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      1 /* Declarations for math functions.
      2    Copyright (C) 1991-1993, 1995-1999, 2001, 2002, 2004, 2006, 2009, 2011
      3    Free Software Foundation, Inc.
      4    This file is part of the GNU C Library.
      5 
      6    The GNU C Library is free software; you can redistribute it and/or
      7    modify it under the terms of the GNU Lesser General Public
      8    License as published by the Free Software Foundation; either
      9    version 2.1 of the License, or (at your option) any later version.
     10 
     11    The GNU C Library is distributed in the hope that it will be useful,
     12    but WITHOUT ANY WARRANTY; without even the implied warranty of
     13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14    Lesser General Public License for more details.
     15 
     16    You should have received a copy of the GNU Lesser General Public
     17    License along with the GNU C Library; if not, write to the Free
     18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
     19    02111-1307 USA.  */
     20 
     21 /*
     22  *	ISO C99 Standard: 7.12 Mathematics	<math.h>
     23  */
     24 
     25 #ifndef	_MATH_H
     26 #define	_MATH_H	1
     27 
     28 #include <features.h>
     29 
     30 __BEGIN_DECLS
     31 
     32 /* Get machine-dependent HUGE_VAL value (returned on overflow).
     33    On all IEEE754 machines, this is +Infinity.  */
     34 #include <bits/huge_val.h>
     35 #ifdef __USE_ISOC99
     36 # include <bits/huge_valf.h>
     37 # include <bits/huge_vall.h>
     38 
     39 /* Get machine-dependent INFINITY value.  */
     40 # include <bits/inf.h>
     41 
     42 /* Get machine-dependent NAN value (returned for some domain errors).  */
     43 # include <bits/nan.h>
     44 #endif /* __USE_ISOC99 */
     45 
     46 /* Get general and ISO C99 specific information.  */
     47 #include <bits/mathdef.h>
     48 
     49 /* The file <bits/mathcalls.h> contains the prototypes for all the
     50    actual math functions.  These macros are used for those prototypes,
     51    so we can easily declare each function as both `name' and `__name',
     52    and can declare the float versions `namef' and `__namef'.  */
     53 
     54 #define __MATHCALL(function,suffix, args)	\
     55   __MATHDECL (_Mdouble_,function,suffix, args)
     56 #define __MATHDECL(type, function,suffix, args) \
     57   __MATHDECL_1(type, function,suffix, args); \
     58   __MATHDECL_1(type, __CONCAT(__,function),suffix, args)
     59 #define __MATHCALLX(function,suffix, args, attrib)	\
     60   __MATHDECLX (_Mdouble_,function,suffix, args, attrib)
     61 #define __MATHDECLX(type, function,suffix, args, attrib) \
     62   __MATHDECL_1(type, function,suffix, args) __attribute__ (attrib); \
     63   __MATHDECL_1(type, __CONCAT(__,function),suffix, args) __attribute__ (attrib)
     64 #define __MATHDECL_1(type, function,suffix, args) \
     65   extern type __MATH_PRECNAME(function,suffix) args __THROW
     66 
     67 #define _Mdouble_		double
     68 #define __MATH_PRECNAME(name,r)	__CONCAT(name,r)
     69 #define _Mdouble_BEGIN_NAMESPACE __BEGIN_NAMESPACE_STD
     70 #define _Mdouble_END_NAMESPACE   __END_NAMESPACE_STD
     71 #include <bits/mathcalls.h>
     72 #undef	_Mdouble_
     73 #undef _Mdouble_BEGIN_NAMESPACE
     74 #undef _Mdouble_END_NAMESPACE
     75 #undef	__MATH_PRECNAME
     76 
     77 #if defined __USE_MISC || defined __USE_ISOC99
     78 
     79 
     80 /* Include the file of declarations again, this time using `float'
     81    instead of `double' and appending f to each function name.  */
     82 
     83 # ifndef _Mfloat_
     84 #  define _Mfloat_		float
     85 # endif
     86 # define _Mdouble_		_Mfloat_
     87 # ifdef __STDC__
     88 #  define __MATH_PRECNAME(name,r) name##f##r
     89 # else
     90 #  define __MATH_PRECNAME(name,r) name/**/f/**/r
     91 # endif
