1 /* Copyright (C) 2011-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
20 #include <math_private.h>
21 #include <math-svid-compat.h>
22 #include <libm-alias-float.h>
25 #if LIBM_SVID_COMPAT && SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_27)
26 /* wrapper log2f(x) */
28 __log2f_compat (float x
)
30 if (__builtin_expect (islessequal (x
, 0.0f
), 0) && _LIB_VERSION
!= _IEEE_
)
34 feraiseexcept (FE_DIVBYZERO
);
35 return __kernel_standard_f (x
, x
, 148); /* log2(0) */
39 feraiseexcept (FE_INVALID
);
40 return __kernel_standard_f (x
, x
, 149); /* log2(x<0) */
44 return __ieee754_log2f (x
);
46 compat_symbol (libm
, __log2f_compat
, log2f
, GLIBC_2_1
);