xref: /freebsd/lib/libc/gen/fpclassify.c (revision ae477ca7da55f76d28859e1bd01cd1051e36f28f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
30 #include <sys/endian.h>
31 
32 #include <machine/float.h>
33 
34 #include <math.h>
35 #include <stdint.h>
36 
37 #include "fpmath.h"
38 
39 int
40 __fpclassifyf(float f)
41 {
42 	union IEEEf2bits u;
43 
44 	u.f = f;
45 	if (u.bits.exp == 0) {
46 		if (u.bits.man == 0)
47 			return (FP_ZERO);
48 		return (FP_SUBNORMAL);
49 	}
50 	if (u.bits.exp == 255) {
51 		if (u.bits.man == 0)
52 			return (FP_INFINITE);
53 		return (FP_NAN);
54 	}
55 	return (FP_NORMAL);
56 }
57 
58 int
59 __fpclassifyd(double d)
60 {
61 	union IEEEd2bits u;
62 
63 	u.d = d;
64 	if (u.bits.exp == 0) {
65 		if ((u.bits.manl | u.bits.manh) == 0)
66 			return (FP_ZERO);
67 		return (FP_SUBNORMAL);
68 	}
69 	if (u.bits.exp == 2047) {
70 		if ((u.bits.manl | u.bits.manh) == 0)
71 			return (FP_INFINITE);
72 		return (FP_NAN);
73 	}
74 	return (FP_NORMAL);
75 }
76 
77 int
78 __fpclassifyl(long double e)
79 {
80 	union IEEEl2bits u;
81 
82 	u.e = e;
83 	if (u.bits.exp == 0) {
84 		if ((u.bits.manl | u.bits.manh) == 0)
85 			return (FP_ZERO);
86 		return (FP_SUBNORMAL);
87 	}
88 	mask_nbit_l(u);		/* Mask normalization bit if applicable. */
89 #if LDBL_MANT_DIG == 53
90 	if (u.bits.exp == 2047) {
91 		if ((u.bits.manl | u.bits.manh) == 0)
92 			return (FP_INFINITE);
93 		return (FP_NAN);
94 	}
95 #else
96 	if (u.bits.exp == 32767) {
97 		if ((u.bits.manl | u.bits.manh) == 0)
98 			return (FP_INFINITE);
99 		return (FP_NAN);
100 	}
101 #endif
102 	return (FP_NORMAL);
103 }
104