     92 # define _Mdouble_BEGIN_NAMESPACE __BEGIN_NAMESPACE_C99
     93 # define _Mdouble_END_NAMESPACE   __END_NAMESPACE_C99
     94 # include <bits/mathcalls.h>
     95 # undef	_Mdouble_
     96 # undef _Mdouble_BEGIN_NAMESPACE
     97 # undef _Mdouble_END_NAMESPACE
     98 # undef	__MATH_PRECNAME
     99 
    100 # if (__STDC__ - 0 || __GNUC__ - 0) \
    101      && (!(defined __NO_LONG_DOUBLE_MATH && defined _LIBC) \
    102 	 || defined __LDBL_COMPAT)
    103 #  ifdef __LDBL_COMPAT
    104 
    105 #   ifdef __USE_ISOC99
    106 extern float __nldbl_nexttowardf (float __x, long double __y)
    107 				  __THROW __attribute__ ((__const__));
    108 #    ifdef __REDIRECT_NTH
    109 extern float __REDIRECT_NTH (nexttowardf, (float __x, long double __y),
    110 			     __nldbl_nexttowardf)
    111      __attribute__ ((__const__));
    112 extern double __REDIRECT_NTH (nexttoward, (double __x, long double __y),
    113 			      nextafter) __attribute__ ((__const__));
    114 extern long double __REDIRECT_NTH (nexttowardl,
    115 				   (long double __x, long double __y),
    116 				   nextafter) __attribute__ ((__const__));
    117 #    endif
    118 #   endif
    119 #  endif
    120 
    121 #  if defined __LDBL_COMPAT || defined __NO_LONG_DOUBLE_MATH
    122 
    123 #   undef __MATHDECL_1
    124 #   define __MATHDECL_2(type, function,suffix, args, alias) \
    125   extern type __REDIRECT_NTH(__MATH_PRECNAME(function,suffix), \
    126 			     args, alias)
    127 #   define __MATHDECL_1(type, function,suffix, args) \
    128   __MATHDECL_2(type, function,suffix, args, __CONCAT(function,suffix))
    129 #  endif
    130 
    131 /* Include the file of declarations again, this time using `long double'
    132    instead of `double' and appending l to each function name.  */
    133 
    134 #  ifndef _Mlong_double_
    135 #   define _Mlong_double_	long double
    136 #  endif
    137 #  define _Mdouble_		_Mlong_double_
    138 #  ifdef __STDC__
    139 #   define __MATH_PRECNAME(name,r) name##l##r
    140 #  else
    141 #   define __MATH_PRECNAME(name,r) name/**/l/**/r
    142 #  endif
    143 #  define _Mdouble_BEGIN_NAMESPACE __BEGIN_NAMESPACE_C99
    144 #  define _Mdouble_END_NAMESPACE   __END_NAMESPACE_C99
    145 #  define __MATH_DECLARE_LDOUBLE   1
    146 #  include <bits/mathcalls.h>
    147 #  undef _Mdouble_
    148 #  undef _Mdouble_BEGIN_NAMESPACE
    149 #  undef _Mdouble_END_NAMESPACE
    150 #  undef __MATH_PRECNAME
    151 
    152 # endif /* __STDC__ || __GNUC__ */
    153 
    154 #endif	/* Use misc or ISO C99.  */
    155 #undef	__MATHDECL_1
    156 #undef	__MATHDECL
    157 #undef	__MATHCALL
    158 
    159 
    160 #if defined __USE_MISC || defined __USE_XOPEN
    161 /* This variable is used by `gamma' and `lgamma'.  */
    162 extern int signgam;
    163 #endif
    164 
    165 
    166 /* ISO C99 defines some generic macros which work on any data type.  */
    167 #ifdef __USE_ISOC99
    168 
    169 /* Get the architecture specific values describing the floating-point
    170    evaluation.  The following symbols will get defined:
    171 
    172     float_t	floating-point type at least as wide as `float' used
    173 		to evaluate `float' expressions
    174     double_t	floating-point type at least as wide as `double' used
    175 		to evaluate `double' expressions
    176 
    177     FLT_EVAL_METHOD
    178 		Defined to
    179 		  0	if `float_t' is `float' and `double_t' is `double'
    180 		  1	if `float_t' and `double_t' are `double'
    181 		  2	if `float_t' and `double_t' are `long double'
    182 		  else	`float_t' and `double_t' are unspecified
    183 
    184     INFINITY	representation of the infinity value of type `float'
    185 
    186     FP_FAST_FMA
    187     FP_FAST_FMAF
    188     FP_FAST_FMAL
    189 		If defined it indicates that the `fma' function
    190 		generally executes about as fast as a multiply and an add.
