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 DEF_NONSTD(scalb);
29
30 #else
31
32 double
scalb(double x,double fn)33 scalb(double x, double fn)
34 {
35 if (isnan(x)||isnan(fn)) return x*fn;
36 if (!isfinite(fn)) {
37 if(fn>0.0) return x*fn;
38 else return x/(-fn);
39 }
40 if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
41 if ( fn > 65000.0) return scalbn(x, 65000);
42 if (-fn > 65000.0) return scalbn(x,-65000);
43 return scalbn(x,(int)fn);
44 }
45 DEF_NONSTD(scalb);
46 #endif
47