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>
26 #define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION
27 #include <bits/libc-header-start.h>
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>
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 (""))
57 /* Get __GLIBC_FLT_EVAL_METHOD. */
58 #include <bits/flt-eval-method.h>
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
;
96 # error "Unknown __GLIBC_FLT_EVAL_METHOD"
100 /* Define macros for the return values of ilogb and llogb, based on
101 __FP_LOGB0_IS_MIN and __FP_LOGBNAN_IS_MIN.
103 FP_ILOGB0 Expands to a value returned by `ilogb (0.0)'.
104 FP_ILOGBNAN Expands to a value returned by `ilogb (NAN)'.
105 FP_LLOGB0 Expands to a value returned by `llogb (0.0)'.
106 FP_LLOGBNAN Expands to a value returned by `llogb (NAN)'.
110 #include <bits/fp-logb.h>
112 # if __FP_LOGB0_IS_MIN
113 # define FP_ILOGB0 (-2147483647 - 1)
115 # define FP_ILOGB0 (-2147483647)
117 # if __FP_LOGBNAN_IS_MIN
118 # define FP_ILOGBNAN (-2147483647 - 1)
120 # define FP_ILOGBNAN 2147483647
123 #if __GLIBC_USE (IEC_60559_BFP_EXT)
124 # if __WORDSIZE == 32
125 # define __FP_LONG_MAX 0x7fffffffL
127 # define __FP_LONG_MAX 0x7fffffffffffffffL
129 # if __FP_LOGB0_IS_MIN
130 # define FP_LLOGB0 (-__FP_LONG_MAX - 1)
132 # define FP_LLOGB0 (-__FP_LONG_MAX)
134 # if __FP_LOGBNAN_IS_MIN
135 # define FP_LLOGBNAN (-__FP_LONG_MAX - 1)
137 # define FP_LLOGBNAN __FP_LONG_MAX
141 /* Get information about long double. */
143 #include <bits/mathdef.h>
145 /* Get the architecture specific values describing the floating-point
146 evaluation. The following symbols will get defined:
151 If defined it indicates that the `fma' function
152 generally executes about as fast as a multiply and an add.
153 This macro is defined only iff the `fma' function is
154 implemented directly with a hardware multiply-add instructions.
157 #include <bits/fp-fast.h>
159 /* The file <bits/mathcalls.h> contains the prototypes for all the
160 actual math functions. These macros are used for those prototypes,
161 so we can easily declare each function as both `name' and `__name',
162 and can declare the float versions `namef' and `__namef'. */
164 #define __SIMD_DECL(function) __CONCAT (__DECL_SIMD_, function)
166 #define __MATHCALL_VEC(function, suffix, args) \
167 __SIMD_DECL (__MATH_PRECNAME (function, suffix)) \
168 __MATHCALL (function, suffix, args)
170 #define __MATHDECL_VEC(type, function,suffix, args) \
171 __SIMD_DECL (__MATH_PRECNAME (function, suffix)) \
172 __MATHDECL(type, function,suffix, args)
174 #define __MATHCALL(function,suffix, args) \
175 __MATHDECL (_Mdouble_,function,suffix, args)
176 #define __MATHDECL(type, function,suffix, args) \
177 __MATHDECL_1(type, function,suffix, args); \
178 __MATHDECL_1(type, __CONCAT(__,function),suffix, args)
179 #define __MATHCALLX(function,suffix, args, attrib) \
180 __MATHDECLX (_Mdouble_,function,suffix, args, attrib)
181 #define __MATHDECLX(type, function,suffix, args, attrib) \
182 __MATHDECL_1(type, function,suffix, args) __attribute__ (attrib); \
