1 /* wf_gamma.c -- float version of w_gamma.c.
2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3  */
4 
5 /*
6  * ====================================================
7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8  *
9  * Developed at SunPro, a Sun Microsystems, Inc. business.
10  * Permission to use, copy, modify, and distribute this
11  * software is freely granted, provided that this notice
12  * is preserved.
13  * ====================================================
14  *
15  */
16 
17 #include "fdlibm.h"
18 #include <reent.h>
19 #include <errno.h>
20 
21 #ifdef __STDC__
gammaf(float x)22 	float gammaf(float x)
23 #else
24 	float gammaf(x)
25 	float x;
26 #endif
27 {
28 #ifdef _IEEE_LIBM
29 	return __ieee754_gammaf_r(x,&(_REENT_SIGNGAM(_REENT)));
30 #else
31         float y;
32 	struct exception exc;
33         y = __ieee754_gammaf_r(x,&(_REENT_SIGNGAM(_REENT)));
34         if(_LIB_VERSION == _IEEE_) return y;
35         if(!finitef(y)&&finitef(x)) {
36 #ifndef HUGE_VAL
37 #define HUGE_VAL inf
38 	    double inf = 0.0;
39 
40 	    SET_HIGH_WORD(inf,0x7ff00000);	/* set inf to infinite */
41 #endif
42 	    if(floorf(x)==x&&x<=(float)0.0) {
43 		/* gammaf(-integer) or gammaf(0) */
44 		exc.type = SING;
45 		exc.name = "gammaf";
46 		exc.err = 0;
47 		exc.arg1 = exc.arg2 = (double)x;
48                 if (_LIB_VERSION == _SVID_)
49                   exc.retval = HUGE;
50                 else
51                   exc.retval = HUGE_VAL;
52 		if (_LIB_VERSION == _POSIX_)
53 		  errno = EDOM;
54 		else if (!matherr(&exc)) {
55 		  errno = EDOM;
56 		}
57             } else {
58 		/* gammaf(finite) overflow */
59 		exc.type = OVERFLOW;
60 		exc.name = "gammaf";
61 		exc.err = 0;
62 		exc.arg1 = exc.arg2 = (double)x;
63                 if (_LIB_VERSION == _SVID_)
64                   exc.retval = HUGE;
65                 else
66                   exc.retval = HUGE_VAL;
67                 if (_LIB_VERSION == _POSIX_)
68 		  errno = ERANGE;
69                 else if (!matherr(&exc)) {
70                   errno = ERANGE;
71                 }
72             }
73 	    if (exc.err != 0)
74 	       errno = exc.err;
75 	    return (float)exc.retval;
76         } else
77             return y;
78 #endif
79 }
80 
81 #ifdef _DOUBLE_IS_32BITS
82 
83 #ifdef __STDC__
gamma(double x)84 	double gamma(double x)
85 #else
86 	double gamma(x)
87 	double x;
88 #endif
89 {
90 	return (double) gammaf((float) x);
91 }
92 
93 #endif /* defined(_DOUBLE_IS_32BITS) */
94