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1 /* Copyright (C) 2002-2020 Free Software Foundation, Inc.
3 This file is part of GCC.
5 GCC is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3, or (at your option)
10 GCC is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 Under Section 7 of GPL version 3, you are granted additional
16 permissions described in the GCC Runtime Library Exception, version
17 3.1, as published by the Free Software Foundation.
19 You should have received a copy of the GNU General Public License and
20 a copy of the GCC Runtime Library Exception along with this program;
21 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
22 <http://www.gnu.org/licenses/>. */
25 * ISO C Standard: 5.2.4.2.2 Characteristics of floating types <float.h>
31 /* Radix of exponent representation, b. */
33 #define FLT_RADIX __FLT_RADIX__
35 /* Number of base-FLT_RADIX digits in the significand, p. */
39 #define FLT_MANT_DIG __FLT_MANT_DIG__
40 #define DBL_MANT_DIG __DBL_MANT_DIG__
41 #define LDBL_MANT_DIG __LDBL_MANT_DIG__
43 /* Number of decimal digits, q, such that any floating-point number with q
44 decimal digits can be rounded into a floating-point number with p radix b
45 digits and back again without change to the q decimal digits,
47 p * log10(b) if b is a power of 10
48 floor((p - 1) * log10(b)) otherwise
53 #define FLT_DIG __FLT_DIG__
54 #define DBL_DIG __DBL_DIG__
55 #define LDBL_DIG __LDBL_DIG__
57 /* Minimum int x such that FLT_RADIX**(x-1) is a normalized float, emin */
61 #define FLT_MIN_EXP __FLT_MIN_EXP__
62 #define DBL_MIN_EXP __DBL_MIN_EXP__
63 #define LDBL_MIN_EXP __LDBL_MIN_EXP__
65 /* Minimum negative integer such that 10 raised to that power is in the
66 range of normalized floating-point numbers,
68 ceil(log10(b) * (emin - 1))
72 #undef LDBL_MIN_10_EXP
73 #define FLT_MIN_10_EXP __FLT_MIN_10_EXP__
74 #define DBL_MIN_10_EXP __DBL_MIN_10_EXP__
75 #define LDBL_MIN_10_EXP __LDBL_MIN_10_EXP__
77 /* Maximum int x such that FLT_RADIX**(x-1) is a representable float, emax. */
81 #define FLT_MAX_EXP __FLT_MAX_EXP__
82 #define DBL_MAX_EXP __DBL_MAX_EXP__
83 #define LDBL_MAX_EXP __LDBL_MAX_EXP__
85 /* Maximum integer such that 10 raised to that power is in the range of
86 representable finite floating-point numbers,
88 floor(log10((1 - b**-p) * b**emax))
92 #undef LDBL_MAX_10_EXP
93 #define FLT_MAX_10_EXP __FLT_MAX_10_EXP__
94 #define DBL_MAX_10_EXP __DBL_MAX_10_EXP__
95 #define LDBL_MAX_10_EXP __LDBL_MAX_10_EXP__
97 /* Maximum representable finite floating-point number,
104 #define FLT_MAX __FLT_MAX__
105 #define DBL_MAX __DBL_MAX__
106 #define LDBL_MAX __LDBL_MAX__
108 /* The difference between 1 and the least value greater than 1 that is
109 representable in the given floating point type, b**1-p. */
113 #define FLT_EPSILON __FLT_EPSILON__
114 #define DBL_EPSILON __DBL_EPSILON__
115 #define LDBL_EPSILON __LDBL_EPSILON__
117 /* Minimum normalized positive floating-point number, b**(emin - 1). */
121 #define FLT_MIN __FLT_MIN__
122 #define DBL_MIN __DBL_MIN__
123 #define LDBL_MIN __LDBL_MIN__
125 /* Addition rounds to 0: zero, 1: nearest, 2: +inf, 3: -inf, -1: unknown. */
126 /* ??? This is supposed to change with calls to fesetround in <fenv.h>. */
130 #if (defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) \
131 || (defined (__cplusplus) && __cplusplus >= 201103L)
132 /* The floating-point expression evaluation method. The precise
133 definitions of these values are generalised to include support for
134 the interchange and extended types defined in ISO/IEC TS 18661-3.
