math/w_lgammal.c

   1 /* w_lgammal.c -- long double version of w_lgamma.c.
   2  * Conversion to long double by Ulrich Drepper,
   3  * Cygnus Support, drepper@cygnus.com.
   4  */
   5
   6 /*
   7  * ====================================================
   8  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   9  *
  10  * Developed at SunPro, a Sun Microsystems, Inc. business.
  11  * Permission to use, copy, modify, and distribute this
  12  * software is freely granted, provided that this notice
  13  * is preserved.
  14  * ====================================================
  15  */
  16
  17 /* long double lgammal(long double x)
  18  * Return the logarithm of the Gamma function of x.
  19  *
  20  * Method: call __ieee754_lgammal_r
  21  */
  22
  23 #include <math.h>
  24 #include <math_private.h>
  25
  26 long double
  27 __lgammal(long double x)
  28 {
  29         int local_signgam = 0;
  30         long double y = __ieee754_lgammal_r(x,
  31                                             _LIB_VERSION != _ISOC_
  32                                             /* ISO C99 does not define the
  33                                                global variable.  */
  34                                             ? &signgam
  35                                             : &local_signgam);
  36         if(__builtin_expect(!isfinite(y), 0)
  37            && isfinite(x) && _LIB_VERSION != _IEEE_)
  38                 return __kernel_standard_l(x, x,
  39                                            __floorl(x)==x&&x<=0.0L
  40                                            ? 215 /* lgamma pole */
  41                                            : 214); /* lgamma overflow */
  42
  43         return y;
  44 }
  45 weak_alias (__lgammal, lgammal)
  46 strong_alias (__lgammal, __gammal)
  47 weak_alias (__gammal, gammal)