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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.
* ====================================================
*/
#ifndef lint
static char rcsid[] = "$FreeBSD$";
#endif
/* double gamma(double x)
* Return the logarithm of the Gamma function of x.
*
* Method: call gamma_r
*/
#include "math.h"
#include "math_private.h"
extern int signgam;
#ifdef __STDC__
double gamma(double x)
#else
double gamma(x)
double x;
#endif
{
#ifdef _IEEE_LIBM
return __ieee754_gamma_r(x,&signgam);
#else
double y;
y = __ieee754_gamma_r(x,&signgam);
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 */
} else
return y;
#endif
}
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