1 /* Copyright (C) 2011-2016 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19 #include <math.h>
20 #include "math_private.h"
21 #if defined(__UCLIBC_HAS_FENV__)
22 #include <fenv.h>
23 #endif
24
25 /* wrapper log(x) */
26 double
log(double x)27 log (double x)
28 {
29 #if defined(__UCLIBC_HAS_FENV__)
30 if (__builtin_expect (islessequal (x, 0.0), 0) && _LIB_VERSION != _IEEE_)
31 {
32 if (x == 0.0)
33 {
34 feraiseexcept (FE_DIVBYZERO);
35 return __kernel_standard (x, x, 16); /* log(0) */
36 }
37 else
38 {
39 feraiseexcept (FE_INVALID);
40 return __kernel_standard (x, x, 17); /* log(x<0) */
41 }
42 }
43 #endif /* __UCLIBC_HAS_FENV__ */
44 return __ieee754_log (x);
45 }
46 libm_hidden_def(log)
47