// -*- C++ -*-
-// Copyright (C) 2007 Free Software Foundation, Inc.
+// 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 2, or (at your option) any later
+// Foundation; either version 3, or (at your option) any later
// version.
// This library is distributed in the hope that it will be useful, but
// 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
-// file, or you compile this file and link it with other files to
-// produce an executable, this file does not by itself cause the
-// resulting executable to be covered by the GNU General Public
-// License. This exception does not however invalidate any other
-// reasons why the executable file might be covered by the GNU General
-// Public License.
+// 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/losertree.h
* @brief Many generic loser tree variants.
#ifndef _GLIBCXX_PARALLEL_LOSERTREE_H
#define _GLIBCXX_PARALLEL_LOSERTREE_H 1
-#include <functional>
-
#include <bits/stl_algobase.h>
+#include <bits/stl_function.h>
#include <parallel/features.h>
#include <parallel/base.h>
namespace __gnu_parallel
{
-
-#if _GLIBCXX_LOSER_TREE_EXPLICIT
-
-/** @brief Guarded loser tree, copying the whole element into the
-* tree structure.
-*
-* Guarding is done explicitly through two flags per element, inf
-* and sup This is a quite slow variant.
-*/
-template<typename T, typename Comparator = std::less<T> >
- class LoserTreeExplicit
- {
- private:
- struct Loser
+ /**
+ * @brief Guarded loser/tournament tree.
+ *
+ * The smallest element is at the top.
+ *
+ * Guarding is done explicitly through one flag _M_sup per element,
+ * inf is not needed due to a better initialization routine. This
+ * is a well-performing variant.
+ *
+ * @param _Tp the element type
+ * @param _Compare the comparator to use, defaults to std::less<_Tp>
+ */
+ template<typename _Tp, typename _Compare>
+ class _LoserTreeBase
{
- // The relevant element.
- T key;
-
- // Is this an infimum or supremum element?
- bool inf, sup;
-
- // Number of the sequence the element comes from.
- int source;
+ protected:
+ /** @brief Internal representation of a _LoserTree element. */
+ struct _Loser
+ {
+ /** @brief flag, true iff this is a "maximum" __sentinel. */
+ bool _M_sup;
+ /** @brief __index of the __source __sequence. */
+ int _M_source;
+ /** @brief _M_key of the element in the _LoserTree. */
+ _Tp _M_key;
+ };
+
+ unsigned int _M_ik, _M_k, _M_offset;
+
+ /** log_2{_M_k} */
+ unsigned int _M_log_k;
+
+ /** @brief _LoserTree __elements. */
+ _Loser* _M_losers;
+
+ /** @brief _Compare to use. */
+ _Compare _M_comp;
+
+ /**
+ * @brief State flag that determines whether the _LoserTree is empty.
+ *
+ * Only used for building the _LoserTree.
+ */
+ bool _M_first_insert;
+
+ public:
+ /**
+ * @brief The constructor.
+ *
+ * @param __k The number of sequences to merge.
+ * @param __comp The comparator to use.
+ */
+ _LoserTreeBase(unsigned int __k, _Compare __comp)
+ : _M_comp(__comp)
+ {
+ _M_ik = __k;
+
+ // Compute log_2{_M_k} for the _Loser Tree
+ _M_log_k = __rd_log2(_M_ik - 1) + 1;
+
+ // Next greater power of 2.
+ _M_k = 1 << _M_log_k;
+ _M_offset = _M_k;
+
+ // Avoid default-constructing _M_losers[]._M_key
+ _M_losers = static_cast<_Loser*>(::operator new(2 * _M_k
+ * sizeof(_Loser)));
+ for (unsigned int __i = _M_ik - 1; __i < _M_k; ++__i)
+ _M_losers[__i + _M_k]._M_sup = true;
+
+ _M_first_insert = true;
+ }
+
+ /**
+ * @brief The destructor.
+ */
+ ~_LoserTreeBase()
+ {
+ for (unsigned int __i = 0; __i < (2 * _M_k); ++__i)
+ _M_losers[__i].~_Loser();
+ ::operator delete(_M_losers);
+ }
+
+ /**
+ * @brief Initializes the sequence "_M_source" with the element "__key".
+ *
+ * @param __key the element to insert
+ * @param __source __index of the __source __sequence
+ * @param __sup flag that determines whether the value to insert is an
+ * explicit __supremum.
+ */
+ void
+ __insert_start(const _Tp& __key, int __source, bool __sup)
+ {
+ unsigned int __pos = _M_k + __source;
+
+ if (_M_first_insert)
+ {
+ // Construct all keys, so we can easily destruct them.
+ for (unsigned int __i = 0; __i < (2 * _M_k); ++__i)
+ ::new(&(_M_losers[__i]._M_key)) _Tp(__key);
+ _M_first_insert = false;
+ }
+ else
+ _M_losers[__pos]._M_key = __key;
+
+ _M_losers[__pos]._M_sup = __sup;
+ _M_losers[__pos]._M_source = __source;
+ }
+
+ /**
+ * @return the index of the sequence with the smallest element.
+ */
+ int __get_min_source()
+ { return _M_losers[0]._M_source; }
};
- unsigned int size, offset;
- Loser* losers;
- Comparator comp;
-
- public:
- inline
- LoserTreeExplicit(unsigned int _size, Comparator _comp = std::less<T>())
- : comp(_comp)
- {
- size = _size;
- offset = size;
- losers = new Loser[size];
- for (unsigned int l = 0; l < size; l++)
- {
- //losers[l].key = ... stays unset
- losers[l].inf = true;
- losers[l].sup = false;
- //losers[l].source = -1; //sentinel
- }
- }
-
- inline ~LoserTreeExplicit()
- { delete[] losers; }
-
- inline int
- get_min_source()
- { return losers[0].source; }
-
- inline void
- insert_start(T key, int source, bool sup)
- {
- bool inf = false;
- for (unsigned int pos = (offset + source) / 2; pos > 0; pos /= 2)
- {
- if ((!inf && !losers[pos].inf && !sup && !losers[pos].sup
- && comp(losers[pos].key, key)) || losers[pos].inf || sup)
- {
- // The other one is smaller.
- std::swap(losers[pos].key, key);
- std::swap(losers[pos].inf, inf);
- std::swap(losers[pos].sup, sup);
- std::swap(losers[pos].source, source);
- }
- }
-
- losers[0].key = key;
- losers[0].inf = inf;
- losers[0].sup = sup;
- losers[0].source = source;
- }
-
- inline void
- init() { }
-
- inline void
- delete_min_insert(T key, bool sup)
- {
- bool inf = false;
- int source = losers[0].source;
- for (unsigned int pos = (offset + source) / 2; pos > 0; pos /= 2)
- {
- // The smaller one gets promoted.
- if ((!inf && !losers[pos].inf && !sup && !losers[pos].sup
- && comp(losers[pos].key, key))
- || losers[pos].inf || sup)
- {
- // The other one is smaller.
