1/* @(#)w_log10.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: w_log10.c,v 1.9 2002/05/26 22:02:02 wiz Exp $");
16#endif
17
18/*
19 * wrapper log2(X)
20 */
21
22#include "math.h"
23#include "math_private.h"
24
25
26double
27log2(double x)		/* wrapper log10 */
28{
29#ifdef _IEEE_LIBM
30	return __ieee754_log2(x);
31#else
32	double z;
33	z = __ieee754_log2(x);
34	if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
35	if(x<=0.0) {
36	    if(x==0.0)
37	        return __kernel_standard(x,x,48); /* log2(0) */
38	    else
39	        return __kernel_standard(x,x,49); /* log2(x<0) */
40	} else
41	    return z;
42#endif
43}
44