1 /* $NetBSD: isinfd_ieee754.c,v 1.1 2004/03/04 23:42:39 kleink Exp $ */
2
3 /*
4 * Copyright (c) 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This software was developed by the Computer Systems Engineering group
8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9 * contributed to Berkeley.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * from: Header: isinf.c,v 1.1 91/07/08 19:03:34 torek Exp
36 */
37
38 #include <sys/cdefs.h>
39 #if defined(LIBC_SCCS) && !defined(lint)
40 #if 0
41 static char sccsid[] = "@(#)isinf.c 8.1 (Berkeley) 6/4/93";
42 #else
43 __RCSID("$NetBSD: isinfd_ieee754.c,v 1.1 2004/03/04 23:42:39 kleink Exp $");
44 #endif
45 #endif /* LIBC_SCCS and not lint */
46
47 #include <machine/ieee.h>
48 #include <math.h>
49
50 /* libc.so.12 ABI compatbility */
51 #ifdef __weak_alias
__weak_alias(isinf,__isinfd)52 __weak_alias(isinf,__isinfd)
53 #endif
54
55 /*
56 * 7.12.3.3 isinf - test for infinity
57 * IEEE 754 double-precision version
58 */
59 int
60 __isinfd(double x)
61 {
62 union ieee_double_u u;
63
64 u.dblu_d = x;
65
66 return (u.dblu_dbl.dbl_exp == DBL_EXP_INFNAN &&
67 (u.dblu_dbl.dbl_frach == 0 && u.dblu_dbl.dbl_fracl == 0));
68 }
69