- std::swap(losers[pos].key, key);
- std::swap(losers[pos].inf, inf);
- std::swap(losers[pos].sup, sup);
- std::swap(losers[pos].source, source);
- }
- }
-
- losers[0].key = key;
- losers[0].inf = inf;
- losers[0].sup = sup;
- losers[0].source = source;
- }
-
- inline void
- insert_start_stable(T key, int source, bool sup)
- {
- bool inf = false;
- for (unsigned int pos = (offset + source) / 2; pos > 0; pos /= 2)
- {
- if ((!inf && !losers[pos].inf && !sup && !losers[pos].sup &&
- ((comp(losers[pos].key, key)) ||
- (!comp(key, losers[pos].key) && losers[pos].source < source)))
- || losers[pos].inf || sup)
- {
- // Take next key.
- std::swap(losers[pos].key, key);
- std::swap(losers[pos].inf, inf);
- std::swap(losers[pos].sup, sup);
- std::swap(losers[pos].source, source);
- }
- }
-
- losers[0].key = key;
- losers[0].inf = inf;
- losers[0].sup = sup;
- losers[0].source = source;
- }
-
- inline void
- init_stable() { }
-
- inline void
- delete_min_insert_stable(T key, bool sup)
+ /**
+ * @brief Stable _LoserTree variant.
+ *
+ * Provides the stable implementations of insert_start, __init_winner,
+ * __init and __delete_min_insert.
+ *
+ * Unstable variant is done using partial specialisation below.
+ */
+ template<bool __stable/* default == true */, typename _Tp,
+ typename _Compare>
+ class _LoserTree
+ : public _LoserTreeBase<_Tp, _Compare>
{
- bool inf = false;
- int source = losers[0].source;
- for (unsigned int pos = (offset + source) / 2; pos > 0; pos /= 2)
- {
- if ((!inf && !losers[pos].inf && !sup && !losers[pos].sup
- && ((comp(losers[pos].key, key)) ||
- (!comp(key, losers[pos].key) && losers[pos].source < source)))
- || losers[pos].inf || sup)
- {
- std::swap(losers[pos].key, key);
- std::swap(losers[pos].inf, inf);
- std::swap(losers[pos].sup, sup);
- std::swap(losers[pos].source, source);
- }
- }
-
- losers[0].key = key;
- losers[0].inf = inf;
- losers[0].sup = sup;
- losers[0].source = source;
- }
- };
-
+ typedef _LoserTreeBase<_Tp, _Compare> _Base;
+ using _Base::_M_k;
+ using _Base::_M_losers;
+ using _Base::_M_first_insert;
+
+ public:
+ _LoserTree(unsigned int __k, _Compare __comp)
+ : _Base::_LoserTreeBase(__k, __comp)
+ { }
+
+ unsigned int
+ __init_winner(unsigned int __root)
+ {
+ if (__root >= _M_k)
+ return __root;
+ else
+ {
+ unsigned int __left = __init_winner(2 * __root);
+ unsigned int __right = __init_winner(2 * __root + 1);
+ if (_M_losers[__right]._M_sup
+ || (!_M_losers[__left]._M_sup
+ && !_M_comp(_M_losers[__right]._M_key,
+ _M_losers[__left]._M_key)))
+ {
+ // Left one is less or equal.
+ _M_losers[__root] = _M_losers[__right];
+ return __left;
+ }
+ else
+ {
+ // Right one is less.
+ _M_losers[__root] = _M_losers[__left];
+ return __right;
+ }
+ }
+ }
+
+ void __init()
+ { _M_losers[0] = _M_losers[__init_winner(1)]; }
+
+ /**
+ * @brief Delete the smallest element and insert a new element from
+ * the previously smallest element's sequence.
+ *
+ * This implementation is stable.
+ */
+ // Do not pass a const reference since __key will be used as
+ // local variable.
+ void
+ __delete_min_insert(_Tp __key, bool __sup)
+ {
+ using std::swap;
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top!
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
#endif
-#if _GLIBCXX_LOSER_TREE
-
-/** @brief Guarded loser tree, either copying the whole element into
-* the tree structure, or looking up the element via the index.
-*
-* Guarding is done explicitly through one flag sup per element,
-* inf is not needed due to a better initialization routine. This
-* is a well-performing variant.
-*/
-template<typename T, typename Comparator = std::less<T> >
- class LoserTree
- {
- private:
- struct Loser
- {
- bool sup;
- int source;
- T key;
+ int __source = _M_losers[0]._M_source;
+ for (unsigned int __pos = (_M_k + __source) / 2; __pos > 0;
+ __pos /= 2)
+ {
+ // The smaller one gets promoted, ties are broken by _M_source.
+ if ((__sup && (!_M_losers[__pos]._M_sup
+ || _M_losers[__pos]._M_source < __source))
+ || (!__sup && !_M_losers[__pos]._M_sup
+ && ((_M_comp(_M_losers[__pos]._M_key, __key))
+ || (!_M_comp(__key, _M_losers[__pos]._M_key)
+ && _M_losers[__pos]._M_source < __source))))
+ {
+ // The other one is smaller.
+ std::swap(_M_losers[__pos]._M_sup, __sup);
+ std::swap(_M_losers[__pos]._M_source, __source);
+ swap(_M_losers[__pos]._M_key, __key);
+ }
+ }
+
+ _M_losers[0]._M_sup = __sup;
+ _M_losers[0]._M_source = __source;
+ _M_losers[0]._M_key = __key;
+ }
};
- unsigned int ik, k, offset;
- Loser* losers;
- Comparator comp;
- bool first_insert;
-
- public:
- inline LoserTree(unsigned int _k, Comparator _comp = std::less<T>())
- : comp(_comp)
- {
- ik = _k;
-
- // Next greater power of 2.
- k = 1 << (log2(ik - 1) + 1);
- offset = k;
- // Avoid default-constructing losers[].key
- losers = static_cast<Loser*>(::operator new(2 * k * sizeof(Loser)));
- for (unsigned int i = ik - 1; i < k; ++i)
- losers[i + k].sup = true;
-
- first_insert = true;
- }
-
- inline ~LoserTree()
- { delete[] losers; }
-
- inline int
- get_min_source()
- { return losers[0].source; }
-
- inline void
- insert_start(const T& key, int source, bool sup)
- {
- unsigned int pos = k + source;
-
- if(first_insert)
- {
- // Construct all keys, so we can easily deconstruct them.
- for (unsigned int i = 0; i < (2 * k); ++i)
- ::new(&(losers[i].key)) T(key);
- first_insert = false;
- }
- else
- ::new(&(losers[pos].key)) T(key);
-
- losers[pos].sup = sup;
- losers[pos].source = source;
- }
-
- unsigned int
- init_winner (unsigned int root)
+ /**
+ * @brief Unstable _LoserTree variant.
+ *
+ * Stability (non-stable here) is selected with partial specialization.
+ */
+ template<typename _Tp, typename _Compare>
+ class _LoserTree</* __stable == */false, _Tp, _Compare>
+ : public _LoserTreeBase<_Tp, _Compare>
{
- if (root >= k)
- {
- return root;
- }
- else
- {
- unsigned int left = init_winner (2 * root);
- unsigned int right = init_winner (2 * root + 1);
- if (losers[right].sup ||
- (!losers[left].sup
- && !comp(losers[right].key, losers[left].key)))
- {
- // Left one is less or equal.
- losers[root] = losers[right];
- return left;
- }
- else
- {
- // Right one is less.
- losers[root] = losers[left];
- return right;
- }
- }
- }
-
- inline void
- init()
- { losers[0] = losers[init_winner(1)]; }
-
- // Do not pass const reference since key will be used as local variable.
