diff options
Diffstat (limited to 'math/w_scalb_compat.c')
| -rw-r--r-- | math/w_scalb_compat.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/math/w_scalb_compat.c b/math/w_scalb_compat.c new file mode 100644 index 0000000000..8354115512 --- /dev/null +++ b/math/w_scalb_compat.c @@ -0,0 +1,80 @@ +/* Copyright (C) 2011-2017 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 <errno.h> +#include <math.h> +#include <math_private.h> + + +static double +__attribute__ ((noinline)) +sysv_scalb (double x, double fn) +{ + double z = __ieee754_scalb (x, fn); + + if (__glibc_unlikely (isinf (z))) + { + if (isfinite (x)) + return __kernel_standard (x, fn, 32); /* scalb overflow */ + else + __set_errno (ERANGE); + } + else if (__builtin_expect (z == 0.0, 0) && z != x) + return __kernel_standard (x, fn, 33); /* scalb underflow */ + + return z; +} + + +/* Wrapper scalb */ +double +__scalb (double x, double fn) +{ + if (__glibc_unlikely (_LIB_VERSION == _SVID_)) + return sysv_scalb (x, fn); + else + { + double z = __ieee754_scalb (x, fn); + + if (__glibc_unlikely (!isfinite (z) || z == 0.0)) + { + if (isnan (z)) + { + if (!isnan (x) && !isnan (fn)) + __set_errno (EDOM); + } + else if (isinf (z)) + { + if (!isinf (x) && !isinf (fn)) + __set_errno (ERANGE); + } + else + { + /* z == 0. */ + if (x != 0.0 && !isinf (fn)) + __set_errno (ERANGE); + } + } + return z; + } +} +weak_alias (__scalb, scalb) +#ifdef NO_LONG_DOUBLE +strong_alias (__scalb, __scalbl) +weak_alias (__scalb, scalbl) +#endif |