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 #include "machmode.h" 26 27 /* An expanded form of the represented number. */ 28 29 /* Enumerate the special cases of numbers that we encounter. */ 30 enum real_value_class { 31 rvc_zero, 32 rvc_normal, 33 rvc_inf, 34 rvc_nan 35 }; 36 37 #define SIGNIFICAND_BITS (128 + HOST_BITS_PER_LONG) 38 #define EXP_BITS (32 - 6) 39 #define MAX_EXP ((1 << (EXP_BITS - 1)) - 1) 40 #define SIGSZ (SIGNIFICAND_BITS / HOST_BITS_PER_LONG) 41 #define SIG_MSB ((unsigned long)1 << (HOST_BITS_PER_LONG - 1)) 42 43 struct GTY(()) real_value { 44 /* Use the same underlying type for all bit-fields, so as to make 45 sure they're packed together, otherwise REAL_VALUE_TYPE_SIZE will 46 be miscomputed. */ 47 unsigned int /* ENUM_BITFIELD (real_value_class) */ cl : 2; 48 unsigned int decimal : 1; 49 unsigned int sign : 1; 50 unsigned int signalling : 1; 51 unsigned int canonical : 1; 52 unsigned int uexp : EXP_BITS; 53 unsigned long sig[SIGSZ]; 54 }; 55 56 #define REAL_EXP(REAL) \ 57 ((int)((REAL)->uexp ^ (unsigned int)(1 << (EXP_BITS - 1))) \ 58 - (1 << (EXP_BITS - 1))) 59 #define SET_REAL_EXP(REAL, EXP) \ 60 ((REAL)->uexp = ((unsigned int)(EXP) & (unsigned int)((1 << EXP_BITS) - 1))) 61 62 /* Various headers condition prototypes on #ifdef REAL_VALUE_TYPE, so it 63 needs to be a macro. We do need to continue to have a structure tag 64 so that other headers can forward declare it. */ 65 #define REAL_VALUE_TYPE struct real_value 66 67 /* We store a REAL_VALUE_TYPE into an rtx, and we do this by putting it in 68 consecutive "w" slots. Moreover, we've got to compute the number of "w" 69 slots at preprocessor time, which means we can't use sizeof. Guess. */ 70 71 #define REAL_VALUE_TYPE_SIZE (SIGNIFICAND_BITS + 32) 72 #define REAL_WIDTH \ 73 (REAL_VALUE_TYPE_SIZE/HOST_BITS_PER_WIDE_INT \ 74 + (REAL_VALUE_TYPE_SIZE%HOST_BITS_PER_WIDE_INT ? 1 : 0)) /* round up */ 75 76 /* Verify the guess. */ 77 extern char test_real_width 78 [sizeof(REAL_VALUE_TYPE) <= REAL_WIDTH*sizeof(HOST_WIDE_INT) ? 1 : -1]; 79 80 /* Calculate the format for CONST_DOUBLE. We need as many slots as 81 are necessary to overlay a REAL_VALUE_TYPE on them. This could be 82 as many as four (32-bit HOST_WIDE_INT, 128-bit REAL_VALUE_TYPE). 83 84 A number of places assume that there are always at least two 'w' 85 slots in a CONST_DOUBLE, so we provide them even if one would suffice. */ 86 87 #if REAL_WIDTH == 1 88 # define CONST_DOUBLE_FORMAT "ww" 89 #else 90 # if REAL_WIDTH == 2 91 # define CONST_DOUBLE_FORMAT "ww" 92 # else 93 # if REAL_WIDTH == 3 94 # define CONST_DOUBLE_FORMAT "www" 95 # else 96 # if REAL_WIDTH == 4 97 # define CONST_DOUBLE_FORMAT "wwww" 98 # else 99 # if REAL_WIDTH == 5 100 # define CONST_DOUBLE_FORMAT "wwwww" 101 # else 102 # if REAL_WIDTH == 6 103 # define CONST_DOUBLE_FORMAT "wwwwww" 104 # else 105 #error "REAL_WIDTH > 6 not supported" 106 # endif 107 # endif 108 # endif 109 # endif 110 # endif 111 #endif 112 113 114 /* Describes the properties of the specific target format in use. */ 115 struct real_format 116 { 117 /* Move to and from the target bytes. */ 118 void (*encode) (const struct real_format *, long *, 119 const REAL_VALUE_TYPE *); 120 void (*decode) (const struct real_format *, REAL_VALUE_TYPE *, 121 const long *); 122 123 /* The radix of the exponent and digits of the significand. */ 124 int b; 125 126 /* Size of the significand in digits of radix B. */ 127 int p; 128 129 /* Size of the significant of a NaN, in digits of radix B. */ 130 int pnan; 131 132 /* The minimum negative integer, x, such that b**(x-1) is normalized. */ 133 int emin; 134 135 /* The maximum integer, x, such that b**(x-1) is representable. */ 136 int emax; 137 138 /* The bit position of the sign bit, for determining whether a value 139 is positive/negative, or -1 for a complex encoding. */ 140 int signbit_ro; 141 142 /* The bit position of the sign bit, for changing the sign of a number, 143 or -1 for a complex encoding. */ 144 int signbit_rw; 145 146 /* Default rounding mode for operations on this format. */ 147 bool round_towards_zero; 148 bool has_sign_dependent_rounding; 149 150 /* Properties of the format. */ 151 bool has_nans; 152 bool has_inf; 153 bool has_denorm; 154 bool has_signed_zero; 155 bool qnan_msb_set; 156 bool canonical_nan_lsbs_set; 157 }; 158 159 160 /* The target format used for each floating point mode. 161 Float modes are followed by decimal float modes, with entries for 162 float modes indexed by (MODE - first float mode), and entries for 163 decimal float modes indexed by (MODE - first decimal float mode) + 164 the number of float modes. */ 165 extern const struct real_format * 166 real_format_for_mode[MAX_MODE_FLOAT - MIN_MODE_FLOAT + 1 167 + MAX_MODE_DECIMAL_FLOAT - MIN_MODE_DECIMAL_FLOAT + 1]; 168 169 #define REAL_MODE_FORMAT(MODE) \ 170 (real_format_for_mode[DECIMAL_FLOAT_MODE_P (MODE) \ 171 ? (((MODE) - MIN_MODE_DECIMAL_FLOAT) \ 172 + (MAX_MODE_FLOAT - MIN_MODE_FLOAT + 1)) \ 173 : ((MODE) - MIN_MODE_FLOAT)]) 174 175 #define FLOAT_MODE_FORMAT(MODE) \ 176 (REAL_MODE_FORMAT (SCALAR_FLOAT_MODE_P (MODE)? (MODE) \ 177 : GET_MODE_INNER (MODE))) 178 179 /* The following macro determines whether the floating point format is 180 composite, i.e. may contain non-consecutive mantissa bits, in which 181 case compile-time FP overflow may not model run-time overflow. */ 182 #define MODE_COMPOSITE_P(MODE) \ 183 (FLOAT_MODE_P (MODE) \ 184 && FLOAT_MODE_FORMAT (MODE)->pnan < FLOAT_MODE_FORMAT (MODE)->p) 185 186 /* Accessor macros for format properties. */ 187 #define MODE_HAS_NANS(MODE) \ 188 (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_nans) 189 #define MODE_HAS_INFINITIES(MODE) \ 190 (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_inf) 191 #define MODE_HAS_SIGNED_ZEROS(MODE) \ 192 (FLOAT_MODE_P (MODE) && FLOAT_MODE_FORMAT (MODE)->has_signed_zero) 193 #define MODE_HAS_SIGN_DEPENDENT_ROUNDING(MODE) \ 194 (FLOAT_MODE_P (MODE) \ 195 && FLOAT_MODE_FORMAT (MODE)->has_sign_dependent_rounding) 196 197 /* True if the given mode has a NaN representation and the treatment of 198 NaN operands is important. Certain optimizations, such as folding 199 x * 0 into 0, are not correct for NaN operands, and are normally 200 disabled for modes with NaNs. The user can ask for them to be 201 done anyway