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// -*- C++ -*- |
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// Copyright (C) 2007-2021 Free Software Foundation, Inc. |
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// |
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// This file is part of the GNU ISO C++ Library. This library is free |
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// software; you can redistribute it and/or modify it under the terms |
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// of the GNU General Public License as published by the Free Software |
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// Foundation; either version 3, or (at your option) any later |
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// version. |
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// This library is distributed in the hope that it will be useful, but |
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// WITHOUT ANY WARRANTY; without even the implied warranty of |
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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// General Public License for more details. |
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|
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// Under Section 7 of GPL version 3, you are granted additional |
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// permissions described in the GCC Runtime Library Exception, version |
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// 3.1, as published by the Free Software Foundation. |
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|
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// You should have received a copy of the GNU General Public License and |
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// a copy of the GCC Runtime Library Exception along with this program; |
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
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// <http://www.gnu.org/licenses/>. |
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|
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/** @file parallel/base.h |
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* @brief Sequential helper functions. |
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* This file is a GNU parallel extension to the Standard C++ Library. |
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*/ |
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// Written by Johannes Singler. |
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|
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#ifndef _GLIBCXX_PARALLEL_BASE_H |
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#define _GLIBCXX_PARALLEL_BASE_H 1 |
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|
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#include <bits/c++config.h> |
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#include <bits/stl_function.h> |
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#include <omp.h> |
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#include <parallel/features.h> |
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#include <parallel/basic_iterator.h> |
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#include <parallel/parallel.h> |
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|
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// Parallel mode namespaces. |
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|
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/** |
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* @namespace std::__parallel |
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* @brief GNU parallel code, replaces standard behavior with parallel behavior. |
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*/ |
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namespace std _GLIBCXX_VISIBILITY(default) |
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{ |
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namespace __parallel { } |
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} |
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|
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/** |
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* @namespace __gnu_parallel |
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* @brief GNU parallel code for public use. |
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*/ |
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namespace __gnu_parallel |
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{ |
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// Import all the parallel versions of components in namespace std. |
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using namespace std::__parallel; |
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} |
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|
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/** |
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* @namespace __gnu_sequential |
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* @brief GNU sequential classes for public use. |
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*/ |
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namespace __gnu_sequential |
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{ |
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// Import whatever is the serial version. |
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#ifdef _GLIBCXX_PARALLEL |
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using namespace std::_GLIBCXX_STD_A; |
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#else |
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using namespace std; |
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#endif |
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} |
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|
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|
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namespace __gnu_parallel |
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{ |
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// NB: Including this file cannot produce (unresolved) symbols from |
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// the OpenMP runtime unless the parallel mode is actually invoked |
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// and active, which imples that the OpenMP runtime is actually |
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// going to be linked in. |
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inline _ThreadIndex |
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__get_max_threads() |
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{ |
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_ThreadIndex __i = omp_get_max_threads(); |
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return __i > 1 ? __i : 1; |
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} |
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|
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|
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inline bool |
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__is_parallel(const _Parallelism __p) { return __p != sequential; } |
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|
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|
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/** @brief Calculates the rounded-down logarithm of @c __n for base 2. |
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* @param __n Argument. |
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* @return Returns 0 for any argument <1. |
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*/ |
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template<typename _Size> |
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inline _Size |
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__rd_log2(_Size __n) |
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{ |
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_Size __k; |
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for (__k = 0; __n > 1; __n >>= 1) |
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++__k; |
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return __k; |
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} |
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|
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/** @brief Encode two integers into one gnu_parallel::_CASable. |
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* @param __a First integer, to be encoded in the most-significant @c |
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* _CASable_bits/2 bits. |
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* @param __b Second integer, to be encoded in the least-significant |
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* @c _CASable_bits/2 bits. |
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* @return value encoding @c __a and @c __b. |
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* @see __decode2 |
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*/ |
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inline _CASable |
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__encode2(int __a, int __b) //must all be non-negative, actually |
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{ |
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return (((_CASable)__a) << (_CASable_bits / 2)) | (((_CASable)__b) << 0); |
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} |
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|
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/** @brief Decode two integers from one gnu_parallel::_CASable. |
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* @param __x __gnu_parallel::_CASable to decode integers from. |
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* @param __a First integer, to be decoded from the most-significant |
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* @c _CASable_bits/2 bits of @c __x. |
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* @param __b Second integer, to be encoded in the least-significant |
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* @c _CASable_bits/2 bits of @c __x. |
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* @see __encode2 |
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*/ |
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inline void |
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__decode2(_CASable __x, int& __a, int& __b) |
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{ |
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__a = (int)((__x >> (_CASable_bits / 2)) & _CASable_mask); |
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__b = (int)((__x >> 0 ) & _CASable_mask); |
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} |
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|
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//needed for parallel "numeric", even if "algorithm" not included |
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|
