xref: /openbsd-src/lib/libc/gen/fpclassify.c (revision 850e275390052b330d93020bf619a739a3c277ac)
1 /*	$OpenBSD: fpclassify.c,v 1.2 2008/09/07 20:36:08 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 #include <sys/types.h>
19 #include <machine/ieee.h>
20 #include <math.h>
21 
22 int
23 __fpclassify(double d)
24 {
25 	struct ieee_double *p = (struct ieee_double *)&d;
26 
27 	if (p->dbl_exp == 0) {
28 		if (p->dbl_frach == 0 && p->dbl_fracl == 0)
29 			return FP_ZERO;
30 		else
31 			return FP_SUBNORMAL;
32 	}
33 
34 	if (p->dbl_exp == DBL_EXP_INFNAN) {
35 		if (p->dbl_frach == 0 && p->dbl_fracl == 0)
36 			return FP_INFINITE;
37 		else
38 			return FP_NAN;
39 	}
40 
41 	return FP_NORMAL;
42 }
43 
44 int
45 __fpclassifyf(float f)
46 {
47 	struct ieee_single *p = (struct ieee_single *)&f;
48 
49 	if (p->sng_exp == 0) {
50 		if (p->sng_frac == 0)
51 			return FP_ZERO;
52 		else
53 			return FP_SUBNORMAL;
54 	}
55 
56 	if (p->sng_exp == SNG_EXP_INFNAN) {
57 		if (p->sng_frac == 0)
58 			return FP_INFINITE;
59 		else
60 			return FP_NAN;
61 	}
62 
63 	return FP_NORMAL;
64 }
65