Refactor FP_FAST_* into bits/fp-fast.h.
[glibc.git] / math / math.h
blob95b39b3d92b2cbf0c47ac25898cdb46f1c927f8a
1 /* Declarations for math functions.
2 Copyright (C) 1991-2016 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library 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 GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
20 * ISO C99 Standard: 7.12 Mathematics <math.h>
23 #ifndef _MATH_H
24 #define _MATH_H 1
26 #define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION
27 #include <bits/libc-header-start.h>
29 __BEGIN_DECLS
31 /* Get machine-dependent vector math functions declarations. */
32 #include <bits/math-vector.h>
34 /* Get machine-dependent HUGE_VAL value (returned on overflow).
35 On all IEEE754 machines, this is +Infinity. */
36 #include <bits/huge_val.h>
37 #ifdef __USE_ISOC99
38 # include <bits/huge_valf.h>
39 # include <bits/huge_vall.h>
41 /* Get machine-dependent INFINITY value. */
42 # include <bits/inf.h>
44 /* Get machine-dependent NAN value (returned for some domain errors). */
45 # include <bits/nan.h>
46 #endif /* __USE_ISOC99 */
48 #if __GLIBC_USE (IEC_60559_BFP_EXT)
49 /* Signaling NaN macros, if supported. */
50 # if __GNUC_PREREQ (3, 3)
51 # define SNANF (__builtin_nansf (""))
52 # define SNAN (__builtin_nans (""))
53 # define SNANL (__builtin_nansl (""))
54 # endif
55 #endif
57 /* Get __GLIBC_FLT_EVAL_METHOD. */
58 #include <bits/flt-eval-method.h>
60 #ifdef __USE_ISOC99
61 /* Define the following typedefs.
63 float_t floating-point type at least as wide as `float' used
64 to evaluate `float' expressions
65 double_t floating-point type at least as wide as `double' used
66 to evaluate `double' expressions
68 # if __GLIBC_FLT_EVAL_METHOD == 0 || __GLIBC_FLT_EVAL_METHOD == 16
69 typedef float float_t;
70 typedef double double_t;
71 # elif __GLIBC_FLT_EVAL_METHOD == 1
72 typedef double float_t;
73 typedef double double_t;
74 # elif __GLIBC_FLT_EVAL_METHOD == 2
75 typedef long double float_t;
76 typedef long double double_t;
77 # elif __GLIBC_FLT_EVAL_METHOD == 32
78 typedef _Float32 float_t;
79 typedef double double_t;
80 # elif __GLIBC_FLT_EVAL_METHOD == 33
81 typedef _Float32x float_t;
82 typedef _Float32x double_t;
83 # elif __GLIBC_FLT_EVAL_METHOD == 64
84 typedef _Float64 float_t;
85 typedef _Float64 double_t;
86 # elif __GLIBC_FLT_EVAL_METHOD == 65
87 typedef _Float64x float_t;
88 typedef _Float64x double_t;
89 # elif __GLIBC_FLT_EVAL_METHOD == 128
90 typedef _Float128 float_t;
91 typedef _Float128 double_t;
92 # elif __GLIBC_FLT_EVAL_METHOD == 129
93 typedef _Float128x float_t;
94 typedef _Float128x double_t;
95 # else
96 # error "Unknown __GLIBC_FLT_EVAL_METHOD"
97 # endif
98 #endif
100 /* Define macros for the return value of ilogb.
102 FP_ILOGB0 Expands to a value returned by `ilogb (0.0)'.
103 FP_ILOGBNAN Expands to a value returned by `ilogb (NAN)'.
107 #include <bits/mathdef.h>
109 /* Get the architecture specific values describing the floating-point
110 evaluation. The following symbols will get defined:
112 FP_FAST_FMA
113 FP_FAST_FMAF
114 FP_FAST_FMAL
115 If defined it indicates that the `fma' function
116 generally executes about as fast as a multiply and an add.
117 This macro is defined only iff the `fma' function is
118 implemented directly with a hardware multiply-add instructions.
