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 /* For binary compat; to be removed in FreeBSD 6.0. */ 14 15 #ifndef lint 16 static char rcsid[] = "$FreeBSD$"; 17 #endif 18 19 /* 20 * isnan(x) returns 1 is x is nan, else 0; 21 * no branching! 22 */ 23 24 #include "math.h" 25 #include "math_private.h" 26 27 #undef isnan 28 29 int isnan(double x) 30 { 31 int32_t hx,lx; 32 EXTRACT_WORDS(hx,lx,x); 33 hx &= 0x7fffffff; 34 hx |= (u_int32_t)(lx|(-lx))>>31; 35 hx = 0x7ff00000 - hx; 36 return (int)((u_int32_t)(hx))>>31; 37 } 38