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      1 /* Declarations for math functions.
      2    Copyright (C) 1991-1993, 1995-1999, 2001, 2002, 2004, 2006
      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 __LDBL_COMPAT)
    102 #  ifdef __LDBL_COMPAT
    103 
    104 #   ifdef __USE_ISOC99
    105 extern float __nldbl_nexttowardf (float __x, long double __y)
    106 				  __THROW __attribute__ ((__const__));
    107 #    ifdef __REDIRECT_NTH
    108 extern float __REDIRECT_NTH (nexttowardf, (float __x, long double __y),
    109 			     __nldbl_nexttowardf)
    110      __attribute__ ((__const__));
    111 extern double __REDIRECT_NTH (nexttoward, (double __x, long double __y),
    112 			      nextafter) __attribute__ ((__const__));
    113 extern long double __REDIRECT_NTH (nexttowardl,
    114 				   (long double __x, long double __y),
    115 				   nextafter) __attribute__ ((__const__));
    116 #    endif
    117 #   endif
    118 
    119 /* Include the file of declarations again, this time using `long double'
    120    instead of `double' and appending l to each function name.  */
    121 
    122 #   undef __MATHDECL_1
    123 #   define __MATHDECL_2(type, function,suffix, args, alias) \
    124   extern type __REDIRECT_NTH(__MATH_PRECNAME(function,suffix), \
    125 			     args, alias)
    126 #   define __MATHDECL_1(type, function,suffix, args) \
    127   __MATHDECL_2(type, function,suffix, args, __CONCAT(function,suffix))
    128 #  endif
    129 
    130 #  ifndef _Mlong_double_
    131 #   define _Mlong_double_	long double
    132 #  endif
    133 #  define _Mdouble_ 		_Mlong_double_
    134 #  ifdef __STDC__
    135 #   define __MATH_PRECNAME(name,r) name##l##r
    136 #  else
    137 #   define __MATH_PRECNAME(name,r) name/**/l/**/r
    138 #  endif
    139 #  define _Mdouble_BEGIN_NAMESPACE __BEGIN_NAMESPACE_C99
    140 #  define _Mdouble_END_NAMESPACE   __END_NAMESPACE_C99
    141 #  include <bits/mathcalls.h>
    142 #  undef _Mdouble_
    143 # undef _Mdouble_BEGIN_NAMESPACE
    144 # undef _Mdouble_END_NAMESPACE
    145 #  undef __MATH_PRECNAME
    146 
    147 # endif /* __STDC__ || __GNUC__ */
    148 
    149 #endif	/* Use misc or ISO C99.  */
    150 #undef	__MATHDECL_1
    151 #undef	__MATHDECL
    152 #undef	__MATHCALL
    153 
    154 
    155 #if defined __USE_MISC || defined __USE_XOPEN
    156 /* This variable is used by `gamma' and `lgamma'.  */
    157 extern int signgam;
    158 #endif
    159 
    160 
    161 /* ISO C99 defines some generic macros which work on any data type.  */
    162 #ifdef __USE_ISOC99
    163 
    164 /* Get the architecture specific values describing the floating-point
    165    evaluation.  The following symbols will get defined:
    166 
    167     float_t	floating-point type at least as wide as `float' used
    168 		to evaluate `float' expressions
    169     double_t	floating-point type at least as wide as `double' used
    170 		to evaluate `double' expressions
    171 
    172     FLT_EVAL_METHOD
    173 		Defined to
    174 		  0	if `float_t' is `float' and `double_t' is `double'
    175 		  1	if `float_t' and `double_t' are `double'
    176 		  2	if `float_t' and `double_t' are `long double'
    177 		  else	`float_t' and `double_t' are unspecified
    178 
    179     INFINITY	representation of the infinity value of type `float'
    180 
    181     FP_FAST_FMA
    182     FP_FAST_FMAF
    183     FP_FAST_FMAL
    184 		If defined it indicates that the `fma' function
    185 		generally executes about as fast as a multiply and an add.
    186 		This macro is defined only iff the `fma' function is
    187 		implemented directly with a hardware multiply-add instructions.
