1/*
2 * Written by J.T. Conklin <jtc@netbsd.org>.
3 * Changed to return -1 for -Inf by Ulrich Drepper <drepper@cygnus.com>.
4 * Public domain.
5 */
6
7#if defined(LIBM_SCCS) && !defined(lint)
8static char rcsid[] = "$NetBSD: s_isinf.c,v 1.3 1995/05/11 23:20:14 jtc Exp $";
9#endif
10
11/*
12 * isinf(x) returns 1 is x is inf, -1 if x is -inf, else 0;
13 * no branching!
14 */
15
16#include "math.h"
17#include "math_private.h"
18
19int
20__isinf (double x)
21{
22	int32_t hx,lx;
23	EXTRACT_WORDS(hx,lx,x);
24	lx |= (hx & 0x7fffffff) ^ 0x7ff00000;
25	lx |= -lx;
26	return ~(lx >> 31) & (hx >> 30);
27}
28hidden_def (__isinf)
29weak_alias (__isinf, isinf)
30#ifdef NO_LONG_DOUBLE
31strong_alias (__isinf, __isinfl)
32weak_alias (__isinf, isinfl)
33#endif
34