e_scalb.c revision 131865 
1/* @(#)e_scalb.c 5.1 93/09/24 */
2/*
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5 *
6 * Developed at SunPro, 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#ifndef lint
14static char rcsid[] = "$FreeBSD: head/lib/msun/src/e_scalb.c 131865 2004-07-09 10:01:10Z das $";
15#endif
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