1/* @(#)s_isnan.c 5.1 93/09/24 */
2/*
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5 *
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
9 * is preserved.
10 * ====================================================
11 */
12
13#if defined(LIBM_SCCS) && !defined(lint)
14static char rcsid[] = "$NetBSD: s_isnan.c,v 1.8 1995/05/10 20:47:36 jtc Exp $";
15#endif
16
17/*
18 * isnan(x) returns 1 is x is nan, else 0;
19 * no branching!
20 */
21
22#include "math.h"
23#include "math_private.h"
24
25#ifdef __STDC__
26	int __isnan(double x)
27#else
28	int __isnan(x)
29	double x;
30#endif
31{
32	int32_t hx,lx;
33	EXTRACT_WORDS(hx,lx,x);
34	hx &= 0x7fffffff;
35	hx |= (u_int32_t)(lx|(-lx))>>31;
36	hx = 0x7ff00000 - hx;
37	return (int)(((u_int32_t)hx)>>31);
38}
39hidden_def (__isnan)
40weak_alias (__isnan, isnan)
41#ifdef NO_LONG_DOUBLE
42strong_alias (__isnan, __isnanl)
43weak_alias (__isnan, isnanl)
44#endif
45