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// -*- C++ -*- |
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|
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// Copyright (C) 2007-2021 Free Software Foundation, Inc. |
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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 terms |
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// of the GNU General Public License as published by the Free Software |
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// Foundation; either version 3, or (at your option) any later |
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// version. |
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|
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// This library is distributed in the hope that it will be useful, but |
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// WITHOUT ANY WARRANTY; without even the implied warranty of |
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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// General Public License for more details. |
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|
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// Under Section 7 of GPL version 3, you are granted additional |
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// permissions described in the GCC Runtime Library Exception, version |
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// 3.1, as published by the Free Software Foundation. |
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|
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// You should have received a copy of the GNU General Public License and |
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// a copy of the GCC Runtime Library Exception along with this program; |
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
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// <http://www.gnu.org/licenses/>. |
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|
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/** |
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* @file parallel/set_operations.h |
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* @brief Parallel implementations of set operations for random-access |
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* iterators. |
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* This file is a GNU parallel extension to the Standard C++ Library. |
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*/ |
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|
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// Written by Marius Elvert and Felix Bondarenko. |
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|
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#ifndef _GLIBCXX_PARALLEL_SET_OPERATIONS_H |
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#define _GLIBCXX_PARALLEL_SET_OPERATIONS_H 1 |
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|
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#include <omp.h> |
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|
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#include <parallel/settings.h> |
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#include <parallel/multiseq_selection.h> |
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|
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namespace __gnu_parallel |
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{ |
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template<typename _IIter, typename _OutputIterator> |
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_OutputIterator |
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__copy_tail(std::pair<_IIter, _IIter> __b, |
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std::pair<_IIter, _IIter> __e, _OutputIterator __r) |
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{ |
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if (__b.first != __e.first) |
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{ |
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do |
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{ |
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*__r++ = *__b.first++; |
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} |
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while (__b.first != __e.first); |
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} |
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else |
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{ |
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while (__b.second != __e.second) |
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*__r++ = *__b.second++; |
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} |
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return __r; |
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} |
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|
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template<typename _IIter, |
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typename _OutputIterator, |
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typename _Compare> |
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struct __symmetric_difference_func |
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{ |
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typedef std::iterator_traits<_IIter> _TraitsType; |
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typedef typename _TraitsType::difference_type _DifferenceType; |
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typedef typename std::pair<_IIter, _IIter> _IteratorPair; |
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|
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__symmetric_difference_func(_Compare __comp) : _M_comp(__comp) {} |
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|
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_Compare _M_comp; |
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|
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_OutputIterator |
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_M_invoke(_IIter __a, _IIter __b, _IIter __c, _IIter __d, |
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_OutputIterator __r) const |
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{ |
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while (__a != __b && __c != __d) |
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{ |
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if (_M_comp(*__a, *__c)) |
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{ |
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*__r = *__a; |
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++__a; |
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++__r; |
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} |
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else if (_M_comp(*__c, *__a)) |
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{ |
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*__r = *__c; |
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++__c; |
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++__r; |
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} |
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else |
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{ |
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++__a; |
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++__c; |
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} |
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} |
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return std::copy(__c, __d, std::copy(__a, __b, __r)); |
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} |
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|
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_DifferenceType |
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__count(_IIter __a, _IIter __b, _IIter __c, _IIter __d) const |
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{ |
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_DifferenceType __counter = 0; |
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|
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while (__a != __b && __c != __d) |
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{ |
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if (_M_comp(*__a, *__c)) |
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{ |
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++__a; |
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++__counter; |
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} |
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else if (_M_comp(*__c, *__a)) |
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{ |
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++__c; |
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++__counter; |
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} |
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else |
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{ |
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++__a; |
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++__c; |
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} |
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} |
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|
