math/w_tgammaf.c

   1 /* w_gammaf.c -- float version of w_gamma.c.
   2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
   3  */
   4
   5 /*
   6  * ====================================================
   7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   8  *
   9  * Developed at SunPro, a Sun Microsystems, Inc. business.
  10  * Permission to use, copy, modify, and distribute this
  11  * software is freely granted, provided that this notice
  12  * is preserved.
  13  * ====================================================
  14  */
  15
  16 #include <errno.h>
  17 #include <math.h>
  18 #include <math_private.h>
  19
  20 float
  21 __tgammaf(float x)
  22 {
  23         int local_signgam;
  24         float y = __ieee754_gammaf_r(x,&local_signgam);
  25
  26         if(__glibc_unlikely (!isfinite (y) || y == 0)
  27            && (isfinite (x) || (isinf (x) && x < 0.0))
  28            && _LIB_VERSION != _IEEE_) {
  29           if (x == (float)0.0)
  30             /* tgammaf pole */
  31             return __kernel_standard_f(x, x, 150);
  32           else if(__floorf(x)==x&&x<0.0f)
  33             /* tgammaf domain */
  34             return __kernel_standard_f(x, x, 141);
  35           else if (y == 0)
  36             /* tgammaf underflow */
  37             __set_errno (ERANGE);
  38           else
  39             /* tgammaf overflow */
  40             return __kernel_standard_f(x, x, 140);
  41         }
  42         return local_signgam < 0 ? - y : y;
  43 }
  44 weak_alias (__tgammaf, tgammaf)