50 lines
1.2 KiB
C
50 lines
1.2 KiB
C
/* @(#)e_scalb.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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#include <sys/cdefs.h>
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#if defined(LIBM_SCCS) && !defined(lint)
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__RCSID("$NetBSD: e_scalb.c,v 1.10 2010/04/23 19:17:07 drochner Exp $");
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#endif
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/*
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* __ieee754_scalb(x, fn) is provide for
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* passing various standard test suite. One
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* should use scalbn() instead.
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*/
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#include "namespace.h"
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#include "math.h"
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#include "math_private.h"
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#ifdef _SCALB_INT
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double
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__ieee754_scalb(double x, int fn)
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#else
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double
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__ieee754_scalb(double x, double fn)
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#endif
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{
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#ifdef _SCALB_INT
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return scalbn(x,fn);
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#else
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if (isnan(x)||isnan(fn)) return x*fn;
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if (!finite(fn)) {
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if(fn>0.0) return x*fn;
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else return x/(-fn);
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}
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if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
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if ( fn > 65000.0) return scalbn(x, 65000);
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if (-fn > 65000.0) return scalbn(x,-65000);
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return scalbn(x,(int)fn);
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#endif
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}
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