183 __MATHDECL_1(type, __CONCAT(__,function),suffix, args) __attribute__ (attrib)
184 #define __MATHDECL_1(type, function,suffix, args) \
185 extern type __MATH_PRECNAME(function,suffix) args __THROW
187 #define _Mdouble_ double
188 #define __MATH_PRECNAME(name,r) __CONCAT(name,r)
189 #define __MATH_DECLARING_DOUBLE 1
190 #define _Mdouble_BEGIN_NAMESPACE __BEGIN_NAMESPACE_STD
191 #define _Mdouble_END_NAMESPACE __END_NAMESPACE_STD
192 #include <bits/mathcalls.h>
194 #undef _Mdouble_BEGIN_NAMESPACE
195 #undef _Mdouble_END_NAMESPACE
196 #undef __MATH_PRECNAME
197 #undef __MATH_DECLARING_DOUBLE
202 /* Include the file of declarations again, this time using `float'
203 instead of `double' and appending f to each function name. */
206 # define _Mfloat_ float
208 # define _Mdouble_ _Mfloat_
209 # define __MATH_PRECNAME(name,r) name##f##r
210 # define __MATH_DECLARING_DOUBLE 0
211 # define _Mdouble_BEGIN_NAMESPACE __BEGIN_NAMESPACE_C99
212 # define _Mdouble_END_NAMESPACE __END_NAMESPACE_C99
213 # include <bits/mathcalls.h>
215 # undef _Mdouble_BEGIN_NAMESPACE
216 # undef _Mdouble_END_NAMESPACE
217 # undef __MATH_PRECNAME
218 # undef __MATH_DECLARING_DOUBLE
220 # if !(defined __NO_LONG_DOUBLE_MATH && defined _LIBC) \
221 || defined __LDBL_COMPAT \
222 || defined _LIBC_TEST
223 # ifdef __LDBL_COMPAT
226 extern float __nldbl_nexttowardf (float __x
, long double __y
)
227 __THROW
__attribute__ ((__const__
));
228 # ifdef __REDIRECT_NTH
229 extern float __REDIRECT_NTH (nexttowardf
, (float __x
, long double __y
),
231 __attribute__ ((__const__
));
232 extern double __REDIRECT_NTH (nexttoward
, (double __x
, long double __y
),
233 nextafter
) __attribute__ ((__const__
));
234 extern long double __REDIRECT_NTH (nexttowardl
,
235 (long double __x
, long double __y
),
236 nextafter
) __attribute__ ((__const__
));
241 # define __MATHDECL_2(type, function,suffix, args, alias) \
242 extern type __REDIRECT_NTH(__MATH_PRECNAME(function,suffix), \
244 # define __MATHDECL_1(type, function,suffix, args) \
245 __MATHDECL_2(type, function,suffix, args, __CONCAT(function,suffix))
248 /* Include the file of declarations again, this time using `long double'
249 instead of `double' and appending l to each function name. */
251 # ifndef _Mlong_double_
252 # define _Mlong_double_ long double
254 # define _Mdouble_ _Mlong_double_
255 # define __MATH_PRECNAME(name,r) name##l##r
256 # define __MATH_DECLARING_DOUBLE 0
257 # define _Mdouble_BEGIN_NAMESPACE __BEGIN_NAMESPACE_C99
258 # define _Mdouble_END_NAMESPACE __END_NAMESPACE_C99
259 # define __MATH_DECLARE_LDOUBLE 1
260 # include <bits/mathcalls.h>
262 # undef _Mdouble_BEGIN_NAMESPACE
263 # undef _Mdouble_END_NAMESPACE
264 # undef __MATH_PRECNAME
265 # undef __MATH_DECLARING_DOUBLE
267 # endif /* !(__NO_LONG_DOUBLE_MATH && _LIBC) || __LDBL_COMPAT */
269 #endif /* Use ISO C99. */
275 #if defined __USE_MISC || defined __USE_XOPEN
276 /* This variable is used by `gamma' and `lgamma'. */
281 /* Depending on the type of TG_ARG, call an appropriately suffixed
282 version of FUNC with arguments (including parentheses) ARGS.
