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Diffstat (limited to 'REORG.TODO/math/e_exp2_template.c')
| -rw-r--r-- | REORG.TODO/math/e_exp2_template.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/REORG.TODO/math/e_exp2_template.c b/REORG.TODO/math/e_exp2_template.c new file mode 100644 index 0000000000..f1b34882d2 --- /dev/null +++ b/REORG.TODO/math/e_exp2_template.c @@ -0,0 +1,61 @@ +/* Compute 2^x. + Copyright (C) 2012-2017 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 + <http://www.gnu.org/licenses/>. */ + +#include <math.h> +#include <math_private.h> +#include <float.h> + +#define declare_mgen_finite_alias_x(from, to) \ + strong_alias (from, to ## _finite) +#define declare_mgen_finite_alias_s(from,to) \ + declare_mgen_finite_alias_x (from, to) +#define declare_mgen_finite_alias(from, to) \ + declare_mgen_finite_alias_s (M_SUF (from), M_SUF (to)) + +FLOAT +M_DECL_FUNC (__ieee754_exp2) (FLOAT x) +{ + if (__glibc_likely (isless (x, (FLOAT) M_MAX_EXP))) + { + if (__builtin_expect (isgreaterequal (x, (FLOAT) (M_MIN_EXP - M_MANT_DIG + - 1)), 1)) + { + int intx = (int) x; + FLOAT fractx = x - intx; + FLOAT result; + if (M_FABS (fractx) < M_EPSILON / 4) + result = M_SCALBN (1 + fractx, intx); + else + result = M_SCALBN (M_EXP (M_SUF (M_LN2) * fractx), intx); + math_check_force_underflow_nonneg (result); + return result; + } + else + { + /* Underflow or exact zero. */ + if (isinf (x)) + return 0; + else + return M_MIN * M_MIN; + } + } + else + /* Infinity, NaN or overflow. */ + return M_MAX * x; +} +declare_mgen_finite_alias (__ieee754_exp2, __exp2) |