1 /* @(#)s_isnan.c 5.1 93/09/24 */ 2 /* 3 * ==================================================== 4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. 5 * 6 * Developed at SunPro, a Sun Microsystems, Inc. business. 7 * Permission to use, copy, modify, and distribute this 8 * software is freely granted, provided that this notice 9 * is preserved. 10 * ==================================================== 11 */ 12 13 #include <sys/cdefs.h> 14 #if defined(LIBM_SCCS) && !defined(lint) 15 __RCSID("$NetBSD: s_isnan.c,v 1.9 1997/10/09 11:32:25 lukem Exp $"); 16 #endif 17 18 /* 19 * isnan(x) returns 1 is x is nan, else 0; 20 * no branching! 21 */ 22 23 #include "math.h" 24 #include "math_private.h" 25 26 #ifdef __STDC__ 27 int isnan(double x) 28 #else 29 int isnan(x) 30 double x; 31 #endif 32 { 33 int32_t hx,lx; 34 EXTRACT_WORDS(hx,lx,x); 35 hx &= 0x7fffffff; 36 hx |= (u_int32_t)(lx|(-lx))>>31; 37 hx = 0x7ff00000 - hx; 38 return (int)((u_int32_t)(hx))>>31; 39 } 40