Update.
[glibc.git] / sysdeps / libm-ieee754 / s_isnan.c
blob1aed525af1b9fbb8994c3c02538a278369786ce1
1 /* @(#)s_isnan.c 5.1 93/09/24 */
2 /*
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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 * ====================================================
13 #if defined(LIBM_SCCS) && !defined(lint)
14 static char rcsid[] = "$NetBSD: s_isnan.c,v 1.8 1995/05/10 20:47:36 jtc Exp $";
15 #endif
18 * isnan(x) returns 1 is x is nan, else 0;
19 * no branching!
22 #include "math.h"
23 #include "math_private.h"
25 #ifdef __STDC__
26 int __isnan(double x)
27 #else
28 int __isnan(x)
29 double x;
30 #endif
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;
39 weak_alias (__isnan, isnan)
40 #ifdef NO_LONG_DOUBLE
41 strong_alias (__isnan, __isnanl)
42 weak_alias (__isnan, isnanl)
43 #endif