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/** @brief Equivalent to std::min. */ |
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template<typename _Tp> |
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inline const _Tp& |
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min(const _Tp& __a, const _Tp& __b) |
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{ return (__a < __b) ? __a : __b; } |
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|
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/** @brief Equivalent to std::max. */ |
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template<typename _Tp> |
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inline const _Tp& |
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max(const _Tp& __a, const _Tp& __b) |
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{ return (__a > __b) ? __a : __b; } |
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|
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/** @brief Constructs predicate for equality from strict weak |
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* ordering predicate |
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*/ |
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template<typename _T1, typename _T2, typename _Compare> |
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class _EqualFromLess : public std::binary_function<_T1, _T2, bool> |
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{ |
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private: |
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_Compare& _M_comp; |
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|
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public: |
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_EqualFromLess(_Compare& __comp) : _M_comp(__comp) { } |
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bool operator()(const _T1& __a, const _T2& __b) |
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{ return !_M_comp(__a, __b) && !_M_comp(__b, __a); } |
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}; |
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|
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|
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/** @brief Similar to std::unary_negate, |
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* but giving the argument types explicitly. */ |
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template<typename _Predicate, typename argument_type> |
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class __unary_negate |
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: public std::unary_function<argument_type, bool> |
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{ |
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protected: |
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_Predicate _M_pred; |
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|
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public: |
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explicit |
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__unary_negate(const _Predicate& __x) : _M_pred(__x) { } |
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|
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bool |
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operator()(const argument_type& __x) |
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{ return !_M_pred(__x); } |
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}; |
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|
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/** @brief Similar to std::binder1st, |
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* but giving the argument types explicitly. */ |
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template<typename _Operation, typename _FirstArgumentType, |
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typename _SecondArgumentType, typename _ResultType> |
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class __binder1st |
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: public std::unary_function<_SecondArgumentType, _ResultType> |
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{ |
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protected: |
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_Operation _M_op; |
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_FirstArgumentType _M_value; |
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|
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public: |
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__binder1st(const _Operation& __x, const _FirstArgumentType& __y) |
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: _M_op(__x), _M_value(__y) { } |
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|
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_ResultType |
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operator()(const _SecondArgumentType& __x) |
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{ return _M_op(_M_value, __x); } |
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|
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// _GLIBCXX_RESOLVE_LIB_DEFECTS |
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// 109. Missing binders for non-const sequence elements |
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_ResultType |
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operator()(_SecondArgumentType& __x) const |
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{ return _M_op(_M_value, __x); } |
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}; |
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|
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/** |
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* @brief Similar to std::binder2nd, but giving the argument types |
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* explicitly. |
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*/ |
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template<typename _Operation, typename _FirstArgumentType, |
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typename _SecondArgumentType, typename _ResultType> |
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class __binder2nd |
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: public std::unary_function<_FirstArgumentType, _ResultType> |
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{ |
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protected: |
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_Operation _M_op; |
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_SecondArgumentType _M_value; |
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|
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public: |
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__binder2nd(const _Operation& __x, const _SecondArgumentType& __y) |
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: _M_op(__x), _M_value(__y) { } |
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|
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_ResultType |
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operator()(const _FirstArgumentType& __x) const |
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{ return _M_op(__x, _M_value); } |
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|
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// _GLIBCXX_RESOLVE_LIB_DEFECTS |
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// 109. Missing binders for non-const sequence elements |
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_ResultType |
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operator()(_FirstArgumentType& __x) |
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{ return _M_op(__x, _M_value); } |
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}; |
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|
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/** @brief Similar to std::equal_to, but allows two different types. */ |
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template<typename _T1, typename _T2> |
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struct _EqualTo : std::binary_function<_T1, _T2, bool> |
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{ |
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bool operator()(const _T1& __t1, const _T2& __t2) const |
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{ return __t1 == __t2; } |
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}; |
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/** @brief Similar to std::less, but allows two different types. */ |
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template<typename _T1, typename _T2> |
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struct _Less : std::binary_function<_T1, _T2, bool> |
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{ |
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bool |
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operator()(const _T1& __t1, const _T2& __t2) const |
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{ return __t1 < __t2; } |
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bool |
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operator()(const _T2& __t2, const _T1& __t1) const |
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{ return __t2 < __t1; } |
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}; |
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// Partial specialization for one type. Same as std::less. |
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template<typename _Tp> |
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struct _Less<_Tp, _Tp> |
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: public std::less<_Tp> { }; |
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|
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/** @brief Similar to std::plus, but allows two different types. */ |
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template<typename _Tp1, typename _Tp2, typename _Result |
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= __typeof__(*static_cast<_Tp1*>(0) |
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+ *static_cast<_Tp2*>(0))> |
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struct _Plus : public std::binary_function<_Tp1, _Tp2, _Result> |
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{ |
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_Result |
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operator()(const _Tp1& __x, const _Tp2& __y) const |
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{ return __x + __y; } |
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}; |
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// Partial specialization for one type. Same as std::plus. |
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template<typename _Tp> |
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struct _Plus<_Tp, _Tp, _Tp> |
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: public std::plus<_Tp> { }; |
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|
