1
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 /*
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 #else
26 double
27 scalb(double x, double fn)
28 #endif
29 {
30 #ifdef _SCALB_INT
31 return scalbn(x,fn);
32 #else
33 if (isnan(x)||isnan(fn)) return x*fn;
34 if (!finite(fn)) {
35 if(fn>0.0) return x*fn;
36 else return x/(-fn);
37 }
38 if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
39 if ( fn > 65000.0) return scalbn(x, 65000);
40 if (-fn > 65000.0) return scalbn(x,-65000);
41 return scalbn(x,(int)fn);
42 #endif
43 }
44