--- /dev/null
+// -*- C++ -*-
+
+// Copyright (C) 2007, 2008, 2009, 2010, 2011 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.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
+// <http://www.gnu.org/licenses/>.
+
+/**
+ * @file parallel/set_operations.h
+ * @brief Parallel implementations of set operations for random-access
+ * iterators.
+ * This file is a GNU parallel extension to the Standard C++ Library.
+ */
+
+// Written by Marius Elvert and Felix Bondarenko.
+
+#ifndef _GLIBCXX_PARALLEL_SET_OPERATIONS_H
+#define _GLIBCXX_PARALLEL_SET_OPERATIONS_H 1
+
+#include <omp.h>
+
+#include <parallel/settings.h>
+#include <parallel/multiseq_selection.h>
+
+namespace __gnu_parallel
+{
+ template<typename _IIter, typename _OutputIterator>
+ _OutputIterator
+ __copy_tail(std::pair<_IIter, _IIter> __b,
+ std::pair<_IIter, _IIter> __e, _OutputIterator __r)
+ {
+ if (__b.first != __e.first)
+ {
+ do
+ {
+ *__r++ = *__b.first++;
+ }
+ while (__b.first != __e.first);
+ }
+ else
+ {
+ while (__b.second != __e.second)
+ *__r++ = *__b.second++;
+ }
+ return __r;
+ }
+
+ template<typename _IIter,
+ typename _OutputIterator,
+ typename _Compare>
+ struct __symmetric_difference_func
+ {
+ typedef std::iterator_traits<_IIter> _TraitsType;
+ typedef typename _TraitsType::difference_type _DifferenceType;
+ typedef typename std::pair<_IIter, _IIter> _IteratorPair;
+
+ __symmetric_difference_func(_Compare __comp) : _M_comp(__comp) {}
+
+ _Compare _M_comp;
+
+ _OutputIterator
+ _M_invoke(_IIter __a, _IIter __b, _IIter __c, _IIter __d,
+ _OutputIterator __r) const
+ {
+ while (__a != __b && __c != __d)
+ {
+ if (_M_comp(*__a, *__c))
+ {
+ *__r = *__a;
+ ++__a;
+ ++__r;
+ }
+ else if (_M_comp(*__c, *__a))
+ {
+ *__r = *__c;
+ ++__c;
+ ++__r;
+ }
+ else
+ {
+ ++__a;
+ ++__c;
+ }
+ }
+ return std::copy(__c, __d, std::copy(__a, __b, __r));
+ }
+
+ _DifferenceType
+ __count(_IIter __a, _IIter __b, _IIter __c, _IIter __d) const
+ {
+ _DifferenceType __counter = 0;
+
+ while (__a != __b && __c != __d)
+ {
+ if (_M_comp(*__a, *__c))
+ {
+ ++__a;
+ ++__counter;
+ }
+ else if (_M_comp(*__c, *__a))
+ {
+ ++__c;
+ ++__counter;
+ }
+ else
+ {
+ ++__a;
+ ++__c;
+ }
+ }
+
+ return __counter + (__b - __a) + (__d - __c);
+ }
+
+ _OutputIterator
+ __first_empty(_IIter __c, _IIter __d, _OutputIterator __out) const
+ { return std::copy(__c, __d, __out); }
+
+ _OutputIterator
+ __second_empty(_IIter __a, _IIter __b, _OutputIterator __out) const
+ { return std::copy(__a, __b, __out); }
+ };
+
+
+ template<typename _IIter,
+ typename _OutputIterator,
+ typename _Compare>
+ struct __difference_func
+ {
+ typedef std::iterator_traits<_IIter> _TraitsType;
+ typedef typename _TraitsType::difference_type _DifferenceType;
+ typedef typename std::pair<_IIter, _IIter> _IteratorPair;
+