- inline void
- delete_min_insert(T key, bool sup)
- {
- int source = losers[0].source;
- for (unsigned int pos = (k + source) / 2; pos > 0; pos /= 2)
- {
- // The smaller one gets promoted.
- if (sup || (!losers[pos].sup && comp(losers[pos].key, key)))
- {
- // The other one is smaller.
- std::swap(losers[pos].sup, sup);
- std::swap(losers[pos].source, source);
- std::swap(losers[pos].key, key);
- }
- }
-
- losers[0].sup = sup;
- losers[0].source = source;
- losers[0].key = key;
- }
-
- inline void
- insert_start_stable(const T& key, int source, bool sup)
- { return insert_start(key, source, sup); }
-
- unsigned int
- init_winner_stable (unsigned int root)
- {
- if (root >= k)
- {
- return root;
- }
- else
- {
- unsigned int left = init_winner (2 * root);
- unsigned int right = init_winner (2 * root + 1);
- if (losers[right].sup
- || (!losers[left].sup
- && !comp(losers[right].key, losers[left].key)))
- {
- // Left one is less or equal.
- losers[root] = losers[right];
- return left;
- }
- else
- {
- // Right one is less.
- losers[root] = losers[left];
- return right;
- }
- }
- }
-
- inline void
- init_stable()
- { losers[0] = losers[init_winner_stable(1)]; }
-
- // Do not pass const reference since key will be used as local variable.
- inline void
- delete_min_insert_stable(T key, bool sup)
- {
- int source = losers[0].source;
- for (unsigned int pos = (k + source) / 2; pos > 0; pos /= 2)
- {
- // The smaller one gets promoted, ties are broken by source.
- if ( (sup && (!losers[pos].sup || losers[pos].source < source))
- || (!sup && !losers[pos].sup
- && ((comp(losers[pos].key, key))
- || (!comp(key, losers[pos].key)
- && losers[pos].source < source))))
- {
- // The other one is smaller.
- std::swap(losers[pos].sup, sup);
- std::swap(losers[pos].source, source);
- std::swap(losers[pos].key, key);
- }
- }
-
- losers[0].sup = sup;
- losers[0].source = source;
- losers[0].key = key;
- }
- };
-
+ typedef _LoserTreeBase<_Tp, _Compare> _Base;
+ using _Base::_M_log_k;
+ using _Base::_M_k;
+ using _Base::_M_losers;
+ using _Base::_M_first_insert;
+
+ public:
+ _LoserTree(unsigned int __k, _Compare __comp)
+ : _Base::_LoserTreeBase(__k, __comp)
+ { }
+
+ /**
+ * Computes the winner of the competition at position "__root".
+ *
+ * Called recursively (starting at 0) to build the initial tree.
+ *
+ * @param __root __index of the "game" to start.
+ */
+ unsigned int
+ __init_winner(unsigned int __root)
+ {
+ if (__root >= _M_k)
+ return __root;
+ else
+ {
+ unsigned int __left = __init_winner(2 * __root);
+ unsigned int __right = __init_winner(2 * __root + 1);
+ if (_M_losers[__right]._M_sup
+ || (!_M_losers[__left]._M_sup
+ && !_M_comp(_M_losers[__right]._M_key,
+ _M_losers[__left]._M_key)))
+ {
+ // Left one is less or equal.
+ _M_losers[__root] = _M_losers[__right];
+ return __left;
+ }
+ else
+ {
+ // Right one is less.
+ _M_losers[__root] = _M_losers[__left];
+ return __right;
+ }
+ }
+ }
+
+ void
+ __init()
+ { _M_losers[0] = _M_losers[__init_winner(1)]; }
+
+ /**
+ * Delete the _M_key smallest element and insert the element __key
+ * instead.
+ *
+ * @param __key the _M_key to insert
+ * @param __sup true iff __key is an explicitly marked supremum
+ */
+ // Do not pass a const reference since __key will be used as local
+ // variable.
+ void
+ __delete_min_insert(_Tp __key, bool __sup)
+ {
+ using std::swap;
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top!
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
#endif
-#if _GLIBCXX_LOSER_TREE_REFERENCE
+ int __source = _M_losers[0]._M_source;
+ for (unsigned int __pos = (_M_k + __source) / 2; __pos > 0;
+ __pos /= 2)
+ {
+ // The smaller one gets promoted.
+ if (__sup || (!_M_losers[__pos]._M_sup
+ && _M_comp(_M_losers[__pos]._M_key, __key)))
+ {
+ // The other one is smaller.
+ std::swap(_M_losers[__pos]._M_sup, __sup);
+ std::swap(_M_losers[__pos]._M_source, __source);
+ swap(_M_losers[__pos]._M_key, __key);
+ }
+ }
+
+ _M_losers[0]._M_sup = __sup;
+ _M_losers[0]._M_source = __source;
+ _M_losers[0]._M_key = __key;
+ }
+ };
-/** @brief Guarded loser tree, either copying the whole element into
-* the tree structure, or looking up the element via the index.
-*
-* Guarding is done explicitly through one flag sup per element,
-* inf is not needed due to a better initialization routine. This
-* is a well-performing variant.
-*/
-template<typename T, typename Comparator = std::less<T> >
- class LoserTreeReference
- {
-#undef COPY
-#ifdef COPY
-#define KEY(i) losers[i].key
-#define KEY_SOURCE(i) key
-#else
-#define KEY(i) keys[losers[i].source]
-#define KEY_SOURCE(i) keys[i]
-#endif
- private:
- struct Loser
+ /**
+ * @brief Base class of _Loser Tree implementation using pointers.
+ */
+ template<typename _Tp, typename _Compare>
+ class _LoserTreePointerBase
{
- bool sup;
- int source;
-#ifdef COPY
- T key;
-#endif
+ protected:
+ /** @brief Internal representation of _LoserTree __elements. */
+ struct _Loser
+ {
+ bool _M_sup;
+ int _M_source;
+ const _Tp* _M_keyp;
+ };
+
+ unsigned int _M_ik, _M_k, _M_offset;
+ _Loser* _M_losers;
+ _Compare _M_comp;
+
+ public:
+ _LoserTreePointerBase(unsigned int __k,
+ _Compare __comp = std::less<_Tp>())
+ : _M_comp(__comp)
+ {
+ _M_ik = __k;
+
+ // Next greater power of 2.
+ _M_k = 1 << (__rd_log2(_M_ik - 1) + 1);
+ _M_offset = _M_k;
+ _M_losers = new _Loser[_M_k * 2];
+ for (unsigned int __i = _M_ik - 1; __i < _M_k; __i++)
+ _M_losers[__i + _M_k]._M_sup = true;
+ }
+
+ ~_LoserTreePointerBase()
+ { delete[] _M_losers; }
+
+ int __get_min_source()
+ { return _M_losers[0]._M_source; }
+
+ void __insert_start(const _Tp& __key, int __source, bool __sup)
+ {
+ unsigned int __pos = _M_k + __source;
+
+ _M_losers[__pos]._M_sup = __sup;
+ _M_losers[__pos]._M_source = __source;
+ _M_losers[__pos]._M_keyp = &__key;
+ }
};
- unsigned int ik, k, offset;
- Loser* losers;
-#ifndef COPY
- T* keys;
-#endif
- Comparator comp;
-
- public:
- inline
- LoserTreeReference(unsigned int _k, Comparator _comp = std::less<T>())
- : comp(_comp)
+ /**
+ * @brief Stable _LoserTree implementation.
