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 #include <sys/cdefs.h>
14 #if defined(LIBM_SCCS) && !defined(lint)
15 __RCSID("$NetBSD: s_isnan.c,v 1.11 2002/05/26 22:01:56 wiz Exp $");
16 #endif
17
18 /*
19 * isnan(x) returns 1 is x is nan, else 0;
20 * no branching!
21 */
22
23 #include "math.h"
24 #include "math_private.h"
25
26 int
isnan(double x)27 isnan(double x)
28 {
29 int32_t hx,lx;
30 EXTRACT_WORDS(hx,lx,x);
31 hx &= 0x7fffffff;
32 hx |= (u_int32_t)(lx|(-lx))>>31;
33 hx = 0x7ff00000 - hx;
34 return (int)((u_int32_t)(hx))>>31;
35 }
36