diff options
Diffstat (limited to 'math/w_log2_compat.c')
-rw-r--r-- | math/w_log2_compat.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/math/w_log2_compat.c b/math/w_log2_compat.c new file mode 100644 index 0000000..b8e842d --- /dev/null +++ b/math/w_log2_compat.c @@ -0,0 +1,48 @@ +/* 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 |