PR libstdc++/54562
[official-gcc.git] / gcc / real.h
blobb92453411d7406fa2f3431b80769538d5c8c0243
1 /* Definitions of floating-point access for GNU compiler.
2 Copyright (C) 1989-2013 Free Software Foundation, Inc.
4 This file is part of GCC.
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.
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.
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/>. */
20 #ifndef GCC_REAL_H
21 #define GCC_REAL_H
23 #include "machmode.h"
25 /* An expanded form of the represented number. */
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
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))
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];
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)))
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
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. */
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 */
74 /* Verify the guess. */
75 extern char test_real_width
76 [sizeof (REAL_VALUE_TYPE) <= REAL_WIDTH * sizeof (HOST_WIDE_INT) ? 1 : -1];
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).
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. */
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
112 /* Describes the properties of the specific target format in use. */
113 struct real_format
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 *);
121 /* The radix of the exponent and digits of the significand. */
122 int b;
124 /* Size of the significand in digits of radix B. */
125 int p;
127 /* Size of the significant of a NaN, in digits of radix B. */
128 int pnan;
130 /* The minimum negative integer, x, such that b**(x-1) is normalized. */
131 int emin;
133 /* The maximum integer, x, such that b**(x-1) is representable. */
134 int emax;
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;
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;
144 /* Default rounding mode for operations on this format. */
145 bool round_towards_zero;
146 bool has_sign_dependent_rounding;
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;
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];
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)])
173 #define FLOAT_MODE_FORMAT(MODE) \
174 (REAL_MODE_FORMAT (SCALAR_FLOAT_MODE_P (MODE)? (MODE) \
175 : GET_MODE_INNER (MODE)))
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)
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)
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)
203 /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs). */
204 #define HONOR_SNANS(MODE) (flag_signaling_nans && HONOR_NANS (MODE))
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)
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)
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)
221 /* Declare functions in real.c. */
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 *);
227 /* Compare reals by tree_code. */
228 extern bool real_compare (int, const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
230 /* Determine whether a floating-point value X is infinite. */
231 extern bool real_isinf (const REAL_VALUE_TYPE *);
233 /* Determine whether a floating-point value X is a NaN. */
234 extern bool real_isnan (const REAL_VALUE_TYPE *);
236 /* Determine whether a floating-point value X is finite. */
237 extern bool real_isfinite (const REAL_VALUE_TYPE *);
239 /* Determine whether a floating-point value X is negative. */
240 extern bool real_isneg (const REAL_VALUE_TYPE *);
242 /* Determine whether a floating-point value X is minus zero. */
243 extern bool real_isnegzero (const REAL_VALUE_TYPE *);
245 /* Compare two floating-point objects for bitwise identity. */
246 extern bool real_identical (const REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
248 /* Extend or truncate to a new mode. */
249 extern void real_convert (REAL_VALUE_TYPE *, enum machine_mode,
250 const REAL_VALUE_TYPE *);
252 /* Return true if truncating to NEW is exact. */
253 extern bool exact_real_truncate (enum machine_mode, const REAL_VALUE_TYPE *);
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);
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);
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);
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 *);
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);
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);
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);
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);
292 extern void real_inf (REAL_VALUE_TYPE *);
294 extern bool real_nan (REAL_VALUE_TYPE *, const char *, int, enum machine_mode);
296 extern void real_maxval (REAL_VALUE_TYPE *, int, enum machine_mode);
298 extern void real_2expN (REAL_VALUE_TYPE *, int, enum machine_mode);
300 extern unsigned int real_hash (const REAL_VALUE_TYPE *);
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;
