1*2fe8fb19SBen Gras /* @(#)s_isnan.c 5.1 93/09/24 */
2*2fe8fb19SBen Gras /*
3*2fe8fb19SBen Gras * ====================================================
4*2fe8fb19SBen Gras * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5*2fe8fb19SBen Gras *
6*2fe8fb19SBen Gras * Developed at SunPro, a Sun Microsystems, Inc. business.
7*2fe8fb19SBen Gras * Permission to use, copy, modify, and distribute this
8*2fe8fb19SBen Gras * software is freely granted, provided that this notice
9*2fe8fb19SBen Gras * is preserved.
10*2fe8fb19SBen Gras * ====================================================
11*2fe8fb19SBen Gras */
12*2fe8fb19SBen Gras
13*2fe8fb19SBen Gras #include <sys/cdefs.h>
14*2fe8fb19SBen Gras #if defined(LIBM_SCCS) && !defined(lint)
15*2fe8fb19SBen Gras __RCSID("$NetBSD: s_isnan.c,v 1.11 2002/05/26 22:01:56 wiz Exp $");
16*2fe8fb19SBen Gras #endif
17*2fe8fb19SBen Gras
18*2fe8fb19SBen Gras /*
19*2fe8fb19SBen Gras * isnan(x) returns 1 is x is nan, else 0;
20*2fe8fb19SBen Gras * no branching!
21*2fe8fb19SBen Gras */
22*2fe8fb19SBen Gras
23*2fe8fb19SBen Gras #include "math.h"
24*2fe8fb19SBen Gras #include "math_private.h"
25*2fe8fb19SBen Gras
26*2fe8fb19SBen Gras int
isnan(double x)27*2fe8fb19SBen Gras isnan(double x)
28*2fe8fb19SBen Gras {
29*2fe8fb19SBen Gras int32_t hx,lx;
30*2fe8fb19SBen Gras EXTRACT_WORDS(hx,lx,x);
31*2fe8fb19SBen Gras hx &= 0x7fffffff;
32*2fe8fb19SBen Gras hx |= (u_int32_t)(lx|(-lx))>>31;
33*2fe8fb19SBen Gras hx = 0x7ff00000 - hx;
34*2fe8fb19SBen Gras return (int)((u_int32_t)(hx))>>31;
35*2fe8fb19SBen Gras }
36