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