1 /* Base 10 logarithmic function.
2 Copyright (C) 2011-2021 Free Software Foundation, Inc.
3
4 This file is free software: you can redistribute it and/or modify
5 it under the terms of the GNU Lesser General Public License as
6 published by the Free Software Foundation; either version 3 of the
7 License, or (at your option) any later version.
8
9 This file is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public License
15 along with this program. If not, see <https://www.gnu.org/licenses/>. */
16
17 #include <config.h>
18
19 /* Specification. */
20 #include <math.h>
21
22 float
23 log10f (float x)
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*/
24 #undef log10f
25 {
26 #if HAVE_LOG10F
27 if (x <= 0.0f)
28 {
29 /* Work around the OSF/1 5.1 bug. */
30 if (x == 0.0f)
31 /* Return -Infinity. */
32 return -1.0f / 0.0f;
33 /* Work around the NetBSD 5.1 bug. */
34 else /* x < 0.0 */
35 /* Return NaN. */
36 return 0.0f / 0.0f;
37 }
38 return log10f (x);
39 #else
40 return (float) log10 ((double) x);
41 #endif
42 }