isinf.c revision 331722 
1/*-
2 * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: stable/11/lib/libc/gen/isinf.c 331722 2018-03-29 02:50:57Z eadler $
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
42int
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
51int
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
60int
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