1 /* @(#)s_finite.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 #ifndef lint 14 static char rcsid[] = "$Id: s_finite.c,v 1.4 1994/03/03 17:04:34 jtc Exp $"; 15 #endif 16 17 /* 18 * finite(x) returns 1 is x is finite, else 0; 19 * no branching! 20 */ 21 22 #include <math.h> 23 #include <machine/endian.h> 24 25 #if BYTE_ORDER == LITTLE_ENDIAN 26 #define n0 1 27 #else 28 #define n0 0 29 #endif 30 31 #ifdef __STDC__ 32 int finite(double x) 33 #else 34 int finite(x) 35 double x; 36 #endif 37 { 38 int hx; 39 hx = *(n0+(int*)&x); 40 return (unsigned)((hx&0x7fffffff)-0x7ff00000)>>31; 41 } 42