math/w_tgammaf_compat.c

   1 /* w_gammaf.c -- float version of w_gamma.c.
   2  */
   3
   4 /*
   5  * ====================================================
   6  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   7  *
   8  * Developed at SunPro, a Sun Microsystems, Inc. business.
   9  * Permission to use, copy, modify, and distribute this
  10  * software is freely granted, provided that this notice
  11  * is preserved.
  12  * ====================================================
  13  */
  14
  15 #include <errno.h>
  16 #include <math.h>
  17 #include <math_private.h>
  18 #include <math-svid-compat.h>
  19 #include <libm-alias-float.h>
  20
  21 #if LIBM_SVID_COMPAT
  22 float
  23 __tgammaf(float x)
  24 {
  25         int local_signgam;
  26         float y = __ieee754_gammaf_r(x,&local_signgam);
  27
  28         if(__glibc_unlikely (!isfinite (y) || y == 0)
  29            && (isfinite (x) || (isinf (x) && x < 0.0))
  30            && _LIB_VERSION != _IEEE_) {
  31           if (x == (float)0.0)
  32             /* tgammaf pole */
  33             return __kernel_standard_f(x, x, 150);
  34           else if(floorf(x)==x&&x<0.0f)
  35             /* tgammaf domain */
  36             return __kernel_standard_f(x, x, 141);
  37           else if (y == 0)
  38             /* tgammaf underflow */
  39             __set_errno (ERANGE);
  40           else
  41             /* tgammaf overflow */
  42             return __kernel_standard_f(x, x, 140);
  43         }
  44         return local_signgam < 0 ? - y : y;
  45 }
  46 libm_alias_float (__tgamma, tgamma)
  47 #endif