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 0 /* vstr */
8 #if defined(LIBM_SCCS) && !defined(lint)
9 static char rcsid[] = "$NetBSD: s_isinf.c,v 1.3 1995/05/11 23:20:14 jtc Exp $";
10 #endif
11 
12 /*
13  * isinf(x) returns 1 is x is inf, -1 if x is -inf, else 0;
14  * no branching!
15  */
16 
17 #include "math.h"
18 #include "math_private.h"
19 
20 #endif /* vstr */
21 static
22 int
__isinf(double x)23 __isinf (double x)
24 {
25 	int32_t hx,lx;
26 	EXTRACT_WORDS(hx,lx,x);
27 	lx |= (hx & 0x7fffffff) ^ 0x7ff00000;
28 	lx |= -lx;
29 	return ~(lx >> 31) & (hx >> 30);
30 }
31 #if 0 /* vstr */
32 hidden_def (__isinf)
33 weak_alias (__isinf, isinf)
34 #ifdef NO_LONG_DOUBLE
35 strong_alias (__isinf, __isinfl)
36 weak_alias (__isinf, isinfl)
37 #endif
38 #endif /* vstr */
39