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https://github.com/sockspls/badfish
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Language guarantees that c'tor is called, but without any c'tor it happens to work by accident because OS zeroes out the freshly allocated pages. The problem is that if I deallocate and allocate again, the second time pages are no more newly come by the OS and so could contain stale info. A practical case could be if we change TT size or numbers of threads on the fly while already running. Bug spotted by Justin Blanchard. No functional change. Signed-off-by: Marco Costalba <mcostalba@gmail.com>
433 lines
15 KiB
C++
433 lines
15 KiB
C++
/*
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Stockfish, a UCI chess playing engine derived from Glaurung 2.1
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Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
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Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
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Stockfish is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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Stockfish is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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////
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//// Includes
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////
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#include <cassert>
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#include <cstring>
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#include <sstream>
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#include <map>
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#include "material.h"
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using namespace std;
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////
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//// Local definitions
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////
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namespace {
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// Values modified by Joona Kiiski
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const Value MidgameLimit = Value(15581);
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const Value EndgameLimit = Value(3998);
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// Polynomial material balance parameters
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const Value RedundantQueenPenalty = Value(320);
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const Value RedundantRookPenalty = Value(554);
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const int LinearCoefficients[6] = { 1617, -162, -1172, -190, 105, 26 };
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const int QuadraticCoefficientsSameColor[][6] = {
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{ 7, 7, 7, 7, 7, 7 }, { 39, 2, 7, 7, 7, 7 }, { 35, 271, -4, 7, 7, 7 },
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{ 7, 25, 4, 7, 7, 7 }, { -27, -2, 46, 100, 56, 7 }, { 58, 29, 83, 148, -3, -25 } };
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const int QuadraticCoefficientsOppositeColor[][6] = {
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{ 41, 41, 41, 41, 41, 41 }, { 37, 41, 41, 41, 41, 41 }, { 10, 62, 41, 41, 41, 41 },
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{ 57, 64, 39, 41, 41, 41 }, { 50, 40, 23, -22, 41, 41 }, { 106, 101, 3, 151, 171, 41 } };
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typedef EndgameEvaluationFunctionBase EF;
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typedef EndgameScalingFunctionBase SF;
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typedef map<Key, EF*> EFMap;
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typedef map<Key, SF*> SFMap;
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// Endgame evaluation and scaling functions accessed direcly and not through
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// the function maps because correspond to more then one material hash key.
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EvaluationFunction<KmmKm> EvaluateKmmKm[] = { EvaluationFunction<KmmKm>(WHITE), EvaluationFunction<KmmKm>(BLACK) };
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EvaluationFunction<KXK> EvaluateKXK[] = { EvaluationFunction<KXK>(WHITE), EvaluationFunction<KXK>(BLACK) };
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ScalingFunction<KBPsK> ScaleKBPsK[] = { ScalingFunction<KBPsK>(WHITE), ScalingFunction<KBPsK>(BLACK) };
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ScalingFunction<KQKRPs> ScaleKQKRPs[] = { ScalingFunction<KQKRPs>(WHITE), ScalingFunction<KQKRPs>(BLACK) };
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ScalingFunction<KPsK> ScaleKPsK[] = { ScalingFunction<KPsK>(WHITE), ScalingFunction<KPsK>(BLACK) };
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ScalingFunction<KPKP> ScaleKPKP[] = { ScalingFunction<KPKP>(WHITE), ScalingFunction<KPKP>(BLACK) };
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// Helper templates used to detect a given material distribution
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template<Color Us> bool is_KXK(const Position& pos) {
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const Color Them = (Us == WHITE ? BLACK : WHITE);
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return pos.non_pawn_material(Them) == VALUE_ZERO
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&& pos.piece_count(Them, PAWN) == 0
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&& pos.non_pawn_material(Us) >= RookValueMidgame;
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}
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template<Color Us> bool is_KBPsK(const Position& pos) {
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return pos.non_pawn_material(Us) == BishopValueMidgame
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&& pos.piece_count(Us, BISHOP) == 1
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&& pos.piece_count(Us, PAWN) >= 1;
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}
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template<Color Us> bool is_KQKRPs(const Position& pos) {
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const Color Them = (Us == WHITE ? BLACK : WHITE);
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return pos.piece_count(Us, PAWN) == 0
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&& pos.non_pawn_material(Us) == QueenValueMidgame
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&& pos.piece_count(Us, QUEEN) == 1
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&& pos.piece_count(Them, ROOK) == 1
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&& pos.piece_count(Them, PAWN) >= 1;
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}
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}
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////
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//// Classes
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////
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/// EndgameFunctions class stores endgame evaluation and scaling functions
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/// in two std::map. Because STL library is not guaranteed to be thread
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/// safe even for read access, the maps, although with identical content,
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/// are replicated for each thread. This is faster then using locks.
