1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
23 */
24 /*
25 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
26 * Use is subject to license terms.
27 */
28
29 #pragma weak __log10f = log10f
30
31 #include "libm.h"
32
33 static const float zero = 0.0f, mone = -1.0f;
34
35 float
log10f(float x)36 log10f(float x) {
37 int hx, ix;
38 float w;
39
40 hx = *(int *)&x;
41 ix = hx & ~0x80000000;
42 if (ix > 0x7f800000)
43 return (x * x);
44 if (ix == 0x7f800000)
45 return (x + x * x);
46 if (ix == 0) {
47 w = mone;
48 return (w / zero);
49 }
50 if (hx < 0) {
51 w = zero;
52 return (w / zero);
53 }
54 return ((float)log10((double)x));
55 }
56