using the -funsafe-math-optimizations switch. */ 202 #define HONOR_NANS(MODE) \ 203 (MODE_HAS_NANS (MODE) && !flag_finite_math_only) 204 205 /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs). */ 206 #define HONOR_SNANS(MODE) (flag_signaling_nans && HONOR_NANS (MODE)) 207 208 /* As for HONOR_NANS, but true if the mode can represent infinity and 209 the treatment of infinite values is important. */ 210 #define HONOR_INFINITIES(MODE) \ 211 (MODE_HAS_INFINITIES (MODE) && !flag_finite_math_only) 212 213 /* Like HONOR_NANS, but true if the given mode distinguishes between 214 positive and negative zero, and the sign of zero is important. */ 215 #define HONOR_SIGNED_ZEROS(MODE) \ 216 (MODE_HAS_SIGNED_ZEROS (MODE) && flag_signed_zeros) 217 218 /* Like HONOR_NANS, but true if given mode supports sign-dependent rounding, 219 and the rounding mode is important. */ 220 #define HONOR_SIGN_DEPENDENT_ROUNDING(MODE) \ 221 (MODE_HAS_SIGN_DEPENDENT_ROUNDING (MODE) && flag_rounding_math) 222 223 /* Declare functions in real.c. */ 224 225 /* Binary or unary arithmetic on tree_code. */ 226 extern bool real_arithmetic (REAL_VALUE_TYPE *, int, const REAL_VALUE_TYPE *, 227 const REAL_VALUE_TYPE *); 228 229 /* Compare reals by tree_code. */ 230 extern bool real_compare (int, const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *); 231 232 /* Determine whether a floating-point value X is infinite. */ 233 extern bool real_isinf (const REAL_VALUE_TYPE *); 234 235 /* Determine whether a floating-point value X is a NaN. */ 236 extern bool real_isnan (const REAL_VALUE_TYPE *); 237 238 /* Determine whether a floating-point value X is finite. */ 239 extern bool real_isfinite (const REAL_VALUE_TYPE *); 240 241 /* Determine whether a floating-point value X is negative. */ 242 extern bool real_isneg (const REAL_VALUE_TYPE *); 243 244 /* Determine whether a floating-point value X is minus zero. */ 245 extern bool real_isnegzero (const REAL_VALUE_TYPE *); 246 247 /* Compare two floating-point objects for bitwise identity. */ 248 extern bool real_identical (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *); 249 250 /* Extend or truncate to a new mode. */ 251 extern void real_convert (REAL_VALUE_TYPE *, enum machine_mode, 252 const REAL_VALUE_TYPE *); 253 254 /* Return true if truncating to NEW is exact. */ 255 extern bool exact_real_truncate (enum machine_mode, const REAL_VALUE_TYPE *); 256 257 /* Render R as a decimal floating point constant. */ 258 extern void real_to_decimal (char *, const REAL_VALUE_TYPE *, size_t, 259 size_t, int); 260 261 /* Render R as a decimal floating point constant, rounded so as to be 262 parsed back to the same value when interpreted in mode MODE. */ 263 extern void real_to_decimal_for_mode (char *, const REAL_VALUE_TYPE *, size_t, 264 size_t, int, enum machine_mode); 265 266 /* Render R as a hexadecimal floating point constant. */ 267 extern void real_to_hexadecimal (char *, const REAL_VALUE_TYPE *, 268 size_t, size_t, int); 269 270 /* Render R as an integer. */ 271 extern HOST_WIDE_INT real_to_integer (const REAL_VALUE_TYPE *); 272 extern void real_to_integer2 (HOST_WIDE_INT *, HOST_WIDE_INT *, 273 const REAL_VALUE_TYPE *); 274 275 /* Initialize R from a decimal or hexadecimal string. Return -1 if 276 the value underflows, +1 if overflows, and 0 otherwise. */ 277 extern int real_from_string (REAL_VALUE_TYPE *, const char *); 278 /* Wrapper to allow different internal representation for decimal floats. */ 279 extern void real_from_string3 (REAL_VALUE_TYPE *, const char *, enum machine_mode); 280 281 /* Initialize R from an integer pair HIGH/LOW. */ 282 extern void real_from_integer (REAL_VALUE_TYPE *, enum machine_mode, 283 unsigned HOST_WIDE_INT, HOST_WIDE_INT, int); 284 285 extern long real_to_target_fmt (long *, const REAL_VALUE_TYPE *, 286 const struct real_format *); 287 extern long real_to_target (long *, const REAL_VALUE_TYPE *, enum machine_mode); 288 289 extern void real_from_target_fmt (REAL_VALUE_TYPE *, const long *, 290 const struct real_format *); 291 extern void real_from_target (REAL_VALUE_TYPE *, const long *, 292 enum machine_mode); 293 294 extern void real_inf (REAL_VALUE_TYPE *); 295 296 extern bool real_nan (REAL_VALUE_TYPE *, const char *, int, enum machine_mode); 297 298 extern void real_maxval (REAL_VALUE_TYPE *, int, enum machine_mode); 299 300 extern void real_2expN (REAL_VALUE_TYPE *, int, enum machine_mode); 301 302 extern unsigned int real_hash (const REAL_VALUE_TYPE *); 303 304 305 /* Target formats defined in real.c. */ 306 extern const struct real_format ieee_single_format; 307 extern const struct real_format mips_single_format; 308 extern const struct real_format motorola_single_format; 309 extern const struct real_format spu_single_format; 310 extern const struct real_format ieee_double_format; 311 extern const struct real_format mips_double_format; 312 extern const struct real_format motorola_double_format; 313 extern const struct real_format ieee_extended_motorola_format; 314 extern const struct real_format ieee_extended_intel_96_format; 315 extern const struct real_format ieee_extended_intel_96_round_53_format; 316 extern const struct real_format ieee_extended_intel_128_format; 317 extern const struct real_format ibm_extended_format; 318 extern const struct real_format mips_extended_format; 319 extern const struct real_format ieee_quad_format; 320 extern const struct real_format mips_quad_format; 321 extern const struct real_format vax_f_format; 322 extern const struct real_format vax_d_format; 323 extern const struct real_format vax_g_format; 324 extern const struct real_format real_internal_format; 325 extern const struct real_format decimal_single_format; 326 extern const struct real_format decimal_double_format; 327 extern const struct real_format decimal_quad_format; 328 extern const struct real_format ieee_half_format; 329 extern const struct real_format arm_half_format; 330 331 332 /* ====================================================================== */ 333 /* Crap. */ 334 335 #define REAL_ARITHMETIC(value, code, d1, d2) \ 336 real_arithmetic (&(value), code, &(d1), &(d2)) 337 338 #define REAL_VALUES_IDENTICAL(x, y) real_identical (&(x), &(y)) 339 #define REAL_VALUES_EQUAL(x, y) real_compare (EQ_EXPR, &(x), &(y)) 340 #define