283 Suffixed functions may not exist for long double if it has the same
284 format as double, or for other types with the same format as float,
285 double or long double. The behavior is undefined if the argument
286 does not have a real floating type. The definition may use a
287 conditional expression, so all suffixed versions of FUNC must
288 return the same type (FUNC may include a cast if necessary rather
289 than being a single identifier). */
290 #ifdef __NO_LONG_DOUBLE_MATH
291 # define __MATH_TG(TG_ARG, FUNC, ARGS) \
292 (sizeof (TG_ARG) == sizeof (float) ? FUNC ## f ARGS : FUNC ARGS)
294 # define __MATH_TG(TG_ARG, FUNC, ARGS) \
295 (sizeof (TG_ARG) == sizeof (float) \
297 : sizeof (TG_ARG) == sizeof (double) \
302 /* ISO C99 defines some generic macros which work on any data type. */
305 /* All floating-point numbers can be put in one of these categories. */
312 # define FP_INFINITE 1
318 # define FP_SUBNORMAL 3
325 /* GCC bug 66462 means we cannot use the math builtins with -fsignaling-nan,
326 so disable builtins if this is enabled. When fixed in a newer GCC,
327 the __SUPPORT_SNAN__ check may be skipped for those versions. */
329 /* Return number of classification appropriate for X. */
330 # if __GNUC_PREREQ (4,4) && !defined __SUPPORT_SNAN__ \
331 && !defined __OPTIMIZE_SIZE__
332 # define fpclassify(x) __builtin_fpclassify (FP_NAN, FP_INFINITE, \
333 FP_NORMAL, FP_SUBNORMAL, FP_ZERO, x)
335 # define fpclassify(x) __MATH_TG ((x), __fpclassify, (x))
338 /* Return nonzero value if sign of X is negative. */
339 # if __GNUC_PREREQ (4,0)
340 # define signbit(x) __MATH_TG ((x), __builtin_signbit, (x))
342 # define signbit(x) __MATH_TG ((x), __signbit, (x))
345 /* Return nonzero value if X is not +-Inf or NaN. */
346 # if __GNUC_PREREQ (4,4) && !defined __SUPPORT_SNAN__
347 # define isfinite(x) __builtin_isfinite (x)
349 # define isfinite(x) __MATH_TG ((x), __finite, (x))
352 /* Return nonzero value if X is neither zero, subnormal, Inf, nor NaN. */
353 # if __GNUC_PREREQ (4,4) && !defined __SUPPORT_SNAN__
354 # define isnormal(x) __builtin_isnormal (x)
356 # define isnormal(x) (fpclassify (x) == FP_NORMAL)
359 /* Return nonzero value if X is a NaN. We could use `fpclassify' but
360 we already have this functions `__isnan' and it is faster. */
361 # if __GNUC_PREREQ (4,4) && !defined __SUPPORT_SNAN__
362 # define isnan(x) __builtin_isnan (x)
364 # define isnan(x) __MATH_TG ((x), __isnan, (x))
367 /* Return nonzero value if X is positive or negative infinity. */
368 # if __GNUC_PREREQ (4,4) && !defined __SUPPORT_SNAN__
369 # define isinf(x) __builtin_isinf_sign (x)
371 # define isinf(x) __MATH_TG ((x), __isinf, (x))
374 /* Bitmasks for the math_errhandling macro. */
375 # define MATH_ERRNO 1 /* errno set by math functions. */
376 # define MATH_ERREXCEPT 2 /* Exceptions raised by math functions. */
378 /* By default all functions support both errno and exception handling.
