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
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
/* wf_gamma.c -- float version of w_gamma.c.
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
*/
/*
* ====================================================
* 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.
* ====================================================
*
*/
#include "fdlibm.h"
#include <reent.h>
#include <errno.h>
#ifdef __STDC__
float gammaf(float x)
#else
float gammaf(x)
float x;
#endif
{
#ifdef _IEEE_LIBM
return __ieee754_gammaf_r(x,&(_REENT_SIGNGAM(_REENT)));
#else
float y;
struct exception exc;
y = __ieee754_gammaf_r(x,&(_REENT_SIGNGAM(_REENT)));
if(_LIB_VERSION == _IEEE_) return y;
if(!finitef(y)&&finitef(x)) {
#ifndef HUGE_VAL
#define HUGE_VAL inf
double inf = 0.0;
SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */
#endif
if(floorf(x)==x&&x<=(float)0.0) {
/* gammaf(-integer) or gammaf(0) */
exc.type = SING;
exc.name = "gammaf";
exc.err = 0;
exc.arg1 = exc.arg2 = (double)x;
if (_LIB_VERSION == _SVID_)
exc.retval = HUGE;
else
exc.retval = HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = EDOM;
else if (!matherr(&exc)) {
errno = EDOM;
}
} else {
/* gammaf(finite) overflow */
exc.type = OVERFLOW;
exc.name = "gammaf";
exc.err = 0;
exc.arg1 = exc.arg2 = (double)x;
if (_LIB_VERSION == _SVID_)
exc.retval = HUGE;
else
exc.retval = HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
}
if (exc.err != 0)
errno = exc.err;
return (float)exc.retval;
} else
return y;
#endif
}
#ifdef _DOUBLE_IS_32BITS
#ifdef __STDC__
double gamma(double x)
#else
double gamma(x)
double x;
#endif
{
return (double) gammaf((float) x);
}
#endif /* defined(_DOUBLE_IS_32BITS) */
|