+ __difference_func(_Compare __comp) : _M_comp(__comp) {}
+
+ _Compare _M_comp;
+
+ _OutputIterator
+ _M_invoke(_IIter __a, _IIter __b, _IIter __c, _IIter __d,
+ _OutputIterator __r) const
+ {
+ while (__a != __b && __c != __d)
+ {
+ if (_M_comp(*__a, *__c))
+ {
+ *__r = *__a;
+ ++__a;
+ ++__r;
+ }
+ else if (_M_comp(*__c, *__a))
+ { ++__c; }
+ else
+ {
+ ++__a;
+ ++__c;
+ }
+ }
+ return std::copy(__a, __b, __r);
+ }
+
+ _DifferenceType
+ __count(_IIter __a, _IIter __b,
+ _IIter __c, _IIter __d) const
+ {
+ _DifferenceType __counter = 0;
+
+ while (__a != __b && __c != __d)
+ {
+ if (_M_comp(*__a, *__c))
+ {
+ ++__a;
+ ++__counter;
+ }
+ else if (_M_comp(*__c, *__a))
+ { ++__c; }
+ else
+ { ++__a; ++__c; }
+ }
+
+ return __counter + (__b - __a);
+ }
+
+ _OutputIterator
+ __first_empty(_IIter, _IIter, _OutputIterator __out) const
+ { return __out; }
+
+ _OutputIterator
+ __second_empty(_IIter __a, _IIter __b, _OutputIterator __out) const
+ { return std::copy(__a, __b, __out); }
+ };
+
+
+ template<typename _IIter,
+ typename _OutputIterator,
+ typename _Compare>
+ struct __intersection_func
+ {
+ typedef std::iterator_traits<_IIter> _TraitsType;
+ typedef typename _TraitsType::difference_type _DifferenceType;
+ typedef typename std::pair<_IIter, _IIter> _IteratorPair;
+
+ __intersection_func(_Compare __comp) : _M_comp(__comp) {}
+
+ _Compare _M_comp;
+
+ _OutputIterator
+ _M_invoke(_IIter __a, _IIter __b, _IIter __c, _IIter __d,
+ _OutputIterator __r) const
+ {
+ while (__a != __b && __c != __d)
+ {
+ if (_M_comp(*__a, *__c))
+ { ++__a; }
+ else if (_M_comp(*__c, *__a))
+ { ++__c; }
+ else
+ {
+ *__r = *__a;
+ ++__a;
+ ++__c;
+ ++__r;
+ }
+ }
+
+ return __r;
+ }
+
+ _DifferenceType
+ __count(_IIter __a, _IIter __b, _IIter __c, _IIter __d) const
+ {
+ _DifferenceType __counter = 0;
+
+ while (__a != __b && __c != __d)
+ {
+ if (_M_comp(*__a, *__c))
+ { ++__a; }
+ else if (_M_comp(*__c, *__a))
+ { ++__c; }
+ else
+ {
+ ++__a;
+ ++__c;
+ ++__counter;
+ }
+ }
+
+ return __counter;
+ }
+
+ _OutputIterator
+ __first_empty(_IIter, _IIter, _OutputIterator __out) const
+ { return __out; }
+
+ _OutputIterator
+ __second_empty(_IIter, _IIter, _OutputIterator __out) const
+ { return __out; }
+ };
+
+ template<class _IIter, class _OutputIterator, class _Compare>
+ struct __union_func
+ {
+ typedef typename std::iterator_traits<_IIter>::difference_type
+ _DifferenceType;
+
+ __union_func(_Compare __comp) : _M_comp(__comp) {}
+
+ _Compare _M_comp;
+
+ _OutputIterator
+ _M_invoke(_IIter __a, const _IIter __b, _IIter __c,
+ const _IIter __d, _OutputIterator __r) const
+ {
+ while (__a != __b && __c != __d)
+ {
+ if (_M_comp(*__a, *__c))
+ {
+ *__r = *__a;
+ ++__a;
+ }
+ else if (_M_comp(*__c, *__a))
+ {
+ *__r = *__c;
+ ++__c;
+ }
+ else
+ {
+ *__r = *__a;
+ ++__a;
+ ++__c;
+ }
+ ++__r;
+ }