135 Prior to this (for C99/C11) the definitions were:
138 0 evaluate all operations and constants just to the range and
139 precision of the type
140 1 evaluate operations and constants of type float and double
141 to the range and precision of the double type, evaluate
142 long double operations and constants to the range and
143 precision of the long double type
144 2 evaluate all operations and constants to the range and
145 precision of the long double type
147 The TS 18661-3 definitions are:
150 0 evaluate all operations and constants, whose semantic type has
151 at most the range and precision of float, to the range and
152 precision of float; evaluate all other operations and constants
153 to the range and precision of the semantic type.
154 1 evaluate all operations and constants, whose semantic type has
155 at most the range and precision of double, to the range and
156 precision of double; evaluate all other operations and constants
157 to the range and precision of the semantic type.
158 2 evaluate all operations and constants, whose semantic type has
159 at most the range and precision of long double, to the range and
160 precision of long double; evaluate all other operations and
161 constants to the range and precision of the semantic type.
162 N where _FloatN is a supported interchange floating type
163 evaluate all operations and constants, whose semantic type has
164 at most the range and precision of the _FloatN type, to the
165 range and precision of the _FloatN type; evaluate all other
166 operations and constants to the range and precision of the
168 N + 1, where _FloatNx is a supported extended floating type
169 evaluate operations and constants, whose semantic type has at
170 most the range and precision of the _FloatNx type, to the range
171 and precision of the _FloatNx type; evaluate all other
172 operations and constants to the range and precision of the
175 The compiler predefines two macros:
178 Which, depending on the value given for
179 -fpermitted-flt-eval-methods, may be limited to only those values
180 for FLT_EVAL_METHOD defined in C99/C11.
182 __FLT_EVAL_METHOD_TS_18661_3__
183 Which always permits the values for FLT_EVAL_METHOD defined in
186 Here we want to use __FLT_EVAL_METHOD__, unless
187 __STDC_WANT_IEC_60559_TYPES_EXT__ is defined, in which case the user
188 is specifically asking for the ISO/IEC TS 18661-3 types, so we use
189 __FLT_EVAL_METHOD_TS_18661_3__.
191 ??? This ought to change with the setting of the fp control word;
192 the value provided by the compiler assumes the widest setting. */
193 #undef FLT_EVAL_METHOD
194 #ifdef __STDC_WANT_IEC_60559_TYPES_EXT__
