forsyth20121205-174063a80cc13 years agoHistory
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/* derived from /netlib/fdlibm */ /* @(#)s_isnan.c 1.3 95/01/18 *//* * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. * * Developed at SunSoft, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this * software is freely granted, provided that this notice  * is preserved. * ==================================================== */ /* * isnan(x) returns 1 is x is nan, else 0; * no branching! */ #include "fdlibm.h" 	int isnan(double x){	int hx,lx;	hx = (__HI(x)&0x7fffffff);	lx = __LO(x);	hx |= (unsigned)(lx|(-lx))>>31;		hx = 0x7ff00000 - hx;	return ((unsigned)(hx))>>31;}