_mode);
 238 extern bool HONOR_NANS (const_tree);
 239 extern bool HONOR_NANS (const_rtx);
 240
 241 /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs).  */
 242 extern bool HONOR_SNANS (machine_mode);
 243 extern bool HONOR_SNANS (const_tree);
 244 extern bool HONOR_SNANS (const_rtx);
 245
 246 /* As for HONOR_NANS, but true if the mode can represent infinity and
 247    the treatment of infinite values is important.  */
 248 extern bool HONOR_INFINITIES (machine_mode);
 249 extern bool HONOR_INFINITIES (const_tree);
 250 extern bool HONOR_INFINITIES (const_rtx);
 251
 252 /* Like HONOR_NANS, but true if the given mode distinguishes between
 253    positive and negative zero, and the sign of zero is important.  */
 254 extern bool HONOR_SIGNED_ZEROS (machine_mode);
 255 extern bool HONOR_SIGNED_ZEROS (const_tree);
 256 extern bool HONOR_SIGNED_ZEROS (const_rtx);
 257
 258 /* Like HONOR_NANS, but true if given mode supports sign-dependent rounding,
 259    and the rounding mode is important.  */
 260 extern bool HONOR_SIGN_DEPENDENT_ROUNDING (machine_mode);
 261 extern bool HONOR_SIGN_DEPENDENT_ROUNDING (const_tree);
 262 extern bool HONOR_SIGN_DEPENDENT_ROUNDING (const_rtx);
 263
 264 /* Binary or unary arithmetic on tree_code.  */
 265 extern bool real_arithmetic (REAL_VALUE_TYPE *, int, const REAL_VALUE_TYPE *,
 266                              const REAL_VALUE_TYPE *);
 267
 268 /* Compare reals by tree_code.  */
 269 extern bool real_compare (int, const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
 270
 271 /* Determine whether a floating-point value X is infinite.  */
 272 extern bool real_isinf (const REAL_VALUE_TYPE *);
 273
 274 /* Determine whether a floating-point value X is a NaN.  */
 275 extern bool real_isnan (const REAL_VALUE_TYPE *);
 276
 277 /* Determine whether a floating-point value X is a signaling NaN.  */
 278 extern bool real_issignaling_nan (const REAL_VALUE_TYPE *);
 279
 280 /* Determine whether a floating-point value X is finite.  */
 281 extern bool real_isfinite (const REAL_VALUE_TYPE *);
 282
 283 /* Determine whether a floating-point value X is negative.  */
 284 extern bool real_isneg (const REAL_VALUE_TYPE *);
 285
 286 /* Determine whether a floating-point value X is minus zero.  */
 287 extern bool real_isnegzero (const REAL_VALUE_TYPE *);
 288
 289 /* Test relationships between reals.  */
 290 extern bool real_identical (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
 291 extern bool real_equal (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
 292 extern bool real_less (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
 293
 294 /* Extend or truncate to a new format.  */
 295 extern void real_convert (REAL_VALUE_TYPE *, format_helper,
 296                           const REAL_VALUE_TYPE *);
 297
 298 /* Return true if truncating to NEW is exact.  */
 299 extern bool exact_real_truncate (format_helper, const REAL_VALUE_TYPE *);
 300
 301 /* Render R as a decimal floating point constant.  */
 302 extern void real_to_decimal (char *, const REAL_VALUE_TYPE *, size_t,
 303                              size_t, int);
 304
 305 /* Render R as a decimal floating point constant, rounded so as to be
 306    parsed back to the same value when interpreted in mode MODE.  */
 307 extern void real_to_decimal_for_mode (char *, const REAL_VALUE_TYPE *, size_t,
 308                                       size_t, int, machine_mode);
 309
 310 /* Render R as a hexadecimal floating point constant.  */
 311 extern void real_to_hexadecimal (char *, const REAL_VALUE_TYPE *,
 312                                  size_t, size_t, int);
 313
 314 /* Render R as an integer.  */
 315 extern HOST_WIDE_INT real_to_integer (const REAL_VALUE_TYPE *);
 316
 317 /* Initialize R from a decimal or hexadecimal string.  Return -1 if
 318    the value underflows, +1 if overflows, and 0 otherwise.  */
 319 extern int real_from_string (REAL_VALUE_TYPE *, const char *);
 320 /* Wrapper to allow different internal representation for decimal floats. */
 321 extern void real_from_string3 (REAL_VALUE_TYPE *, const char *, format_helper);
 322
 323 extern long real_to_target (long *, const REAL_VALUE_TYPE *, format_helper);
 324
 325 extern void real_from_target (REAL_VALUE_TYPE *, const long *,
 326                               format_helper);
 327
 328 extern void real_inf (REAL_VALUE_TYPE *);
 329
 330 extern bool real_nan (REAL_VALUE_TYPE *, const char *, int, format_helper);
 331
 332 extern void real_maxval (REAL_VALUE_TYPE *, int, machine_mode);
 333
