xref: /freebsd/lib/libc/gen/fpclassify.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2003 Mike Barcroft <mike@FreeBSD.org>
5  * Copyright (c) 2002, 2003 David Schultz <das@FreeBSD.ORG>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #include <sys/endian.h>
33 
34 #include <machine/float.h>
35 
36 #include <math.h>
37 #include <stdint.h>
38 
39 #include "fpmath.h"
40 
41 int
42 __fpclassifyf(float f)
43 {
44 	union IEEEf2bits u;
45 
46 	u.f = f;
47 	if (u.bits.exp == 0) {
48 		if (u.bits.man == 0)
49 			return (FP_ZERO);
50 		return (FP_SUBNORMAL);
51 	}
52 	if (u.bits.exp == 255) {
53 		if (u.bits.man == 0)
54 			return (FP_INFINITE);
55 		return (FP_NAN);
56 	}
57 	return (FP_NORMAL);
58 }
59 
60 int
61 __fpclassifyd(double d)
62 {
63 	union IEEEd2bits u;
64 
65 	u.d = d;
66 	if (u.bits.exp == 0) {
67 		if ((u.bits.manl | u.bits.manh) == 0)
68 			return (FP_ZERO);
69 		return (FP_SUBNORMAL);
70 	}
71 	if (u.bits.exp == 2047) {
72 		if ((u.bits.manl | u.bits.manh) == 0)
73 			return (FP_INFINITE);
74 		return (FP_NAN);
75 	}
76 	return (FP_NORMAL);
77 }
78 
79 int
80 __fpclassifyl(long double e)
81 {
82 	union IEEEl2bits u;
83 
84 	u.e = e;
85 	if (u.bits.exp == 0) {
86 		if ((u.bits.manl | u.bits.manh) == 0)
87 			return (FP_ZERO);
88 		return (FP_SUBNORMAL);
89 	}
90 	mask_nbit_l(u);		/* Mask normalization bit if applicable. */
91 #if LDBL_MANT_DIG == 53
92 	if (u.bits.exp == 2047) {
93 		if ((u.bits.manl | u.bits.manh) == 0)
94 			return (FP_INFINITE);
95 		return (FP_NAN);
96 	}
97 #else
98 	if (u.bits.exp == 32767) {
99 		if ((u.bits.manl | u.bits.manh) == 0)
100 			return (FP_INFINITE);
101 		return (FP_NAN);
102 	}
103 #endif
104 	return (FP_NORMAL);
105 }
106