+ *
+ * The unstable variant is implemented using partial instantiation below.
+ */
+ template<bool __stable/* default == true */, typename _Tp, typename _Compare>
+ class _LoserTreePointer
+ : public _LoserTreePointerBase<_Tp, _Compare>
{
- ik = _k;
-
- // Next greater power of 2.
- k = 1 << (log2(ik - 1) + 1);
- offset = k;
- losers = new Loser[k * 2];
-#ifndef COPY
- keys = new T[ik];
+ typedef _LoserTreePointerBase<_Tp, _Compare> _Base;
+ using _Base::_M_k;
+ using _Base::_M_losers;
+
+ public:
+ _LoserTreePointer(unsigned int __k, _Compare __comp = std::less<_Tp>())
+ : _Base::_LoserTreePointerBase(__k, __comp)
+ { }
+
+ unsigned int
+ __init_winner(unsigned int __root)
+ {
+ if (__root >= _M_k)
+ return __root;
+ else
+ {
+ unsigned int __left = __init_winner(2 * __root);
+ unsigned int __right = __init_winner(2 * __root + 1);
+ if (_M_losers[__right]._M_sup
+ || (!_M_losers[__left]._M_sup
+ && !_M_comp(*_M_losers[__right]._M_keyp,
+ *_M_losers[__left]._M_keyp)))
+ {
+ // Left one is less or equal.
+ _M_losers[__root] = _M_losers[__right];
+ return __left;
+ }
+ else
+ {
+ // Right one is less.
+ _M_losers[__root] = _M_losers[__left];
+ return __right;
+ }
+ }
+ }
+
+ void __init()
+ { _M_losers[0] = _M_losers[__init_winner(1)]; }
+
+ void __delete_min_insert(const _Tp& __key, bool __sup)
+ {
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top!
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
#endif
- for (unsigned int i = ik - 1; i < k; i++)
- losers[i + k].sup = true;
- }
- inline ~LoserTreeReference()
+ const _Tp* __keyp = &__key;
+ int __source = _M_losers[0]._M_source;
+ for (unsigned int __pos = (_M_k + __source) / 2; __pos > 0;
+ __pos /= 2)
+ {
+ // The smaller one gets promoted, ties are broken by __source.
+ if ((__sup && (!_M_losers[__pos]._M_sup
+ || _M_losers[__pos]._M_source < __source))
+ || (!__sup && !_M_losers[__pos]._M_sup &&
+ ((_M_comp(*_M_losers[__pos]._M_keyp, *__keyp))
+ || (!_M_comp(*__keyp, *_M_losers[__pos]._M_keyp)
+ && _M_losers[__pos]._M_source < __source))))
+ {
+ // The other one is smaller.
+ std::swap(_M_losers[__pos]._M_sup, __sup);
+ std::swap(_M_losers[__pos]._M_source, __source);
+ std::swap(_M_losers[__pos]._M_keyp, __keyp);
+ }
+ }
+
+ _M_losers[0]._M_sup = __sup;
+ _M_losers[0]._M_source = __source;
+ _M_losers[0]._M_keyp = __keyp;
+ }
+ };
+
+ /**
+ * @brief Unstable _LoserTree implementation.
+ *
+ * The stable variant is above.
+ */
+ template<typename _Tp, typename _Compare>
+ class _LoserTreePointer</* __stable == */false, _Tp, _Compare>
+ : public _LoserTreePointerBase<_Tp, _Compare>
{
- delete[] losers;
-#ifndef COPY
- delete[] keys;
+ typedef _LoserTreePointerBase<_Tp, _Compare> _Base;
+ using _Base::_M_k;
+ using _Base::_M_losers;
+
+ public:
+ _LoserTreePointer(unsigned int __k, _Compare __comp = std::less<_Tp>())
+ : _Base::_LoserTreePointerBase(__k, __comp)
+ { }
+
+ unsigned int
+ __init_winner(unsigned int __root)
+ {
+ if (__root >= _M_k)
+ return __root;
+ else
+ {
+ unsigned int __left = __init_winner(2 * __root);
+ unsigned int __right = __init_winner(2 * __root + 1);
+ if (_M_losers[__right]._M_sup
+ || (!_M_losers[__left]._M_sup
+ && !_M_comp(*_M_losers[__right]._M_keyp,
+ *_M_losers[__left]._M_keyp)))
+ {
+ // Left one is less or equal.
+ _M_losers[__root] = _M_losers[__right];
+ return __left;
+ }
+ else
+ {
+ // Right one is less.
+ _M_losers[__root] = _M_losers[__left];
+ return __right;
+ }
+ }
+ }
+
+ void __init()
+ { _M_losers[0] = _M_losers[__init_winner(1)]; }
+
+ void __delete_min_insert(const _Tp& __key, bool __sup)
+ {
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top!
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
#endif
- }
- inline int
- get_min_source()
- { return losers[0].source; }
+ const _Tp* __keyp = &__key;
+ int __source = _M_losers[0]._M_source;
+ for (unsigned int __pos = (_M_k + __source) / 2; __pos > 0;
+ __pos /= 2)
+ {
+ // The smaller one gets promoted.
+ if (__sup || (!_M_losers[__pos]._M_sup
+ && _M_comp(*_M_losers[__pos]._M_keyp, *__keyp)))
+ {
+ // The other one is smaller.
+ std::swap(_M_losers[__pos]._M_sup, __sup);
+ std::swap(_M_losers[__pos]._M_source, __source);
+ std::swap(_M_losers[__pos]._M_keyp, __keyp);
+ }
+ }
+
+ _M_losers[0]._M_sup = __sup;
+ _M_losers[0]._M_source = __source;
+ _M_losers[0]._M_keyp = __keyp;
+ }
+ };
- inline void
- insert_start(T key, int source, bool sup)
+ /** @brief Base class for unguarded _LoserTree implementation.
+ *
+ * The whole element is copied into the tree structure.
+ *
+ * No guarding is done, therefore not a single input sequence must
+ * run empty. Unused __sequence heads are marked with a sentinel which
+ * is > all elements that are to be merged.
+ *
+ * This is a very fast variant.
+ */
+ template<typename _Tp, typename _Compare>
+ class _LoserTreeUnguardedBase
{
- unsigned int pos = k + source;
+ protected:
+ struct _Loser
+ {
+ int _M_source;
+ _Tp _M_key;
+ };
+
+ unsigned int _M_ik, _M_k, _M_offset;
+ _Loser* _M_losers;
+ _Compare _M_comp;
+
+ public:
+ _LoserTreeUnguardedBase(unsigned int __k, const _Tp& __sentinel,
+ _Compare __comp = std::less<_Tp>())
+ : _M_comp(__comp)
+ {
+ _M_ik = __k;
+
+ // Next greater power of 2.