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class EndgameFunctions {
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public:
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EndgameFunctions();
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~EndgameFunctions();
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template<class T> T* get(Key key) const;
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private:
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template<class T> void add(const string& keyCode);
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static Key buildKey(const string& keyCode);
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static const string swapColors(const string& keyCode);
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// Here we store two maps, for evaluate and scaling functions...
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pair<EFMap, SFMap> maps;
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// ...and here is the accessing template function
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template<typename T> const map<Key, T*>& get() const;
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};
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// Explicit specializations of a member function shall be declared in
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// the namespace of which the class template is a member.
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template<> const EFMap& EndgameFunctions::get<EF>() const { return maps.first; }
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template<> const SFMap& EndgameFunctions::get<SF>() const { return maps.second; }
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////
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//// Functions
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////
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/// MaterialInfoTable c'tor and d'tor, called once by each thread
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MaterialInfoTable::MaterialInfoTable() {
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entries = new MaterialInfo[MaterialTableSize];
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funcs = new EndgameFunctions();
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if (!entries || !funcs)
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{
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cerr << "Failed to allocate " << MaterialTableSize * sizeof(MaterialInfo)
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<< " bytes for material hash table." << endl;
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Application::exit_with_failure();
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}
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memset(entries, 0, MaterialTableSize * sizeof(MaterialInfo));
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}
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MaterialInfoTable::~MaterialInfoTable() {
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delete funcs;
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delete [] entries;
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}
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/// MaterialInfoTable::game_phase() calculates the phase given the current
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/// position. Because the phase is strictly a function of the material, it
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/// is stored in MaterialInfo.
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Phase MaterialInfoTable::game_phase(const Position& pos) {
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Value npm = pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK);
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if (npm >= MidgameLimit)
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return PHASE_MIDGAME;
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if (npm <= EndgameLimit)
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return PHASE_ENDGAME;
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return Phase(((npm - EndgameLimit) * 128) / (MidgameLimit - EndgameLimit));
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}
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/// MaterialInfoTable::get_material_info() takes a position object as input,
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/// computes or looks up a MaterialInfo object, and returns a pointer to it.
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/// If the material configuration is not already present in the table, it
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/// is stored there, so we don't have to recompute everything when the
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/// same material configuration occurs again.
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MaterialInfo* MaterialInfoTable::get_material_info(const Position& pos) {
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Key key = pos.get_material_key();
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unsigned index = unsigned(key & (MaterialTableSize - 1));
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MaterialInfo* mi = entries + index;
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// If mi->key matches the position's material hash key, it means that we
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// have analysed this material configuration before, and we can simply
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// return the information we found the last time instead of recomputing it.
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if (mi->key == key)
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return mi;
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// Clear the MaterialInfo object, and set its key
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memset(mi, 0, sizeof(MaterialInfo));
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mi->factor[WHITE] = mi->factor[BLACK] = uint8_t(SCALE_FACTOR_NORMAL);
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mi->key = key;
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// Store game phase
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mi->gamePhase = MaterialInfoTable::game_phase(pos);
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// Let's look if we have a specialized evaluation function for this
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// particular material configuration. First we look for a fixed
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// configuration one, then a generic one if previous search failed.
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if ((mi->evaluationFunction = funcs->get<EF>(key)) != NULL)
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return mi;
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if (is_KXK<WHITE>(pos) || is_KXK<BLACK>(pos))
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{
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mi->evaluationFunction = is_KXK<WHITE>(pos) ? &EvaluateKXK[WHITE] : &EvaluateKXK[BLACK];
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return mi;
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}
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if ( pos.pieces(PAWN) == EmptyBoardBB
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&& pos.pieces(ROOK) == EmptyBoardBB
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&& pos.pieces(QUEEN) == EmptyBoardBB)
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{
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// Minor piece endgame with at least one minor piece per side and
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// no pawns. Note that the case KmmK is already handled by KXK.