+ return std::copy(__c, __d, std::copy(__a, __b, __r));
+ }
+
+ _DifferenceType
+ __count(_IIter __a, _IIter __b, _IIter __c, _IIter __d) const
+ {
+ _DifferenceType __counter = 0;
+
+ while (__a != __b && __c != __d)
+ {
+ if (_M_comp(*__a, *__c))
+ { ++__a; }
+ else if (_M_comp(*__c, *__a))
+ { ++__c; }
+ else
+ {
+ ++__a;
+ ++__c;
+ }
+ ++__counter;
+ }
+
+ __counter += (__b - __a);
+ __counter += (__d - __c);
+ return __counter;
+ }
+
+ _OutputIterator
+ __first_empty(_IIter __c, _IIter __d, _OutputIterator __out) const
+ { return std::copy(__c, __d, __out); }
+
+ _OutputIterator
+ __second_empty(_IIter __a, _IIter __b, _OutputIterator __out) const
+ { return std::copy(__a, __b, __out); }
+ };
+
+ template<typename _IIter,
+ typename _OutputIterator,
+ typename _Operation>
+ _OutputIterator
+ __parallel_set_operation(_IIter __begin1, _IIter __end1,
+ _IIter __begin2, _IIter __end2,
+ _OutputIterator __result, _Operation __op)
+ {
+ _GLIBCXX_CALL((__end1 - __begin1) + (__end2 - __begin2))
+
+ typedef std::iterator_traits<_IIter> _TraitsType;
+ typedef typename _TraitsType::difference_type _DifferenceType;
+ typedef typename std::pair<_IIter, _IIter> _IteratorPair;
+
+ if (__begin1 == __end1)
+ return __op.__first_empty(__begin2, __end2, __result);
+
+ if (__begin2 == __end2)
+ return __op.__second_empty(__begin1, __end1, __result);
+
+ const _DifferenceType __size = (__end1 - __begin1) + (__end2 - __begin2);
+
+ const _IteratorPair __sequence[2] = { std::make_pair(__begin1, __end1),
+ std::make_pair(__begin2, __end2) };
+ _OutputIterator __return_value = __result;
+ _DifferenceType *__borders;
+ _IteratorPair *__block_begins;
+ _DifferenceType* __lengths;
+
+ _ThreadIndex __num_threads =
+ std::min<_DifferenceType>(__get_max_threads(),
+ std::min(__end1 - __begin1, __end2 - __begin2));
+
+# pragma omp parallel num_threads(__num_threads)
+ {
+# pragma omp single
+ {
+ __num_threads = omp_get_num_threads();
+
+ __borders = new _DifferenceType[__num_threads + 2];
+ __equally_split(__size, __num_threads + 1, __borders);
+ __block_begins = new _IteratorPair[__num_threads + 1];
+ // Very __start.
+ __block_begins[0] = std::make_pair(__begin1, __begin2);
+ __lengths = new _DifferenceType[__num_threads];
+ } //single
+
+ _ThreadIndex __iam = omp_get_thread_num();
+
+ // _Result from multiseq_partition.
+ _IIter __offset[2];
+ const _DifferenceType __rank = __borders[__iam + 1];
+
+ multiseq_partition(__sequence, __sequence + 2,
+ __rank, __offset, __op._M_comp);
+
+ // allowed to read?
+ // together
+ // *(__offset[ 0 ] - 1) == *__offset[ 1 ]
+ if (__offset[ 0 ] != __begin1 && __offset[1] != __end2
+ && !__op._M_comp(*(__offset[0] - 1), *__offset[1])
+ && !__op._M_comp(*__offset[1], *(__offset[0] - 1)))
+ {
+ // Avoid split between globally equal elements: move one to
+ // front in first sequence.
