Update.
[glibc.git] / sysdeps / libm-ieee754 / s_isinf.c
blob4f063d09c599d273fbd9968417e195475e5377ab
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 */
7 #if defined(LIBM_SCCS) && !defined(lint)
8 static char rcsid[] = "$NetBSD: s_isinf.c,v 1.3 1995/05/11 23:20:14 jtc Exp $";
9 #endif
12 * isinf(x) returns 1 is x is inf, -1 if x is -inf, else 0;
13 * no branching!
16 #include "math.h"
17 #include "math_private.h"
19 int
20 __isinf (double x)
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);
28 weak_alias (__isinf, isinf)
29 #ifdef NO_LONG_DOUBLE
30 strong_alias (__isinf, __isinfl)
31 weak_alias (__isinf, isinfl)
32 #endif