1 /* Definitions of floating-point access for GNU compiler. 2 Copyright (C) 1989-2014 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 #include "machmode.h" 24 25 /* An expanded form of the represented number. */ 26 27 /* Enumerate the special cases of numbers that we encounter. */ 28 enum real_value_class { 29 rvc_zero, 30 rvc_normal, 31 rvc_inf, 32 rvc_nan 33 }; 34 35 #define SIGNIFICAND_BITS (128 + HOST_BITS_PER_LONG) 36 #define EXP_BITS (32 - 6) 37 #define MAX_EXP ((1 << (EXP_BITS - 1)) - 1) 38 #define SIGSZ (SIGNIFICAND_BITS / HOST_BITS_PER_LONG) 39 #define SIG_MSB ((unsigned long)1 << (HOST_BITS_PER_LONG - 1)) 40 41 struct GTY(()) real_value { 42 /* Use the same underlying type for all bit-fields, so as to make 43 sure they're packed together, otherwise REAL_VALUE_TYPE_SIZE will 44 be miscomputed. */ 45 unsigned int /* ENUM_BITFIELD (real_value_class) */ cl : 2; 46 unsigned int decimal : 1; 47 unsigned int sign : 1; 48 unsigned int signalling : 1; 49 unsigned int canonical : 1; 50 unsigned int uexp : EXP_BITS; 51 unsigned long sig[SIGSZ]; 52 }; 53 54 #define REAL_EXP(REAL) \ 55 ((int)((REAL)->uexp ^ (unsigned int)(1 << (EXP_BITS - 1))) \ 56 - (1 << (EXP_BITS - 1))) 57 #define SET_REAL_EXP(REAL, EXP) \ 58 ((REAL)->uexp = ((unsigned int)(EXP) & (unsigned int)((1 << EXP_BITS) - 1))) 59 60 /* Various headers condition prototypes on #ifdef REAL_VALUE_TYPE, so it 61 needs to be a macro. We do need to continue to have a structure tag 62 so that other headers can forward declare it. */ 63 #define REAL_VALUE_TYPE struct real_value 64 65 /* We store a REAL_VALUE_TYPE into an rtx, and we do this by putting it in 66 consecutive "w" slots. Moreover, we've got to compute the number of "w" 67 slots at preprocessor time, which means we can't use sizeof. Guess. */ 68 69 #define REAL_VALUE_TYPE_SIZE (SIGNIFICAND_BITS + 32) 70 #define REAL_WIDTH \ 71 (REAL_VALUE_TYPE_SIZE/HOST_BITS_PER_WIDE_INT \ 72 + (REAL_VALUE_TYPE_SIZE%HOST_BITS_PER_WIDE_INT ? 1 : 0)) /* round up */ 73 74 /* Verify the guess. */ 75 extern char test_real_width 76 [sizeof (REAL_VALUE_TYPE) <= REAL_WIDTH * sizeof (HOST_WIDE_INT) ? 1 : -1]; 77 78 /* Calculate the format for CONST_DOUBLE. We need as many slots as 79 are necessary to overlay a REAL_VALUE_TYPE on them. This could be 80 as many as four (32-bit HOST_WIDE_INT, 128-bit REAL_VALUE_TYPE). 81 82 A number of places assume that there are always at least two 'w' 83 slots in a CONST_DOUBLE, so we provide them even if one would suffice. */ 84 85 #if REAL_WIDTH == 1 86 # define CONST_DOUBLE_FORMAT "ww" 87 #else 88 # if REAL_WIDTH == 2 89 # define CONST_DOUBLE_FORMAT "ww" 90 # else 91 # if REAL_WIDTH == 3 92 # define CONST_DOUBLE_FORMAT "www" 93 # else 94 # if REAL_WIDTH == 4 95 # define CONST_DOUBLE_FORMAT "wwww" 96 # else 97 # if REAL_WIDTH == 5 98 # define CONST_DOUBLE_FORMAT "wwwww" 99 # else 100 # if REAL_WIDTH == 6 101 # define CONST_DOUBLE_FORMAT "wwwwww" 102 # else 103 #error "REAL_WIDTH > 6 not supported" 104 # endif 105 # endif 106 # endif 107 # endif 108 # endif 109 #endif 110 111 112 /* Describes the properties of the specific target format in use. */ 113 struct real_format 114 { 115 /* Move to and from the target bytes. */ 116 void (*encode) (const struct real_format *, long *, 117 const REAL_VALUE_TYPE *); 118 void (*decode) (const struct real_format *, REAL_VALUE_TYPE *, 119 const long *); 120 121 /* The radix of the exponent and digits of the significand. */ 122 int b; 123 124 /* Size of the significand in digits of radix B. */ 125 int p; 126 127 /* Size of the significant of a NaN, in digits of radix B. */ 128 int pnan; 129 130 /* The minimum negative integer, x, such that b**(x-1) is normalized. */ 131 int emin; 132 133 /* The maximum integer, x, such that b**(x-1) is representable. */ 