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Diffstat (limited to 'gcc-4.4.3/libstdc++-v3/include/parallel/for_each_selectors.h')
| -rw-r--r-- | gcc-4.4.3/libstdc++-v3/include/parallel/for_each_selectors.h | 360 |
1 files changed, 360 insertions, 0 deletions
diff --git a/gcc-4.4.3/libstdc++-v3/include/parallel/for_each_selectors.h b/gcc-4.4.3/libstdc++-v3/include/parallel/for_each_selectors.h new file mode 100644 index 000000000..b46d30f51 --- /dev/null +++ b/gcc-4.4.3/libstdc++-v3/include/parallel/for_each_selectors.h @@ -0,0 +1,360 @@ +// -*- 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/for_each_selectors.h + * @brief Functors representing different tasks to be plugged into the + * generic parallelization methods for embarrassingly parallel functions. + * This file is a GNU parallel extension to the Standard C++ Library. + */ + +// Written by Felix Putze. + +#ifndef _GLIBCXX_PARALLEL_FOR_EACH_SELECTORS_H +#define _GLIBCXX_PARALLEL_FOR_EACH_SELECTORS_H 1 + +#include <parallel/basic_iterator.h> + +namespace __gnu_parallel +{ + + /** @brief Generic selector for embarrassingly parallel functions. */ + template<typename It> + struct generic_for_each_selector + { + /** @brief Iterator on last element processed; needed for some + * algorithms (e. g. std::transform()). + */ + It finish_iterator; + }; + + + /** @brief std::for_each() selector. */ + template<typename It> + struct for_each_selector : public generic_for_each_selector<It> + { + /** @brief Functor execution. + * @param o Operator. + * @param i Iterator referencing object. */ + template<typename Op> + bool + operator()(Op& o, It i) + { + o(*i); + return true; + } + }; + + /** @brief std::generate() selector. */ + template<typename It> + struct generate_selector : public generic_for_each_selector<It> + { + /** @brief Functor execution. + * @param o Operator. + * @param i Iterator referencing object. */ + template<typename Op> + bool + operator()(Op& o, It i) + { + *i = o(); + return true; + } + }; + + /** @brief std::fill() selector. */ + template<typename It> + struct fill_selector : public generic_for_each_selector<It> + { + /** @brief Functor execution. + * @param v Current value. + * @param i Iterator referencing object. */ + template<typename Val> + bool + operator()(Val& v, It i) + { + *i = v; + return true; + } + }; + + /** @brief std::transform() selector, one input sequence variant. */ + template<typename It> + struct transform1_selector : public generic_for_each_selector<It> + { + /** @brief Functor execution. + * @param o Operator. + * @param i Iterator referencing object. */ + template<typename Op> + bool + operator()(Op& o, It i) + { + *i.second = o(*i.first); + return true; + } + }; + + /** @brief std::transform() selector, two input sequences variant. */ + template<typename It> + struct transform2_selector : public generic_for_each_selector<It> + { + /** @brief Functor execution. + * @param o Operator. + * @param i Iterator referencing object. */ + template<typename Op> + bool + operator()(Op& o, It i) + { + *i.third = o(*i.first, *i.second); + return true; + } + }; + + /** @brief std::replace() selector. */ + template<typename It, typename T> + struct replace_selector : public generic_for_each_selector<It> + { + /** @brief Value to replace with. */ + const T& new_val; + + /** @brief Constructor + * @param new_val Value to replace with. */ + explicit + replace_selector(const T &new_val) : new_val(new_val) {} + + /** @brief Functor execution. + * @param v Current value. + * @param i Iterator referencing object. */ + bool + operator()(T& v, It i) + { + if (*i == v) + *i = new_val; + return true; + } + }; + + /** @brief std::replace() selector. */ + template<typename It, typename Op, typename T> + struct replace_if_selector : public generic_for_each_selector<It> + { + /** @brief Value to replace with. */ + const T& new_val; + + /** @brief Constructor. + * @param new_val Value to replace with. */ + explicit + replace_if_selector(const T &new_val) : new_val(new_val) { } + + /** @brief Functor execution. + * @param o Operator. + * @param i Iterator referencing object. */ + bool + operator()(Op& o, It i) + { + if (o(*i)) + *i = new_val; + return true; + } + }; + + /** @brief std::count() selector. */ + template<typename It, typename Diff> + struct count_selector : public generic_for_each_selector<It> + { + /** @brief Functor execution. + * @param v Current value. + * @param i Iterator referencing object. + * @return 1 if count, 0 if does not count. */ + template<typename Val> + Diff + operator()(Val& v, It i) + { return (v == *i) ? 