1/* Copyright (C) 2011-2020 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 <https://www.gnu.org/licenses/>. */
18
19#include <fenv.h>
20#include <math.h>
21#include <math_private.h>
22#include <math-svid-compat.h>
23#include <libm-alias-float.h>
24
25
26#if LIBM_SVID_COMPAT && SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_27)
27/* wrapper log2f(x) */
28float
29__log2f_compat (float x)
30{
31 if (__builtin_expect (islessequal (x, 0.0f), 0) && _LIB_VERSION != _IEEE_)
32 {
33 if (x == 0.0)
34 {
35 feraiseexcept (FE_DIVBYZERO);
36 return __kernel_standard_f (x, x, 148); /* log2(0) */
37 }
38 else
39 {
40 feraiseexcept (FE_INVALID);
41 return __kernel_standard_f (x, x, 149); /* log2(x<0) */
42 }
43 }
44
45 return __ieee754_log2f (x);
46}
47compat_symbol (libm, __log2f_compat, log2f, GLIBC_2_1);
48#endif
49