xref: /netbsd-src/lib/libm/src/s_isinf.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*
2  * Written by J.T. Conklin <jtc@netbsd.org>.
3  * Public domain.
4  */
5 
6 #include <sys/cdefs.h>
7 #if defined(LIBM_SCCS) && !defined(lint)
8 __RCSID("$NetBSD: s_isinf.c,v 1.4 1997/10/09 11:32:19 lukem Exp $");
9 #endif
10 
11 /*
12  * isinf(x) returns 1 is x is inf, else 0;
13  * no branching!
14  */
15 
16 #include "math.h"
17 #include "math_private.h"
18 
19 #ifdef __STDC__
20 	int isinf(double x)
21 #else
22 	int isinf(x)
23 	double x;
24 #endif
25 {
26 	int32_t hx,lx;
27 	EXTRACT_WORDS(hx,lx,x);
28 	hx &= 0x7fffffff;
29 	hx ^= 0x7ff00000;
30 	hx |= lx;
31 	return (hx == 0);
32 }
33