1 : 0; } + }; + + /** @brief std::count_if () selector. */ + template<typename It, typename Diff> + struct count_if_selector : public generic_for_each_selector<It> + { + /** @brief Functor execution. + * @param o Operator. + * @param i Iterator referencing object. + * @return 1 if count, 0 if does not count. */ + template<typename Op> + Diff + operator()(Op& o, It i) + { return (o(*i)) ? 1 : 0; } + }; + + /** @brief std::accumulate() selector. */ + template<typename It> + struct accumulate_selector : public generic_for_each_selector<It> + { + /** @brief Functor execution. + * @param o Operator (unused). + * @param i Iterator referencing object. + * @return The current value. */ + template<typename Op> + typename std::iterator_traits<It>::value_type operator()(Op o, It i) + { return *i; } + }; + + /** @brief std::inner_product() selector. */ + template<typename It, typename It2, typename T> + struct inner_product_selector : public generic_for_each_selector<It> + { + /** @brief Begin iterator of first sequence. */ + It begin1_iterator; + + /** @brief Begin iterator of second sequence. */ + It2 begin2_iterator; + + /** @brief Constructor. + * @param b1 Begin iterator of first sequence. + * @param b2 Begin iterator of second sequence. */ + explicit + inner_product_selector(It b1, It2 b2) + : begin1_iterator(b1), begin2_iterator(b2) { } + + /** @brief Functor execution. + * @param mult Multiplication functor. + * @param current Iterator referencing object. + * @return Inner product elemental result. */ + template<typename Op> + T + operator()(Op mult, It current) + { + typename std::iterator_traits<It>::difference_type position + = current - begin1_iterator; + return mult(*current, *(begin2_iterator + position)); + } + }; + + /** @brief Selector that just returns the passed iterator. */ + template<typename It> + struct identity_selector : public generic_for_each_selector<It> + { + /** @brief Functor execution. + * @param o Operator (unused). + * @param i Iterator referencing object. + * @return Passed iterator. */ + template<typename Op> + It + operator()(Op o, It i) + { return i; } + }; + + /** @brief Selector that returns the difference between two adjacent + * elements. + */ + template<typename It> + struct adjacent_difference_selector : public generic_for_each_selector<It> + { + template<typename Op> + bool + operator()(Op& o, It i) + { + typename It::first_type go_back_one = i.first; + --go_back_one; + *i.second = o(*i.first, *go_back_one); + return true; + } + }; + + // XXX move into type_traits? + /** @brief Functor doing nothing + * + * For some reduction tasks (this is not a function object, but is + * passed as selector dummy parameter. + */ + struct nothing + { + /** @brief Functor execution. + * @param i Iterator referencing object. */ + template<typename It> + void + operator()(It i) { } + }; + + /** @brief Reduction function doing nothing. */ + struct dummy_reduct + { + bool + operator()(bool /*x*/, bool /*y*/) const + { return true; } + }; + + /** @brief Reduction for finding the maximum element, using a comparator. */ + template<typename Comp, typename It> + struct min_element_reduct + { + Comp& comp; + + explicit + min_element_reduct(Comp &c) : comp(c) { } + + It + operator()(It x, It y) + { + if (comp(*x, *y)) + return x; + else + return y; + } + }; + + /** @brief Reduction for finding the maximum element, using a comparator. */ + template<typename Comp, typename It> + struct max_element_reduct + { + Comp& comp; + + explicit + max_element_reduct(Comp& c) : comp(c) { } + + It + operator()(It x, It y) + { + if (comp(*x, *y)) + return y; + else + return x; + } + }; + + /** @brief General reduction, using a binary operator. */ + template<typename BinOp> + struct accumulate_binop_reduct + { + BinOp& binop; + + explicit + accumulate_binop_reduct(BinOp& b) : binop(b) { } + + template<typename Result, typename Addend> + Result + operator()(const Result& x, const Addend& y) + { return binop(x, y); } + }; +} + +#endif /* _GLIBCXX_PARALLEL_FOR_EACH_SELECTORS_H */ |