330 /* ====================================================================== */
331 /* Crap. */
333 #define REAL_ARITHMETIC(value, code, d1, d2) \
334 real_arithmetic (&(value), code, &(d1), &(d2))
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))
340 /* Determine whether a floating-point value X is infinite. */
341 #define REAL_VALUE_ISINF(x) real_isinf (&(x))
343 /* Determine whether a floating-point value X is a NaN. */
344 #define REAL_VALUE_ISNAN(x) real_isnan (&(x))
346 /* Determine whether a floating-point value X is negative. */
347 #define REAL_VALUE_NEGATIVE(x) real_isneg (&(x))
349 /* Determine whether a floating-point value X is minus zero. */
350 #define REAL_VALUE_MINUS_ZERO(x) real_isnegzero (&(x))
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))
357 #define REAL_VALUE_TO_TARGET_DOUBLE(IN, OUT) \
358 real_to_target (OUT, &(IN), mode_for_size (64, MODE_FLOAT, 0))
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)))
364 #define REAL_VALUE_FROM_INT(r, lo, hi, mode) \
365 real_from_integer (&(r), mode, lo, hi, 0)
367 #define REAL_VALUE_FROM_UNSIGNED_INT(r, lo, hi, mode) \
368 real_from_integer (&(r), mode, lo, hi, 1)
370 /* Real values to IEEE 754 decimal floats. */
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))
376 #define REAL_VALUE_TO_TARGET_DECIMAL64(IN, OUT) \
377 real_to_target (OUT, &(IN), mode_for_size (64, MODE_DECIMAL_FLOAT, 0))
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)))
383 extern REAL_VALUE_TYPE real_value_truncate (enum machine_mode,
384 REAL_VALUE_TYPE);
386 #define REAL_VALUE_TO_INT(plow, phigh, r) \
387 real_to_integer2 (plow, phigh, &(r))
389 extern REAL_VALUE_TYPE real_value_negate (const REAL_VALUE_TYPE *);
390 extern REAL_VALUE_TYPE real_value_abs (const REAL_VALUE_TYPE *);
392 extern int significand_size (enum machine_mode);
394 extern REAL_VALUE_TYPE real_from_string2 (const char *, enum machine_mode);
396 #define REAL_VALUE_ATOF(s, m) \
397 real_from_string2 (s, m)
399 #define CONST_DOUBLE_ATOF(s, m) \
400 CONST_DOUBLE_FROM_REAL_VALUE (real_from_string2 (s, m), m)
402 #define REAL_VALUE_FIX(r) \
403 real_to_integer (&(r))
405 /* ??? Not quite right. */
406 #define REAL_VALUE_UNSIGNED_FIX(r) \
407 real_to_integer (&(r))
409 /* ??? These were added for Paranoia support. */
411 /* Return floor log2(R). */
412 extern int real_exponent (const REAL_VALUE_TYPE *);
414 /* R = A * 2**EXP. */
415 extern void real_ldexp (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *, int);
417 /* **** End of software floating point emulator interface macros **** */
419 /* Constant real values 0, 1, 2, -1 and 0.5. */
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;
427 #define dconst_e() (*dconst_e_ptr ())
428 #define dconst_third() (*dconst_third_ptr ())
429 #define dconst_sqrt2() (*dconst_sqrt2_ptr ())
431 /* Function to return the real value special constant 'e'. */
432 extern const REAL_VALUE_TYPE * dconst_e_ptr (void);
434 /* Returns the special REAL_VALUE_TYPE corresponding to 1/3. */
435 extern const REAL_VALUE_TYPE * dconst_third_ptr (void);
437 /* Returns the special REAL_VALUE_TYPE corresponding to sqrt(2). */
438 extern const REAL_VALUE_TYPE * dconst_sqrt2_ptr (void);
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);
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))
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);
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 *);
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);
461 /* In tree.c: wrap up a REAL_VALUE_TYPE in a tree node. */
462 extern tree build_real (tree, REAL_VALUE_TYPE);
464 /* Calculate R as the square root of X in the given machine mode. */
465 extern bool real_sqrt (REAL_VALUE_TYPE *, enum machine_mode,
466 const REAL_VALUE_TYPE *);
468 /* Calculate R as X raised to the integer exponent N in mode MODE. */
469 extern bool real_powi (REAL_VALUE_TYPE *, enum machine_mode,
470 const REAL_VALUE_TYPE *, HOST_WIDE_INT);
472 /* Standard round to integer value functions. */
473 extern void real_trunc (REAL_VALUE_TYPE *, enum machine_mode,
474 const REAL_VALUE_TYPE *);
475 extern void real_floor (REAL_VALUE_TYPE *, enum machine_mode,
476 const REAL_VALUE_TYPE *);
477 extern void real_ceil (REAL_VALUE_TYPE *, enum machine_mode,
478 const REAL_VALUE_TYPE *);
479 extern void real_round (REAL_VALUE_TYPE *, enum machine_mode,
480 const REAL_VALUE_TYPE *);
482 /* Set the sign of R to the sign of X. */
483 extern void real_copysign (REAL_VALUE_TYPE *, const REAL_VALUE_TYPE *);
485 /* Check whether the real constant value given is an integer. */
486 extern bool real_isinteger (const REAL_VALUE_TYPE *c, enum machine_mode mode);
488 /* Write into BUF the maximum representable finite floating-point
489 number, (1 - b**-p) * b**emax for a given FP format FMT as a hex
490 float string. BUF must be large enough to contain the result. */
491 extern void get_max_float (const struct real_format *, char *, size_t);
492 #endif /* ! GCC_REAL_H */