195 #define FLT_EVAL_METHOD __FLT_EVAL_METHOD_TS_18661_3__
197 #define FLT_EVAL_METHOD __FLT_EVAL_METHOD__
200 /* Number of decimal digits, n, such that any floating-point number in the
201 widest supported floating type with pmax radix b digits can be rounded
202 to a floating-point number with n decimal digits and back again without
205 pmax * log10(b) if b is a power of 10
206 ceil(1 + pmax * log10(b)) otherwise
209 #define DECIMAL_DIG __DECIMAL_DIG__
213 #if (defined (__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) \
214 || (defined (__cplusplus) && __cplusplus >= 201703L)
215 /* Versions of DECIMAL_DIG for each floating-point type. */
216 #undef FLT_DECIMAL_DIG
217 #undef DBL_DECIMAL_DIG
218 #undef LDBL_DECIMAL_DIG
219 #define FLT_DECIMAL_DIG __FLT_DECIMAL_DIG__
220 #define DBL_DECIMAL_DIG __DBL_DECIMAL_DIG__
221 #define LDBL_DECIMAL_DIG __LDBL_DECIMAL_DIG__
223 /* Whether types support subnormal numbers. */
224 #undef FLT_HAS_SUBNORM
225 #undef DBL_HAS_SUBNORM
226 #undef LDBL_HAS_SUBNORM
227 #define FLT_HAS_SUBNORM __FLT_HAS_DENORM__
228 #define DBL_HAS_SUBNORM __DBL_HAS_DENORM__
229 #define LDBL_HAS_SUBNORM __LDBL_HAS_DENORM__
231 /* Minimum positive values, including subnormals. */
235 #define FLT_TRUE_MIN __FLT_DENORM_MIN__
236 #define DBL_TRUE_MIN __DBL_DENORM_MIN__
237 #define LDBL_TRUE_MIN __LDBL_DENORM_MIN__
241 #if defined __STDC_VERSION__ && __STDC_VERSION__ > 201710L
242 /* Maximum finite positive value with MANT_DIG digits in the
243 significand taking their maximum value. */
247 #define FLT_NORM_MAX __FLT_NORM_MAX__
248 #define DBL_NORM_MAX __DBL_NORM_MAX__
249 #define LDBL_NORM_MAX __LDBL_NORM_MAX__
253 #ifdef __STDC_WANT_IEC_60559_BFP_EXT__
254 /* Number of decimal digits for which conversions between decimal
255 character strings and binary formats, in both directions, are
256 correctly rounded. */
257 #define CR_DECIMAL_DIG __UINTMAX_MAX__
260 #ifdef __STDC_WANT_IEC_60559_TYPES_EXT__
261 /* Constants for _FloatN and _FloatNx types from TS 18661-3. See
262 comments above for their semantics. */
264 #ifdef __FLT16_MANT_DIG__
265 #undef FLT16_MANT_DIG
266 #define FLT16_MANT_DIG __FLT16_MANT_DIG__
268 #define FLT16_DIG __FLT16_DIG__
270 #define FLT16_MIN_EXP __FLT16_MIN_EXP__
271 #undef FLT16_MIN_10_EXP
272 #define FLT16_MIN_10_EXP __FLT16_MIN_10_EXP__
274 #define FLT16_MAX_EXP __FLT16_MAX_EXP__
275 #undef FLT16_MAX_10_EXP
276 #define FLT16_MAX_10_EXP __FLT16_MAX_10_EXP__
278 #define FLT16_MAX __FLT16_MAX__
280 #define FLT16_EPSILON __FLT16_EPSILON__
282 #define FLT16_MIN __FLT16_MIN__
283 #undef FLT16_DECIMAL_DIG
284 #define FLT16_DECIMAL_DIG __FLT16_DECIMAL_DIG__
285 #undef FLT16_TRUE_MIN