121 #include <bits/fp-fast.h>
123 /* The file <bits/mathcalls.h> contains the prototypes for all the
124 actual math functions. These macros are used for those prototypes,
125 so we can easily declare each function as both `name' and `__name',
126 and can declare the float versions `namef' and `__namef'. */
128 #define __SIMD_DECL(function) __CONCAT (__DECL_SIMD_, function)
130 #define __MATHCALL_VEC(function, suffix, args) \
131 __SIMD_DECL (__MATH_PRECNAME (function, suffix)) \
132 __MATHCALL (function, suffix, args)
134 #define __MATHDECL_VEC(type, function,suffix, args) \
135 __SIMD_DECL (__MATH_PRECNAME (function, suffix)) \
136 __MATHDECL(type, function,suffix, args)
138 #define __MATHCALL(function,suffix, args) \
139 __MATHDECL (_Mdouble_,function,suffix, args)
140 #define __MATHDECL(type, function,suffix, args) \
141 __MATHDECL_1(type, function,suffix, args); \
142 __MATHDECL_1(type, __CONCAT(__,function),suffix, args)
143 #define __MATHCALLX(function,suffix, args, attrib) \
144 __MATHDECLX (_Mdouble_,function,suffix, args, attrib)
145 #define __MATHDECLX(type, function,suffix, args, attrib) \
146 __MATHDECL_1(type, function,suffix, args) __attribute__ (attrib); \
147 __MATHDECL_1(type, __CONCAT(__,function),suffix, args) __attribute__ (attrib)
148 #define __MATHDECL_1(type, function,suffix, args) \
149 extern type __MATH_PRECNAME(function,suffix) args __THROW
151 #define _Mdouble_ double
152 #define __MATH_PRECNAME(name,r) __CONCAT(name,r)
153 #define __MATH_DECLARING_DOUBLE 1
154 #define _Mdouble_BEGIN_NAMESPACE __BEGIN_NAMESPACE_STD
155 #define _Mdouble_END_NAMESPACE __END_NAMESPACE_STD
156 #include <bits/mathcalls.h>
157 #undef _Mdouble_
158 #undef _Mdouble_BEGIN_NAMESPACE
159 #undef _Mdouble_END_NAMESPACE
160 #undef __MATH_PRECNAME
161 #undef __MATH_DECLARING_DOUBLE
163 #ifdef __USE_ISOC99
166 /* Include the file of declarations again, this time using `float'
167 instead of `double' and appending f to each function name. */
169 # ifndef _Mfloat_
170 # define _Mfloat_ float
171 # endif
172 # define _Mdouble_ _Mfloat_
173 # define __MATH_PRECNAME(name,r) name##f##r
174 # define __MATH_DECLARING_DOUBLE 0
175 # define _Mdouble_BEGIN_NAMESPACE __BEGIN_NAMESPACE_C99
176 # define _Mdouble_END_NAMESPACE __END_NAMESPACE_C99
177 # include <bits/mathcalls.h>
178 # undef _Mdouble_
179 # undef _Mdouble_BEGIN_NAMESPACE
180 # undef _Mdouble_END_NAMESPACE
181 # undef __MATH_PRECNAME
182 # undef __MATH_DECLARING_DOUBLE
184 # if !(defined __NO_LONG_DOUBLE_MATH && defined _LIBC) \
185 || defined __LDBL_COMPAT \
186 || defined _LIBC_TEST
187 # ifdef __LDBL_COMPAT
189 # ifdef __USE_ISOC99
190 extern float __nldbl_nexttowardf (float __x, long double __y)
191 __THROW __attribute__ ((__const__));
192 # ifdef __REDIRECT_NTH
193 extern float __REDIRECT_NTH (nexttowardf, (float __x, long double __y),
194 __nldbl_nexttowardf)
195 __attribute__ ((__const__));
196 extern double __REDIRECT_NTH (nexttoward, (double __x, long double __y),
197 nextafter) __attribute__ ((__const__));
198 extern long double __REDIRECT_NTH (nexttowardl,
199 (long double __x, long double __y),
200 nextafter) __attribute__ ((__const__));
201 # endif
202 # endif
204 # undef __MATHDECL_1
205 # define __MATHDECL_2(type, function,suffix, args, alias) \
