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Diffstat (limited to 'libm/w_scalbl.c')
| -rw-r--r-- | libm/w_scalbl.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/libm/w_scalbl.c b/libm/w_scalbl.c new file mode 100644 index 000000000..0d5c0c791 --- /dev/null +++ b/libm/w_scalbl.c @@ -0,0 +1,83 @@ +/* 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" +#if __UCLIBC_HAS_FENV__ +#include <errno.h> +#endif + +#if !defined __NO_LONG_DOUBLE_MATH +# if __UCLIBC_HAS_FENV__ +static long double +__attribute__ ((noinline)) +sysv_scalbl (long double x, long double fn) +{ + long double z = (long double) __ieee754_scalb ((double) x, (double) fn); + + if (__builtin_expect (isinf (z), 0)) + { + if (isfinite (x)) + return __kernel_standard_l (x, fn, 232); /* scalb overflow */ + else + __set_errno (ERANGE); + } + else if (__builtin_expect (z == 0.0L, 0) && z != x) + return __kernel_standard_l (x, fn, 233); /* scalb underflow */ + + return z; +} +# endif /* __UCLIBC_HAS_FENV__ */ + +/* Wrapper scalbl */ +long double +scalbl (long double x, long double fn) +{ +# if __UCLIBC_HAS_FENV__ + if (__builtin_expect (_LIB_VERSION == _SVID_, 0)) + return sysv_scalbl (x, fn); + else + { + long double z = (long double) __ieee754_scalb ((double) x, (double) fn); + + if (__builtin_expect (!isfinite (z) || z == 0.0L, 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 != 0.0L && !isinf (fn)) + __set_errno (ERANGE); + } + } + return z; + } +# else + return (long double) __ieee754_scalb ((double) x, (double) fn); +# endif /* __UCLIBC_HAS_FENV__ */ +} +#endif /* __NO_LONG_DOUBLE_MATH */
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