/* 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" /* wrapper exp2(x) */ double exp2 (double x) { #if defined(__UCLIBC_HAS_FENV__) double z = pow(2.0, x); if (__builtin_expect (!isfinite (z) || z == 0, 0) && isfinite (x) && _LIB_VERSION != _IEEE_) /* exp2 overflow: 44, exp2 underflow: 45 */ return __kernel_standard (x, x, 44 + !!signbit (x)); return z; #else return pow(2.0, x); #endif } libm_hidden_def(exp2)