    191 		This macro is defined only iff the `fma' function is
    192 		implemented directly with a hardware multiply-add instructions.
    193 
    194     FP_ILOGB0	Expands to a value returned by `ilogb (0.0)'.
    195     FP_ILOGBNAN	Expands to a value returned by `ilogb (NAN)'.
    196 
    197     DECIMAL_DIG	Number of decimal digits supported by conversion between
    198 		decimal and all internal floating-point formats.
    199 
    200 */
    201 
    202 /* All floating-point numbers can be put in one of these categories.  */
    203 enum
    204   {
    205     FP_NAN,
    206 # define FP_NAN FP_NAN
    207     FP_INFINITE,
    208 # define FP_INFINITE FP_INFINITE
    209     FP_ZERO,
    210 # define FP_ZERO FP_ZERO
    211     FP_SUBNORMAL,
    212 # define FP_SUBNORMAL FP_SUBNORMAL
    213     FP_NORMAL
    214 # define FP_NORMAL FP_NORMAL
    215   };
    216 
    217 /* Return number of classification appropriate for X.  */
    218 # ifdef __NO_LONG_DOUBLE_MATH
    219 #  define fpclassify(x) \
    220      (sizeof (x) == sizeof (float) ? __fpclassifyf (x) : __fpclassify (x))
    221 # else
    222 #  define fpclassify(x) \
    223      (sizeof (x) == sizeof (float)					      \
    224       ? __fpclassifyf (x)						      \
    225       : sizeof (x) == sizeof (double)					      \
    226       ? __fpclassify (x) : __fpclassifyl (x))
    227 # endif
    228 
    229 /* Return nonzero value if sign of X is negative.  */
    230 # ifdef __NO_LONG_DOUBLE_MATH
    231 #  define signbit(x) \
    232      (sizeof (x) == sizeof (float) ? __signbitf (x) : __signbit (x))
    233 # else
    234 #  define signbit(x) \
    235      (sizeof (x) == sizeof (float)					      \
    236       ? __signbitf (x)							      \
    237       : sizeof (x) == sizeof (double)					      \
    238       ? __signbit (x) : __signbitl (x))
    239 # endif
    240 
    241 /* Return nonzero value if X is not +-Inf or NaN.  */
    242 # ifdef __NO_LONG_DOUBLE_MATH
    243 #  define isfinite(x) \
    244      (sizeof (x) == sizeof (float) ? __finitef (x) : __finite (x))
    245 # else
    246 #  define isfinite(x) \
    247      (sizeof (x) == sizeof (float)					      \
    248       ? __finitef (x)							      \
    249       : sizeof (x) == sizeof (double)					      \
    250       ? __finite (x) : __finitel (x))
    251 # endif
    252 
    253 /* Return nonzero value if X is neither zero, subnormal, Inf, nor NaN.  */
    254 # define isnormal(x) (fpclassify (x) == FP_NORMAL)
    255 
    256 /* Return nonzero value if X is a NaN.  We could use `fpclassify' but
    257    we already have this functions `__isnan' and it is faster.  */
    258 # ifdef __NO_LONG_DOUBLE_MATH
    259 #  define isnan(x) \
    260      (sizeof (x) == sizeof (float) ? __isnanf (x) : __isnan (x))
    261 # else
    262 #  define isnan(x) \
    263      (sizeof (x) == sizeof (float)					      \
    264       ? __isnanf (x)							      \
    265       : sizeof (x) == sizeof (double)					      \
    266       ? __isnan (x) : __isnanl (x))
    267 # endif
    268 
    269 /* Return nonzero value if X is positive or negative infinity.  */
    270 # ifdef __NO_LONG_DOUBLE_MATH
    271 #  define isinf(x) \
    272      (sizeof (x) == sizeof (float) ? __isinff (x) : __isinf (x))
    273 # else
    274 #  define isinf(x) \
    275      (sizeof (x) == sizeof (float)					      \
    276       ? __isinff (x)							      \
    277       : sizeof (x) == sizeof (double)					      \
    278       ? __isinf (x) : __isinfl (x))
    279 # endif
    280 
    281 /* Bitmasks for the math_errhandling macro.  */
    282 # define MATH_ERRNO	1	/* errno set by math functions.  */
    283 # define MATH_ERREXCEPT	2	/* Exceptions raised by math functions.  */
    284 
    285 /* By default all functions support both errno and exception handling.
