glibc/math/w_tgammal.c

46 lines
1.3 KiB
C

/* w_gammal.c -- long double version of w_gamma.c.
* Conversion to long double by Ulrich Drepper,
* Cygnus Support, drepper@cygnus.com.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
/* long double gammal(double x)
* Return the Gamma function of x.
*/
#include <errno.h>
#include <math.h>
#include <math_private.h>
long double
__tgammal(long double x)
{
int local_signgam;
long double y = __ieee754_gammal_r(x,&local_signgam);
if(__glibc_unlikely (!isfinite (y) || y == 0)
&& (isfinite (x) || isinf (x) < 0)
&& _LIB_VERSION != _IEEE_) {
if(x==0.0)
return __kernel_standard_l(x,x,250); /* tgamma pole */
else if(__floorl(x)==x&&x<0.0L)
return __kernel_standard_l(x,x,241); /* tgamma domain */
else if (y == 0)
__set_errno (ERANGE); /* tgamma underflow */
else
return __kernel_standard_l(x,x,240); /* tgamma overflow */
}
return local_signgam < 0 ? - y : y;
}
weak_alias (__tgammal, tgammal)