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return __counter + (__b - __a) + (__d - __c); |
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} |
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|
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_OutputIterator |
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__first_empty(_IIter __c, _IIter __d, _OutputIterator __out) const |
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{ return std::copy(__c, __d, __out); } |
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|
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_OutputIterator |
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__second_empty(_IIter __a, _IIter __b, _OutputIterator __out) const |
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{ return std::copy(__a, __b, __out); } |
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}; |
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|
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|
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template<typename _IIter, |
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typename _OutputIterator, |
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typename _Compare> |
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struct __difference_func |
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{ |
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typedef std::iterator_traits<_IIter> _TraitsType; |
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typedef typename _TraitsType::difference_type _DifferenceType; |
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typedef typename std::pair<_IIter, _IIter> _IteratorPair; |
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|
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__difference_func(_Compare __comp) : _M_comp(__comp) {} |
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|
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_Compare _M_comp; |
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|
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_OutputIterator |
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_M_invoke(_IIter __a, _IIter __b, _IIter __c, _IIter __d, |
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_OutputIterator __r) const |
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{ |
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while (__a != __b && __c != __d) |
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{ |
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if (_M_comp(*__a, *__c)) |
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{ |
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*__r = *__a; |
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++__a; |
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++__r; |
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} |
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else if (_M_comp(*__c, *__a)) |
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{ ++__c; } |
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else |
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{ |
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++__a; |
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++__c; |
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} |
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} |
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return std::copy(__a, __b, __r); |
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} |
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|
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_DifferenceType |
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__count(_IIter __a, _IIter __b, |
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_IIter __c, _IIter __d) const |
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{ |
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_DifferenceType __counter = 0; |
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|
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while (__a != __b && __c != __d) |
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{ |
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if (_M_comp(*__a, *__c)) |
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{ |
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++__a; |
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++__counter; |
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} |
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else if (_M_comp(*__c, *__a)) |
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{ ++__c; } |
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else |
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{ ++__a; ++__c; } |
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} |
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|
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return __counter + (__b - __a); |
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} |
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|
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_OutputIterator |
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__first_empty(_IIter, _IIter, _OutputIterator __out) const |
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{ return __out; } |
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|
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_OutputIterator |
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__second_empty(_IIter __a, _IIter __b, _OutputIterator __out) const |
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{ return std::copy(__a, __b, __out); } |
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}; |
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|
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|
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template<typename _IIter, |
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typename _OutputIterator, |
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typename _Compare> |
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struct __intersection_func |
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{ |
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typedef std::iterator_traits<_IIter> _TraitsType; |
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typedef typename _TraitsType::difference_type _DifferenceType; |
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typedef typename std::pair<_IIter, _IIter> _IteratorPair; |
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|
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__intersection_func(_Compare __comp) : _M_comp(__comp) {} |
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|
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_Compare _M_comp; |
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|
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_OutputIterator |
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_M_invoke(_IIter __a, _IIter __b, _IIter __c, _IIter __d, |
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_OutputIterator __r) const |
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{ |
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while (__a != __b && __c != __d) |
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{ |
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if (_M_comp(*__a, *__c)) |
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{ ++__a; } |
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else if (_M_comp(*__c, *__a)) |
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{ ++__c; } |
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else |
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{ |
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*__r = *__a; |
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++__a; |
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++__c; |
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++__r; |
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} |
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} |
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|
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return __r; |
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} |
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|
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_DifferenceType |
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__count(_IIter __a, _IIter __b, _IIter __c, _IIter __d) const |
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{ |
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_DifferenceType __counter = 0; |
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|
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while (__a != __b && __c != __d) |
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{ |
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if (_M_comp(*__a, *__c)) |
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{ ++__a; } |
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else if (_M_comp(*__c, *__a)) |
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{ ++__c; } |
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else |
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{ |
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++__a; |
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++__c; |
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++__counter; |
