1
2 /* @(#)e_scalb.c 1.3 95/01/18 */
3 /*
4 * ====================================================
5 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6 *
7 * Developed at SunSoft, a Sun Microsystems, Inc. business.
8 * Permission to use, copy, modify, and distribute this
9 * software is freely granted, provided that this notice
10 * is preserved.
11 * ====================================================
12 */
13
14 #include <sys/cdefs.h>
15 __FBSDID("$FreeBSD$");
16
17 /*
18 * 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
27 double
scalb(double x,int fn)28 scalb(double x, int fn)
29 #else
30 double
31 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