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) 8 static 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 19 int 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 } 28 hidden_def (__isinf) 29 weak_alias (__isinf, isinf) 30 #ifdef NO_LONG_DOUBLE 31 strong_alias (__isinf, __isinfl) 32 weak_alias (__isinf, isinfl) 33 #endif 34