+ --__offset[0];
+ }
+
+ _IteratorPair __block_end = __block_begins[__iam + 1] =
+ _IteratorPair(__offset[0], __offset[1]);
+
+ // Make sure all threads have their block_begin result written out.
+# pragma omp barrier
+
+ _IteratorPair __block_begin = __block_begins[__iam];
+
+ // Begin working for the first block, while the others except
+ // the last start to count.
+ if (__iam == 0)
+ {
+ // The first thread can copy already.
+ __lengths[ __iam ] =
+ __op._M_invoke(__block_begin.first, __block_end.first,
+ __block_begin.second, __block_end.second,
+ __result) - __result;
+ }
+ else
+ {
+ __lengths[ __iam ] =
+ __op.__count(__block_begin.first, __block_end.first,
+ __block_begin.second, __block_end.second);
+ }
+
+ // Make sure everyone wrote their lengths.
+# pragma omp barrier
+
+ _OutputIterator __r = __result;
+
+ if (__iam == 0)
+ {
+ // Do the last block.
+ for (_ThreadIndex __i = 0; __i < __num_threads; ++__i)
+ __r += __lengths[__i];
+
+ __block_begin = __block_begins[__num_threads];
+
+ // Return the result iterator of the last block.
+ __return_value =
+ __op._M_invoke(__block_begin.first, __end1,
+ __block_begin.second, __end2, __r);
+
+ }
+ else
+ {
+ for (_ThreadIndex __i = 0; __i < __iam; ++__i)
+ __r += __lengths[ __i ];
+
+ // Reset begins for copy pass.
+ __op._M_invoke(__block_begin.first, __block_end.first,
+ __block_begin.second, __block_end.second, __r);
+ }
+ }
+ return __return_value;
+ }
+
+ template<typename _IIter,
+ typename _OutputIterator,
+ typename _Compare>
+ inline _OutputIterator
+ __parallel_set_union(_IIter __begin1, _IIter __end1,
+ _IIter __begin2, _IIter __end2,
+ _OutputIterator __result, _Compare __comp)
+ {
+ return __parallel_set_operation(__begin1, __end1, __begin2, __end2,
+ __result,
+ __union_func< _IIter, _OutputIterator,
+ _Compare>(__comp));
+ }
+
+ template<typename _IIter,
+ typename _OutputIterator,
+ typename _Compare>
+ inline _OutputIterator
+ __parallel_set_intersection(_IIter __begin1, _IIter __end1,
+ _IIter __begin2, _IIter __end2,
+ _OutputIterator __result, _Compare __comp)
+ {
+ return __parallel_set_operation(__begin1, __end1, __begin2, __end2,
+ __result,
+ __intersection_func<_IIter,
+ _OutputIterator, _Compare>(__comp));
+ }
+
+ template<typename _IIter,
+ typename _OutputIterator,
+ typename _Compare>
+ inline _OutputIterator
+ __parallel_set_difference(_IIter __begin1, _IIter __end1,
+ _IIter __begin2, _IIter __end2,
+ _OutputIterator __result, _Compare __comp)
+ {
+ return __parallel_set_operation(__begin1, __end1, __begin2, __end2,
+ __result,
+ __difference_func<_IIter,
+ _OutputIterator, _Compare>(__comp));
+ }
+
+ template<typename _IIter,
+ typename _OutputIterator,
+ typename _Compare>
+ inline _OutputIterator
+ __parallel_set_symmetric_difference(_IIter __begin1, _IIter __end1,
+ _IIter __begin2, _IIter __end2,
+ _OutputIterator __result,
+ _Compare __comp)
+ {
+ return __parallel_set_operation(__begin1, __end1, __begin2, __end2,
+ __result,
+ __symmetric_difference_func<_IIter,
+ _OutputIterator, _Compare>(__comp));
+ }
+}
+
+#endif /* _GLIBCXX_PARALLEL_SET_OPERATIONS_H */
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