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/** @brief Similar to std::multiplies, but allows two different types. */ |
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template<typename _Tp1, typename _Tp2, typename _Result |
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= __typeof__(*static_cast<_Tp1*>(0) |
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* *static_cast<_Tp2*>(0))> |
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struct _Multiplies : public std::binary_function<_Tp1, _Tp2, _Result> |
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{ |
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_Result |
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operator()(const _Tp1& __x, const _Tp2& __y) const |
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{ return __x * __y; } |
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}; |
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// Partial specialization for one type. Same as std::multiplies. |
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template<typename _Tp> |
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struct _Multiplies<_Tp, _Tp, _Tp> |
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: public std::multiplies<_Tp> { }; |
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|
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/** @brief _Iterator associated with __gnu_parallel::_PseudoSequence. |
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* If features the usual random-access iterator functionality. |
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* @param _Tp Sequence _M_value type. |
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* @param _DifferenceTp Sequence difference type. |
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*/ |
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template<typename _Tp, typename _DifferenceTp> |
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class _PseudoSequenceIterator |
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{ |
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public: |
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typedef _DifferenceTp _DifferenceType; |
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|
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_PseudoSequenceIterator(const _Tp& __val, _DifferenceType __pos) |
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: _M_val(__val), _M_pos(__pos) { } |
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|
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// Pre-increment operator. |
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_PseudoSequenceIterator& |
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operator++() |
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{ |
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++_M_pos; |
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return *this; |
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} |
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// Post-increment operator. |
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_PseudoSequenceIterator |
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operator++(int) |
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{ return _PseudoSequenceIterator(_M_pos++); } |
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const _Tp& |
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operator*() const |
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{ return _M_val; } |
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const _Tp& |
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operator[](_DifferenceType) const |
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{ return _M_val; } |
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bool |
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operator==(const _PseudoSequenceIterator& __i2) |
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{ return _M_pos == __i2._M_pos; } |
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|
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bool |
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operator!=(const _PseudoSequenceIterator& __i2) |
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{ return _M_pos != __i2._M_pos; } |
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|
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_DifferenceType |
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operator-(const _PseudoSequenceIterator& __i2) |
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{ return _M_pos - __i2._M_pos; } |
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|
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private: |
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const _Tp& _M_val; |
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_DifferenceType _M_pos; |
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}; |
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|
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/** @brief Sequence that conceptually consists of multiple copies of |
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the same element. |
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* The copies are not stored explicitly, of course. |
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* @param _Tp Sequence _M_value type. |
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* @param _DifferenceTp Sequence difference type. |
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*/ |
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template<typename _Tp, typename _DifferenceTp> |
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class _PseudoSequence |
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{ |
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public: |
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typedef _DifferenceTp _DifferenceType; |
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|
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// Better cast down to uint64_t, than up to _DifferenceTp. |
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typedef _PseudoSequenceIterator<_Tp, uint64_t> iterator; |
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|
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/** @brief Constructor. |
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* @param __val Element of the sequence. |
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* @param __count Number of (virtual) copies. |
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*/ |
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_PseudoSequence(const _Tp& __val, _DifferenceType __count) |
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: _M_val(__val), _M_count(__count) { } |
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|
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/** @brief Begin iterator. */ |
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iterator |
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begin() const |
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{ return iterator(_M_val, 0); } |
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|
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/** @brief End iterator. */ |
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iterator |
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end() const |
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{ return iterator(_M_val, _M_count); } |
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|
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private: |
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const _Tp& _M_val; |
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_DifferenceType _M_count; |
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}; |
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|
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/** @brief Compute the median of three referenced elements, |
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according to @c __comp. |
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* @param __a First iterator. |
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* @param __b Second iterator. |
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* @param __c Third iterator. |
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* @param __comp Comparator. |
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*/ |
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template<typename _RAIter, typename _Compare> |
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_RAIter |
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__median_of_three_iterators(_RAIter __a, _RAIter __b, |
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_RAIter __c, _Compare __comp) |
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{ |
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if (__comp(*__a, *__b)) |
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if (__comp(*__b, *__c)) |
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return __b; |
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else |
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if (__comp(*__a, *__c)) |
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return __c; |
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else |
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return __a; |
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else |
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{ |
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// Just swap __a and __b. |
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if (__comp(*__a, *__c)) |
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return __a; |
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else |
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if (__comp(*__b, *__c)) |
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return __c; |
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else |
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return __b; |
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} |
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} |
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|
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#if _GLIBCXX_PARALLEL_ASSERTIONS && defined(__glibcxx_assert_impl) |
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# define _GLIBCXX_PARALLEL_ASSERT(_Condition) \ |
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do { __glibcxx_assert_impl(_Condition); } while (false) |
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#else |
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# define _GLIBCXX_PARALLEL_ASSERT(_Condition) do { } while (false) |
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#endif |
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|
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} //namespace __gnu_parallel |
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|
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#endif /* _GLIBCXX_PARALLEL_BASE_H */ |