    188 
    189     FP_ILOGB0	Expands to a value returned by `ilogb (0.0)'.
    190     FP_ILOGBNAN	Expands to a value returned by `ilogb (NAN)'.
    191 
    192     DECIMAL_DIG	Number of decimal digits supported by conversion between
    193 		decimal and all internal floating-point formats.
    194 
    195 */
    196 
    197 /* All floating-point numbers can be put in one of these categories.  */
    198 enum
    199   {
    200     FP_NAN,
    201 # define FP_NAN FP_NAN
    202     FP_INFINITE,
    203 # define FP_INFINITE FP_INFINITE
    204     FP_ZERO,
    205 # define FP_ZERO FP_ZERO
    206     FP_SUBNORMAL,
    207 # define FP_SUBNORMAL FP_SUBNORMAL
    208     FP_NORMAL
    209 # define FP_NORMAL FP_NORMAL
    210   };
    211 
    212 /* Return number of classification appropriate for X.  */
    213 # ifdef __NO_LONG_DOUBLE_MATH
    214 #  define fpclassify(x) \
    215      (sizeof (x) == sizeof (float) ? __fpclassifyf (x) : __fpclassify (x))
    216 # else
    217 #  define fpclassify(x) \
    218      (sizeof (x) == sizeof (float)					      \
    219       ? __fpclassifyf (x)						      \
    220       : sizeof (x) == sizeof (double)					      \
    221       ? __fpclassify (x) : __fpclassifyl (x))
    222 # endif
    223 
    224 /* Return nonzero value if sign of X is negative.  */
    225 # ifdef __NO_LONG_DOUBLE_MATH
    226 #  define signbit(x) \
    227      (sizeof (x) == sizeof (float) ? __signbitf (x) : __signbit (x))
    228 # else
    229 #  define signbit(x) \
    230      (sizeof (x) == sizeof (float)					      \
    231       ? __signbitf (x)							      \
    232       : sizeof (x) == sizeof (double)					      \
    233       ? __signbit (x) : __signbitl (x))
    234 # endif
    235 
    236 /* Return nonzero value if X is not +-Inf or NaN.  */
    237 # ifdef __NO_LONG_DOUBLE_MATH
    238 #  define isfinite(x) \
    239      (sizeof (x) == sizeof (float) ? __finitef (x) : __finite (x))
    240 # else
    241 #  define isfinite(x) \
    242      (sizeof (x) == sizeof (float)					      \
    243       ? __finitef (x)							      \
    244       : sizeof (x) == sizeof (double)					      \
    245       ? __finite (x) : __finitel (x))
    246 # endif
    247 
    248 /* Return nonzero value if X is neither zero, subnormal, Inf, nor NaN.  */
    249 # define isnormal(x) (fpclassify (x) == FP_NORMAL)
    250 
    251 /* Return nonzero value if X is a NaN.  We could use `fpclassify' but
    252    we already have this functions `__isnan' and it is faster.  */
    253 # ifdef __NO_LONG_DOUBLE_MATH
    254 #  define isnan(x) \
    255      (sizeof (x) == sizeof (float) ? __isnanf (x) : __isnan (x))
    256 # else
    257 #  define isnan(x) \
    258      (sizeof (x) == sizeof (float)					      \
    259       ? __isnanf (x)							      \
    260       : sizeof (x) == sizeof (double)					      \
    261       ? __isnan (x) : __isnanl (x))
    262 # endif
    263 
    264 /* Return nonzero value is X is positive or negative infinity.  */
    265 # ifdef __NO_LONG_DOUBLE_MATH
    266 #  define isinf(x) \
    267      (sizeof (x) == sizeof (float) ? __isinff (x) : __isinf (x))
    268 # else
    269 #  define isinf(x) \
    270      (sizeof (x) == sizeof (float)					      \
    271       ? __isinff (x)							      \
    272       : sizeof (x) == sizeof (double)					      \
    273       ? __isinf (x) : __isinfl (x))
    274 # endif
    275 
    276 /* Bitmasks for the math_errhandling macro.  */
    277 # define MATH_ERRNO	1	/* errno set by math functions.  */
    278 # define MATH_ERREXCEPT	2	/* Exceptions raised by math functions.  */
    279 
    280 #endif /* Use ISO C99.  */
    281 
    282 #ifdef	__USE_MISC
    283 /* Support for various different standard error handling behaviors.  */
    284 typedef enum
    285 {
    286   _IEEE_ = -1,	/* According to IEEE 754/IEEE 854.  */
    287   _SVID_,	/* According to System V, release 4.  */
    288   _XOPEN_,	/* Nowadays also Unix98.  */
    289   _POSIX_,
    290   _ISOC_	/* Actually this is ISO C99.  */
    291 } _LIB_VERSION_TYPE;
    292 
    293 /* This variable can be changed at run-time to any of the values above to
    294    affect floating point error handling behavior (it may also be necessary
    295    to change the hardware FPU exception settings).  */
    296 extern _LIB_VERSION_TYPE _LIB_VERSION;
    297 #endif
    298 
    299 
    300 #ifdef __USE_SVID
    301 /* In SVID error handling, `matherr' is called with this description
    302    of the exceptional condition.
