xref: /freebsd/lib/libc/gen/isinf.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <machine/float.h>
30 
31 #include <math.h>
32 
33 #include "fpmath.h"
34 
35 /*
36  * XXX These routines belong in libm, but they must remain in libc for
37  *     binary compat until we can bump libm's major version number.
38  */
39 
40 __weak_reference(__isinf, isinf);
41 
42 int
43 __isinf(double d)
44 {
45 	union IEEEd2bits u;
46 
47 	u.d = d;
48 	return (u.bits.exp == 2047 && u.bits.manl == 0 && u.bits.manh == 0);
49 }
50 
51 int
52 __isinff(float f)
53 {
54 	union IEEEf2bits u;
55 
56 	u.f = f;
57 	return (u.bits.exp == 255 && u.bits.man == 0);
58 }
59 
60 int
61 __isinfl(long double e)
62 {
63 	union IEEEl2bits u;
64 
65 	u.e = e;
66 	mask_nbit_l(u);
67 #if LDBL_MANT_DIG == 53
68 	return (u.bits.exp == 2047 && u.bits.manl == 0 && u.bits.manh == 0);
69 #else
70 	return (u.bits.exp == 32767 && u.bits.manl == 0 && u.bits.manh == 0);
71 #endif
72 }
73