+ _M_k = 1 << (__rd_log2(_M_ik - 1) + 1);
+ _M_offset = _M_k;
+ // Avoid default-constructing _M_losers[]._M_key
+ _M_losers = static_cast<_Loser*>(::operator new(2 * _M_k
+ * sizeof(_Loser)));
+
+ for (unsigned int __i = 0; __i < _M_k; ++__i)
+ {
+ ::new(&(_M_losers[__i]._M_key)) _Tp(__sentinel);
+ _M_losers[__i]._M_source = -1;
+ }
+ for (unsigned int __i = _M_k + _M_ik - 1; __i < (2 * _M_k); ++__i)
+ {
+ ::new(&(_M_losers[__i]._M_key)) _Tp(__sentinel);
+ _M_losers[__i]._M_source = -1;
+ }
+ }
+
+ ~_LoserTreeUnguardedBase()
+ {
+ for (unsigned int __i = 0; __i < (2 * _M_k); ++__i)
+ _M_losers[__i].~_Loser();
+ ::operator delete(_M_losers);
+ }
+
+ int
+ __get_min_source()
+ {
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top!
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
+#endif
+ return _M_losers[0]._M_source;
+ }
- losers[pos].sup = sup;
- losers[pos].source = source;
- KEY(pos) = key;
- }
+ void
+ __insert_start(const _Tp& __key, int __source, bool)
+ {
+ unsigned int __pos = _M_k + __source;
- unsigned int
- init_winner(unsigned int root)
- {
- if (root >= k)
- {
- return root;
- }
- else
- {
- unsigned int left = init_winner (2 * root);
- unsigned int right = init_winner (2 * root + 1);
- if ( losers[right].sup ||
- (!losers[left].sup && !comp(KEY(right), KEY(left))))
- {
- // Left one is less or equal.
- losers[root] = losers[right];
- return left;
- }
- else
- {
- // Right one is less.
- losers[root] = losers[left];
- return right;
- }
- }
- }
-
- inline void
- init()
- {
- losers[0] = losers[init_winner(1)];
- }
+ ::new(&(_M_losers[__pos]._M_key)) _Tp(__key);
+ _M_losers[__pos]._M_source = __source;
+ }
+ };
- inline void
- delete_min_insert(T key, bool sup)
+ /**
+ * @brief Stable implementation of unguarded _LoserTree.
+ *
+ * Unstable variant is selected below with partial specialization.
+ */
+ template<bool __stable/* default == true */, typename _Tp, typename _Compare>
+ class _LoserTreeUnguarded
+ : public _LoserTreeUnguardedBase<_Tp, _Compare>
{
- int source = losers[0].source;
- for (unsigned int pos = (k + source) / 2; pos > 0; pos /= 2)
- {
- // The smaller one gets promoted.
- if (sup || (!losers[pos].sup && comp(KEY(pos), KEY_SOURCE(source))))
- {
- // The other one is smaller.
- std::swap(losers[pos].sup, sup);
- std::swap(losers[pos].source, source);
-#ifdef COPY
- std::swap(KEY(pos), KEY_SOURCE(source));
-#endif
- }
- }
+ typedef _LoserTreeUnguardedBase<_Tp, _Compare> _Base;
+ using _Base::_M_k;
+ using _Base::_M_losers;
- losers[0].sup = sup;
- losers[0].source = source;
-#ifdef COPY
- KEY(0) = KEY_SOURCE(source);
+ public:
+ _LoserTreeUnguarded(unsigned int __k, const _Tp& __sentinel,
+ _Compare __comp = std::less<_Tp>())
+ : _Base::_LoserTreeUnguardedBase(__k, __sentinel, __comp)
+ { }
+
+ unsigned int
+ __init_winner(unsigned int __root)
+ {
+ if (__root >= _M_k)
+ return __root;
+ else
+ {
+ unsigned int __left = __init_winner(2 * __root);
+ unsigned int __right = __init_winner(2 * __root + 1);
+ if (!_M_comp(_M_losers[__right]._M_key,
+ _M_losers[__left]._M_key))
+ {
+ // Left one is less or equal.
+ _M_losers[__root] = _M_losers[__right];
+ return __left;
+ }
+ else
+ {
+ // Right one is less.
+ _M_losers[__root] = _M_losers[__left];
+ return __right;
+ }
+ }
+ }
+
+ void
+ __init()
+ {
+ _M_losers[0] = _M_losers[__init_winner(1)];
+
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top at the beginning
+ // (0 sequences!)
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
+#endif
+ }
+
+ // Do not pass a const reference since __key will be used as
+ // local variable.
+ void
+ __delete_min_insert(_Tp __key, bool)
+ {
+ using std::swap;
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top!
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
#endif
- }
- inline void
- insert_start_stable(T key, int source, bool sup)
- { return insert_start(key, source, sup); }
+ int __source = _M_losers[0]._M_source;
+ for (unsigned int __pos = (_M_k + __source) / 2; __pos > 0;
+ __pos /= 2)
+ {
+ // The smaller one gets promoted, ties are broken by _M_source.
+ if (_M_comp(_M_losers[__pos]._M_key, __key)
+ || (!_M_comp(__key, _M_losers[__pos]._M_key)
+ && _M_losers[__pos]._M_source < __source))
+ {
+ // The other one is smaller.
+ std::swap(_M_losers[__pos]._M_source, __source);
+ swap(_M_losers[__pos]._M_key, __key);
+ }
+ }
+
+ _M_losers[0]._M_source = __source;
+ _M_losers[0]._M_key = __key;
+ }
+ };
- unsigned int
- init_winner_stable(unsigned int root)
+ /**
+ * @brief Non-Stable implementation of unguarded _LoserTree.
+ *
+ * Stable implementation is above.
+ */
+ template<typename _Tp, typename _Compare>
+ class _LoserTreeUnguarded</* __stable == */false, _Tp, _Compare>
+ : public _LoserTreeUnguardedBase<_Tp, _Compare>
{
- if (root >= k)
- {
- return root;
- }
- else
- {
- unsigned int left = init_winner (2 * root);
- unsigned int right = init_winner (2 * root + 1);
- if (losers[right].sup
- || (!losers[left].sup && !comp(KEY(right), KEY(left))))
- {
- // Left one is less or equal.
- losers[root] = losers[right];
- return left;
- }
- else
- {
- // Right one is less.
- losers[root] = losers[left];
- return right;
- }
- }
- }
-
- inline void
- init_stable()
- { losers[0] = losers[init_winner_stable(1)]; }
-
- inline void
- delete_min_insert_stable(T key, bool sup)
- {
- int source = losers[0].source;
- for (unsigned int pos = (k + source) / 2; pos > 0; pos /= 2)
- {
- // The smaller one gets promoted, ties are broken by source.
- if ( (sup && (!losers[pos].sup || losers[pos].source < source)) ||
- (!sup && !losers[pos].sup &&
- ((comp(KEY(pos), KEY_SOURCE(source))) ||
- (!comp(KEY_SOURCE(source), KEY(pos))
- && losers[pos].source < source))))
- {
- // The other one is smaller.
- std::swap(losers[pos].sup, sup);
- std::swap(losers[pos].source, source);
-#ifdef COPY
- std::swap(KEY(pos), KEY_SOURCE(source));
+ typedef _LoserTreeUnguardedBase<_Tp, _Compare> _Base;
+ using _Base::_M_k;
+ using _Base::_M_losers;
+
+ public:
+ _LoserTreeUnguarded(unsigned int __k, const _Tp& __sentinel,
+ _Compare __comp = std::less<_Tp>())
+ : _Base::_LoserTreeUnguardedBase(__k, __sentinel, __comp)
+ { }
+
+ unsigned int
+ __init_winner(unsigned int __root)
+ {
+ if (__root >= _M_k)
+ return __root;
+ else
+ {
+ unsigned int __left = __init_winner(2 * __root);
+ unsigned int __right = __init_winner(2 * __root + 1);
+
+#if _GLIBCXX_ASSERTIONS
+ // If __left one is sentinel then __right one must be, too.