    286    In gcc's fast math mode and if inline functions are defined this
    287    might not be true.  */
    288 # ifndef __FAST_MATH__
    289 #  define math_errhandling	(MATH_ERRNO | MATH_ERREXCEPT)
    290 # endif
    291 
    292 #endif /* Use ISO C99.  */
    293 
    294 #ifdef	__USE_MISC
    295 /* Support for various different standard error handling behaviors.  */
    296 typedef enum
    297 {
    298   _IEEE_ = -1,	/* According to IEEE 754/IEEE 854.  */
    299   _SVID_,	/* According to System V, release 4.  */
    300   _XOPEN_,	/* Nowadays also Unix98.  */
    301   _POSIX_,
    302   _ISOC_	/* Actually this is ISO C99.  */
    303 } _LIB_VERSION_TYPE;
    304 
    305 /* This variable can be changed at run-time to any of the values above to
    306    affect floating point error handling behavior (it may also be necessary
    307    to change the hardware FPU exception settings).  */
    308 extern _LIB_VERSION_TYPE _LIB_VERSION;
    309 #endif
    310 
    311 
    312 #ifdef __USE_SVID
    313 /* In SVID error handling, `matherr' is called with this description
    314    of the exceptional condition.
    315 
    316    We have a problem when using C++ since `exception' is a reserved
    317    name in C++.  */
    318 # ifdef __cplusplus
    319 struct __exception
    320 # else
    321 struct exception
    322 # endif
    323   {
    324     int type;
    325     char *name;
    326     double arg1;
    327     double arg2;
    328     double retval;
    329   };
    330 
    331 # ifdef __cplusplus
    332 extern int matherr (struct __exception *__exc) throw ();
    333 # else
    334 extern int matherr (struct exception *__exc);
    335 # endif
    336 
    337 # define X_TLOSS	1.41484755040568800000e+16
    338 
    339 /* Types of exceptions in the `type' field.  */
    340 # define DOMAIN		1
    341 # define SING		2
    342 # define OVERFLOW	3
    343 # define UNDERFLOW	4
    344 # define TLOSS		5
    345 # define PLOSS		6
    346 
    347 /* SVID mode specifies returning this large value instead of infinity.  */
    348 # define HUGE		3.40282347e+38F
    349 
    350 #else	/* !SVID */
    351 
    352 # ifdef __USE_XOPEN
    353 /* X/Open wants another strange constant.  */
    354 #  define MAXFLOAT	3.40282347e+38F
    355 # endif
    356 
    357 #endif	/* SVID */
    358 
    359 
    360 /* Some useful constants.  */
    361 #if defined __USE_BSD || defined __USE_XOPEN
    362 # define M_E		2.7182818284590452354	/* e */
    363 # define M_LOG2E	1.4426950408889634074	/* log_2 e */
    364 # define M_LOG10E	0.43429448190325182765	/* log_10 e */
    365 # define M_LN2		0.69314718055994530942	/* log_e 2 */
    366 # define M_LN10		2.30258509299404568402	/* log_e 10 */
    367 # define M_PI		3.14159265358979323846	/* pi */
    368 # define M_PI_2		1.57079632679489661923	/* pi/2 */
    369 # define M_PI_4		0.78539816339744830962	/* pi/4 */
    370 # define M_1_PI		0.31830988618379067154	/* 1/pi */
    371 # define M_2_PI		0.63661977236758134308	/* 2/pi */
    372 # define M_2_SQRTPI	1.12837916709551257390	/* 2/sqrt(pi) */
    373 # define M_SQRT2	1.41421356237309504880	/* sqrt(2) */
    374 # define M_SQRT1_2	0.70710678118654752440	/* 1/sqrt(2) */
    375 #endif
    376 
    377 /* The above constants are not adequate for computation using `long double's.
