xref: /minix/lib/libm/src/s_isinf.c (revision 0a6a1f1d)
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 1.6 2003/07/26 19:25:05 salo 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 int
20 isinf(double x)
21 {
22 	int32_t hx,lx;
23 	EXTRACT_WORDS(hx,lx,x);
24 	hx &= 0x7fffffff;
25 	hx ^= 0x7ff00000;
26 	hx |= lx;
27 	return (hx == 0);
28 }
29