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} |
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} |
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|
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return __counter; |
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} |
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|
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_OutputIterator |
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__first_empty(_IIter, _IIter, _OutputIterator __out) const |
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{ return __out; } |
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|
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_OutputIterator |
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__second_empty(_IIter, _IIter, _OutputIterator __out) const |
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{ return __out; } |
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}; |
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|
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template<class _IIter, class _OutputIterator, class _Compare> |
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struct __union_func |
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{ |
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typedef typename std::iterator_traits<_IIter>::difference_type |
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_DifferenceType; |
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|
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__union_func(_Compare __comp) : _M_comp(__comp) {} |
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|
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_Compare _M_comp; |
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|
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_OutputIterator |
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_M_invoke(_IIter __a, const _IIter __b, _IIter __c, |
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const _IIter __d, _OutputIterator __r) const |
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{ |
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while (__a != __b && __c != __d) |
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{ |
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if (_M_comp(*__a, *__c)) |
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{ |
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*__r = *__a; |
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++__a; |
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} |
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else if (_M_comp(*__c, *__a)) |
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{ |
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*__r = *__c; |
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++__c; |
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} |
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else |
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{ |
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*__r = *__a; |
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++__a; |
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++__c; |
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} |
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++__r; |
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} |
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return std::copy(__c, __d, std::copy(__a, __b, __r)); |
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} |
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|
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_DifferenceType |
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__count(_IIter __a, _IIter __b, _IIter __c, _IIter __d) const |
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{ |
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_DifferenceType __counter = 0; |
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|
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while (__a != __b && __c != __d) |
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{ |
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if (_M_comp(*__a, *__c)) |
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{ ++__a; } |
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else if (_M_comp(*__c, *__a)) |
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{ ++__c; } |
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else |
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{ |
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++__a; |
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++__c; |
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} |
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++__counter; |
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} |
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|
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__counter += (__b - __a); |
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__counter += (__d - __c); |
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return __counter; |
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} |
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|
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_OutputIterator |
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__first_empty(_IIter __c, _IIter __d, _OutputIterator __out) const |
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{ return std::copy(__c, __d, __out); } |
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|
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_OutputIterator |
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__second_empty(_IIter __a, _IIter __b, _OutputIterator __out) const |
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{ return std::copy(__a, __b, __out); } |
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}; |
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|
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template<typename _IIter, |
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typename _OutputIterator, |
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typename _Operation> |
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_OutputIterator |
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__parallel_set_operation(_IIter __begin1, _IIter __end1, |
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_IIter __begin2, _IIter __end2, |
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_OutputIterator __result, _Operation __op) |
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{ |
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_GLIBCXX_CALL((__end1 - __begin1) + (__end2 - __begin2)) |
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|
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typedef std::iterator_traits<_IIter> _TraitsType; |
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typedef typename _TraitsType::difference_type _DifferenceType; |
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typedef typename std::pair<_IIter, _IIter> _IteratorPair; |
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|
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if (__begin1 == __end1) |
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return __op.__first_empty(__begin2, __end2, __result); |
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|
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if (__begin2 == __end2) |
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return __op.__second_empty(__begin1, __end1, __result); |
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|
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const _DifferenceType __size = (__end1 - __begin1) + (__end2 - __begin2); |
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|
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const _IteratorPair __sequence[2] = { std::make_pair(__begin1, __end1), |
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std::make_pair(__begin2, __end2) }; |
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_OutputIterator __return_value = __result; |
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_DifferenceType *__borders; |
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_IteratorPair *__block_begins; |
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_DifferenceType* __lengths; |
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|
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_ThreadIndex __num_threads = |
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std::min<_DifferenceType>(__get_max_threads(), |
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std::min(__end1 - __begin1, __end2 - __begin2)); |
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|
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# pragma omp parallel num_threads(__num_threads) |
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{ |
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# pragma omp single |
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{ |
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__num_threads = omp_get_num_threads(); |
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|
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__borders = new _DifferenceType[__num_threads + 2]; |
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__equally_split(__size, __num_threads + 1, __borders); |