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assert((pos.pieces(KNIGHT, WHITE) | pos.pieces(BISHOP, WHITE)));
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assert((pos.pieces(KNIGHT, BLACK) | pos.pieces(BISHOP, BLACK)));
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if ( pos.piece_count(WHITE, BISHOP) + pos.piece_count(WHITE, KNIGHT) <= 2
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&& pos.piece_count(BLACK, BISHOP) + pos.piece_count(BLACK, KNIGHT) <= 2)
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{
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mi->evaluationFunction = &EvaluateKmmKm[WHITE];
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return mi;
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}
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}
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// OK, we didn't find any special evaluation function for the current
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// material configuration. Is there a suitable scaling function?
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//
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// We face problems when there are several conflicting applicable
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// scaling functions and we need to decide which one to use.
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SF* sf;
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if ((sf = funcs->get<SF>(key)) != NULL)
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{
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mi->scalingFunction[sf->color()] = sf;
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return mi;
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}
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// Generic scaling functions that refer to more then one material
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// distribution. Should be probed after the specialized ones.
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// Note that these ones don't return after setting the function.
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if (is_KBPsK<WHITE>(pos))
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mi->scalingFunction[WHITE] = &ScaleKBPsK[WHITE];
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if (is_KBPsK<BLACK>(pos))
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mi->scalingFunction[BLACK] = &ScaleKBPsK[BLACK];
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if (is_KQKRPs<WHITE>(pos))
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mi->scalingFunction[WHITE] = &ScaleKQKRPs[WHITE];
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else if (is_KQKRPs<BLACK>(pos))
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mi->scalingFunction[BLACK] = &ScaleKQKRPs[BLACK];
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if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) == VALUE_ZERO)
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{
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if (pos.piece_count(BLACK, PAWN) == 0)
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{
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assert(pos.piece_count(WHITE, PAWN) >= 2);
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mi->scalingFunction[WHITE] = &ScaleKPsK[WHITE];
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}
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else if (pos.piece_count(WHITE, PAWN) == 0)
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{
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assert(pos.piece_count(BLACK, PAWN) >= 2);
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mi->scalingFunction[BLACK] = &ScaleKPsK[BLACK];
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}
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else if (pos.piece_count(WHITE, PAWN) == 1 && pos.piece_count(BLACK, PAWN) == 1)
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{
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// This is a special case because we set scaling functions
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// for both colors instead of only one.
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mi->scalingFunction[WHITE] = &ScaleKPKP[WHITE];
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mi->scalingFunction[BLACK] = &ScaleKPKP[BLACK];
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}
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}
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// Compute the space weight
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if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >=
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2*QueenValueMidgame + 4*RookValueMidgame + 2*KnightValueMidgame)
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{
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int minorPieceCount = pos.piece_count(WHITE, KNIGHT)
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+ pos.piece_count(BLACK, KNIGHT)
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+ pos.piece_count(WHITE, BISHOP)
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+ pos.piece_count(BLACK, BISHOP);
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mi->spaceWeight = minorPieceCount * minorPieceCount;
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}
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// Evaluate the material balance
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const int pieceCount[2][6] = { { pos.piece_count(WHITE, BISHOP) > 1, pos.piece_count(WHITE, PAWN), pos.piece_count(WHITE, KNIGHT),
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pos.piece_count(WHITE, BISHOP), pos.piece_count(WHITE, ROOK), pos.piece_count(WHITE, QUEEN) },
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{ pos.piece_count(BLACK, BISHOP) > 1, pos.piece_count(BLACK, PAWN), pos.piece_count(BLACK, KNIGHT),
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pos.piece_count(BLACK, BISHOP), pos.piece_count(BLACK, ROOK), pos.piece_count(BLACK, QUEEN) } };
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Color c, them;
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int sign, pt1, pt2, pc;
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int v, vv, matValue = 0;
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for (c = WHITE, sign = 1; c <= BLACK; c++, sign = -sign)
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{
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// No pawns makes it difficult to win, even with a material advantage
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if ( pos.piece_count(c, PAWN) == 0
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&& pos.non_pawn_material(c) - pos.non_pawn_material(opposite_color(c)) <= BishopValueMidgame)
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{
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if ( pos.non_pawn_material(c) == pos.non_pawn_material(opposite_color(c))
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|| pos.non_pawn_material(c) < RookValueMidgame)
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mi->factor[c] = 0;
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else
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{
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switch (pos.piece_count(c, BISHOP)) {
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case 2:
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mi->factor[c] = 32;
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break;
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case 1:
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mi->factor[c] = 12;
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break;
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case 0:
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mi->factor[c] = 6;
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break;
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}
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}
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}
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// Redundancy of major pieces, formula based on Kaufman's paper
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// "The Evaluation of Material Imbalances in Chess"
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// http://mywebpages.comcast.net/danheisman/Articles/evaluation_of_material_imbalance.htm
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if (pieceCount[c][ROOK] >= 1)
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matValue -= sign * ((pieceCount[c][ROOK] - 1) * RedundantRookPenalty + pieceCount[c][QUEEN] * RedundantQueenPenalty);
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them = opposite_color(c);
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v = 0;
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// Second-degree polynomial material imbalance by Tord Romstad
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//
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// We use PIECE_TYPE_NONE as a place holder for the bishop pair "extended piece",
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// this allow us to be more flexible in defining bishop pair bonuses.
