36 lines
925 B
C
36 lines
925 B
C
/* origin: FreeBSD /usr/src/lib/msun/src/e_scalb.c */
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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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* 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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#define _GNU_SOURCE
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#include "libc/math/math.h"
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double scalb(double x, double fn)
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{
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if (isnan(x) || isnan(fn))
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return x*fn;
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if (!isfinite(fn)) {
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if (fn > 0.0)
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return x*fn;
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else
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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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}
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