cpp-d1064d

[cross.git] / i686-linux-gnu-4.7 / usr / include / c++ / 4.7 / parallel / par_loop.h

diff --git a/i686-linux-gnu-4.7/usr/include/c++/4.7/parallel/par_loop.h b/i686-linux-gnu-4.7/usr/include/c++/4.7/parallel/par_loop.h
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+// -*- 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/par_loop.h
+ *  @brief Parallelization of embarrassingly parallel execution by
+ *  means of equal splitting.
+ *  This file is a GNU parallel extension to the Standard C++ Library.
+ */
+
+// Written by Felix Putze.
+
+#ifndef _GLIBCXX_PARALLEL_PAR_LOOP_H
+#define _GLIBCXX_PARALLEL_PAR_LOOP_H 1
+
+#include <omp.h>
+#include <parallel/settings.h>
+#include <parallel/base.h>
+#include <parallel/equally_split.h>
+
+namespace __gnu_parallel
+{
+  /** @brief Embarrassingly parallel algorithm for random access
+   * iterators, using hand-crafted parallelization by equal splitting
+   * the work.
+   *
+   *  @param __begin Begin iterator of element sequence.
+   *  @param __end End iterator of element sequence.
+   *  @param __o User-supplied functor (comparator, predicate, adding
+   *  functor, ...)
+   *  @param __f Functor to "process" an element with __op (depends on
+   *  desired functionality, e. g. for std::for_each(), ...).
+   *  @param __r Functor to "add" a single __result to the already
+   *  processed elements (depends on functionality).
+   *  @param __base Base value for reduction.
+   *  @param __output Pointer to position where final result is written to
+   *  @param __bound Maximum number of elements processed (e. g. for
+   *  std::count_n()).
+   *  @return User-supplied functor (that may contain a part of the result).
+   */
+  template<typename _RAIter,
+          typename _Op,
+          typename _Fu,
+          typename _Red,
+          typename _Result>
+    _Op
+    __for_each_template_random_access_ed(_RAIter __begin, _RAIter __end,
+                                        _Op __o, _Fu& __f, _Red __r,
+                                        _Result __base, _Result& __output,
+      typename std::iterator_traits<_RAIter>::difference_type __bound)
+    {
+      typedef std::iterator_traits<_RAIter> _TraitsType;
+      typedef typename _TraitsType::difference_type _DifferenceType;
+      const _DifferenceType __length = __end - __begin;
+      _Result *__thread_results;
+      bool* __constructed;
+
+      _ThreadIndex __num_threads = __gnu_parallel::min<_DifferenceType>
+       (__get_max_threads(), __length);
+
+#     pragma omp parallel num_threads(__num_threads)
+      {
+#       pragma omp single
+       {
+         __num_threads = omp_get_num_threads();
+         __thread_results = static_cast<_Result*>
+           (::operator new(__num_threads * sizeof(_Result)));
+         __constructed = new bool[__num_threads];
+       }
+
+       _ThreadIndex __iam = omp_get_thread_num();
+
+       // Neutral element.
+       _Result* __reduct;
+
+       _DifferenceType
+         __start = __equally_split_point(__length, __num_threads, __iam),
+         __stop = __equally_split_point(__length, __num_threads, __iam + 1);
+
+       if (__start < __stop)
+         {
+           __reduct = new _Result(__f(__o, __begin + __start));
+           ++__start;
+           __constructed[__iam] = true;
+         }
+       else
+         __constructed[__iam] = false;
+
+       for (; __start < __stop; ++__start)
+         *__reduct = __r(*__reduct, __f(__o, __begin + __start));
+
+       if (__constructed[__iam])
+         {
+           ::new(&__thread_results[__iam]) _Result(*__reduct);
+           delete __reduct;
+         }
+      } //parallel
+
+      for (_ThreadIndex __i = 0; __i < __num_threads; ++__i)
+       if (__constructed[__i])
+         {
+           __output = __r(__output, __thread_results[__i]);
+           __thread_results[__i].~_Result();
+         }
+
+      // Points to last element processed (needed as return value for
+      // some algorithms like transform).
+      __f._M_finish_iterator = __begin + __length;
+
+      ::operator delete(__thread_results);
+
+      delete[] __constructed;
+
+      return __o;
+    }
+
+} // end namespace
+
+#endif /* _GLIBCXX_PARALLEL_PAR_LOOP_H */