286 #define FLT16_TRUE_MIN __FLT16_DENORM_MIN__
287 #endif /* __FLT16_MANT_DIG__. */
289 #ifdef __FLT32_MANT_DIG__
290 #undef FLT32_MANT_DIG
291 #define FLT32_MANT_DIG __FLT32_MANT_DIG__
293 #define FLT32_DIG __FLT32_DIG__
295 #define FLT32_MIN_EXP __FLT32_MIN_EXP__
296 #undef FLT32_MIN_10_EXP
297 #define FLT32_MIN_10_EXP __FLT32_MIN_10_EXP__
299 #define FLT32_MAX_EXP __FLT32_MAX_EXP__
300 #undef FLT32_MAX_10_EXP
301 #define FLT32_MAX_10_EXP __FLT32_MAX_10_EXP__
303 #define FLT32_MAX __FLT32_MAX__
305 #define FLT32_EPSILON __FLT32_EPSILON__
307 #define FLT32_MIN __FLT32_MIN__
308 #undef FLT32_DECIMAL_DIG
309 #define FLT32_DECIMAL_DIG __FLT32_DECIMAL_DIG__
310 #undef FLT32_TRUE_MIN
311 #define FLT32_TRUE_MIN __FLT32_DENORM_MIN__
312 #endif /* __FLT32_MANT_DIG__. */
314 #ifdef __FLT64_MANT_DIG__
315 #undef FLT64_MANT_DIG
316 #define FLT64_MANT_DIG __FLT64_MANT_DIG__
318 #define FLT64_DIG __FLT64_DIG__
320 #define FLT64_MIN_EXP __FLT64_MIN_EXP__
321 #undef FLT64_MIN_10_EXP
322 #define FLT64_MIN_10_EXP __FLT64_MIN_10_EXP__
324 #define FLT64_MAX_EXP __FLT64_MAX_EXP__
325 #undef FLT64_MAX_10_EXP
326 #define FLT64_MAX_10_EXP __FLT64_MAX_10_EXP__
328 #define FLT64_MAX __FLT64_MAX__
330 #define FLT64_EPSILON __FLT64_EPSILON__
332 #define FLT64_MIN __FLT64_MIN__
333 #undef FLT64_DECIMAL_DIG
334 #define FLT64_DECIMAL_DIG __FLT64_DECIMAL_DIG__
335 #undef FLT64_TRUE_MIN
336 #define FLT64_TRUE_MIN __FLT64_DENORM_MIN__
337 #endif /* __FLT64_MANT_DIG__. */
339 #ifdef __FLT128_MANT_DIG__
340 #undef FLT128_MANT_DIG
341 #define FLT128_MANT_DIG __FLT128_MANT_DIG__
343 #define FLT128_DIG __FLT128_DIG__
344 #undef FLT128_MIN_EXP
345 #define FLT128_MIN_EXP __FLT128_MIN_EXP__
346 #undef FLT128_MIN_10_EXP
347 #define FLT128_MIN_10_EXP __FLT128_MIN_10_EXP__
348 #undef FLT128_MAX_EXP
349 #define FLT128_MAX_EXP __FLT128_MAX_EXP__
350 #undef FLT128_MAX_10_EXP
351 #define FLT128_MAX_10_EXP __FLT128_MAX_10_EXP__
353 #define FLT128_MAX __FLT128_MAX__
354 #undef FLT128_EPSILON
355 #define FLT128_EPSILON __FLT128_EPSILON__
357 #define FLT128_MIN __FLT128_MIN__
358 #undef FLT128_DECIMAL_DIG
359 #define FLT128_DECIMAL_DIG __FLT128_DECIMAL_DIG__
360 #undef FLT128_TRUE_MIN
361 #define FLT128_TRUE_MIN __FLT128_DENORM_MIN__
362 #endif /* __FLT128_MANT_DIG__. */
364 #ifdef __FLT32X_MANT_DIG__
365 #undef FLT32X_MANT_DIG
366 #define FLT32X_MANT_DIG __FLT32X_MANT_DIG__
368 #define FLT32X_DIG __FLT32X_DIG__
369 #undef FLT32X_MIN_EXP
370 #define FLT32X_MIN_EXP __FLT32X_MIN_EXP__
371 #undef FLT32X_MIN_10_EXP
372 #define FLT32X_MIN_10_EXP __FLT32X_MIN_10_EXP__
373 #undef FLT32X_MAX_EXP
374 #define FLT32X_MAX_EXP __FLT32X_MAX_EXP__
375 #undef FLT32X_MAX_10_EXP
376 #define FLT32X_MAX_10_EXP __FLT32X_MAX_10_EXP__
