xref: /freebsd/lib/libc/gen/isinf.c (revision 43a5ec4eb41567cc92586503212743d89686d78f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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  * $FreeBSD$
29  */
30 
31 #include <machine/float.h>
32 
33 #include <math.h>
34 
35 #include "fpmath.h"
36 
37 /*
38  * XXX These routines belong in libm, but they must remain in libc for
39  *     binary compat until we can bump libm's major version number.
40  */
41 
42 __weak_reference(__isinf, isinf);
43 
44 int
45 __isinf(double d)
46 {
47 	union IEEEd2bits u;
48 
49 	u.d = d;
50 	return (u.bits.exp == 2047 && u.bits.manl == 0 && u.bits.manh == 0);
51 }
52 
53 int
54 __isinff(float f)
55 {
56 	union IEEEf2bits u;
57 
58 	u.f = f;
59 	return (u.bits.exp == 255 && u.bits.man == 0);
60 }
61 
62 int
63 __isinfl(long double e)
64 {
65 	union IEEEl2bits u;
66 
67 	u.e = e;
68 	mask_nbit_l(u);
69 #if LDBL_MANT_DIG == 53
70 	return (u.bits.exp == 2047 && u.bits.manl == 0 && u.bits.manh == 0);
71 #else
72 	return (u.bits.exp == 32767 && u.bits.manl == 0 && u.bits.manh == 0);
73 #endif
74 }
75