This patch improves strncat performance by using strlen. Strlen has a fast C implemen...
[glibc.git] / sysdeps / ieee754 / dbl-64 / s_isnan.c
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)
14 static 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 #undef __isnan
26 int
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 hidden_def (__isnan)
37 weak_alias (__isnan, isnan)
38 #ifdef NO_LONG_DOUBLE
39 strong_alias (__isnan, __isnanl)
40 weak_alias (__isnan, isnanl)
41 #endif