117 lines
3.1 KiB
C++
117 lines
3.1 KiB
C++
/*
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Stockfish, a UCI chess playing engine derived from Glaurung 2.1
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Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file)
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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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#ifndef SEARCH_H_INCLUDED
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#define SEARCH_H_INCLUDED
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#include <vector>
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#include "misc.h"
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#include "movepick.h"
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#include "types.h"
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namespace Stockfish {
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class Position;
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namespace Search {
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/// Threshold used for countermoves based pruning
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constexpr int CounterMovePruneThreshold = 0;
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/// Stack struct keeps track of the information we need to remember from nodes
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/// shallower and deeper in the tree during the search. Each search thread has
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/// its own array of Stack objects, indexed by the current ply.
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struct Stack {
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Move* pv;
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PieceToHistory* continuationHistory;
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int ply;
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Move currentMove;
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Move excludedMove;
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Move killers[2];
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Value staticEval;
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Depth depth;
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int statScore;
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int moveCount;
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bool inCheck;
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bool ttPv;
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bool ttHit;
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int doubleExtensions;
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};
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/// RootMove struct is used for moves at the root of the tree. For each root move
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/// we store a score and a PV (really a refutation in the case of moves which
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/// fail low). Score is normally set at -VALUE_INFINITE for all non-pv moves.
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struct RootMove {
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explicit RootMove(Move m) : pv(1, m) {}
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bool extract_ponder_from_tt(Position& pos);
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bool operator==(const Move& m) const { return pv[0] == m; }
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bool operator<(const RootMove& m) const { // Sort in descending order
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return m.score != score ? m.score < score
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: m.previousScore < previousScore;
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}
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Value score = -VALUE_INFINITE;
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Value previousScore = -VALUE_INFINITE;
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Value averageScore = -VALUE_INFINITE;
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int selDepth = 0;
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int tbRank = 0;
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Value tbScore;
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std::vector<Move> pv;
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};
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typedef std::vector<RootMove> RootMoves;
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/// LimitsType struct stores information sent by GUI about available time to
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/// search the current move, maximum depth/time, or if we are in analysis mode.
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struct LimitsType {
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LimitsType() { // Init explicitly due to broken value-initialization of non POD in MSVC
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time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = npmsec = movetime = TimePoint(0);
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movestogo = depth = mate = perft = infinite = 0;
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nodes = 0;
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}
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bool use_time_management() const {
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return time[WHITE] || time[BLACK];
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}
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std::vector<Move> searchmoves;
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TimePoint time[COLOR_NB], inc[COLOR_NB], npmsec, movetime, startTime;
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int movestogo, depth, mate, perft, infinite;
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int64_t nodes;
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};
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extern LimitsType Limits;
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void init();
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void clear();
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} // namespace Search
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} // namespace Stockfish
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#endif // #ifndef SEARCH_H_INCLUDED
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