gcc/libstdc++-v3/include/parallel/sort.h

// -*- C++ -*-

// Copyright (C) 2007 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 2, 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 COPYING.  If not, write to
// the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
// MA 02111-1307, USA.

// As a special exception, you may use this file as part of a free
// software library without restriction.  Specifically, if other files
// instantiate templates or use macros or inline functions from this
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/** @file parallel/sort.h
 *  @brief Parallel sorting algorithm switch.
 *  This file is a GNU parallel extension to the Standard C++ Library.
 */

// Written by Johannes Singler.

#ifndef _GLIBCXX_PARALLEL_SORT_H
#define _GLIBCXX_PARALLEL_SORT_H 1

#include <parallel/basic_iterator.h>
#include <parallel/features.h>
#include <parallel/parallel.h>

#if _GLIBCXX_ASSERTIONS
#include <parallel/checkers.h>
#endif

#if _GLIBCXX_MERGESORT
#include <parallel/multiway_mergesort.h>
#endif

#if _GLIBCXX_QUICKSORT
#include <parallel/quicksort.h>
#endif

#if _GLIBCXX_BAL_QUICKSORT
#include <parallel/balanced_quicksort.h>
#endif

namespace __gnu_parallel
{
  /** 
   *  @brief Choose a parallel sorting algorithm.
   *  @param begin Begin iterator of input sequence.
   *  @param end End iterator of input sequence.
   *  @param comp Comparator.
   *  @param stable Sort stable.
   *  @callgraph 
   */
  template<typename RandomAccessIterator, typename Comparator>
  inline void
  parallel_sort(RandomAccessIterator begin, RandomAccessIterator end,
		Comparator comp, bool stable)
  {
    _GLIBCXX_CALL(end - begin)
    typedef std::iterator_traits<RandomAccessIterator> traits_type;
    typedef typename traits_type::value_type value_type;
    typedef typename traits_type::difference_type difference_type;

    if (begin != end)
      {
	difference_type n = end - begin;

	if (false) ;
#if _GLIBCXX_MERGESORT
	else if (Settings::sort_algorithm == Settings::MWMS || stable)
	  parallel_sort_mwms(begin, end, comp, n, get_max_threads(), stable);
#endif
#if _GLIBCXX_QUICKSORT
	else if (Settings::sort_algorithm == Settings::QS && !stable)
	  parallel_sort_qs(begin, end, comp, n, get_max_threads());
#endif
#if _GLIBCXX_BAL_QUICKSORT
	else if (Settings::sort_algorithm == Settings::QS_BALANCED && !stable)
	  parallel_sort_qsb(begin, end, comp, n, get_max_threads());
#endif
	else
	  __gnu_sequential::sort(begin, end, comp);
      }
  }
} // end namespace __gnu_parallel

#endif