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/* @(#)w_gamma.c 5.1 93/09/24 */
/*
* ====================================================
* 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.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: w_gamma.c,v 1.7 1995/11/20 22:06:43 jtc Exp $";
#endif
/* double gamma(double x)
* Return the logarithm of the Gamma function of x or the Gamma function of x,
* depending on the library mode.
*/
#include "math.h"
#include "math_private.h"
#ifdef __STDC__
double __gamma(double x)
#else
double __gamma(x)
double x;
#endif
{
double y;
#ifndef _IEEE_LIBM
if (_LIB_VERSION == _SVID_)
{
y = __ieee754_lgamma_r(x,&signgam);
if(!__finite(y)&&__finite(x)) {
if(__floor(x)==x&&x<=(double)0.0)
/* lgamma pole */
return __kernel_standard(x,x,15);
else
/* lgamma overflow */
return __kernel_standard(x,x,14);
}
}
else
{
#endif
int local_signgam;
y = __ieee754_gamma_r(x,&local_signgam);
if (local_signgam < 0) y = -y;
#ifdef _IEEE_LIBM
return y;
#else
if(_LIB_VERSION == _IEEE_) return y;
if(!__finite(y)&&__finite(x)) {
if(__floor(x)==x&&x<=0.0)
return __kernel_standard(x,x,41); /* gamma pole */
else
return __kernel_standard(x,x,40); /* gamma overflow */
}
}
return y;
#endif
}
weak_alias (__gamma, gamma)
#ifdef NO_LONG_DOUBLE
strong_alias (__gamma, __gammal)
weak_alias (__gamma, gammal)
#endif
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