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
scalb(double x,int fn)24 scalb(double x, int fn)
25 {
26 return scalbn(x, fn);
27 }
28
29 #else
30
31 double
scalb(double x,double fn)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