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 /*
14  * scalb(x, fn) is provide for
15  * passing various standard test suite. One
16  * should use scalbn() instead.
17  */
18 
19 #include "math.h"
20 #include "math_private.h"
21 
22 #ifdef _SCALB_INT
23 double
24 scalb(double x, int fn)
25 {
26 	return scalbn(x, fn);
27 }
28 
29 #else
30 
31 double
32 scalb(double x, double fn)
33 {
34 	if (isnan(x)||isnan(fn)) return x*fn;
35 	if (!finite(fn)) {
36 	    if(fn>0.0) return x*fn;
37 	    else       return x/(-fn);
38 	}
39 	if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
40 	if ( fn > 65000.0) return scalbn(x, 65000);
41 	if (-fn > 65000.0) return scalbn(x,-65000);
42 	return scalbn(x,(int)fn);
43 }
44 #endif
45