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/* Copyright (C) 2011-2016 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 <math.h>
#include "math_private.h"
#if __UCLIBC_HAS_FENV__
#include <fenv.h>
#endif
/* wrapper log2f(x) */
float
log2f (float x)
{
#if __UCLIBC_HAS_FENV__
if (__builtin_expect (islessequal (x, 0.0f), 0) && _LIB_VERSION != _IEEE_)
{
if (x == 0.0)
{
feraiseexcept (FE_DIVBYZERO);
return __kernel_standard_f (x, x, 148); /* log2(0) */
}
else
{
feraiseexcept (FE_INVALID);
return __kernel_standard_f (x, x, 149); /* log2(x<0) */
}
}
#endif
return (float) __ieee754_log2 ((double) x);
}
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