isnan.c revision 1.5 
1/*	$OpenBSD: isnan.c,v 1.5 2011/05/30 17:28:15 martynas Exp $	*/
2/*
3 * Copyright (c) 2008 Martynas Venckus <martynas@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/* LINTLIBRARY */
19
20#include <sys/types.h>
21#include <sys/cdefs.h>
22#include <machine/ieee.h>
23#include <float.h>
24
25int
26__isnan(double d)
27{
28	struct ieee_double *p = (struct ieee_double *)&d;
29
30	return (p->dbl_exp == DBL_EXP_INFNAN &&
31	    (p->dbl_frach != 0 || p->dbl_fracl != 0));
32}
33
34int
35__isnanf(float f)
36{
37	struct ieee_single *p = (struct ieee_single *)&f;
38
39	return (p->sng_exp == SNG_EXP_INFNAN && p->sng_frac != 0);
40}
41
42#if	LDBL_MANT_DIG == 53
43#ifdef	lint
44/* PROTOLIB1 */
45int __isnanl(long double);
46#else	/* lint */
47__weak_alias(__isnanl, __isnan);
48#endif	/* lint */
49#endif	/* LDBL_MANT_DIG == 53 */
50
51/*
52 * 3BSD compatibility aliases.
53 */
54__weak_alias(isnan, __isnan);
55__weak_alias(isnanf, __isnanf);
56