+ if (_M_losers[__left]._M_source == -1)
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[__right]._M_source == -1);
#endif
- }
- }
- losers[0].sup = sup;
- losers[0].source = source;
-#ifdef COPY
- KEY(0) = KEY_SOURCE(source);
+ if (!_M_comp(_M_losers[__right]._M_key,
+ _M_losers[__left]._M_key))
+ {
+ // Left one is less or equal.
+ _M_losers[__root] = _M_losers[__right];
+ return __left;
+ }
+ else
+ {
+ // Right one is less.
+ _M_losers[__root] = _M_losers[__left];
+ return __right;
+ }
+ }
+ }
+
+ void
+ __init()
+ {
+ _M_losers[0] = _M_losers[__init_winner(1)];
+
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top at the beginning
+ // (0 sequences!)
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
#endif
- }
- };
-#undef KEY
-#undef KEY_SOURCE
-
+ }
+
+ // Do not pass a const reference since __key will be used as
+ // local variable.
+ void
+ __delete_min_insert(_Tp __key, bool)
+ {
+ using std::swap;
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top!
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
#endif
-#if _GLIBCXX_LOSER_TREE_POINTER
-
-/** @brief Guarded loser tree, either copying the whole element into
- the tree structure, or looking up the element via the index.
-* Guarding is done explicitly through one flag sup per element,
-* inf is not needed due to a better initialization routine.
-* This is a well-performing variant.
-*/
-template<typename T, typename Comparator = std::less<T> >
- class LoserTreePointer
- {
- private:
- struct Loser
- {
- bool sup;
- int source;
- const T* keyp;
+ int __source = _M_losers[0]._M_source;
+ for (unsigned int __pos = (_M_k + __source) / 2; __pos > 0;
+ __pos /= 2)
+ {
+ // The smaller one gets promoted.
+ if (_M_comp(_M_losers[__pos]._M_key, __key))
+ {
+ // The other one is smaller.
+ std::swap(_M_losers[__pos]._M_source, __source);
+ swap(_M_losers[__pos]._M_key, __key);
+ }
+ }
+
+ _M_losers[0]._M_source = __source;
+ _M_losers[0]._M_key = __key;
+ }
};
- unsigned int ik, k, offset;
- Loser* losers;
- Comparator comp;
-
- public:
- inline
- LoserTreePointer(unsigned int _k, Comparator _comp = std::less<T>())
- : comp(_comp)
- {
- ik = _k;
-
- // Next greater power of 2.
- k = 1 << (log2(ik - 1) + 1);
- offset = k;
- losers = new Loser[k * 2];
- for (unsigned int i = ik - 1; i < k; i++)
- losers[i + k].sup = true;
- }
-
- inline ~LoserTreePointer()
- { delete[] losers; }
-
- inline int
- get_min_source()
- { return losers[0].source; }
-
- inline void
- insert_start(const T& key, int source, bool sup)
- {
- unsigned int pos = k + source;
-
- losers[pos].sup = sup;
- losers[pos].source = source;
- losers[pos].keyp = &key;
- }
-
- unsigned int
- init_winner(unsigned int root)
- {
- if (root >= k)
- {
- return root;
- }
- else
- {
- unsigned int left = init_winner (2 * root);
- unsigned int right = init_winner (2 * root + 1);
- if (losers[right].sup
- || (!losers[left].sup
- && !comp(*losers[right].keyp, *losers[left].keyp)))
- {
- // Left one is less or equal.
- losers[root] = losers[right];
- return left;
- }
- else
- {
- // Right one is less.
- losers[root] = losers[left];
- return right;
- }
- }
- }
-
- inline void
- init()
- { losers[0] = losers[init_winner(1)]; }
-
- inline void
- delete_min_insert(const T& key, bool sup)
+ /** @brief Unguarded loser tree, keeping only pointers to the
+ * elements in the tree structure.
+ *
+ * No guarding is done, therefore not a single input sequence must
+ * run empty. This is a very fast variant.
+ */
+ template<typename _Tp, typename _Compare>
+ class _LoserTreePointerUnguardedBase
{
- const T* keyp = &key;
- int source = losers[0].source;
- for (unsigned int pos = (k + source) / 2; pos > 0; pos /= 2)
- {
- // The smaller one gets promoted.
- if (sup || (!losers[pos].sup && comp(*losers[pos].keyp, *keyp)))
- {
- // The other one is smaller.
- std::swap(losers[pos].sup, sup);
- std::swap(losers[pos].source, source);
- std::swap(losers[pos].keyp, keyp);
- }
- }
-
- losers[0].sup = sup;
- losers[0].source = source;
- losers[0].keyp = keyp;
- }
-
- inline void
- insert_start_stable(const T& key, int source, bool sup)
- { return insert_start(key, source, sup); }
-
- unsigned int
- init_winner_stable(unsigned int root)
- {
- if (root >= k)
- {
- return root;
- }
- else
- {
- unsigned int left = init_winner (2 * root);
- unsigned int right = init_winner (2 * root + 1);
- if (losers[right].sup
- || (!losers[left].sup && !comp(*losers[right].keyp,
- *losers[left].keyp)))
- {
- // Left one is less or equal.
- losers[root] = losers[right];
- return left;
- }
- else
- {
- // Right one is less.
- losers[root] = losers[left];
- return right;
- }
- }
- }
-
- inline void
- init_stable()
- { losers[0] = losers[init_winner_stable(1)]; }
-
- inline void
- delete_min_insert_stable(const T& key, bool sup)
- {
- const T* keyp = &key;
- int source = losers[0].source;
- for (unsigned int pos = (k + source) / 2; pos > 0; pos /= 2)
- {
- // The smaller one gets promoted, ties are broken by source.
- if ( (sup && (!losers[pos].sup || losers[pos].source < source)) ||
- (!sup && !losers[pos].sup &&
- ((comp(*losers[pos].keyp, *keyp)) ||
- (!comp(*keyp, *losers[pos].keyp)
- && losers[pos].source < source))))
- {
- // The other one is smaller.
- std::swap(losers[pos].sup, sup);
- std::swap(losers[pos].source, source);
- std::swap(losers[pos].keyp, keyp);
- }
- }
-
- losers[0].sup = sup;
- losers[0].source = source;
- losers[0].keyp = keyp;
- }
- };
-
+ protected:
+ struct _Loser
+ {
+ int _M_source;
+ const _Tp* _M_keyp;
+ };
+
+ unsigned int _M_ik, _M_k, _M_offset;
+ _Loser* _M_losers;
+ _Compare _M_comp;
+
+ public:
+
+ _LoserTreePointerUnguardedBase(unsigned int __k, const _Tp& __sentinel,
+ _Compare __comp = std::less<_Tp>())
+ : _M_comp(__comp)
+ {
+ _M_ik = __k;
+
+ // Next greater power of 2.