206 extern type __REDIRECT_NTH(__MATH_PRECNAME(function,suffix), \
207 args, alias)
208 # define __MATHDECL_1(type, function,suffix, args) \
209 __MATHDECL_2(type, function,suffix, args, __CONCAT(function,suffix))
210 # endif
212 /* Include the file of declarations again, this time using `long double'
213 instead of `double' and appending l to each function name. */
215 # ifndef _Mlong_double_
216 # define _Mlong_double_ long double
217 # endif
218 # define _Mdouble_ _Mlong_double_
219 # define __MATH_PRECNAME(name,r) name##l##r
220 # define __MATH_DECLARING_DOUBLE 0
221 # define _Mdouble_BEGIN_NAMESPACE __BEGIN_NAMESPACE_C99
222 # define _Mdouble_END_NAMESPACE __END_NAMESPACE_C99
223 # define __MATH_DECLARE_LDOUBLE 1
224 # include <bits/mathcalls.h>
225 # undef _Mdouble_
226 # undef _Mdouble_BEGIN_NAMESPACE
227 # undef _Mdouble_END_NAMESPACE
228 # undef __MATH_PRECNAME
229 # undef __MATH_DECLARING_DOUBLE
231 # endif /* !(__NO_LONG_DOUBLE_MATH && _LIBC) || __LDBL_COMPAT */
233 #endif /* Use ISO C99. */
234 #undef __MATHDECL_1
235 #undef __MATHDECL
236 #undef __MATHCALL
239 #if defined __USE_MISC || defined __USE_XOPEN
240 /* This variable is used by `gamma' and `lgamma'. */
241 extern int signgam;
242 #endif
245 /* Depending on the type of TG_ARG, call an appropriately suffixed
246 version of FUNC with arguments (including parentheses) ARGS.
247 Suffixed functions may not exist for long double if it has the same
248 format as double, or for other types with the same format as float,
249 double or long double. The behavior is undefined if the argument
250 does not have a real floating type. The definition may use a
251 conditional expression, so all suffixed versions of FUNC must
252 return the same type (FUNC may include a cast if necessary rather
253 than being a single identifier). */
254 #ifdef __NO_LONG_DOUBLE_MATH
255 # define __MATH_TG(TG_ARG, FUNC, ARGS) \
256 (sizeof (TG_ARG) == sizeof (float) ? FUNC ## f ARGS : FUNC ARGS)
257 #else
258 # define __MATH_TG(TG_ARG, FUNC, ARGS) \
259 (sizeof (TG_ARG) == sizeof (float) \
260 ? FUNC ## f ARGS \
261 : sizeof (TG_ARG) == sizeof (double) \
262 ? FUNC ARGS \
263 : FUNC ## l ARGS)
264 #endif
266 /* ISO C99 defines some generic macros which work on any data type. */
267 #ifdef __USE_ISOC99
269 /* All floating-point numbers can be put in one of these categories. */
270 enum
272 FP_NAN =
273 # define FP_NAN 0
274 FP_NAN,
275 FP_INFINITE =
276 # define FP_INFINITE 1
277 FP_INFINITE,
278 FP_ZERO =
279 # define FP_ZERO 2
280 FP_ZERO,
281 FP_SUBNORMAL =
282 # define FP_SUBNORMAL 3
283 FP_SUBNORMAL,
284 FP_NORMAL =
285 # define FP_NORMAL 4
286 FP_NORMAL
289 /* GCC bug 66462 means we cannot use the math builtins with -fsignaling-nan,
290 so disable builtins if this is enabled. When fixed in a newer GCC,
291 the __SUPPORT_SNAN__ check may be skipped for those versions. */
293 /* Return number of classification appropriate for X. */
294 # if __GNUC_PREREQ (4,4) && !defined __SUPPORT_SNAN__ \
295 && !defined __OPTIMIZE_SIZE__
296 # define fpclassify(x) __builtin_fpclassify (FP_NAN, FP_INFINITE, \
297 FP_NORMAL, FP_SUBNORMAL, FP_ZERO, x)
298 # else
299 # define fpclassify(x) __MATH_TG ((x), __fpclassify, (x))
300 # endif
302 /* Return nonzero value if sign of X is negative. */
303 # if __GNUC_PREREQ (4,0)
