1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
|
/* Copyright (C) 2011-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <fenv.h>
#include <math.h>
#include <math_private.h>
/* wrapper log2(x) */
double
__log2 (double x)
{
if (__builtin_expect (islessequal (x, 0.0), 0) && _LIB_VERSION != _IEEE_)
{
if (x == 0.0)
{
feraiseexcept (FE_DIVBYZERO);
return __kernel_standard (x, x, 48); /* log2(0) */
}
else
{
feraiseexcept (FE_INVALID);
return __kernel_standard (x, x, 49); /* log2(x<0) */
}
}
return __ieee754_log2 (x);
}
weak_alias (__log2, log2)
#ifdef NO_LONG_DOUBLE
strong_alias (__log2, __log2l)
weak_alias (__log2, log2l)
#endif
|
