glibc/math/w_log2f_compat.c

48 lines
1.4 KiB
C

/* Copyright (C) 2011-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
#include <fenv.h>
#include <math.h>
#include <math_private.h>
#include <math-svid-compat.h>
#include <libm-alias-float.h>
#if LIBM_SVID_COMPAT && SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_27)
/* wrapper log2f(x) */
float
__log2f_compat (float x)
{
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) */
}
}
return __ieee754_log2f (x);
}
compat_symbol (libm, __log2f_compat, log2f, GLIBC_2_1);
#endif