xref: /freebsd/lib/msun/src/e_scalb.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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 #ifndef lint
15 static char rcsid[] = "$FreeBSD$";
16 #endif
17 
18 /*
19  * __ieee754_scalb(x, fn) is provide for
20  * passing various standard test suite. One
21  * should use scalbn() instead.
22  */
23 
24 #include "math.h"
25 #include "math_private.h"
26 
27 #ifdef _SCALB_INT
28 double
29 __ieee754_scalb(double x, int fn)
30 #else
31 double
32 __ieee754_scalb(double x, double fn)
33 #endif
34 {
35 #ifdef _SCALB_INT
36 	return scalbn(x,fn);
37 #else
38 	if (isnan(x)||isnan(fn)) return x*fn;
39 	if (!finite(fn)) {
40 	    if(fn>0.0) return x*fn;
41 	    else       return x/(-fn);
42 	}
43 	if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
44 	if ( fn > 65000.0) return scalbn(x, 65000);
45 	if (-fn > 65000.0) return scalbn(x,-65000);
46 	return scalbn(x,(int)fn);
47 #endif
48 }
49