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