379 In gcc's fast math mode and if inline functions are defined this
380 might not be true. */
381 # ifndef __FAST_MATH__
382 # define math_errhandling (MATH_ERRNO | MATH_ERREXCEPT)
385 #endif /* Use ISO C99. */
387 #if __GLIBC_USE (IEC_60559_BFP_EXT)
388 # include <bits/iscanonical.h>
390 /* Return nonzero value if X is a signaling NaN. */
391 # define issignaling(x) __MATH_TG ((x), __issignaling, (x))
393 /* Return nonzero value if X is subnormal. */
394 # define issubnormal(x) (fpclassify (x) == FP_SUBNORMAL)
396 /* Return nonzero value if X is zero. */
398 # ifdef __SUPPORT_SNAN__
399 # define iszero(x) (fpclassify (x) == FP_ZERO)
401 # define iszero(x) (((__typeof (x)) (x)) == 0)
403 # else /* __cplusplus */
405 template <class __T
> inline bool
408 # ifdef __SUPPORT_SNAN__
409 return fpclassify (__val
) == FP_ZERO
;
415 # endif /* __cplusplus */
416 #endif /* Use IEC_60559_BFP_EXT. */
419 /* Support for various different standard error handling behaviors. */
422 _IEEE_
= -1, /* According to IEEE 754/IEEE 854. */
423 _SVID_
, /* According to System V, release 4. */
424 _XOPEN_
, /* Nowadays also Unix98. */
426 _ISOC_
/* Actually this is ISO C99. */
429 /* This variable can be changed at run-time to any of the values above to
430 affect floating point error handling behavior (it may also be necessary
431 to change the hardware FPU exception settings). */
432 extern _LIB_VERSION_TYPE _LIB_VERSION
;
437 /* In SVID error handling, `matherr' is called with this description
438 of the exceptional condition.
440 We have a problem when using C++ since `exception' is a reserved
456 extern int matherr (struct __exception
*__exc
) throw ();
458 extern int matherr (struct exception
*__exc
);
461 # define X_TLOSS 1.41484755040568800000e+16
463 /* Types of exceptions in the `type' field. */
471 /* SVID mode specifies returning this large value instead of infinity. */
472 # define HUGE 3.40282347e+38F
477 /* X/Open wants another strange constant. */
478 # define MAXFLOAT 3.40282347e+38F
484 /* Some useful constants. */
485 #if defined __USE_MISC || defined __USE_XOPEN
486 # define M_E 2.7182818284590452354 /* e */
487 # define M_LOG2E 1.4426950408889634074 /* log_2 e */
488 # define M_LOG10E 0.43429448190325182765 /* log_10 e */
489 # define M_LN2 0.69314718055994530942 /* log_e 2 */
490 # define M_LN10 2.30258509299404568402 /* log_e 10 */
491 # define M_PI 3.14159265358979323846 /* pi */
492 # define M_PI_2 1.57079632679489661923 /* pi/2 */
493 # define M_PI_4 0.78539816339744830962 /* pi/4 */
494 # define M_1_PI 0.31830988618379067154 /* 1/pi */
495 # define M_2_PI 0.63661977236758134308 /* 2/pi */
496 # define M_2_SQRTPI 1.12837916709551257390 /* 2/sqrt(pi) */
497 # define M_SQRT2 1.41421356237309504880 /* sqrt(2) */
498 # define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */
501 /* The above constants are not adequate for computation using `long double's.
