1/* origin: FreeBSD /usr/src/lib/msun/src/e_scalb.c */
 2/*
 3 * ====================================================
 4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 5 *
 6 * Developed at SunSoft, a Sun Microsystems, Inc. business.
 7 * Permission to use, copy, modify, and distribute this
 8 * software is freely granted, provided that this notice
 9 * is preserved.
10 * ====================================================
11 */
12/*
13 * scalb(x, fn) is provide for
14 * passing various standard test suite. One
15 * should use scalbn() instead.
16 */
17
18#define _GNU_SOURCE
19#include <math.h>
20
21double scalb(double x, double fn)
22{
23	if (isnan(x) || isnan(fn))
24		return x*fn;
25	if (!isfinite(fn)) {
26		if (fn > 0.0)
27			return x*fn;
28		else
29			return x/(-fn);
30	}
31	if (rint(fn) != fn) return (fn-fn)/(fn-fn);
32	if ( fn > 65000.0) return scalbn(x, 65000);
33	if (-fn > 65000.0) return scalbn(x,-65000);
34	return scalbn(x,(int)fn);
35}