304 # define signbit(x) __MATH_TG ((x), __builtin_signbit, (x))
305 # else
306 # define signbit(x) __MATH_TG ((x), __signbit, (x))
307 # endif
309 /* Return nonzero value if X is not +-Inf or NaN. */
310 # if __GNUC_PREREQ (4,4) && !defined __SUPPORT_SNAN__
311 # define isfinite(x) __builtin_isfinite (x)
312 # else
313 # define isfinite(x) __MATH_TG ((x), __finite, (x))
314 # endif
316 /* Return nonzero value if X is neither zero, subnormal, Inf, nor NaN. */
317 # if __GNUC_PREREQ (4,4) && !defined __SUPPORT_SNAN__
318 # define isnormal(x) __builtin_isnormal (x)
319 # else
320 # define isnormal(x) (fpclassify (x) == FP_NORMAL)
321 # endif
323 /* Return nonzero value if X is a NaN. We could use `fpclassify' but
324 we already have this functions `__isnan' and it is faster. */
325 # if __GNUC_PREREQ (4,4) && !defined __SUPPORT_SNAN__
326 # define isnan(x) __builtin_isnan (x)
327 # else
328 # define isnan(x) __MATH_TG ((x), __isnan, (x))
329 # endif
331 /* Return nonzero value if X is positive or negative infinity. */
332 # if __GNUC_PREREQ (4,4) && !defined __SUPPORT_SNAN__
333 # define isinf(x) __builtin_isinf_sign (x)
334 # else
335 # define isinf(x) __MATH_TG ((x), __isinf, (x))
336 # endif
338 /* Bitmasks for the math_errhandling macro. */
339 # define MATH_ERRNO 1 /* errno set by math functions. */
340 # define MATH_ERREXCEPT 2 /* Exceptions raised by math functions. */
342 /* By default all functions support both errno and exception handling.
343 In gcc's fast math mode and if inline functions are defined this
344 might not be true. */
345 # ifndef __FAST_MATH__
346 # define math_errhandling (MATH_ERRNO | MATH_ERREXCEPT)
347 # endif
349 #endif /* Use ISO C99. */
351 #if __GLIBC_USE (IEC_60559_BFP_EXT)
352 # include <bits/iscanonical.h>
354 /* Return nonzero value if X is a signaling NaN. */
355 # define issignaling(x) __MATH_TG ((x), __issignaling, (x))
357 /* Return nonzero value if X is subnormal. */
358 # define issubnormal(x) (fpclassify (x) == FP_SUBNORMAL)
360 /* Return nonzero value if X is zero. */
361 # ifndef __cplusplus
362 # ifdef __SUPPORT_SNAN__
363 # define iszero(x) (fpclassify (x) == FP_ZERO)
364 # else
365 # define iszero(x) (((__typeof (x)) (x)) == 0)
366 # endif
367 # else /* __cplusplus */
368 extern "C++" {
369 template <class __T> inline bool
370 iszero (__T __val)
372 # ifdef __SUPPORT_SNAN__
373 return fpclassify (__val) == FP_ZERO;
374 # else
375 return __val == 0;
376 # endif
378 } /* extern C++ */
379 # endif /* __cplusplus */
380 #endif /* Use IEC_60559_BFP_EXT. */
382 #ifdef __USE_MISC
383 /* Support for various different standard error handling behaviors. */
384 typedef enum
386 _IEEE_ = -1, /* According to IEEE 754/IEEE 854. */
387 _SVID_, /* According to System V, release 4. */
388 _XOPEN_, /* Nowadays also Unix98. */
389 _POSIX_,
390 _ISOC_ /* Actually this is ISO C99. */
391 } _LIB_VERSION_TYPE;
393 /* This variable can be changed at run-time to any of the values above to
394 affect floating point error handling behavior (it may also be necessary
395 to change the hardware FPU exception settings). */
396 extern _LIB_VERSION_TYPE _LIB_VERSION;
397 #endif
400 #ifdef __USE_MISC
401 /* In SVID error handling, `matherr' is called with this description
402 of the exceptional condition.
