libm/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 <math.h>
  17 #include "math_private.h"
  18 #if defined(__UCLIBC_HAS_FENV__)
  19 #include <errno.h>
  20 #endif
  21
  22 float
  23 tgammaf(float x)
  24 {
  25 #if defined(__UCLIBC_HAS_FENV__)
  26         float y = (float) __ieee754_tgamma((double)x);
  27
  28         if(__builtin_expect (!isfinite (y) || y == 0, 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 y;
  45 #else
  46         return (float) __ieee754_tgamma((double)x);
  47 #endif /* __UCLIBC_HAS_FENV__ */
  48 }