43 lines
979 B
C
43 lines
979 B
C
/* @(#)s_copysign.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[] = "$Id: s_copysign.c,v 1.4 1994/03/03 17:04:30 jtc Exp $";
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#endif
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/*
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* copysign(double x, double y)
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* copysign(x,y) returns a value with the magnitude of x and
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* with the sign bit of y.
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*/
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#include <math.h>
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#include <machine/endian.h>
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#if BYTE_ORDER == LITTLE_ENDIAN
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#define n0 1
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#else
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#define n0 0
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#endif
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#ifdef __STDC__
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double copysign(double x, double y)
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#else
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double copysign(x,y)
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double x,y;
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#endif
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{
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*(n0+(unsigned*)&x) =
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(*(n0+(unsigned*)&x)&0x7fffffff)|(*(n0+(unsigned*)&y)&0x80000000);
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return x;
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}
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