134 int emax; 135 136 /* The bit position of the sign bit, for determining whether a value 137 is positive/negative, or -1 for a complex encoding. */ 138 int signbit_ro; 139 140 /* The bit position of the sign bit, for changing the sign of a number, 141 or -1 for a complex encoding. */ 142 int signbit_rw; 143 144 /* Default rounding mode for operations on this format. */ 145 bool round_towards_zero; 146 bool has_sign_dependent_rounding; 147 148 /* Properties of the format. */ 149 bool has_nans; 150 bool has_inf; 151 bool has_denorm; 152 bool has_signed_zero; 153 bool qnan_msb_set; 154 bool canonical_nan_lsbs_set; 155 }; 156 157 158 /* The target format used for each floating point mode. 159 Float modes are followed by decimal float modes, with entries for 160 float modes indexed by (MODE - first float mode), and entries for 161 decimal float modes indexed by (MODE - first decimal float mode) + 162 the number of float modes. */ 163 extern const struct real_format * 164 real_format_for_mode[MAX_MODE_FLOAT - MIN_MODE_FLOAT + 1 165 + MAX_MODE_DECIMAL_FLOAT - MIN_MODE_DECIMAL_FLOAT + 1]; 166 167 #define REAL_MODE_FORMAT(MODE) \ 168 (real_format_for_mode[DECIMAL_FLOAT_MODE_P (MODE) \ 169 ? (((MODE) - MIN_MODE_DECIMAL_FLOAT) \ 170 + (MAX_MODE_FLOAT - MIN_MODE_FLOAT + 1)) \ 171 : ((MODE) - MIN_MODE_FLOAT)]) 172 173 #define FLOAT_MODE_FORMAT(MODE) \ 174 (REAL_MODE_FORMAT (SCALAR_FLOAT_MODE_P (MODE)? (MODE) \ 175 : GET_MODE_INNER (MODE))) 176 177 /* The following macro determines whether the floating point format is 178 composite, i.e. may contain non-consecutive mantissa bits, in which 179 case compile-time FP overflow may not model run-time overflow. */ 180 #define MODE_COMPOSITE_P(MODE) \ 181 (FLOAT_MODE_P (MODE) \ 182 && FLOAT_MODE_FORMAT (MODE)->pnan < FLOAT_MODE_FORMAT (MODE)->p) 183 184 /* Accessor macros for format properties. */ 185 #define MODE_HAS_NANS(MODE) \ 186 (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_nans) 187 #define MODE_HAS_INFINITIES(MODE) \ 188 (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_inf) 189 #define MODE_HAS_SIGNED_ZEROS(MODE) \ 190 (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_signed_zero) 191 #define MODE_HAS_SIGN_DEPENDENT_ROUNDING(MODE) \ 192 (FLOAT_MODE_P (MODE) \ 193 && FLOAT_MODE_FORMAT (MODE)->has_sign_dependent_rounding) 194 195 /* True if the given mode has a NaN representation and the treatment of 196 NaN operands is important. Certain optimizations, such as folding 197 x * 0 into 0, are not correct for NaN operands, and are normally 198 disabled for modes with NaNs. The user can ask for them to be 199 done anyway using the -funsafe-math-optimizations switch. */ 200 #define HONOR_NANS(MODE) \ 201 (MODE_HAS_NANS (MODE) && !flag_finite_math_only) 202 203 /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs). */ 204 #define HONOR_SNANS(MODE) (flag_signaling_nans && HONOR_NANS (MODE)) 205 206 /* As for HONOR_NANS, but true if the mode can represent infinity and 207 the treatment of infinite values is important. */ 208 #define HONOR_INFINITIES(MODE) \ 209 (MODE_HAS_INFINITIES (MODE) && !flag_finite_math_only) 210 211 /* Like HONOR_NANS, but true if the given mode distinguishes between 212 positive and negative zero, and the sign of zero is important. */ 213 #define HONOR_SIGNED_ZEROS(MODE) \ 214 (MODE_HAS_SIGNED_ZEROS (MODE) && flag_signed_zeros) 215 216 /* Like HONOR_NANS, but true if given mode supports sign-dependent rounding, 217 and the rounding mode is important. */ 218 #define HONOR_SIGN_DEPENDENT_ROUNDING(MODE) \ 219 (MODE_HAS_SIGN_DEPENDENT_ROUNDING (MODE) && flag_rounding_math) 220 221 /* Declare functions in real.c. */ 222 223 /* Binary or unary arithmetic on tree_code. */ 224 extern bool real_arithmetic (REAL_VALUE_TYPE *, int, const