0,0 → 1,50 |
/* 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 |
} |