diff options
Diffstat (limited to 'libstdc++-v3/testsuite/tr1/5_numerical_facilities/special_functions/15_expint/pr68397.cc')
-rw-r--r-- | libstdc++-v3/testsuite/tr1/5_numerical_facilities/special_functions/15_expint/pr68397.cc | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/libstdc++-v3/testsuite/tr1/5_numerical_facilities/special_functions/15_expint/pr68397.cc b/libstdc++-v3/testsuite/tr1/5_numerical_facilities/special_functions/15_expint/pr68397.cc new file mode 100644 index 00000000000..60d0b68bad6 --- /dev/null +++ b/libstdc++-v3/testsuite/tr1/5_numerical_facilities/special_functions/15_expint/pr68397.cc @@ -0,0 +1,46 @@ +// Copyright (C) 2017 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. +// +// This 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 General Public License for more details. +// +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// <http://www.gnu.org/licenses/>. + +// PR libstdc++/68397 - std::tr1::expint fails in __expint_En_cont_frac +// for some long double arguments due to low __max_iter value + +#include <tr1/cmath> +#include <testsuite_hooks.h> + +void +test01() +{ + // Answers from Wolfram Alpha. + long double ans_ok = -0.10001943365331651406888645149537315243646135979573L; + long double ans_bomb = -0.10777727809650077516264612749163100483995270163783L; + + long double Ei_ok = std::tr1::expint(-1.500001L); + long double diff_ok = std::abs(Ei_ok - ans_ok); + VERIFY(diff_ok < 1.0e-15L); + + long double Ei_bomb = std::tr1::expint(-1.450001L); + long double diff_bomb = std::abs(Ei_bomb - ans_bomb); + VERIFY(diff_bomb < 1.0e-15L); +} + +int +main() +{ + test01(); + return 0; +} + |