1/* @(#)w_lgamma.c 5.1 93/09/24 */
2/*
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5 *
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
9 * is preserved.
10 * ====================================================
11 */
12
13#include <sys/cdefs.h>
14#if defined(LIBM_SCCS) && !defined(lint)
15__RCSID("$NetBSD: w_lgamma.c,v 1.9 2001/01/06 00:15:00 christos Exp $");
16#endif
17
18/* double lgamma(double x)
19 * Return the logarithm of the Gamma function of x.
20 *
21 * Method: call __ieee754_lgamma_r
22 */
23
24#include "math.h"
25#include "math_private.h"
26
27double
28lgamma(double x)
29{
30#ifdef _IEEE_LIBM
31	return __ieee754_lgamma_r(x,&signgam);
32#else
33        double y;
34        y = __ieee754_lgamma_r(x,&signgam);
35        if(_LIB_VERSION == _IEEE_) return y;
36        if(!finite(y)&&finite(x)) {
37            if(floor(x)==x&&x<=0.0)
38                return __kernel_standard(x,x,15); /* lgamma pole */
39            else
40                return __kernel_standard(x,x,14); /* lgamma overflow */
41        } else
42            return y;
43#endif
44}
45