378 #define FLT32X_MAX __FLT32X_MAX__
379 #undef FLT32X_EPSILON
380 #define FLT32X_EPSILON __FLT32X_EPSILON__
382 #define FLT32X_MIN __FLT32X_MIN__
383 #undef FLT32X_DECIMAL_DIG
384 #define FLT32X_DECIMAL_DIG __FLT32X_DECIMAL_DIG__
385 #undef FLT32X_TRUE_MIN
386 #define FLT32X_TRUE_MIN __FLT32X_DENORM_MIN__
387 #endif /* __FLT32X_MANT_DIG__. */
389 #ifdef __FLT64X_MANT_DIG__
390 #undef FLT64X_MANT_DIG
391 #define FLT64X_MANT_DIG __FLT64X_MANT_DIG__
393 #define FLT64X_DIG __FLT64X_DIG__
394 #undef FLT64X_MIN_EXP
395 #define FLT64X_MIN_EXP __FLT64X_MIN_EXP__
396 #undef FLT64X_MIN_10_EXP
397 #define FLT64X_MIN_10_EXP __FLT64X_MIN_10_EXP__
398 #undef FLT64X_MAX_EXP
399 #define FLT64X_MAX_EXP __FLT64X_MAX_EXP__
400 #undef FLT64X_MAX_10_EXP
401 #define FLT64X_MAX_10_EXP __FLT64X_MAX_10_EXP__
403 #define FLT64X_MAX __FLT64X_MAX__
404 #undef FLT64X_EPSILON
405 #define FLT64X_EPSILON __FLT64X_EPSILON__
407 #define FLT64X_MIN __FLT64X_MIN__
408 #undef FLT64X_DECIMAL_DIG
409 #define FLT64X_DECIMAL_DIG __FLT64X_DECIMAL_DIG__
410 #undef FLT64X_TRUE_MIN
411 #define FLT64X_TRUE_MIN __FLT64X_DENORM_MIN__
412 #endif /* __FLT64X_MANT_DIG__. */
414 #ifdef __FLT128X_MANT_DIG__
415 #undef FLT128X_MANT_DIG
416 #define FLT128X_MANT_DIG __FLT128X_MANT_DIG__
418 #define FLT128X_DIG __FLT128X_DIG__
419 #undef FLT128X_MIN_EXP
420 #define FLT128X_MIN_EXP __FLT128X_MIN_EXP__
421 #undef FLT128X_MIN_10_EXP
422 #define FLT128X_MIN_10_EXP __FLT128X_MIN_10_EXP__
423 #undef FLT128X_MAX_EXP
424 #define FLT128X_MAX_EXP __FLT128X_MAX_EXP__
425 #undef FLT128X_MAX_10_EXP
426 #define FLT128X_MAX_10_EXP __FLT128X_MAX_10_EXP__
428 #define FLT128X_MAX __FLT128X_MAX__
429 #undef FLT128X_EPSILON
430 #define FLT128X_EPSILON __FLT128X_EPSILON__
432 #define FLT128X_MIN __FLT128X_MIN__
433 #undef FLT128X_DECIMAL_DIG
434 #define FLT128X_DECIMAL_DIG __FLT128X_DECIMAL_DIG__
435 #undef FLT128X_TRUE_MIN
436 #define FLT128X_TRUE_MIN __FLT128X_DENORM_MIN__
437 #endif /* __FLT128X_MANT_DIG__. */
439 #endif /* __STDC_WANT_IEC_60559_TYPES_EXT__. */
441 #ifdef __DEC32_MANT_DIG__
442 #if (defined __STDC_WANT_DEC_FP__ \
443 || defined __STDC_WANT_IEC_60559_DFP_EXT__ \
444 || (defined __STDC_VERSION__ && __STDC_VERSION__ > 201710L))
445 /* C2X; formerly Technical Report 24732, extension for decimal
446 floating-point arithmetic: Characteristic of decimal floating types
447 <float.h>, and TS 18661-2. */
449 /* Number of base-FLT_RADIX digits in the significand, p. */
450 #undef DEC32_MANT_DIG
451 #undef DEC64_MANT_DIG
452 #undef DEC128_MANT_DIG
453 #define DEC32_MANT_DIG __DEC32_MANT_DIG__
454 #define DEC64_MANT_DIG __DEC64_MANT_DIG__
455 #define DEC128_MANT_DIG __DEC128_MANT_DIG__
