xref: /openbsd-src/lib/libc/gen/fpclassify.c (revision ac9b4aacc1da35008afea06a5d23c2f2dea9b93e)
1 /*	$OpenBSD: fpclassify.c,v 1.5 2011/05/30 17:28:15 martynas Exp $	*/
2 /*
3  * Copyright (c) 2008 Martynas Venckus <martynas@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 /* LINTLIBRARY */
19 
20 #include <sys/types.h>
21 #include <sys/cdefs.h>
22 #include <machine/ieee.h>
23 #include <float.h>
24 #include <math.h>
25 
26 int
27 __fpclassify(double d)
28 {
29 	struct ieee_double *p = (struct ieee_double *)&d;
30 
31 	if (p->dbl_exp == 0) {
32 		if (p->dbl_frach == 0 && p->dbl_fracl == 0)
33 			return FP_ZERO;
34 		else
35 			return FP_SUBNORMAL;
36 	}
37 
38 	if (p->dbl_exp == DBL_EXP_INFNAN) {
39 		if (p->dbl_frach == 0 && p->dbl_fracl == 0)
40 			return FP_INFINITE;
41 		else
42 			return FP_NAN;
43 	}
44 
45 	return FP_NORMAL;
46 }
47 
48 int
49 __fpclassifyf(float f)
50 {
51 	struct ieee_single *p = (struct ieee_single *)&f;
52 
53 	if (p->sng_exp == 0) {
54 		if (p->sng_frac == 0)
55 			return FP_ZERO;
56 		else
57 			return FP_SUBNORMAL;
58 	}
59 
60 	if (p->sng_exp == SNG_EXP_INFNAN) {
61 		if (p->sng_frac == 0)
62 			return FP_INFINITE;
63 		else
64 			return FP_NAN;
65 	}
66 
67 	return FP_NORMAL;
68 }
69 
70 #if	LDBL_MANT_DIG == 53
71 #ifdef	lint
72 /* PROTOLIB1 */
73 int __fpclassifyl(long double);
74 #else	/* lint */
75 __weak_alias(__fpclassifyl, __fpclassify);
76 #endif	/* lint */
77 #endif	/* LDBL_MANT_DIG == 53 */
78