| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* @(#)w_lgamma.c 5.1 93/09/24 */ |
| 2 | /* |
| 3 | * ==================================================== |
| 4 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
| 5 | * |
| 6 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
| 7 | * Permission to use, copy, modify, and distribute this |
| 8 | * software is freely granted, provided that this notice |
| 9 | * is preserved. |
| 10 | * ==================================================== |
| 11 | */ |
| 12 | |
| 13 | /* double lgamma(double x) |
| 14 | * Return the logarithm of the Gamma function of x. |
| 15 | * |
| 16 | * Method: call __ieee754_lgamma_r |
| 17 | */ |
| 18 | |
| 19 | #include <math.h> |
| 20 | #include <math_private.h> |
| 21 | |
| 22 | double |
| 23 | __lgamma(double x) |
| 24 | { |
| 25 | int local_signgam = 0; |
| 26 | double y = __ieee754_lgamma_r(x, |
| 27 | _LIB_VERSION != _ISOC_ |
| 28 | /* ISO C99 does not define the |
| 29 | global variable. */ |
| 30 | ? &signgam |
| 31 | : &local_signgam); |
| 32 | if(__builtin_expect(!isfinite(y), 0) |
| 33 | && isfinite(x) && _LIB_VERSION != _IEEE_) |
| 34 | return __kernel_standard(x, x, |
| 35 | __floor(x)==x&&x<=0.0 |
| 36 | ? 15 /* lgamma pole */ |
| 37 | : 14); /* lgamma overflow */ |
| 38 | |
| 39 | return y; |
| 40 | } |
| 41 | weak_alias (__lgamma, lgamma) |
| 42 | strong_alias (__lgamma, __gamma) |
| 43 | weak_alias (__gamma, gamma) |
| 44 | #ifdef NO_LONG_DOUBLE |
| 45 | strong_alias (__lgamma, __lgammal) |
| 46 | weak_alias (__lgamma, lgammal) |
| 47 | strong_alias (__gamma, __gammal) |
| 48 | weak_alias (__gamma, gammal) |
| 49 | #endif |