forked from KolibriOS/kolibrios
51 lines
1.3 KiB
C
Executable File
51 lines
1.3 KiB
C
Executable File
/* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */
|
|
/* @(#)w_lgamma.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[] = "$Id: w_lgamma.c,v 1.4 1994/08/10 20:34:53 jtc Exp $";
|
|
#endif
|
|
|
|
/* double lgamma(double x)
|
|
* Return the logarithm of the Gamma function of x.
|
|
*
|
|
* Method: call __ieee754_lgamma_r
|
|
*/
|
|
|
|
#include "math.h"
|
|
#include "math_private.h"
|
|
|
|
extern int signgam;
|
|
|
|
#ifdef __STDC__
|
|
double lgamma(double x)
|
|
#else
|
|
double lgamma(x)
|
|
double x;
|
|
#endif
|
|
{
|
|
#ifdef _IEEE_LIBM
|
|
return __ieee754_lgamma_r(x,&signgam);
|
|
#else
|
|
double y;
|
|
y = __ieee754_lgamma_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,15); /* lgamma pole */
|
|
else
|
|
return __kernel_standard(x,x,14); /* lgamma overflow */
|
|
} else
|
|
return y;
|
|
#endif
|
|
}
|