1
2/* @(#)e_scalb.c 1.3 95/01/18 */
3/*
4 * ====================================================
5 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6 *
7 * Developed at SunSoft, 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#include <sys/cdefs.h>
15__FBSDID("$FreeBSD$");
16
17/*
18 * __ieee754_scalb(x, fn) is provide for
19 * passing various standard test suite. One
20 * should use scalbn() instead.
21 */
22
23#include "math.h"
24#include "math_private.h"
25
26#ifdef _SCALB_INT
27double
28__ieee754_scalb(double x, int fn)
29#else
30double
31__ieee754_scalb(double x, double fn)
32#endif
33{
34#ifdef _SCALB_INT
35	return scalbn(x,fn);
36#else
37	if (isnan(x)||isnan(fn)) return x*fn;
38	if (!finite(fn)) {
39	    if(fn>0.0) return x*fn;
40	    else       return x/(-fn);
41	}
42	if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
43	if ( fn > 65000.0) return scalbn(x, 65000);
44	if (-fn > 65000.0) return scalbn(x,-65000);
45	return scalbn(x,(int)fn);
46#endif
47}
48