+ _M_k = 1 << (__rd_log2(_M_ik - 1) + 1);
+ _M_offset = _M_k;
+ // Avoid default-constructing _M_losers[]._M_key
+ _M_losers = new _Loser[2 * _M_k];
+
+ for (unsigned int __i = _M_k + _M_ik - 1; __i < (2 * _M_k); ++__i)
+ {
+ _M_losers[__i]._M_keyp = &__sentinel;
+ _M_losers[__i]._M_source = -1;
+ }
+ }
+
+ ~_LoserTreePointerUnguardedBase()
+ { delete[] _M_losers; }
+
+ int
+ __get_min_source()
+ {
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top!
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
#endif
+ return _M_losers[0]._M_source;
+ }
-#if _GLIBCXX_LOSER_TREE_UNGUARDED
+ void
+ __insert_start(const _Tp& __key, int __source, bool)
+ {
+ unsigned int __pos = _M_k + __source;
-/** @brief Unguarded loser tree, copying the whole element into the
-* tree structure.
-*
-* No guarding is done, therefore not a single input sequence must
-* run empty. This is a very fast variant.
-*/
-template<typename T, typename Comparator = std::less<T> >
- class LoserTreeUnguarded
- {
- private:
- struct Loser
- {
- int source;
- T key;
+ _M_losers[__pos]._M_keyp = &__key;
+ _M_losers[__pos]._M_source = __source;
+ }
};
- unsigned int ik, k, offset;
- unsigned int* mapping;
- Loser* losers;
- Comparator comp;
-
- void
- map(unsigned int root, unsigned int begin, unsigned int end)
- {
- if (begin + 1 == end)
- mapping[begin] = root;
- else
- {
- // Next greater or equal power of 2.
- unsigned int left = 1 << (log2(end - begin - 1));
- map(root * 2, begin, begin + left);
- map(root * 2 + 1, begin + left, end);
- }
- }
-
- public:
- inline
- LoserTreeUnguarded(unsigned int _k, Comparator _comp = std::less<T>())
- : comp(_comp)
- {
- ik = _k;
- // Next greater or equal power of 2.
- k = 1 << (log2(ik - 1) + 1);
- offset = k;
- losers = new Loser[k + ik];
- mapping = new unsigned int[ik];
- map(1, 0, ik);
- }
-
- inline ~LoserTreeUnguarded()
- {
- delete[] losers;
- delete[] mapping;
- }
-
- inline int
- get_min_source()
- { return losers[0].source; }
-
- inline void
- insert_start(const T& key, int source, bool)
+ /**
+ * @brief Stable unguarded _LoserTree variant storing pointers.
+ *
+ * Unstable variant is implemented below using partial specialization.
+ */
+ template<bool __stable/* default == true */, typename _Tp, typename _Compare>
+ class _LoserTreePointerUnguarded
+ : public _LoserTreePointerUnguardedBase<_Tp, _Compare>
{
- unsigned int pos = mapping[source];
- losers[pos].source = source;
- losers[pos].key = key;
- }
-
- unsigned int
- init_winner(unsigned int root, unsigned int begin, unsigned int end)
- {
- if (begin + 1 == end)
- return mapping[begin];
- else
- {
- // Next greater or equal power of 2.
- unsigned int division = 1 << (log2(end - begin - 1));
- unsigned int left = init_winner(2 * root, begin, begin + division);
- unsigned int right =
- init_winner(2 * root + 1, begin + division, end);
- if (!comp(losers[right].key, losers[left].key))
- {
- // Left one is less or equal.
- losers[root] = losers[right];
- return left;
- }
- else
- {
- // Right one is less.
- losers[root] = losers[left];
- return right;
- }
- }
- }
-
- inline void
- init()
- { losers[0] = losers[init_winner(1, 0, ik)]; }
-
- // Do not pass const reference since key will be used as local variable.
- inline void
- delete_min_insert(const T& key, bool)
- {
- losers[0].key = key;
- T& keyr = losers[0].key;
- int& source = losers[0].source;
- for (int pos = mapping[source] / 2; pos > 0; pos /= 2)
- {
- // The smaller one gets promoted.
- if (comp(losers[pos].key, keyr))
- {
- // The other one is smaller.
- std::swap(losers[pos].source, source);
- std::swap(losers[pos].key, keyr);
- }
- }
- }
-
- inline void
- insert_start_stable(const T& key, int source, bool)
- { return insert_start(key, source, false); }
-
- inline void
- init_stable()
- { init(); }
-
- inline void
- delete_min_insert_stable(const T& key, bool)
- {
- losers[0].key = key;
- T& keyr = losers[0].key;
- int& source = losers[0].source;
- for (int pos = mapping[source] / 2; pos > 0; pos /= 2)
- {
- // The smaller one gets promoted, ties are broken by source.
- if (comp(losers[pos].key, keyr)
- || (!comp(keyr, losers[pos].key)
- && losers[pos].source < source))
- {
- // The other one is smaller.
- std::swap(losers[pos].source, source);
- std::swap(losers[pos].key, keyr);
- }
- }
- }
- };
-
+ typedef _LoserTreePointerUnguardedBase<_Tp, _Compare> _Base;
+ using _Base::_M_k;
+ using _Base::_M_losers;
+
+ public:
+ _LoserTreePointerUnguarded(unsigned int __k, const _Tp& __sentinel,
+ _Compare __comp = std::less<_Tp>())
+ : _Base::_LoserTreePointerUnguardedBase(__k, __sentinel, __comp)
+ { }
+
+ unsigned int
+ __init_winner(unsigned int __root)
+ {
+ if (__root >= _M_k)
+ return __root;
+ else
+ {
+ unsigned int __left = __init_winner(2 * __root);
+ unsigned int __right = __init_winner(2 * __root + 1);
+ if (!_M_comp(*_M_losers[__right]._M_keyp,
+ *_M_losers[__left]._M_keyp))
+ {
+ // Left one is less or equal.
+ _M_losers[__root] = _M_losers[__right];
+ return __left;
+ }
+ else
+ {
+ // Right one is less.
+ _M_losers[__root] = _M_losers[__left];
+ return __right;
+ }
+ }
+ }
+
+ void
+ __init()
+ {
+ _M_losers[0] = _M_losers[__init_winner(1)];
+
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top at the beginning
+ // (0 sequences!)
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
+#endif
+ }
+
+ void
+ __delete_min_insert(const _Tp& __key, bool __sup)
+ {
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top!
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
#endif
-#if _GLIBCXX_LOSER_TREE_POINTER_UNGUARDED
-
-/** @brief Unguarded loser tree, keeping only pointers to the
-* elements in the tree structure.
-*
-* No guarding is done, therefore not a single input sequence must
-* run empty. This is a very fast variant.
-*/
-template<typename T, typename Comparator = std::less<T> >
- class LoserTreePointerUnguarded
- {
- private:
- struct Loser
- {
- int source;
- const T* keyp;
+ const _Tp* __keyp = &__key;
+ int __source = _M_losers[0]._M_source;
+ for (unsigned int __pos = (_M_k + __source) / 2; __pos > 0;
+ __pos /= 2)
+ {
+ // The smaller one gets promoted, ties are broken by _M_source.
+ if (_M_comp(*_M_losers[__pos]._M_keyp, *__keyp)
+ || (!_M_comp(*__keyp, *_M_losers[__pos]._M_keyp)
+ && _M_losers[__pos]._M_source < __source))
+ {
+ // The other one is smaller.
