xref: /netbsd-src/lib/libm/src/e_scalbf.c (revision d4def06880b057e77ee86e4a4a3f87e29850fb1d)
1 /* e_scalbf.c -- float version of e_scalb.c.
2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3  */
4 
5 /*
6  * ====================================================
7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8  *
9  * Developed at SunPro, a Sun Microsystems, Inc. business.
10  * Permission to use, copy, modify, and distribute this
11  * software is freely granted, provided that this notice
12  * is preserved.
13  * ====================================================
14  */
15 
16 #include <sys/cdefs.h>
17 #if defined(LIBM_SCCS) && !defined(lint)
18 __RCSID("$NetBSD: e_scalbf.c,v 1.7 2010/04/23 19:17:07 drochner Exp $");
19 #endif
20 
21 #include "namespace.h"
22 #include "math.h"
23 #include "math_private.h"
24 
25 #ifdef _SCALB_INT
26 float
__ieee754_scalbf(float x,int fn)27 __ieee754_scalbf(float x, int fn)
28 #else
29 float
30 __ieee754_scalbf(float x, float fn)
31 #endif
32 {
33 #ifdef _SCALB_INT
34 	return scalbnf(x,fn);
35 #else
36 	if (isnanf(x)||isnanf(fn)) return x*fn;
37 	if (!finitef(fn)) {
38 	    if(fn>(float)0.0) return x*fn;
39 	    else       return x/(-fn);
40 	}
41 	if (rintf(fn)!=fn) return (fn-fn)/(fn-fn);
42 	if ( fn > (float)65000.0) return scalbnf(x, 65000);
43 	if (-fn > (float)65000.0) return scalbnf(x,-65000);
44 	return scalbnf(x,(int)fn);
45 #endif
46 }
47