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__block_begins = new _IteratorPair[__num_threads + 1]; |
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// Very __start. |
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__block_begins[0] = std::make_pair(__begin1, __begin2); |
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__lengths = new _DifferenceType[__num_threads]; |
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} //single |
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|
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_ThreadIndex __iam = omp_get_thread_num(); |
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|
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// _Result from multiseq_partition. |
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_IIter __offset[2]; |
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const _DifferenceType __rank = __borders[__iam + 1]; |
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|
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multiseq_partition(__sequence, __sequence + 2, |
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__rank, __offset, __op._M_comp); |
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|
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// allowed to read? |
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// together |
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// *(__offset[ 0 ] - 1) == *__offset[ 1 ] |
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if (__offset[ 0 ] != __begin1 && __offset[1] != __end2 |
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&& !__op._M_comp(*(__offset[0] - 1), *__offset[1]) |
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&& !__op._M_comp(*__offset[1], *(__offset[0] - 1))) |
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{ |
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// Avoid split between globally equal elements: move one to |
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// front in first sequence. |
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--__offset[0]; |
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} |
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|
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_IteratorPair __block_end = __block_begins[__iam + 1] = |
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_IteratorPair(__offset[0], __offset[1]); |
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|
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// Make sure all threads have their block_begin result written out. |
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# pragma omp barrier |
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|
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_IteratorPair __block_begin = __block_begins[__iam]; |
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|
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// Begin working for the first block, while the others except |
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// the last start to count. |
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if (__iam == 0) |
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{ |
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// The first thread can copy already. |
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__lengths[ __iam ] = |
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__op._M_invoke(__block_begin.first, __block_end.first, |
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__block_begin.second, __block_end.second, |
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__result) - __result; |
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} |
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else |
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{ |
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__lengths[ __iam ] = |
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__op.__count(__block_begin.first, __block_end.first, |
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__block_begin.second, __block_end.second); |
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} |
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|
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// Make sure everyone wrote their lengths. |
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# pragma omp barrier |
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|
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_OutputIterator __r = __result; |
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|
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if (__iam == 0) |
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{ |
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// Do the last block. |
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for (_ThreadIndex __i = 0; __i < __num_threads; ++__i) |
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__r += __lengths[__i]; |
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|
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__block_begin = __block_begins[__num_threads]; |
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|
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// Return the result iterator of the last block. |
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__return_value = |
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__op._M_invoke(__block_begin.first, __end1, |
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__block_begin.second, __end2, __r); |
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|
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} |
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else |
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{ |
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for (_ThreadIndex __i = 0; __i < __iam; ++__i) |
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__r += __lengths[ __i ]; |
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|
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// Reset begins for copy pass. |
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__op._M_invoke(__block_begin.first, __block_end.first, |
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__block_begin.second, __block_end.second, __r); |
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} |
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} |
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return __return_value; |
| 469 |
} |
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|
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template<typename _IIter, |
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typename _OutputIterator, |
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typename _Compare> |
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inline _OutputIterator |
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__parallel_set_union(_IIter __begin1, _IIter __end1, |
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_IIter __begin2, _IIter __end2, |
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_OutputIterator __result, _Compare __comp) |
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{ |
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return __parallel_set_operation(__begin1, __end1, __begin2, __end2, |
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__result, |
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__union_func< _IIter, _OutputIterator, |
| 482 |
_Compare>(__comp)); |
| 483 |
} |
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|
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template<typename _IIter, |
| 486 |
typename _OutputIterator, |
| 487 |
typename _Compare> |
| 488 |
inline _OutputIterator |
| 489 |
__parallel_set_intersection(_IIter __begin1, _IIter __end1, |
| 490 |
_IIter __begin2, _IIter __end2, |
| 491 |
_OutputIterator __result, _Compare __comp) |
| 492 |
{ |
| 493 |
return __parallel_set_operation(__begin1, __end1, __begin2, __end2, |
| 494 |
__result, |
| 495 |
__intersection_func<_IIter, |
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_OutputIterator, _Compare>(__comp)); |
| 497 |
} |
| 498 |
|
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template<typename _IIter, |
| 500 |
typename _OutputIterator, |
| 501 |
typename _Compare> |
| 502 |
inline _OutputIterator |
| 503 |
__parallel_set_difference(_IIter __begin1, _IIter __end1, |
| 504 |
_IIter __begin2, _IIter __end2, |
| 505 |
_OutputIterator __result, _Compare __comp) |
| 506 |
{ |
| 507 |
return __parallel_set_operation(__begin1, __end1, __begin2, __end2, |
| 508 |
__result, |
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__difference_func<_IIter, |
| 510 |
_OutputIterator, _Compare>(__comp)); |
| 511 |
} |
| 512 |
|
| 513 |
template<typename _IIter, |
| 514 |
typename _OutputIterator, |
| 515 |
typename _Compare> |
| 516 |
inline _OutputIterator |
| 517 |
__parallel_set_symmetric_difference(_IIter __begin1, _IIter __end1, |
| 518 |
_IIter __begin2, _IIter __end2, |
| 519 |
_OutputIterator __result, |
| 520 |
_Compare __comp) |
| 521 |
{ |
| 522 |
return __parallel_set_operation(__begin1, __end1, __begin2, __end2, |
| 523 |
__result, |
| 524 |
__symmetric_difference_func<_IIter, |
| 525 |
_OutputIterator, _Compare>(__comp)); |
| 526 |
} |
| 527 |
} |
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|
| 529 |
#endif /* _GLIBCXX_PARALLEL_SET_OPERATIONS_H */ |
