blob: eeee1e744e5be3bcca4d90658430950666f4c9b9 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
|
/* @(#)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[] = "$FreeBSD$";
#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;
double
gamma(double x)
{
#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
}
|