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for (pt1 = PIECE_TYPE_NONE; pt1 <= QUEEN; pt1++)
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{
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pc = pieceCount[c][pt1];
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if (!pc)
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continue;
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vv = LinearCoefficients[pt1];
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for (pt2 = PIECE_TYPE_NONE; pt2 <= pt1; pt2++)
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vv += pieceCount[c][pt2] * QuadraticCoefficientsSameColor[pt1][pt2]
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+ pieceCount[them][pt2] * QuadraticCoefficientsOppositeColor[pt1][pt2];
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v += pc * vv;
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}
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matValue += sign * v;
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}
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mi->value = int16_t(matValue / 16);
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return mi;
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}
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/// EndgameFunctions member definitions.
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EndgameFunctions::EndgameFunctions() {
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add<EvaluationFunction<KNNK> >("KNNK");
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add<EvaluationFunction<KPK> >("KPK");
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add<EvaluationFunction<KBNK> >("KBNK");
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add<EvaluationFunction<KRKP> >("KRKP");
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add<EvaluationFunction<KRKB> >("KRKB");
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add<EvaluationFunction<KRKN> >("KRKN");
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add<EvaluationFunction<KQKR> >("KQKR");
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add<EvaluationFunction<KBBKN> >("KBBKN");
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add<ScalingFunction<KNPK> >("KNPK");
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add<ScalingFunction<KRPKR> >("KRPKR");
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add<ScalingFunction<KBPKB> >("KBPKB");
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add<ScalingFunction<KBPPKB> >("KBPPKB");
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add<ScalingFunction<KBPKN> >("KBPKN");
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add<ScalingFunction<KRPPKRP> >("KRPPKRP");
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}
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EndgameFunctions::~EndgameFunctions() {
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for (EFMap::const_iterator it = maps.first.begin(); it != maps.first.end(); ++it)
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delete it->second;
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for (SFMap::const_iterator it = maps.second.begin(); it != maps.second.end(); ++it)
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delete it->second;
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}
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Key EndgameFunctions::buildKey(const string& keyCode) {
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assert(keyCode.length() > 0 && keyCode[0] == 'K');
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assert(keyCode.length() < 8);
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stringstream s;
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bool upcase = false;
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// Build up a fen string with the given pieces, note that
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// the fen string could be of an illegal position.
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for (size_t i = 0; i < keyCode.length(); i++)
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{
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if (keyCode[i] == 'K')
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upcase = !upcase;
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s << char(upcase ? toupper(keyCode[i]) : tolower(keyCode[i]));
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}
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s << 8 - keyCode.length() << "/8/8/8/8/8/8/8 w - -";
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return Position(s.str(), 0).get_material_key();
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}
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const string EndgameFunctions::swapColors(const string& keyCode) {
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// Build corresponding key for the opposite color: "KBPKN" -> "KNKBP"
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size_t idx = keyCode.find("K", 1);
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return keyCode.substr(idx) + keyCode.substr(0, idx);
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}
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template<class T>
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void EndgameFunctions::add(const string& keyCode) {
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typedef typename T::Base F;
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typedef map<Key, F*> M;
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const_cast<M&>(get<F>()).insert(pair<Key, F*>(buildKey(keyCode), new T(WHITE)));
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const_cast<M&>(get<F>()).insert(pair<Key, F*>(buildKey(swapColors(keyCode)), new T(BLACK)));
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}
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template<class T>
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T* EndgameFunctions::get(Key key) const {
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typename map<Key, T*>::const_iterator it = get<T>().find(key);
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return it != get<T>().end() ? it->second : NULL;
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}
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