    303 
    304    We have a problem when using C++ since `exception' is a reserved
    305    name in C++.  */
    306 # ifdef __cplusplus
    307 struct __exception
    308 # else
    309 struct exception
    310 # endif
    311   {
    312     int type;
    313     char *name;
    314     double arg1;
    315     double arg2;
    316     double retval;
    317   };
    318 
    319 # ifdef __cplusplus
    320 extern int matherr (struct __exception *__exc) throw ();
    321 # else
    322 extern int matherr (struct exception *__exc);
    323 # endif
    324 
    325 # define X_TLOSS	1.41484755040568800000e+16
    326 
    327 /* Types of exceptions in the `type' field.  */
    328 # define DOMAIN		1
    329 # define SING		2
    330 # define OVERFLOW	3
    331 # define UNDERFLOW	4
    332 # define TLOSS		5
    333 # define PLOSS		6
    334 
    335 /* SVID mode specifies returning this large value instead of infinity.  */
    336 # define HUGE		3.40282347e+38F
    337 
    338 #else	/* !SVID */
    339 
    340 # ifdef __USE_XOPEN
    341 /* X/Open wants another strange constant.  */
    342 #  define MAXFLOAT	3.40282347e+38F
    343 # endif
    344 
    345 #endif	/* SVID */
    346 
    347 
    348 /* Some useful constants.  */
    349 #if defined __USE_BSD || defined __USE_XOPEN
    350 # define M_E		2.7182818284590452354	/* e */
    351 # define M_LOG2E	1.4426950408889634074	/* log_2 e */
    352 # define M_LOG10E	0.43429448190325182765	/* log_10 e */
    353 # define M_LN2		0.69314718055994530942	/* log_e 2 */
    354 # define M_LN10		2.30258509299404568402	/* log_e 10 */
    355 # define M_PI		3.14159265358979323846	/* pi */
    356 # define M_PI_2		1.57079632679489661923	/* pi/2 */
    357 # define M_PI_4		0.78539816339744830962	/* pi/4 */
    358 # define M_1_PI		0.31830988618379067154	/* 1/pi */
    359 # define M_2_PI		0.63661977236758134308	/* 2/pi */
    360 # define M_2_SQRTPI	1.12837916709551257390	/* 2/sqrt(pi) */
    361 # define M_SQRT2	1.41421356237309504880	/* sqrt(2) */
    362 # define M_SQRT1_2	0.70710678118654752440	/* 1/sqrt(2) */
    363 #endif
    364 
    365 /* The above constants are not adequate for computation using `long double's.
