blob: 212a5ee9348fb8b047106b9a5d5c9dfcfa8a297a (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
/* @(#)s_isnan.c 5.1 93/09/24 */
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#ifndef lint
static char rcsid[] = "$Id$";
#endif
/*
* isnan(x) returns 1 is x is nan, else 0;
* no branching!
*/
#include "math.h"
#include "math_private.h"
#ifdef __STDC__
int isnan(double x)
#else
int isnan(x)
double x;
#endif
{
int32_t hx,lx;
EXTRACT_WORDS(hx,lx,x);
hx &= 0x7fffffff;
hx |= (u_int32_t)(lx|(-lx))>>31;
hx = 0x7ff00000 - hx;
return (int)((u_int32_t)(hx))>>31;
}
|
