xref: /openbsd-src/lib/libc/gen/fpclassify.c (revision 91f110e064cd7c194e59e019b83bb7496c1c84d4)
1 /*	$OpenBSD: fpclassify.c,v 1.8 2013/07/03 04:46:36 espie 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 <float.h>
21 #include <math.h>
22 
23 int
24 __fpclassify(double d)
25 {
26 	struct ieee_double *p = (struct ieee_double *)&d;
27 
28 	if (p->dbl_exp == 0) {
29 		if (p->dbl_frach == 0 && p->dbl_fracl == 0)
30 			return FP_ZERO;
31 		else
32 			return FP_SUBNORMAL;
33 	}
34 
35 	if (p->dbl_exp == DBL_EXP_INFNAN) {
36 		if (p->dbl_frach == 0 && p->dbl_fracl == 0)
37 			return FP_INFINITE;
38 		else
39 			return FP_NAN;
40 	}
41 
42 	return FP_NORMAL;
43 }
44 
45 int
46 __fpclassifyf(float f)
47 {
48 	struct ieee_single *p = (struct ieee_single *)&f;
49 
50 	if (p->sng_exp == 0) {
51 		if (p->sng_frac == 0)
52 			return FP_ZERO;
53 		else
54 			return FP_SUBNORMAL;
55 	}
56 
57 	if (p->sng_exp == SNG_EXP_INFNAN) {
58 		if (p->sng_frac == 0)
59 			return FP_INFINITE;
60 		else
61 			return FP_NAN;
62 	}
63 
64 	return FP_NORMAL;
65 }
66 
67 #if	LDBL_MANT_DIG == DBL_MANT_DIG
68 __strong_alias(__fpclassifyl, __fpclassify);
69 #endif	/* LDBL_MANT_DIG == DBL_MANT_DIG */
70