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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
[] = "$\Id: w_gamma.c,v 1.2 1995/05/30 05:51:04 rgrimes Exp $";
#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
}