re PR libstdc++/47913 ([C++0x] improve ratio_add to overflow less often)
2011-03-02 Marc Glisse <marc.glisse@normalesup.org> PR libstdc++/47913 * include/std/ratio (ratio_add): Avoid denominator overflow. * testsuite/20_util/ratio/operations/47913.cc: New. From-SVN: r170616
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2011-03-02 Marc Glisse <marc.glisse@normalesup.org>
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PR libstdc++/47913
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* include/std/ratio (ratio_add): Avoid denominator overflow.
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* testsuite/20_util/ratio/operations/47913.cc: New.
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2011-02-28 Benjamin Kosnik <bkoz@redhat.com>
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* testsuite/20_util/hash/chi2_quality.cc: Use C++0x mode on simulators.
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@ -177,15 +177,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
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struct ratio_add
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{
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private:
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static const intmax_t __gcd =
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static constexpr intmax_t __gcd =
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__static_gcd<_R1::den, _R2::den>::value;
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static constexpr intmax_t __n = __safe_add<
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__safe_multiply<_R1::num, (_R2::den / __gcd)>::value,
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__safe_multiply<_R2::num, (_R1::den / __gcd)>::value>::value;
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// The new numerator may have common factors with the denominator,
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// but they have to also be factors of __gcd.
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static constexpr intmax_t __gcd2 = __static_gcd<__n, __gcd>::value;
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public:
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typedef ratio<
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__safe_add<
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__safe_multiply<_R1::num, (_R2::den / __gcd)>::value,
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__safe_multiply<_R2::num, (_R1::den / __gcd)>::value>::value,
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__safe_multiply<_R1::den, (_R2::den / __gcd)>::value> type;
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typedef ratio<__n / __gcd2,
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__safe_multiply<_R1::den / __gcd2, _R2::den / __gcd>::value> type;
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static constexpr intmax_t num = type::num;
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static constexpr intmax_t den = type::den;
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@ -0,0 +1,42 @@
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// { dg-options "-std=gnu++0x" }
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// { dg-require-cstdint "" }
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// Copyright (C) 2011 Free Software Foundation
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 3, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License
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// along with this library; see the file COPYING3. If not see
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// <http://www.gnu.org/licenses/>.
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#include <ratio>
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#include <testsuite_hooks.h>
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// libstdc++/47913
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void test01()
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{
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bool test __attribute__((unused)) = true;
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using namespace std;
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const intmax_t m = (intmax_t)1 << (4 * sizeof(intmax_t) - 1);
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typedef ratio_add<ratio<1, (m - 1) * (m - 2)>,
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ratio<1, (m - 3) * (m - 2)> > ra_type;
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VERIFY( ra_type::num == 2 );
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VERIFY( ra_type::den == (m - 1) * (m - 3) );
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}
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int main()
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{
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test01();
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return 0;
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}
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