 334 extern void real_2expN (REAL_VALUE_TYPE *, int, format_helper);
 335
 336 extern unsigned int real_hash (const REAL_VALUE_TYPE *);
 337
 338
 339 /* Target formats defined in real.c.  */
 340 extern const struct real_format ieee_single_format;
 341 extern const struct real_format mips_single_format;
 342 extern const struct real_format motorola_single_format;
 343 extern const struct real_format spu_single_format;
 344 extern const struct real_format ieee_double_format;
 345 extern const struct real_format mips_double_format;
 346 extern const struct real_format motorola_double_format;
 347 extern const struct real_format ieee_extended_motorola_format;
 348 extern const struct real_format ieee_extended_intel_96_format;
 349 extern const struct real_format ieee_extended_intel_96_round_53_format;
 350 extern const struct real_format ieee_extended_intel_128_format;
 351 extern const struct real_format ibm_extended_format;
 352 extern const struct real_format mips_extended_format;
 353 extern const struct real_format ieee_quad_format;
 354 extern const struct real_format mips_quad_format;
 355 extern const struct real_format vax_f_format;
 356 extern const struct real_format vax_d_format;
 357 extern const struct real_format vax_g_format;
 358 extern const struct real_format real_internal_format;
 359 extern const struct real_format decimal_single_format;
 360 extern const struct real_format decimal_double_format;
 361 extern const struct real_format decimal_quad_format;
 362 extern const struct real_format ieee_half_format;
 363 extern const struct real_format arm_half_format;
 364
 365
 366 /* ====================================================================== */
 367 /* Crap.  */
 368
 369 /* Determine whether a floating-point value X is infinite.  */
 370 #define REAL_VALUE_ISINF(x)             real_isinf (&(x))
 371
 372 /* Determine whether a floating-point value X is a NaN.  */
 373 #define REAL_VALUE_ISNAN(x)             real_isnan (&(x))
 374
 375 /* Determine whether a floating-point value X is a signaling NaN.  */
 376 #define REAL_VALUE_ISSIGNALING_NAN(x)  real_issignaling_nan (&(x))
 377
 378 /* Determine whether a floating-point value X is negative.  */
 379 #define REAL_VALUE_NEGATIVE(x)          real_isneg (&(x))
 380
 381 /* Determine whether a floating-point value X is minus zero.  */
 382 #define REAL_VALUE_MINUS_ZERO(x)        real_isnegzero (&(x))
 383
 384 /* IN is a REAL_VALUE_TYPE.  OUT is an array of longs.  */
 385 #define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT)                       \
 386   real_to_target (OUT, &(IN),                                           \
 387                   float_mode_for_size (LONG_DOUBLE_TYPE_SIZE).require ())
 388
 389 #define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT) \
 390   real_to_target (OUT, &(IN), float_mode_for_size (64).require ())
 391
 392 /* IN is a REAL_VALUE_TYPE.  OUT is a long.  */
 393 #define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT) \
 394   ((OUT) = real_to_target (NULL, &(IN), float_mode_for_size (32).require ()))
 395
 396 /* Real values to IEEE 754 decimal floats.  */
 397
 398 /* IN is a REAL_VALUE_TYPE.  OUT is an array of longs.  */
 399 #define REAL_VALUE_TO_TARGET_DECIMAL128(IN, OUT) \
 400   real_to_target (OUT, &(IN), decimal_float_mode_for_size (128).require ())
 401
 402 #define REAL_VALUE_TO_TARGET_DECIMAL64(IN, OUT) \
 403   real_to_target (OUT, &(IN), decimal_float_mode_for_size (64).require ())
 404
 405 /* IN is a REAL_VALUE_TYPE.  OUT is a long.  */
 406 #define REAL_VALUE_TO_TARGET_DECIMAL32(IN, OUT) \
 407   ((OUT) = real_to_target (NULL, &(IN), \
 408                            decimal_float_mode_for_size (32).require ()))
 409
 410 extern REAL_VALUE_TYPE real_value_truncate (format_helper, REAL_VALUE_TYPE);
 411
 412 extern REAL_VALUE_TYPE real_value_negate (const REAL_VALUE_TYPE *);
 413 extern REAL_VALUE_TYPE real_value_abs (const REAL_VALUE_TYPE *);
 414
 415 extern int significand_size (format_helper);
 416
 417 extern REAL_VALUE_TYPE real_from_string2 (const char *, format_helper);
 418
 419 #define REAL_VALUE_ATOF(s, m) \
 420   real_from_string2 (s, m)
 421
 422 #define CONST_DOUBLE_ATOF(s, m) \
 423   const_double_from_real_value (real_from_string2 (s, m), m)
 424
 425 #define REAL_VALUE_FIX(r) \
 426   real_to_integer (&(r))
 427
 428 /* ??? Not quite right.  */
 429 #define REAL_VALUE_UNSIGNED_FIX(r) \
 430   real_to_integer (&(r))
 431
 432 /* ??? These were added for Paranoia support.  */
 433
 434 /* Return floor log2(R).  */
