xref: /netbsd/lib/libm/src/e_scalbf.c (revision bf9ec67e)
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 1.6 2002/05/26 22:01:52 wiz Exp $");
19 #endif
20 
21 #include "math.h"
22 #include "math_private.h"
23 
24 #ifdef _SCALB_INT
25 float
26 __ieee754_scalbf(float x, int fn)
27 #else
28 float
29 __ieee754_scalbf(float x, float fn)
30 #endif
31 {
32 #ifdef _SCALB_INT
33 	return scalbnf(x,fn);
34 #else
35 	if (isnanf(x)||isnanf(fn)) return x*fn;
36 	if (!finitef(fn)) {
37 	    if(fn>(float)0.0) return x*fn;
38 	    else       return x/(-fn);
39 	}
40 	if (rintf(fn)!=fn) return (fn-fn)/(fn-fn);
41 	if ( fn > (float)65000.0) return scalbnf(x, 65000);
42 	if (-fn > (float)65000.0) return scalbnf(x,-65000);
43 	return scalbnf(x,(int)fn);
44 #endif
45 }
46