REAL_VALUES_LESS(x, y) real_compare (LT_EXPR, &(x), &(y)) 341 342 /* Determine whether a floating-point value X is infinite. */ 343 #define REAL_VALUE_ISINF(x) real_isinf (&(x)) 344 345 /* Determine whether a floating-point value X is a NaN. */ 346 #define REAL_VALUE_ISNAN(x) real_isnan (&(x)) 347 348 /* Determine whether a floating-point value X is negative. */ 349 #define REAL_VALUE_NEGATIVE(x) real_isneg (&(x)) 350 351 /* Determine whether a floating-point value X is minus zero. */ 352 #define REAL_VALUE_MINUS_ZERO(x) real_isnegzero (&(x)) 353 354 /* IN is a REAL_VALUE_TYPE. OUT is an array of longs. */ 355 #define REAL_VALUE_TO_TARGET_LONG_DOUBLE(IN, OUT) \ 356 real_to_target (OUT, &(IN), \ 357 mode_for_size (LONG_DOUBLE_TYPE_SIZE, MODE_FLOAT, 0)) 358 359 #define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT) \ 360 real_to_target (OUT, &(IN), mode_for_size (64, MODE_FLOAT, 0)) 361 362 /* IN is a REAL_VALUE_TYPE. OUT is a long. */ 363 #define REAL_VALUE_TO_TARGET_SINGLE(IN, OUT) \ 364 ((OUT) = real_to_target (NULL, &(IN), mode_for_size (32, MODE_FLOAT, 0))) 365 366 #define REAL_VALUE_FROM_INT(r, lo, hi, mode) \ 367 real_from_integer (&(r), mode, lo, hi, 0) 368 369 #define REAL_VALUE_FROM_UNSIGNED_INT(r, lo, hi, mode) \ 370 real_from_integer (&(r), mode, lo, hi, 1) 371 372 /* Real values to IEEE 754 decimal floats. */ 373 374 /* IN is a REAL_VALUE_TYPE. OUT is an array of longs. */ 375 #define REAL_VALUE_TO_TARGET_DECIMAL128(IN, OUT) \ 376 real_to_target (OUT, &(IN), mode_for_size (128, MODE_DECIMAL_FLOAT, 0)) 377 378 #define REAL_VALUE_TO_TARGET_DECIMAL64(IN, OUT) \ 379 real_to_target (OUT, &(IN), mode_for_size (64, MODE_DECIMAL_FLOAT, 0)) 380 381 /* IN is a REAL_VALUE_TYPE. OUT is a long. */ 382 #define REAL_VALUE_TO_TARGET_DECIMAL32(IN, OUT) \ 383 ((OUT) = real_to_target (NULL, &(IN), mode_for_size (32, MODE_DECIMAL_FLOAT, 0))) 384 385 extern REAL_VALUE_TYPE real_value_truncate (enum machine_mode, 386 REAL_VALUE_TYPE); 387 388 #define REAL_VALUE_TO_INT(plow, phigh, r) \ 389 real_to_integer2 (plow, phigh, &(r)) 390 391 extern REAL_VALUE_TYPE real_value_negate (const REAL_VALUE_TYPE *); 392 extern REAL_VALUE_TYPE real_value_abs (const REAL_VALUE_TYPE *); 393 394 extern int significand_size (enum machine_mode); 395 396 extern REAL_VALUE_TYPE real_from_string2 (const char *, enum machine_mode); 397 398 #define REAL_VALUE_ATOF(s, m) \ 399 real_from_string2 (s, m) 400 401 #define CONST_DOUBLE_ATOF(s, m) \ 402 CONST_DOUBLE_FROM_REAL_VALUE (real_from_string2 (s, m), m) 403 404 #define REAL_VALUE_FIX(r) \ 405 real_to_integer (&(r)) 406 407 /* ??? Not quite right. */ 408 #define REAL_VALUE_UNSIGNED_FIX(r) \ 409 real_to_integer (&(r)) 410 411 /* ??? These were added for Paranoia support. */ 412 413 /* Return floor log2(R). */ 414 extern int real_exponent (const REAL_VALUE_TYPE *); 415 416 /* R = A * 2**EXP. */ 417 extern void real_ldexp (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *, int); 418 419 /* **** End of software floating point emulator interface macros **** */ 420 421 /* Constant real values 0, 1, 2, -1 and 0.5. */ 422 423 extern REAL_VALUE_TYPE dconst0; 424 extern REAL_VALUE_TYPE dconst1; 425 