39 lines
815 B
C
39 lines
815 B
C
/* @(#)s_isnan.c 5.1 93/09/24 */
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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 SunPro, 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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#ifndef lint
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static char rcsid[] = "$FreeBSD$";
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#endif
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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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#include "math_private.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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int32_t hx,lx;
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EXTRACT_WORDS(hx,lx,x);
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hx &= 0x7fffffff;
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hx |= (u_int32_t)(lx|(-lx))>>31;
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hx = 0x7ff00000 - hx;
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return (int)((u_int32_t)(hx))>>31;
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}
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