    378    Therefore we provide as an extension constants with similar names as a
    379    GNU extension.  Provide enough digits for the 128-bit IEEE quad.  */
    380 #ifdef __USE_GNU
    381 # define M_El		2.7182818284590452353602874713526625L  /* e */
    382 # define M_LOG2El	1.4426950408889634073599246810018921L  /* log_2 e */
    383 # define M_LOG10El	0.4342944819032518276511289189166051L  /* log_10 e */
    384 # define M_LN2l		0.6931471805599453094172321214581766L  /* log_e 2 */
    385 # define M_LN10l	2.3025850929940456840179914546843642L  /* log_e 10 */
    386 # define M_PIl		3.1415926535897932384626433832795029L  /* pi */
    387 # define M_PI_2l	1.5707963267948966192313216916397514L  /* pi/2 */
    388 # define M_PI_4l	0.7853981633974483096156608458198757L  /* pi/4 */
    389 # define M_1_PIl	0.3183098861837906715377675267450287L  /* 1/pi */
    390 # define M_2_PIl	0.6366197723675813430755350534900574L  /* 2/pi */
    391 # define M_2_SQRTPIl	1.1283791670955125738961589031215452L  /* 2/sqrt(pi) */
    392 # define M_SQRT2l	1.4142135623730950488016887242096981L  /* sqrt(2) */
    393 # define M_SQRT1_2l	0.7071067811865475244008443621048490L  /* 1/sqrt(2) */
    394 #endif
    395 
    396 
    397 /* When compiling in strict ISO C compatible mode we must not use the
    398    inline functions since they, among other things, do not set the
    399    `errno' variable correctly.  */
    400 #if defined __STRICT_ANSI__ && !defined __NO_MATH_INLINES
    401 # define __NO_MATH_INLINES	1
    402 #endif
    403 
    404 #if defined __USE_ISOC99 && __GNUC_PREREQ(2,97)
    405 /* ISO C99 defines some macros to compare number while taking care for
    406    unordered numbers.  Many FPUs provide special instructions to support
    407    these operations.  Generic support in GCC for these as builtins went
    408    in before 3.0.0, but not all cpus added their patterns.  We define
    409    versions that use the builtins here, and <bits/mathinline.h> will
    410    undef/redefine as appropriate for the specific GCC version in use.  */
    411 # define isgreater(x, y)	__builtin_isgreater(x, y)
    412 # define isgreaterequal(x, y)	__builtin_isgreaterequal(x, y)
    413 # define isless(x, y)		__builtin_isless(x, y)
    414 # define islessequal(x, y)	__builtin_islessequal(x, y)
    415 # define islessgreater(x, y)	__builtin_islessgreater(x, y)
    416 # define isunordered(u, v)	__builtin_isunordered(u, v)
    417 #endif
    418 
    419 /* Get machine-dependent inline versions (if there are any).  */
    420 #ifdef __USE_EXTERN_INLINES
    421 # include <bits/mathinline.h>
    422 #endif
    423 
    424 /* Define special entry points to use when the compiler got told to
    425    only expect finite results.  */
    426 #if defined __FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ > 0
    427 # include <bits/math-finite.h>
    428 #endif
    429 
    430 #ifdef __USE_ISOC99
    431 /* If we've still got undefined comparison macros, provide defaults.  */
    432 
    433 /* Return nonzero value if X is greater than Y.  */
    434 # ifndef isgreater
    435 #  define isgreater(x, y) \
    436   (__extension__							      \
    437    ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y);			      \
    438       !isunordered (__x, __y) && __x > __y; }))
    439 # endif
    440 
    441 /* Return nonzero value if X is greater than or equal to Y.  */
    442 # ifndef isgreaterequal
    443 #  define isgreaterequal(x, y) \
    444   (__extension__							      \
    445    ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y);			      \
    446       !isunordered (__x, __y) && __x >= __y; }))
    447 # endif
    448 
    449 /* Return nonzero value if X is less than Y.  */
    450 # ifndef isless
    451 #  define isless(x, y) \
    452   (__extension__							      \
    453    ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y);			      \
    454       !isunordered (__x, __y) && __x < __y; }))
    455 # endif
    456 
    457 /* Return nonzero value if X is less than or equal to Y.  */
    458 # ifndef islessequal
    459 #  define islessequal(x, y) \
    460   (__extension__							      \
    461    ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y);			      \
    462       !isunordered (__x, __y) && __x <= __y; }))
    463 # endif
    464 
    465 /* Return nonzero value if either X is less than Y or Y is less than X.  */
    466 # ifndef islessgreater
    467 #  define islessgreater(x, y) \
    468   (__extension__							      \
    469    ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y);			      \
    470       !isunordered (__x, __y) && (__x < __y || __y < __x); }))
    471 # endif
    472 
    473 /* Return nonzero value if arguments are unordered.  */
    474 # ifndef isunordered
    475 #  define isunordered(u, v) \
    476   (__extension__							      \
    477    ({ __typeof__(u) __u = (u); __typeof__(v) __v = (v);			      \
    478       fpclassify (__u) == FP_NAN || fpclassify (__v) == FP_NAN; }))
    479 # endif
    480 
    481 #endif
    482 
    483 __END_DECLS
    484 
    485 
    486 #endif /* math.h  */
    487