extern REAL_VALUE_TYPE dconst2; 426 extern REAL_VALUE_TYPE dconstm1; 427 extern REAL_VALUE_TYPE dconsthalf; 428 429 #define dconst_e() (*dconst_e_ptr ()) 430 #define dconst_third() (*dconst_third_ptr ()) 431 #define dconst_sqrt2() (*dconst_sqrt2_ptr ()) 432 433 /* Function to return the real value special constant 'e'. */ 434 extern const REAL_VALUE_TYPE * dconst_e_ptr (void); 435 436 /* Returns the special REAL_VALUE_TYPE corresponding to 1/3. */ 437 extern const REAL_VALUE_TYPE * dconst_third_ptr (void); 438 439 /* Returns the special REAL_VALUE_TYPE corresponding to sqrt(2). */ 440 extern const REAL_VALUE_TYPE * dconst_sqrt2_ptr (void); 441 442 /* Function to return a real value (not a tree node) 443 from a given integer constant. */ 444 REAL_VALUE_TYPE real_value_from_int_cst (const_tree, const_tree); 445 446 /* Given a CONST_DOUBLE in FROM, store into TO the value it represents. */ 447 #define REAL_VALUE_FROM_CONST_DOUBLE(to, from) \ 448 ((to) = *CONST_DOUBLE_REAL_VALUE (from)) 449 450 /* Return a CONST_DOUBLE with value R and mode M. */ 451 #define CONST_DOUBLE_FROM_REAL_VALUE(r, m) \ 452 const_double_from_real_value (r, m) 453 extern rtx const_double_from_real_value (REAL_VALUE_TYPE, enum machine_mode); 454 455 /* Replace R by 1/R in the given machine mode, if the result is exact. */ 456 extern bool exact_real_inverse (enum machine_mode, REAL_VALUE_TYPE *); 457 458 /* Return true if arithmetic on values in IMODE that were promoted 459 from values in TMODE is equivalent to direct arithmetic on values 460 in TMODE. */ 461 bool real_can_shorten_arithmetic (enum machine_mode, enum machine_mode); 462 463 /* In tree.c: wrap up a REAL_VALUE_TYPE in a tree node. */ 464 extern tree build_real (tree, REAL_VALUE_TYPE); 465 466 /* Calculate R as the square root of X in the given machine mode. */ 467 extern bool real_sqrt (REAL_VALUE_TYPE *, enum machine_mode, 468 const REAL_VALUE_TYPE *); 469 470 /* Calculate R as X raised to the integer exponent N in mode MODE. */ 471 extern bool real_powi (REAL_VALUE_TYPE *, enum machine_mode, 472 const REAL_VALUE_TYPE *, HOST_WIDE_INT); 473 474 /* Standard round to integer value functions. */ 475 extern void real_trunc (REAL_VALUE_TYPE *, enum machine_mode, 476 const REAL_VALUE_TYPE *); 477 extern void real_floor (REAL_VALUE_TYPE *, enum machine_mode, 478 const REAL_VALUE_TYPE *); 479 extern void real_ceil (REAL_VALUE_TYPE *, enum machine_mode, 480 const REAL_VALUE_TYPE *); 481 extern void real_round (REAL_VALUE_TYPE *, enum machine_mode, 482 const REAL_VALUE_TYPE *); 483 484 /* Set the sign of R to the sign of X. */ 485 extern void real_copysign (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *); 486 487 /* Check whether the real constant value given is an integer. */ 488 extern bool real_isinteger (const REAL_VALUE_TYPE *c, enum machine_mode mode); 489 490 /* Write into BUF the maximum representable finite floating-point 491 number, (1 - b**-p) * b**emax for a given FP format FMT as a hex 492 float string. BUF must be large enough to contain the result. */ 493 extern void get_max_float (const struct real_format *, char *, size_t); 494 #endif /* ! GCC_REAL_H */ 495