REAL_VALUE_TYPE *, 225 const REAL_VALUE_TYPE *); 226 227 /* Compare reals by tree_code. */ 228 extern bool real_compare (int, const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *); 229 230 /* Determine whether a floating-point value X is infinite. */ 231 extern bool real_isinf (const REAL_VALUE_TYPE *); 232 233 /* Determine whether a floating-point value X is a NaN. */ 234 extern bool real_isnan (const REAL_VALUE_TYPE *); 235 236 /* Determine whether a floating-point value X is finite. */ 237 extern bool real_isfinite (const REAL_VALUE_TYPE *); 238 239 /* Determine whether a floating-point value X is negative. */ 240 extern bool real_isneg (const REAL_VALUE_TYPE *); 241 242 /* Determine whether a floating-point value X is minus zero. */ 243 extern bool real_isnegzero (const REAL_VALUE_TYPE *); 244 245 /* Compare two floating-point objects for bitwise identity. */ 246 extern bool real_identical (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *); 247 248 /* Extend or truncate to a new mode. */ 249 extern void real_convert (REAL_VALUE_TYPE *, enum machine_mode, 250 const REAL_VALUE_TYPE *); 251 252 /* Return true if truncating to NEW is exact. */ 253 extern bool exact_real_truncate (enum machine_mode, const REAL_VALUE_TYPE *); 254 255 /* Render R as a decimal floating point constant. */ 256 extern void real_to_decimal (char *, const REAL_VALUE_TYPE *, size_t, 257 size_t, int); 258 259 /* Render R as a decimal floating point constant, rounded so as to be 260 parsed back to the same value when interpreted in mode MODE. */ 261 extern void real_to_decimal_for_mode (char *, const REAL_VALUE_TYPE *, size_t, 262 size_t, int, enum machine_mode); 263 264 /* Render R as a hexadecimal floating point constant. */ 265 extern void real_to_hexadecimal (char *, const REAL_VALUE_TYPE *, 266 size_t, size_t, int); 267 268 /* Render R as an integer. */ 269 extern HOST_WIDE_INT real_to_integer (const REAL_VALUE_TYPE *); 270 extern void real_to_integer2 (HOST_WIDE_INT *, HOST_WIDE_INT *, 271 const REAL_VALUE_TYPE *); 272 273 /* Initialize R from a decimal or hexadecimal string. Return -1 if 274 the value underflows, +1 if overflows, and 0 otherwise. */ 275 extern int real_from_string (REAL_VALUE_TYPE *, const char *); 276 /* Wrapper to allow different internal representation for decimal floats. */ 277 extern void real_from_string3 (REAL_VALUE_TYPE *, const char *, enum machine_mode); 278 279 /* Initialize R from an integer pair HIGH/LOW. */ 280 extern void real_from_integer (REAL_VALUE_TYPE *, enum machine_mode, 281 unsigned HOST_WIDE_INT, HOST_WIDE_INT, int); 282 283 extern long real_to_target_fmt (long *, const REAL_VALUE_TYPE *, 284 const struct real_format *); 285 extern long real_to_target (long *, const REAL_VALUE_TYPE *, enum machine_mode); 286 287 extern void real_from_target_fmt (REAL_VALUE_TYPE *, const long *, 288 const struct real_format *); 289 extern void real_from_target (REAL_VALUE_TYPE *, const long *, 290 enum machine_mode); 291 292 extern void real_inf (REAL_VALUE_TYPE *); 293 294 extern bool real_nan (REAL_VALUE_TYPE *, const char *, int, enum machine_mode); 295 296 extern void real_maxval (REAL_VALUE_TYPE *, int, enum machine_mode); 297 298 extern void real_2expN (REAL_VALUE_TYPE *, int, enum machine_mode); 299 300 extern unsigned int real_hash (const REAL_VALUE_TYPE *); 301 302 303 /* Target formats defined in real.c. */ 304 extern const struct real_format ieee_single_format; 305 extern const struct real_format mips_single_format; 306 extern const struct real_format motorola_single_format; 307 extern const struct real_format spu_single_format; 308 extern const struct real_format ieee_double_format; 309 extern const struct real_format mips_double_format; 310 extern const struct real_format motorola_double_format; 