source: trunk/sys/libm/e_scalb.c @ 365

Last change on this file since 365 was 1, checked in by alain, 7 years ago

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1
2/* @(#)e_scalb.c 5.1 93/09/24 */
3/*
4 * ====================================================
5 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6 *
7 * Developed at SunPro, a Sun Microsystems, Inc. business.
8 * Permission to use, copy, modify, and distribute this
9 * software is freely granted, provided that this notice
10 * is preserved.
11 * ====================================================
12 */
13
14/*
15 * __ieee754_scalb(x, fn) is provide for
16 * passing various standard test suite. One
17 * should use scalbn() instead.
18 */
19
20#include <libm/fdlibm.h>
21
22#ifdef _SCALB_INT
23#ifdef __STDC__
24        double __ieee754_scalb(double x, int fn)
25#else
26        double __ieee754_scalb(x,fn)
27        double x; int fn;
28#endif
29#else
30#ifdef __STDC__
31        double __ieee754_scalb(double x, double fn)
32#else
33        double __ieee754_scalb(x,fn)
34        double x, fn;
35#endif
36#endif
37{
38#ifdef _SCALB_INT
39        return scalbn(x,fn);
40#else
41        if (isnan(x)||isnan(fn)) return x*fn;
42        if (!finite(fn)) {
43            if(fn>0.0) return x*fn;
44            else       return x/(-fn);
45        }
46        if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
47        if ( fn > 65000.0) return scalbn(x, 65000);
48        if (-fn > 65000.0) return scalbn(x,-65000);
49        return scalbn(x,(int)fn);
50#endif
51}
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