    366    Therefore we provide as an extension constants with similar names as a
    367    GNU extension.  Provide enough digits for the 128-bit IEEE quad.  */
    368 #ifdef __USE_GNU
    369 # define M_El		2.7182818284590452353602874713526625L  /* e */
    370 # define M_LOG2El	1.4426950408889634073599246810018921L  /* log_2 e */
    371 # define M_LOG10El	0.4342944819032518276511289189166051L  /* log_10 e */
    372 # define M_LN2l		0.6931471805599453094172321214581766L  /* log_e 2 */
    373 # define M_LN10l	2.3025850929940456840179914546843642L  /* log_e 10 */
    374 # define M_PIl		3.1415926535897932384626433832795029L  /* pi */
    375 # define M_PI_2l	1.5707963267948966192313216916397514L  /* pi/2 */
    376 # define M_PI_4l	0.7853981633974483096156608458198757L  /* pi/4 */
    377 # define M_1_PIl	0.3183098861837906715377675267450287L  /* 1/pi */
    378 # define M_2_PIl	0.6366197723675813430755350534900574L  /* 2/pi */
    379 # define M_2_SQRTPIl	1.1283791670955125738961589031215452L  /* 2/sqrt(pi) */
    380 # define M_SQRT2l	1.4142135623730950488016887242096981L  /* sqrt(2) */
    381 # define M_SQRT1_2l	0.7071067811865475244008443621048490L  /* 1/sqrt(2) */
    382 #endif
    383 
    384 
    385 /* When compiling in strict ISO C compatible mode we must not use the
    386    inline functions since they, among other things, do not set the
    387    `errno' variable correctly.  */
    388 #if defined __STRICT_ANSI__ && !defined __NO_MATH_INLINES
    389 # define __NO_MATH_INLINES	1
    390 #endif
    391 
    392 #if defined __USE_ISOC99 && __GNUC_PREREQ(2,97)
    393 /* ISO C99 defines some macros to compare number while taking care for
    394    unordered numbers.  Many FPUs provide special instructions to support
    395    these operations.  Generic support in GCC for these as builtins went
    396    in before 3.0.0, but not all cpus added their patterns.  We define
    397    versions that use the builtins here, and <bits/mathinline.h> will
    398    undef/redefine as appropriate for the specific GCC version in use.  */
    399 # define isgreater(x, y)	__builtin_isgreater(x, y)
    400 # define isgreaterequal(x, y)	__builtin_isgreaterequal(x, y)
    401 # define isless(x, y)		__builtin_isless(x, y)
    402 # define islessequal(x, y)	__builtin_islessequal(x, y)
    403 # define islessgreater(x, y)	__builtin_islessgreater(x, y)
    404 # define isunordered(u, v)	__builtin_isunordered(u, v)
    405 #endif
    406 
    407 /* Get machine-dependent inline versions (if there are any).  */
    408 #ifdef __USE_EXTERN_INLINES
    409 # include <bits/mathinline.h>
    410 #endif
    411 
    412 #ifdef __USE_ISOC99
    413 /* If we've still got undefined comparison macros, provide defaults.  */
    414 
    415 /* Return nonzero value if X is greater than Y.  */
    416 # ifndef isgreater
    417 #  define isgreater(x, y) \
    418   (__extension__							      \
    419    ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y);			      \
    420       !isunordered (__x, __y) && __x > __y; }))
    421 # endif
    422 
    423 /* Return nonzero value if X is greater than or equal to Y.  */
    424 # ifndef isgreaterequal
    425 #  define isgreaterequal(x, y) \
    426   (__extension__							      \
    427    ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y);			      \
    428       !isunordered (__x, __y) && __x >= __y; }))
    429 # endif
    430 
    431 /* Return nonzero value if X is less than Y.  */
    432 # ifndef isless
    433 #  define isless(x, y) \
    434   (__extension__							      \
    435    ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y);			      \
    436       !isunordered (__x, __y) && __x < __y; }))
    437 # endif
    438 
    439 /* Return nonzero value if X is less than or equal to Y.  */
    440 # ifndef islessequal
    441 #  define islessequal(x, y) \
    442   (__extension__							      \
    443    ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y);			      \
    444       !isunordered (__x, __y) && __x <= __y; }))
    445 # endif
    446 
    447 /* Return nonzero value if either X is less than Y or Y is less than X.  */
    448 # ifndef islessgreater
    449 #  define islessgreater(x, y) \
    450   (__extension__							      \
    451    ({ __typeof__(x) __x = (x); __typeof__(y) __y = (y);			      \
    452       !isunordered (__x, __y) && (__x < __y || __y < __x); }))
    453 # endif
    454 
    455 /* Return nonzero value if arguments are unordered.  */
    456 # ifndef isunordered
    457 #  define isunordered(u, v) \
    458   (__extension__							      \
    459    ({ __typeof__(u) __u = (u); __typeof__(v) __v = (v);			      \
    460       fpclassify (__u) == FP_NAN || fpclassify (__v) == FP_NAN; }))
    461 # endif
    462 
    463 #endif
    464 
    465 __END_DECLS
    466 
    467 
    468 #endif /* math.h  */
    469