1/*	$NetBSD: isinfl.c,v 1.4 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
41static char sccsid[] = "@(#)isinf.c	8.1 (Berkeley) 6/4/93";
42#else
43__RCSID("$NetBSD: isinfl.c,v 1.4 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/*
51 * 7.12.3.3 isinf - test for infinity
52 *          IEEE 754 compatible 128-bit extended-precision version
53 */
54int
55__isinfl(long double x)
56{
57	union ieee_ext_u u;
58
59	u.extu_ld = x;
60
61	return (u.extu_ext.ext_exp == EXT_EXP_INFNAN &&
62	    (u.extu_ext.ext_frach  == 0 && u.extu_ext.ext_fracl  == 0));
63}
64