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 #include <sys/cdefs.h>
14 #if defined(LIBM_SCCS) && !defined(lint)
15 __RCSID("$NetBSD: e_scalb.c,v 1.10 2010/04/23 19:17:07 drochner Exp $");
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 "namespace.h"
25 #include "math.h"
26 #include "math_private.h"
27
28 #ifdef _SCALB_INT
29 double
__ieee754_scalb(double x,int fn)30 __ieee754_scalb(double x, int fn)
31 #else
32 double
33 __ieee754_scalb(double x, double fn)
34 #endif
35 {
36 #ifdef _SCALB_INT
37 return scalbn(x,fn);
38 #else
39 if (isnan(x)||isnan(fn)) return x*fn;
40 if (!finite(fn)) {
41 if(fn>0.0) return x*fn;
42 else return x/(-fn);
43 }
44 if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
45 if ( fn > 65000.0) return scalbn(x, 65000);
46 if (-fn > 65000.0) return scalbn(x,-65000);
47 return scalbn(x,(int)fn);
48 #endif
49 }
50