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_scalb.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 libm/w_scalb.c (limited to 'libm/w_scalb.c') diff --git a/libm/w_scalb.c b/libm/w_scalb.c new file mode 100644 index 000000000..c4cecc322 --- /dev/null +++ b/libm/w_scalb.c @@ -0,0 +1,86 @@ +/* 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 + +static double +__attribute__ ((noinline)) +sysv_scalb (double x, double fn) +{ + double z = __ieee754_scalb (x, fn); + + if (__builtin_expect (isinf (z), 0)) + { + 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; +} +#endif /* __UCLIBC_HAS_FENV__ */ + +/* Here might be a check like "#if defined __UCLIBC_SUSV3_LEGACY__" + * but because there is a sysv_scalb() func, it was decided + * not to check yhis macro. + */ + +/* Wrapper scalb */ +double +scalb (double x, double fn) +{ +#if __UCLIBC_HAS_FENV__ + if (__builtin_expect (_LIB_VERSION == _SVID_,0)) + return sysv_scalb (x, fn); + else + { + double z = __ieee754_scalb (x, fn); + + if (__builtin_expect (!isfinite (z) || z == 0.0, 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; + } +#else + return __ieee754_scalb (x, fn); +#endif /* __UCLIBC_HAS_FENV__ */ +} +libm_hidden_def(scalb) -- cgit v1.2.3