math/w_tgammal_compat.c

   1 /* w_gammal.c -- long double 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 /* long double gammal(double x)
  16  * Return the Gamma function of x.
  17  */
  18
  19 #include <errno.h>
  20 #include <math.h>
  21 #include <math_private.h>
  22 #include <math-svid-compat.h>
  23 #include <libm-alias-ldouble.h>
  24
  25 #if LIBM_SVID_COMPAT
  26 long double
  27 __tgammal(long double x)
  28 {
  29         int local_signgam;
  30         long double y = __ieee754_gammal_r(x,&local_signgam);
  31
  32         if(__glibc_unlikely (!isfinite (y) || y == 0)
  33            && (isfinite (x) || (isinf (x) && x < 0.0))
  34            && _LIB_VERSION != _IEEE_) {
  35           if(x==0.0)
  36             return __kernel_standard_l(x,x,250); /* tgamma pole */
  37           else if(floorl(x)==x&&x<0.0L)
  38             return __kernel_standard_l(x,x,241); /* tgamma domain */
  39           else if (y == 0)
  40             __set_errno (ERANGE); /* tgamma underflow */
  41           else
  42             return __kernel_standard_l(x,x,240); /* tgamma overflow */
  43         }
  44         return local_signgam < 0 ? - y : y;
  45 }
  46 libm_alias_ldouble (__tgamma, tgamma)
  47 #endif