404 We have a problem when using C++ since `exception' is a reserved
405 name in C++. */
406 # ifdef __cplusplus
407 struct __exception
408 # else
409 struct exception
410 # endif
412 int type;
413 char *name;
414 double arg1;
415 double arg2;
416 double retval;
419 # ifdef __cplusplus
420 extern int matherr (struct __exception *__exc) throw ();
421 # else
422 extern int matherr (struct exception *__exc);
423 # endif
425 # define X_TLOSS 1.41484755040568800000e+16
427 /* Types of exceptions in the `type' field. */
428 # define DOMAIN 1
429 # define SING 2
430 # define OVERFLOW 3
431 # define UNDERFLOW 4
432 # define TLOSS 5
433 # define PLOSS 6
435 /* SVID mode specifies returning this large value instead of infinity. */
436 # define HUGE 3.40282347e+38F
438 #else /* !Misc. */
440 # ifdef __USE_XOPEN
441 /* X/Open wants another strange constant. */
442 # define MAXFLOAT 3.40282347e+38F
443 # endif
445 #endif /* Misc. */
448 /* Some useful constants. */
449 #if defined __USE_MISC || defined __USE_XOPEN
450 # define M_E 2.7182818284590452354 /* e */
451 # define M_LOG2E 1.4426950408889634074 /* log_2 e */
452 # define M_LOG10E 0.43429448190325182765 /* log_10 e */
453 # define M_LN2 0.69314718055994530942 /* log_e 2 */
454 # define M_LN10 2.30258509299404568402 /* log_e 10 */
455 # define M_PI 3.14159265358979323846 /* pi */
456 # define M_PI_2 1.57079632679489661923 /* pi/2 */
457 # define M_PI_4 0.78539816339744830962 /* pi/4 */
458 # define M_1_PI 0.31830988618379067154 /* 1/pi */
459 # define M_2_PI 0.63661977236758134308 /* 2/pi */
460 # define M_2_SQRTPI 1.12837916709551257390 /* 2/sqrt(pi) */
461 # define M_SQRT2 1.41421356237309504880 /* sqrt(2) */
462 # define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */
463 #endif
465 /* The above constants are not adequate for computation using `long double's.
466 Therefore we provide as an extension constants with similar names as a
467 GNU extension. Provide enough digits for the 128-bit IEEE quad. */
468 #ifdef __USE_GNU
469 # define M_El 2.718281828459045235360287471352662498L /* e */
470 # define M_LOG2El 1.442695040888963407359924681001892137L /* log_2 e */
471 # define M_LOG10El 0.434294481903251827651128918916605082L /* log_10 e */
472 # define M_LN2l 0.693147180559945309417232121458176568L /* log_e 2 */
473 # define M_LN10l 2.302585092994045684017991454684364208L /* log_e 10 */
474 # define M_PIl 3.141592653589793238462643383279502884L /* pi */
475 # define M_PI_2l 1.570796326794896619231321691639751442L /* pi/2 */
476 # define M_PI_4l 0.785398163397448309615660845819875721L /* pi/4 */
477 # define M_1_PIl 0.318309886183790671537767526745028724L /* 1/pi */
478 # define M_2_PIl 0.636619772367581343075535053490057448L /* 2/pi */
479 # define M_2_SQRTPIl 1.128379167095512573896158903121545172L /* 2/sqrt(pi) */
480 # define M_SQRT2l 1.414213562373095048801688724209698079L /* sqrt(2) */
481 # define M_SQRT1_2l 0.707106781186547524400844362104849039L /* 1/sqrt(2) */
482 #endif
485 /* When compiling in strict ISO C compatible mode we must not use the
486 inline functions since they, among other things, do not set the
487 `errno' variable correctly. */
488 #if defined __STRICT_ANSI__ && !defined __NO_MATH_INLINES
489 # define __NO_MATH_INLINES 1
490 #endif
492 #if defined __USE_ISOC99 && __GNUC_PREREQ(2,97)
493 /* ISO C99 defines some macros to compare number while taking care for
494 unordered numbers. Many FPUs provide special instructions to support