502 Therefore we provide as an extension constants with similar names as a
503 GNU extension. Provide enough digits for the 128-bit IEEE quad. */
505 # define M_El 2.718281828459045235360287471352662498L /* e */
506 # define M_LOG2El 1.442695040888963407359924681001892137L /* log_2 e */
507 # define M_LOG10El 0.434294481903251827651128918916605082L /* log_10 e */
508 # define M_LN2l 0.693147180559945309417232121458176568L /* log_e 2 */
509 # define M_LN10l 2.302585092994045684017991454684364208L /* log_e 10 */
510 # define M_PIl 3.141592653589793238462643383279502884L /* pi */
511 # define M_PI_2l 1.570796326794896619231321691639751442L /* pi/2 */
512 # define M_PI_4l 0.785398163397448309615660845819875721L /* pi/4 */
513 # define M_1_PIl 0.318309886183790671537767526745028724L /* 1/pi */
514 # define M_2_PIl 0.636619772367581343075535053490057448L /* 2/pi */
515 # define M_2_SQRTPIl 1.128379167095512573896158903121545172L /* 2/sqrt(pi) */
516 # define M_SQRT2l 1.414213562373095048801688724209698079L /* sqrt(2) */
517 # define M_SQRT1_2l 0.707106781186547524400844362104849039L /* 1/sqrt(2) */
521 /* When compiling in strict ISO C compatible mode we must not use the
522 inline functions since they, among other things, do not set the
523 `errno' variable correctly. */
524 #if defined __STRICT_ANSI__ && !defined __NO_MATH_INLINES
525 # define __NO_MATH_INLINES 1
528 #if defined __USE_ISOC99 && __GNUC_PREREQ(2,97)
529 /* ISO C99 defines some macros to compare number while taking care for
530 unordered numbers. Many FPUs provide special instructions to support
531 these operations. Generic support in GCC for these as builtins went
532 in before 3.0.0, but not all cpus added their patterns. We define
533 versions that use the builtins here, and <bits/mathinline.h> will
534 undef/redefine as appropriate for the specific GCC version in use. */
535 # define isgreater(x, y) __builtin_isgreater(x, y)
536 # define isgreaterequal(x, y) __builtin_isgreaterequal(x, y)
537 # define isless(x, y) __builtin_isless(x, y)
538 # define islessequal(x, y) __builtin_islessequal(x, y)
539 # define islessgreater(x, y) __builtin_islessgreater(x, y)
540 # define isunordered(u, v) __builtin_isunordered(u, v)
543 /* Get machine-dependent inline versions (if there are any). */
544 #ifdef __USE_EXTERN_INLINES
545 # include <bits/mathinline.h>
548 /* Define special entry points to use when the compiler got told to
549 only expect finite results. */
550 #if defined __FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ > 0
551 # include <bits/math-finite.h>
555 /* If we've still got undefined comparison macros, provide defaults. */
557 /* Return nonzero value if X is greater than Y. */
559 # define isgreater(x, y) \
561 ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y); \
562 !isunordered (__x, __y) && __x > __y; }))
565 /* Return nonzero value if X is greater than or equal to Y. */
566 # ifndef isgreaterequal
567 # define isgreaterequal(x, y) \
569 ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y); \
570 !isunordered (__x, __y) && __x >= __y; }))
573 /* Return nonzero value if X is less than Y. */
575 # define isless(x, y) \
577 ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y); \
578 !isunordered (__x, __y) && __x < __y; }))
581 /* Return nonzero value if X is less than or equal to Y. */
583 # define islessequal(x, y) \
585 ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y); \
586 !isunordered (__x, __y) && __x <= __y; }))
589 /* Return nonzero value if either X is less than Y or Y is less than X. */
590 # ifndef islessgreater
591 # define islessgreater(x, y) \
593 ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y); \
594 !isunordered (__x, __y) && (__x < __y || __y < __x); }))
597 /* Return nonzero value if arguments are unordered. */
599 # define isunordered(u, v) \
601 ({ __typeof__(u) __u = (u); __typeof__(v) __v = (v); \
602 fpclassify (__u) == FP_NAN || fpclassify (__v) == FP_NAN; }))
607 #if __GLIBC_USE (IEC_60559_BFP_EXT)
608 /* An expression whose type has the widest of the evaluation formats
609 of X and Y (which are of floating-point types). */
610 # if __FLT_EVAL_METHOD__ == 2 || __FLT_EVAL_METHOD__ > 64
611 # define __MATH_EVAL_FMT2(x, y) ((x) + (y) + 0.0L)
612 # elif __FLT_EVAL_METHOD__ == 1 || __FLT_EVAL_METHOD__ > 32
613 # define __MATH_EVAL_FMT2(x, y) ((x) + (y) + 0.0)
615 # define __MATH_EVAL_FMT2(x, y) ((x) + (y))
618 /* Return X == Y but raising "invalid" and setting errno if X or Y is
620 # define iseqsig(x, y) \
621 __MATH_TG (__MATH_EVAL_FMT2 (x, y), __iseqsig, ((x), (y)))