mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-24 18:23:41 +08:00
61 lines
1.6 KiB
C
61 lines
1.6 KiB
C
/* @(#)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[] = "$NetBSD: w_lgamma.c,v 1.6 1995/05/10 20:49:24 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"
|
|
|
|
#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;
|
|
int local_signgam = 0;
|
|
y = __ieee754_lgamma_r(x,&local_signgam);
|
|
if (_LIB_VERSION != _ISOC_)
|
|
/* ISO C99 does not define the global variable. */
|
|
signgam = local_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
|
|
}
|
|
weak_alias (__lgamma, lgamma)
|
|
strong_alias (__lgamma, __gamma)
|
|
weak_alias (__gamma, gamma)
|
|
#ifdef NO_LONG_DOUBLE
|
|
strong_alias (__lgamma, __lgammal)
|
|
weak_alias (__lgamma, lgammal)
|
|
strong_alias (__gamma, __gammal)
|
|
weak_alias (__gamma, gammal)
|
|
#endif
|