From ea38f4d89c9698895b1cf53a5946429dc1d8bbaa Mon Sep 17 00:00:00 2001 From: Sergey Cherkashin <4erkashin@list.ru> Date: Tue, 3 Oct 2017 15:26:34 +0300 Subject: math: add exception handling functionality According to standards SVID and SYSV. Modified lgamma calling in case when 'signgam' variable should not be used. Signed-off-by: Waldemar Brodkorb --- libm/w_log2f.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 libm/w_log2f.c (limited to 'libm/w_log2f.c') diff --git a/libm/w_log2f.c b/libm/w_log2f.c new file mode 100644 index 000000000..53666b1d3 --- /dev/null +++ b/libm/w_log2f.c @@ -0,0 +1,45 @@ +/* Copyright (C) 2011-2016 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper , 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 + . */ + +#include +#include "math_private.h" +#if __UCLIBC_HAS_FENV__ +#include +#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); +} -- cgit v1.2.3