311 extern const struct real_format ieee_extended_motorola_format; 312 extern const struct real_format ieee_extended_intel_96_format; 313 extern const struct real_format ieee_extended_intel_96_round_53_format; 314 extern const struct real_format ieee_extended_intel_128_format; 315 extern const struct real_format ibm_extended_format; 316 extern const struct real_format mips_extended_format; 317 extern const struct real_format ieee_quad_format; 318 extern const struct real_format mips_quad_format; 319 extern const struct real_format vax_f_format; 320 extern const struct real_format vax_d_format; 321 extern const struct real_format vax_g_format; 322 extern const struct real_format real_internal_format; 323 extern const struct real_format decimal_single_format; 324 extern const struct real_format decimal_double_format; 325 extern const struct real_format decimal_quad_format; 326 extern const struct real_format ieee_half_format; 327 extern const struct real_format arm_half_format; 328 329 330 /* ====================================================================== */ 331 /* Crap. */ 332 333 #define REAL_ARITHMETIC(value, code, d1, d2) \ 334 real_arithmetic (&(value), code, &(d1), &(d2)) 335 336 #define REAL_VALUES_IDENTICAL(x, y) real_identical (&(x), &(y)) 337 #define REAL_VALUES_EQUAL(x, y) real_compare (EQ_EXPR, &(x), &(y)) 338 #define REAL_VALUES_LESS(x, y) real_compare (LT_EXPR, &(x), &(y)) 339 340 /* Determine whether a floating-point value X is infinite. */ 341 #define REAL_VALUE_ISINF(x) real_isinf (&(x)) 342 343 /* Determine whether a floating-point value X is a NaN. */ 344 #define REAL_VALUE_ISNAN(x) real_isnan (&(x)) 345 346 /* Determine whether a floating-point value X is negative. */ 347 #define REAL_VALUE_NEGATIVE(x) real_isneg (&(x)) 348 349 /* Determine whether a floating-point value X is minus zero. */ 350 #define REAL_VALUE_MINUS_ZERO(x) real_isnegzero (&(x)) 351 352 /* IN is a REAL_VALUE_TYPE. OUT is an array of longs. */ 353 #define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT) \ 354 real_to_target (OUT, &(IN), \ 355 mode_for_size (LONG_DOUBLE_TYPE_SIZE, MODE_FLOAT, 0)) 356 357 #define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT) \ 358 real_to_target (OUT, &(IN), mode_for_size (64, MODE_FLOAT, 0)) 359 360 /* IN is a REAL_VALUE_TYPE. OUT is a long. */ 361 #define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT) \ 362 ((OUT) = real_to_target (NULL, &(IN), mode_for_size (32, MODE_FLOAT, 0))) 363 364 #define REAL_VALUE_FROM_INT(r, lo, hi, mode) \ 365 real_from_integer (&(r), mode, lo, hi, 0) 366 367 #define REAL_VALUE_FROM_UNSIGNED_INT(r, lo, hi, mode) \ 368 real_from_integer (&(r), mode, lo, hi, 1) 369 370 /* Real values to IEEE 754 decimal floats. */ 371 372 /* IN is a REAL_VALUE_TYPE. OUT is an array of longs. */ 373 #define REAL_VALUE_TO_TARGET_DECIMAL128(IN, OUT) \ 374 real_to_target (OUT, &(IN), mode_for_size (128, MODE_DECIMAL_FLOAT, 0)) 375 376 #define REAL_VALUE_TO_TARGET_DECIMAL64(IN, OUT) \ 377 real_to_target (OUT, &(IN), mode_for_size (64, MODE_DECIMAL_FLOAT, 0)) 378 379 /* IN is a REAL_VALUE_TYPE. OUT is a long. */ 380 #define REAL_VALUE_TO_TARGET_DECIMAL32(IN, OUT) \ 381 ((OUT) = real_to_target (NULL, &(IN), mode_for_size (32, MODE_DECIMAL_FLOAT, 0))) 382 383 extern REAL_VALUE_TYPE real_value_truncate (enum machine_mode, 384 REAL_VALUE_TYPE); 385 386 #define REAL_VALUE_TO_INT(plow, phigh, r) \ 387 real_to_integer2 (plow, phigh, &(r)) 388 389 extern REAL_VALUE_TYPE real_value_negate (const REAL_VALUE_TYPE *); 390 extern REAL_VALUE_TYPE real_value_abs (const REAL_VALUE_TYPE *); 391 392 extern int significand_size (enum machine_mode); 393 394 extern REAL_VALUE_TYPE real_from_string2 (const char *, enum machine_mode); 395 396 #define REAL_VALUE_ATOF(s, m) \ 