+ std::swap(_M_losers[__pos]._M_source, __source);
+ std::swap(_M_losers[__pos]._M_keyp, __keyp);
+ }
+ }
+
+ _M_losers[0]._M_source = __source;
+ _M_losers[0]._M_keyp = __keyp;
+ }
};
- unsigned int ik, k, offset;
- unsigned int* mapping;
- Loser* losers;
- Comparator comp;
-
- void map(unsigned int root, unsigned int begin, unsigned int end)
+ /**
+ * @brief Unstable unguarded _LoserTree variant storing pointers.
+ *
+ * Stable variant is above.
+ */
+ template<typename _Tp, typename _Compare>
+ class _LoserTreePointerUnguarded</* __stable == */false, _Tp, _Compare>
+ : public _LoserTreePointerUnguardedBase<_Tp, _Compare>
{
- if (begin + 1 == end)
- mapping[begin] = root;
- else
- {
- // Next greater or equal power of 2.
- unsigned int left = 1 << (log2(end - begin - 1));
- map(root * 2, begin, begin + left);
- map(root * 2 + 1, begin + left, end);
- }
- }
+ typedef _LoserTreePointerUnguardedBase<_Tp, _Compare> _Base;
+ using _Base::_M_k;
+ using _Base::_M_losers;
public:
- inline
- LoserTreePointerUnguarded(unsigned int _k,
- Comparator _comp = std::less<T>())
- : comp(_comp)
- {
- ik = _k;
-
- // Next greater power of 2.
- k = 1 << (log2(ik - 1) + 1);
- offset = k;
- losers = new Loser[k + ik];
- mapping = new unsigned int[ik];
- map(1, 0, ik);
- }
-
- inline ~LoserTreePointerUnguarded()
- {
- delete[] losers;
- delete[] mapping;
- }
-
- inline int
- get_min_source()
- { return losers[0].source; }
-
- inline void
- insert_start(const T& key, int source, bool)
- {
- unsigned int pos = mapping[source];
- losers[pos].source = source;
- losers[pos].keyp = &key;
- }
-
- unsigned int
- init_winner(unsigned int root, unsigned int begin, unsigned int end)
- {
- if (begin + 1 == end)
- return mapping[begin];
- else
- {
- // Next greater or equal power of 2.
- unsigned int division = 1 << (log2(end - begin - 1));
- unsigned int left = init_winner(2 * root, begin, begin + division);
- unsigned int right
- = init_winner(2 * root + 1, begin + division, end);
- if (!comp(*losers[right].keyp, *losers[left].keyp))
- {
- // Left one is less or equal.
- losers[root] = losers[right];
- return left;
- }
- else
- {
- // Right one is less.
- losers[root] = losers[left];
- return right;
- }
- }
- }
-
- inline void
- init()
- {
- losers[0] = losers[init_winner(1, 0, ik)];
- }
-
- inline void
- delete_min_insert(const T& key, bool)
- {
- const T* keyp = &key;
- int& source = losers[0].source;
- for (int pos = mapping[source] / 2; pos > 0; pos /= 2)
- {
- // The smaller one gets promoted.
- if (comp(*losers[pos].keyp, *keyp))
- {
- // The other one is smaller.
- std::swap(losers[pos].source, source);
- std::swap(losers[pos].keyp, keyp);
- }
- }
-
- losers[0].keyp = keyp;
- }
-
- inline void
- insert_start_stable(const T& key, int source, bool)
- { return insert_start(key, source, false); }
-
- inline void
- init_stable()
- { init(); }
-
- inline void
- delete_min_insert_stable(const T& key, bool)
- {
- int& source = losers[0].source;
- const T* keyp = &key;
- for (int pos = mapping[source] / 2; pos > 0; pos /= 2)
- {
- // The smaller one gets promoted, ties are broken by source.
- if (comp(*losers[pos].keyp, *keyp)
- || (!comp(*keyp, *losers[pos].keyp)
- && losers[pos].source < source))
- {
- // The other one is smaller.
- std::swap(losers[pos].source, source);
- std::swap(losers[pos].keyp, keyp);
- }
- }
- losers[0].keyp = keyp;
- }
- };
+ _LoserTreePointerUnguarded(unsigned int __k, const _Tp& __sentinel,
+ _Compare __comp = std::less<_Tp>())
+ : _Base::_LoserTreePointerUnguardedBase(__k, __sentinel, __comp)
+ { }
+
+ unsigned int
+ __init_winner(unsigned int __root)
+ {
+ if (__root >= _M_k)
+ return __root;
+ else
+ {
+ unsigned int __left = __init_winner(2 * __root);
+ unsigned int __right = __init_winner(2 * __root + 1);
+
+#if _GLIBCXX_ASSERTIONS
+ // If __left one is sentinel then __right one must be, too.
+ if (_M_losers[__left]._M_source == -1)
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[__right]._M_source == -1);
#endif
-template<typename _ValueTp, class Comparator>
- struct loser_tree_traits
- {
-#if _GLIBCXX_LOSER_TREE
- typedef LoserTree<_ValueTp, Comparator> LT;
-#else
-# if _GLIBCXX_LOSER_TREE_POINTER
- typedef LoserTreePointer<_ValueTp, Comparator> LT;
-# else
-# error Must define some type in losertree.h.
-# endif
+ if (!_M_comp(*_M_losers[__right]._M_keyp,
+ *_M_losers[__left]._M_keyp))
+ {
+ // Left one is less or equal.
+ _M_losers[__root] = _M_losers[__right];
+ return __left;
+ }
+ else
+ {
+ // Right one is less.
+ _M_losers[__root] = _M_losers[__left];
+ return __right;
+ }
+ }
+ }
+
+ void
+ __init()
+ {
+ _M_losers[0] = _M_losers[__init_winner(1)];
+
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top at the beginning
+ // (0 sequences!)
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
#endif
- };
-
-template<typename _ValueTp, class Comparator>
- struct loser_tree_unguarded_traits
- {
-#if _GLIBCXX_LOSER_TREE_UNGUARDED
- typedef LoserTreeUnguarded<_ValueTp, Comparator> LT;
-#else
-# if _GLIBCXX_LOSER_TREE_POINTER_UNGUARDED
- typedef LoserTreePointerUnguarded<_ValueTp, Comparator> LT;
-# else
-# error Must define some unguarded type in losertree.h.
-# endif
+ }
+
+ void
+ __delete_min_insert(const _Tp& __key, bool __sup)
+ {
+#if _GLIBCXX_ASSERTIONS
+ // no dummy sequence can ever be at the top!
+ _GLIBCXX_PARALLEL_ASSERT(_M_losers[0]._M_source != -1);
#endif
- };
-}
+ const _Tp* __keyp = &__key;
+ int __source = _M_losers[0]._M_source;
+ for (unsigned int __pos = (_M_k + __source) / 2; __pos > 0;
+ __pos /= 2)
+ {
+ // The smaller one gets promoted.
+ if (_M_comp(*(_M_losers[__pos]._M_keyp), *__keyp))
+ {
+ // The other one is smaller.
+ std::swap(_M_losers[__pos]._M_source, __source);
+ std::swap(_M_losers[__pos]._M_keyp, __keyp);
+ }
+ }
+
+ _M_losers[0]._M_source = __source;
+ _M_losers[0]._M_keyp = __keyp;
+ }
+ };
+} // namespace __gnu_parallel
-#endif
+#endif /* _GLIBCXX_PARALLEL_LOSERTREE_H */
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