 435 extern int real_exponent (const REAL_VALUE_TYPE *);
 436
 437 /* R = A * 2**EXP.  */
 438 extern void real_ldexp (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *, int);
 439
 440 /* **** End of software floating point emulator interface macros **** */
 441 \f
 442 /* Constant real values 0, 1, 2, -1 and 0.5.  */
 443
 444 extern REAL_VALUE_TYPE dconst0;
 445 extern REAL_VALUE_TYPE dconst1;
 446 extern REAL_VALUE_TYPE dconst2;
 447 extern REAL_VALUE_TYPE dconstm1;
 448 extern REAL_VALUE_TYPE dconsthalf;
 449
 450 #define dconst_e() (*dconst_e_ptr ())
 451 #define dconst_third() (*dconst_third_ptr ())
 452 #define dconst_quarter() (*dconst_quarter_ptr ())
 453 #define dconst_sixth() (*dconst_sixth_ptr ())
 454 #define dconst_ninth() (*dconst_ninth_ptr ())
 455 #define dconst_sqrt2() (*dconst_sqrt2_ptr ())
 456
 457 /* Function to return the real value special constant 'e'.  */
 458 extern const REAL_VALUE_TYPE * dconst_e_ptr (void);
 459
 460 /* Returns a cached REAL_VALUE_TYPE corresponding to 1/n, for various n.  */
 461 extern const REAL_VALUE_TYPE *dconst_third_ptr (void);
 462 extern const REAL_VALUE_TYPE *dconst_quarter_ptr (void);
 463 extern const REAL_VALUE_TYPE *dconst_sixth_ptr (void);
 464 extern const REAL_VALUE_TYPE *dconst_ninth_ptr (void);
 465
 466 /* Returns the special REAL_VALUE_TYPE corresponding to sqrt(2).  */
 467 extern const REAL_VALUE_TYPE * dconst_sqrt2_ptr (void);
 468
 469 /* Function to return a real value (not a tree node)
 470    from a given integer constant.  */
 471 REAL_VALUE_TYPE real_value_from_int_cst (const_tree, const_tree);
 472
 473 /* Return a CONST_DOUBLE with value R and mode M.  */
 474 extern rtx const_double_from_real_value (REAL_VALUE_TYPE, machine_mode);
 475
 476 /* Replace R by 1/R in the given format, if the result is exact.  */
 477 extern bool exact_real_inverse (format_helper, REAL_VALUE_TYPE *);
 478
 479 /* Return true if arithmetic on values in IMODE that were promoted
 480    from values in TMODE is equivalent to direct arithmetic on values
 481    in TMODE.  */
 482 bool real_can_shorten_arithmetic (machine_mode, machine_mode);
 483
 484 /* In tree.c: wrap up a REAL_VALUE_TYPE in a tree node.  */
 485 extern tree build_real (tree, REAL_VALUE_TYPE);
 486
 487 /* Likewise, but first truncate the value to the type.  */
 488 extern tree build_real_truncate (tree, REAL_VALUE_TYPE);
 489
 490 /* Calculate R as X raised to the integer exponent N in format FMT.  */
 491 extern bool real_powi (REAL_VALUE_TYPE *, format_helper,
 492                        const REAL_VALUE_TYPE *, HOST_WIDE_INT);
 493
 494 /* Standard round to integer value functions.  */
 495 extern void real_trunc (REAL_VALUE_TYPE *, format_helper,
 496                         const REAL_VALUE_TYPE *);
 497 extern void real_floor (REAL_VALUE_TYPE *, format_helper,
 498                         const REAL_VALUE_TYPE *);
 499 extern void real_ceil (REAL_VALUE_TYPE *, format_helper,
 500                        const REAL_VALUE_TYPE *);
 501 extern void real_round (REAL_VALUE_TYPE *, format_helper,
 502                         const REAL_VALUE_TYPE *);
 503
 504 /* Set the sign of R to the sign of X.  */
 505 extern void real_copysign (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
 506
 507 /* Check whether the real constant value given is an integer.  */
 508 extern bool real_isinteger (const REAL_VALUE_TYPE *, format_helper);
 509 extern bool real_isinteger (const REAL_VALUE_TYPE *, HOST_WIDE_INT *);
 510
 511 /* Calculate nextafter (X, Y) in format FMT.  */
 512 extern bool real_nextafter (REAL_VALUE_TYPE *, format_helper,
 513                             const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
 514
 515 /* Write into BUF the maximum representable finite floating-point
 516    number, (1 - b**-p) * b**emax for a given FP format FMT as a hex
 517    float string.  BUF must be large enough to contain the result.  */
 518 extern void get_max_float (const struct real_format *, char *, size_t);
 519
 520 #ifndef GENERATOR_FILE
 521 /* real related routines.  */
 522 extern wide_int real_to_integer (const REAL_VALUE_TYPE *, bool *, int);
 523 extern void real_from_integer (REAL_VALUE_TYPE *, format_helper,
 524                                const wide_int_ref &, signop);
 525 #endif
 526
 527 /* Fills r with the largest value such that 1 + r*r won't overflow.
 528    This is used in both sin (atan (x)) and cos (atan(x)) optimizations. */
 529 extern void build_sinatan_real (REAL_VALUE_TYPE *, tree);
 530
 531 #endif /* ! GCC_REAL_H */