397 real_from_string2 (s, m) 398 399 #define CONST_DOUBLE_ATOF(s, m) \ 400 CONST_DOUBLE_FROM_REAL_VALUE (real_from_string2 (s, m), m) 401 402 #define REAL_VALUE_FIX(r) \ 403 real_to_integer (&(r)) 404 405 /* ??? Not quite right. */ 406 #define REAL_VALUE_UNSIGNED_FIX(r) \ 407 real_to_integer (&(r)) 408 409 /* ??? These were added for Paranoia support. */ 410 411 /* Return floor log2(R). */ 412 extern int real_exponent (const REAL_VALUE_TYPE *); 413 414 /* R = A * 2**EXP. */ 415 extern void real_ldexp (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *, int); 416 417 /* **** End of software floating point emulator interface macros **** */ 418 419 /* Constant real values 0, 1, 2, -1 and 0.5. */ 420 421 extern REAL_VALUE_TYPE dconst0; 422 extern REAL_VALUE_TYPE dconst1; 423 extern REAL_VALUE_TYPE dconst2; 424 extern REAL_VALUE_TYPE dconstm1; 425 extern REAL_VALUE_TYPE dconsthalf; 426 427 #define dconst_e() (*dconst_e_ptr ()) 428 #define dconst_third() (*dconst_third_ptr ()) 429 #define dconst_sqrt2() (*dconst_sqrt2_ptr ()) 430 431 /* Function to return the real value special constant 'e'. */ 432 extern const REAL_VALUE_TYPE * dconst_e_ptr (void); 433 434 /* Returns the special REAL_VALUE_TYPE corresponding to 1/3. */ 435 extern const REAL_VALUE_TYPE * dconst_third_ptr (void); 436 437 /* Returns the special REAL_VALUE_TYPE corresponding to sqrt(2). */ 438 extern const REAL_VALUE_TYPE * dconst_sqrt2_ptr (void); 439 440 /* Function to return a real value (not a tree node) 441 from a given integer constant. */ 442 REAL_VALUE_TYPE real_value_from_int_cst (const_tree, const_tree); 443 444 /* Given a CONST_DOUBLE in FROM, store into TO the value it represents. */ 445 #define REAL_VALUE_FROM_CONST_DOUBLE(to, from) \ 446 ((to) = *CONST_DOUBLE_REAL_VALUE (from)) 447 448 /* Return a CONST_DOUBLE with value R and mode M. */ 449 #define CONST_DOUBLE_FROM_REAL_VALUE(r, m) \ 450 const_double_from_real_value (r, m) 451 extern rtx const_double_from_real_value (REAL_VALUE_TYPE, enum machine_mode); 452 453 /* Replace R by 1/R in the given machine mode, if the result is exact. */ 454 extern bool exact_real_inverse (enum machine_mode, REAL_VALUE_TYPE *); 455 456 /* Return true if arithmetic on values in IMODE that were promoted 457 from values in TMODE is equivalent to direct arithmetic on values 458 in TMODE. */ 459 bool real_can_shorten_arithmetic (enum machine_mode, enum machine_mode); 460 461 /* In tree.c: wrap up a REAL_VALUE_TYPE in a tree node. */ 462 extern tree build_real (tree, REAL_VALUE_TYPE); 463 464 /* Calculate R as X raised to the integer exponent N in mode MODE. */ 465 extern bool real_powi (REAL_VALUE_TYPE *, enum machine_mode, 466 const REAL_VALUE_TYPE *, HOST_WIDE_INT); 467 468 /* Standard round to integer value functions. */ 469 extern void real_trunc (REAL_VALUE_TYPE *, enum machine_mode, 470 const REAL_VALUE_TYPE *); 471 extern void real_floor (REAL_VALUE_TYPE *, enum machine_mode, 472 const REAL_VALUE_TYPE *); 473 extern void real_ceil (REAL_VALUE_TYPE *, enum machine_mode, 474 const REAL_VALUE_TYPE *); 475 extern void real_round (REAL_VALUE_TYPE *, enum machine_mode, 476 const REAL_VALUE_TYPE *); 477 478 /* Set the sign of R to the sign of X. */ 479 extern void real_copysign (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *); 480 481 /* Check whether the real constant value given is an integer. */ 482 extern bool real_isinteger (const REAL_VALUE_TYPE *c, enum machine_mode mode); 483 484 /* Write into BUF the maximum representable finite floating-point 485 number, (1 - b**-p) * b**emax for a given FP format FMT as a hex 486 float string. BUF must be large enough to contain the result. */ 487 extern void get_max_float (const struct real_format *, char *, size_t); 488 #endif /* ! GCC_REAL_H */ 489