xref: /openbsd/lib/libm/src/e_scalbf.c (revision 09467b48)
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 "math.h"
17 #include "math_private.h"
18 
19 #ifdef _SCALB_INT
20 float
21 scalbf(float x, int fn)
22 {
23 	return scalbnf(x,fn);
24 }
25 DEF_NONSTD(scalbf);
26 
27 #else
28 
29 float
30 scalbf(float x, float fn)
31 {
32 	if (isnan(x)||isnan(fn)) return x*fn;
33 	if (!isfinite(fn)) {
34 	    if(fn>(float)0.0) return x*fn;
35 	    else       return x/(-fn);
36 	}
37 	if (rintf(fn)!=fn) return (fn-fn)/(fn-fn);
38 	if ( fn > (float)65000.0) return scalbnf(x, 65000);
39 	if (-fn > (float)65000.0) return scalbnf(x,-65000);
40 	return scalbnf(x,(int)fn);
41 }
42 DEF_NONSTD(scalbf);
43 #endif
44