495 these operations. Generic support in GCC for these as builtins went
496 in before 3.0.0, but not all cpus added their patterns. We define
497 versions that use the builtins here, and <bits/mathinline.h> will
498 undef/redefine as appropriate for the specific GCC version in use. */
499 # define isgreater(x, y) __builtin_isgreater(x, y)
500 # define isgreaterequal(x, y) __builtin_isgreaterequal(x, y)
501 # define isless(x, y) __builtin_isless(x, y)
502 # define islessequal(x, y) __builtin_islessequal(x, y)
503 # define islessgreater(x, y) __builtin_islessgreater(x, y)
504 # define isunordered(u, v) __builtin_isunordered(u, v)
505 #endif
507 /* Get machine-dependent inline versions (if there are any). */
508 #ifdef __USE_EXTERN_INLINES
509 # include <bits/mathinline.h>
510 #endif
512 /* Define special entry points to use when the compiler got told to
513 only expect finite results. */
514 #if defined __FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ > 0
515 # include <bits/math-finite.h>
516 #endif
518 #ifdef __USE_ISOC99
519 /* If we've still got undefined comparison macros, provide defaults. */
521 /* Return nonzero value if X is greater than Y. */
522 # ifndef isgreater
523 # define isgreater(x, y) \
524 (__extension__ \
525 ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y); \
526 !isunordered (__x, __y) && __x > __y; }))
527 # endif
529 /* Return nonzero value if X is greater than or equal to Y. */
530 # ifndef isgreaterequal
531 # define isgreaterequal(x, y) \
532 (__extension__ \
533 ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y); \
534 !isunordered (__x, __y) && __x >= __y; }))
535 # endif
537 /* Return nonzero value if X is less than Y. */
538 # ifndef isless
539 # define isless(x, y) \
540 (__extension__ \
541 ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y); \
542 !isunordered (__x, __y) && __x < __y; }))
543 # endif
545 /* Return nonzero value if X is less than or equal to Y. */
546 # ifndef islessequal
547 # define islessequal(x, y) \
548 (__extension__ \
549 ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y); \
550 !isunordered (__x, __y) && __x <= __y; }))
551 # endif
553 /* Return nonzero value if either X is less than Y or Y is less than X. */
554 # ifndef islessgreater
555 # define islessgreater(x, y) \
556 (__extension__ \
557 ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y); \
558 !isunordered (__x, __y) && (__x < __y || __y < __x); }))
559 # endif
561 /* Return nonzero value if arguments are unordered. */
562 # ifndef isunordered
563 # define isunordered(u, v) \
564 (__extension__ \
565 ({ __typeof__(u) __u = (u); __typeof__(v) __v = (v); \
566 fpclassify (__u) == FP_NAN || fpclassify (__v) == FP_NAN; }))
567 # endif
569 #endif
571 #if __GLIBC_USE (IEC_60559_BFP_EXT)
572 /* An expression whose type has the widest of the evaluation formats
573 of X and Y (which are of floating-point types). */
574 # if __FLT_EVAL_METHOD__ == 2 || __FLT_EVAL_METHOD__ > 64
575 # define __MATH_EVAL_FMT2(x, y) ((x) + (y) + 0.0L)
576 # elif __FLT_EVAL_METHOD__ == 1 || __FLT_EVAL_METHOD__ > 32
577 # define __MATH_EVAL_FMT2(x, y) ((x) + (y) + 0.0)
578 # else
579 # define __MATH_EVAL_FMT2(x, y) ((x) + (y))
580 # endif
582 /* Return X == Y but raising "invalid" and setting errno if X or Y is
583 a NaN. */
584 # define iseqsig(x, y) \
585 __MATH_TG (__MATH_EVAL_FMT2 (x, y), __iseqsig, ((x), (y)))
586 #endif
588 __END_DECLS
591 #endif /* math.h */