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Diffstat (limited to 'gcc-4.4.3/libstdc++-v3/include/parallel/quicksort.h')
| -rw-r--r-- | gcc-4.4.3/libstdc++-v3/include/parallel/quicksort.h | 179 |
1 files changed, 0 insertions, 179 deletions
diff --git a/gcc-4.4.3/libstdc++-v3/include/parallel/quicksort.h b/gcc-4.4.3/libstdc++-v3/include/parallel/quicksort.h deleted file mode 100644 index 712b479e7..000000000 --- a/gcc-4.4.3/libstdc++-v3/include/parallel/quicksort.h +++ /dev/null @@ -1,179 +0,0 @@ -// -*- C++ -*- - -// Copyright (C) 2007, 2008, 2009 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/quicksort.h - * @brief Implementation of a unbalanced parallel quicksort (in-place). - * This file is a GNU parallel extension to the Standard C++ Library. - */ - -// Written by Johannes Singler. - -#ifndef _GLIBCXX_PARALLEL_QUICKSORT_H -#define _GLIBCXX_PARALLEL_QUICKSORT_H 1 - -#include <parallel/parallel.h> -#include <parallel/partition.h> - -namespace __gnu_parallel -{ - /** @brief Unbalanced quicksort divide step. - * @param begin Begin iterator of subsequence. - * @param end End iterator of subsequence. - * @param comp Comparator. - * @param pivot_rank Desired rank of the pivot. - * @param num_samples Choose pivot from that many samples. - * @param num_threads Number of threads that are allowed to work on - * this part. - */ - template<typename RandomAccessIterator, typename Comparator> - typename std::iterator_traits<RandomAccessIterator>::difference_type - parallel_sort_qs_divide(RandomAccessIterator begin, - RandomAccessIterator end, - Comparator comp, typename std::iterator_traits - <RandomAccessIterator>::difference_type pivot_rank, - typename std::iterator_traits - <RandomAccessIterator>::difference_type - num_samples, thread_index_t num_threads) - { - typedef std::iterator_traits<RandomAccessIterator> traits_type; - typedef typename traits_type::value_type value_type; - typedef typename traits_type::difference_type difference_type; - - difference_type n = end - begin; - num_samples = std::min(num_samples, n); - - // Allocate uninitialized, to avoid default constructor. - value_type* samples = - static_cast<value_type*>(::operator new(num_samples - * sizeof(value_type))); - - for (difference_type s = 0; s < num_samples; ++s) - { - const unsigned long long index = static_cast<unsigned long long>(s) - * n / num_samples; - ::new(&(samples[s])) value_type(begin[index]); - } - - __gnu_sequential::sort(samples, samples + num_samples, comp); - - value_type& pivot = samples[pivot_rank * num_samples / n]; - - __gnu_parallel::binder2nd<Comparator, value_type, value_type, bool> - pred(comp, pivot); - difference_type split = - parallel_partition(begin, end, pred, num_threads); - - ::operator delete(samples); - - return split; - } - - /** @brief Unbalanced quicksort conquer step. - * @param begin Begin iterator of subsequence. - * @param end End iterator of subsequence. - * @param comp Comparator. - * @param num_threads Number of threads that are allowed to work on - * this part. - */ - template<typename RandomAccessIterator, typename Comparator> - void - parallel_sort_qs_conquer(RandomAccessIterator begin, - RandomAccessIterator end, - Comparator comp, - thread_index_t num_threads) - { - typedef std::iterator_traits<RandomAccessIterator> traits_type; - typedef typename traits_type::value_type value_type; - typedef typename traits_type::difference_type difference_type; - - if (num_threads <= 1) - { - __gnu_sequential::sort(begin, end, comp); - return; - } - - difference_type n = end - begin, pivot_rank; - - if (n <= 1) - return; - - thread_index_t num_threads_left; - - if ((num_threads % 2) == 1) - num_threads_left = num_threads / 2 + 1; - else - num_threads_left = num_threads / 2; - - pivot_rank = n * num_threads_left / num_threads; - - difference_type split = - parallel_sort_qs_divide(begin, end, comp, pivot_rank, - _Settings::get().sort_qs_num_samples_preset, - num_threads); - -#pragma omp parallel sections num_threads(2) - { -#pragma omp section - parallel_sort_qs_conquer(begin, begin + split, - comp, num_threads_left); -#pragma omp section - parallel_sort_qs_conquer(begin + split, end, - comp, num_threads - num_threads_left); - } - } - - - - /** @brief Unbalanced quicksort main call. - * @param begin Begin iterator of input sequence. - * @param end End iterator input sequence, ignored. - * @param comp Comparator. - * @param num_threads Number of threads that are allowed to work on - * this part. - */ - template<typename RandomAccessIterator, typename Comparator> - void - parallel_sort_qs(RandomAccessIterator begin, - RandomAccessIterator end, - Comparator comp, - thread_index_t num_threads) - { - _GLIBCXX_CALL(n) - - typedef std::iterator_traits<RandomAccessIterator> traits_type; - typedef typename traits_type::value_type value_type; - typedef typename traits_type::difference_type difference_type; - - difference_type n = end - begin; - - // At least one element per processor. - if (num_threads > n) - num_threads = static_cast<thread_index_t>(n); - - parallel_sort_qs_conquer(begin, begin + n, comp, num_threads); - } - -} //namespace __gnu_parallel - -#endif /* _GLIBCXX_PARALLEL_QUICKSORT_H */ |