PR libstdc++/68397 std::tr1::expint fails ... long double arguments.

2017-04-20  Edward Smith-Rowland  <3dw4rd@verizon.net>

	PR libstdc++/68397 std::tr1::expint fails ... long double arguments.
	* include/tr1/exp_integral.tcc: Increase iteration limits.
	* testsuite/tr1/5_numerical_facilities/special_functions/15_expint/
	pr68397.cc: New test.
	* testsuite/special_functions/14_expint/pr68397.cc: New test.

From-SVN: r247027
This commit is contained in:
Edward Smith-Rowland 2017-04-20 15:41:59 +00:00 committed by Edward Smith-Rowland
parent 067bc855b2
commit 4ba07ed462
4 changed files with 104 additions and 3 deletions

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@ -1,3 +1,11 @@
2017-04-20 Edward Smith-Rowland <3dw4rd@verizon.net>
PR libstdc++/68397 std::tr1::expint fails ... long double arguments.
* include/tr1/exp_integral.tcc: Increase iteration limits.
* testsuite/tr1/5_numerical_facilities/special_functions/15_expint/
pr68397.cc: New test.
* testsuite/special_functions/14_expint/pr68397.cc: New test.
2017-04-20 Jonathan Wakely <jwakely@redhat.com>
PR libstdc++/79862

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@ -86,7 +86,7 @@ namespace tr1
_Tp __term = _Tp(1);
_Tp __esum = _Tp(0);
_Tp __osum = _Tp(0);
const unsigned int __max_iter = 100;
const unsigned int __max_iter = 1000;
for (unsigned int __i = 1; __i < __max_iter; ++__i)
{
__term *= - __x / __i;
@ -156,7 +156,7 @@ namespace tr1
_Tp
__expint_En_series(unsigned int __n, _Tp __x)
{
const unsigned int __max_iter = 100;
const unsigned int __max_iter = 1000;
const _Tp __eps = std::numeric_limits<_Tp>::epsilon();
const int __nm1 = __n - 1;
_Tp __ans = (__nm1 != 0
@ -202,7 +202,7 @@ namespace tr1
_Tp
__expint_En_cont_frac(unsigned int __n, _Tp __x)
{
const unsigned int __max_iter = 100;
const unsigned int __max_iter = 1000;
const _Tp __eps = std::numeric_limits<_Tp>::epsilon();
const _Tp __fp_min = std::numeric_limits<_Tp>::min();
const int __nm1 = __n - 1;

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@ -0,0 +1,47 @@
// { dg-do run { target c++11 } }
// { dg-options "-D__STDCPP_WANT_MATH_SPEC_FUNCS__" }
// 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 <cmath>
#include <testsuite_hooks.h>
int
test01()
{
// Answers from Wolfram Alpha.
long double ans_ok = -0.10001943365331651406888645149537315243646135979573L;
long double ans_bomb = -0.10777727809650077516264612749163100483995270163783L;
auto Ei_ok = std::expint(-1.500001L);
auto diff_ok = Ei_ok - ans_ok;
VERIFY(std::abs(diff_ok) < 1.0e-15);
auto Ei_bomb = std::expint(-1.450001L);
auto diff_bomb = Ei_bomb - ans_bomb;
VERIFY(std::abs(diff_bomb) < 1.0e-15);
}
int
main()
{
test01();
return 0;
}

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@ -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;
}