xref: /freebsd/lib/libc/gen/fpclassify.c (revision 9336e0699bda8a301cd2bfa37106b6ec5e32012e)
1 /*-
2  * Copyright (c) 2003 Mike Barcroft <mike@FreeBSD.org>
3  * Copyright (c) 2002, 2003 David Schultz <das@FreeBSD.ORG>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 #include <sys/endian.h>
31 
32 #include <math.h>
33 #include <stdint.h>
34 
35 #include "fpmath.h"
36 
37 int
38 __fpclassifyf(float f)
39 {
40 	union IEEEf2bits u;
41 
42 	u.f = f;
43 	if (u.bits.exp == 0) {
44 		if (u.bits.man == 0)
45 			return (FP_ZERO);
46 		return (FP_SUBNORMAL);
47 	}
48 	if (u.bits.exp == 255) {
49 		if (u.bits.man == 0)
50 			return (FP_INFINITE);
51 		return (FP_NAN);
52 	}
53 	return (FP_NORMAL);
54 }
55 
56 int
57 __fpclassifyd(double d)
58 {
59 	union IEEEd2bits u;
60 
61 	u.d = d;
62 	if (u.bits.exp == 0) {
63 		if ((u.bits.manl | u.bits.manh) == 0)
64 			return (FP_ZERO);
65 		return (FP_SUBNORMAL);
66 	}
67 	if (u.bits.exp == 2047) {
68 		if ((u.bits.manl | u.bits.manh) == 0)
69 			return (FP_INFINITE);
70 		return (FP_NAN);
71 	}
72 	return (FP_NORMAL);
73 }
74 
75 int
76 __fpclassifyl(long double e)
77 {
78 	union IEEEl2bits u;
79 
80 	u.e = e;
81 	if (u.bits.exp == 0) {
82 		if ((u.bits.manl | u.bits.manh) == 0)
83 			return (FP_ZERO);
84 		return (FP_SUBNORMAL);
85 	}
86 	mask_nbit_l(u);		/* Mask normalization bit if applicable. */
87 	if (u.bits.exp == 32767) {
88 		if ((u.bits.manl | u.bits.manh) == 0)
89 			return (FP_INFINITE);
90 		return (FP_NAN);
91 	}
92 	return (FP_NORMAL);
93 }
94