457 /* Minimum exponent. */
460 #undef DEC128_MIN_EXP
461 #define DEC32_MIN_EXP __DEC32_MIN_EXP__
462 #define DEC64_MIN_EXP __DEC64_MIN_EXP__
463 #define DEC128_MIN_EXP __DEC128_MIN_EXP__
465 /* Maximum exponent. */
468 #undef DEC128_MAX_EXP
469 #define DEC32_MAX_EXP __DEC32_MAX_EXP__
470 #define DEC64_MAX_EXP __DEC64_MAX_EXP__
471 #define DEC128_MAX_EXP __DEC128_MAX_EXP__
473 /* Maximum representable finite decimal floating-point number
474 (there are 6, 15, and 33 9s after the decimal points respectively). */
478 #define DEC32_MAX __DEC32_MAX__
479 #define DEC64_MAX __DEC64_MAX__
480 #define DEC128_MAX __DEC128_MAX__
482 /* The difference between 1 and the least value greater than 1 that is
483 representable in the given floating point type. */
486 #undef DEC128_EPSILON
487 #define DEC32_EPSILON __DEC32_EPSILON__
488 #define DEC64_EPSILON __DEC64_EPSILON__
489 #define DEC128_EPSILON __DEC128_EPSILON__
491 /* Minimum normalized positive floating-point number. */
495 #define DEC32_MIN __DEC32_MIN__
496 #define DEC64_MIN __DEC64_MIN__
497 #define DEC128_MIN __DEC128_MIN__
499 /* The floating-point expression evaluation method.
501 0 evaluate all operations and constants just to the range and
502 precision of the type
503 1 evaluate operations and constants of type _Decimal32
504 and _Decimal64 to the range and precision of the _Decimal64
505 type, evaluate _Decimal128 operations and constants to the
506 range and precision of the _Decimal128 type;
507 2 evaluate all operations and constants to the range and
508 precision of the _Decimal128 type. */
510 #undef DEC_EVAL_METHOD
511 #define DEC_EVAL_METHOD __DEC_EVAL_METHOD__
513 #endif /* __STDC_WANT_DEC_FP__ || __STDC_WANT_IEC_60559_DFP_EXT__ || C2X. */
515 #ifdef __STDC_WANT_DEC_FP__
517 /* Minimum subnormal positive floating-point number. */
518 #undef DEC32_SUBNORMAL_MIN
519 #undef DEC64_SUBNORMAL_MIN
520 #undef DEC128_SUBNORMAL_MIN
521 #define DEC32_SUBNORMAL_MIN __DEC32_SUBNORMAL_MIN__
522 #define DEC64_SUBNORMAL_MIN __DEC64_SUBNORMAL_MIN__
523 #define DEC128_SUBNORMAL_MIN __DEC128_SUBNORMAL_MIN__
525 #endif /* __STDC_WANT_DEC_FP__. */
527 #if (defined __STDC_WANT_IEC_60559_DFP_EXT__ \
528 || (defined __STDC_VERSION__ && __STDC_VERSION__ > 201710L))
530 /* Minimum subnormal positive floating-point number. */
531 #undef DEC32_TRUE_MIN
532 #undef DEC64_TRUE_MIN
533 #undef DEC128_TRUE_MIN
534 #define DEC32_TRUE_MIN __DEC32_SUBNORMAL_MIN__
535 #define DEC64_TRUE_MIN __DEC64_SUBNORMAL_MIN__
536 #define DEC128_TRUE_MIN __DEC128_SUBNORMAL_MIN__
538 #endif /* __STDC_WANT_IEC_60559_DFP_EXT__ || C2X. */
540 #endif /* __DEC32_MANT_DIG__ */
542 #endif /* _FLOAT_H___ */