/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008 Marco Costalba
+ Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
-<<<<<<< HEAD:src/movepick.h
-=======
-
->>>>>>> d3600c39a745179ed6b094b305d0645e83a1ee86:src/movepick.h
Stockfish is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
#if !defined MOVEPICK_H_INCLUDED
#define MOVEPICK_H_INCLUDED
-////
-//// Includes
-////
+#include <algorithm> // For std::max
+#include <cstring> // For std::memset
-#include "depth.h"
-#include "lock.h"
+#include "movegen.h"
#include "position.h"
+#include "search.h"
+#include "types.h"
-////
-//// Types
-////
+/// The Stats struct stores moves statistics. According to the template parameter
+/// the class can store History, Gains and Countermoves. History records how often
+/// different moves have been successful or unsuccessful during the current search
+/// and is used for reduction and move ordering decisions. Gains records the move's
+/// best evaluation gain from one ply to the next and is used for pruning decisions.
+/// Countermoves store the move that refute a previous one. Entries are stored
+/// according only to moving piece and destination square, hence two moves with
+/// different origin but same destination and piece will be considered identical.
+template<bool Gain, typename T>
+struct Stats {
-/// MovePicker is a class which is used to pick one legal move at a time from
-/// the current position. It is initialized with a Position object and a few
-/// moves we have reason to believe are good. The most important method is
-/// MovePicker::pick_next_move(), which returns a new legal move each time it
-/// is called, until there are no legal moves left, when MOVE_NONE is returned.
-/// In order to improve the efficiency of the alpha beta algorithm, MovePicker
-/// attempts to return the moves which are most likely to be strongest first.
+ static const Value Max = Value(2000);
-class MovePicker {
+ const T* operator[](Piece p) const { return table[p]; }
+ void clear() { std::memset(table, 0, sizeof(table)); }
-public:
+ void update(Piece p, Square to, Move m) {
- enum MovegenPhase {
- PH_TT_MOVE, // Transposition table move
- PH_MATE_KILLER, // Mate killer from the current ply
- PH_GOOD_CAPTURES, // Queen promotions and captures with SEE values >= 0
- PH_BAD_CAPTURES, // Queen promotions and captures with SEE valuse <= 0
- PH_KILLER_1, // Killer move 1 from the current ply (not used yet).
- PH_KILLER_2, // Killer move 2 from the current ply (not used yet).
- PH_NONCAPTURES, // Non-captures and underpromotions
- PH_EVASIONS, // Check evasions
- PH_QCAPTURES, // Captures in quiescence search
- PH_QCHECKS, // Checks in quiescence search
- PH_STOP
- };
-
- MovePicker(const Position& p, bool pvnode, Move ttm, Move mk, Move k1, Move k2, Depth d);
- Move get_next_move();
- Move get_next_move(Lock &lock);
- int number_of_moves() const;
- int current_move_score() const;
- MovegenPhase current_move_type() const;
- Bitboard discovered_check_candidates() const;
-
- static void init_phase_table();
+ if (m == table[p][to].first)
+ return;
-private:
- void score_captures();
- void score_noncaptures();
- void score_evasions();
- void score_qcaptures();
- Move pick_move_from_list();
- int find_best_index();
+ table[p][to].second = table[p][to].first;
+ table[p][to].first = m;
+ }
- const Position& pos;
- Move ttMove, mateKiller, killer1, killer2;
- Bitboard pinned, dc;
- MoveStack moves[256], badCaptures[64];
- bool pvNode;
- Depth depth;
- int phaseIndex;
- int numOfMoves, numOfBadCaptures;
- int movesPicked, badCapturesPicked;
- bool finished;
+ void update(Piece p, Square to, Value v) {
+
+ if (Gain)
+ table[p][to] = std::max(v, table[p][to] - 1);
+
+ else if (abs(table[p][to] + v) < Max)
+ table[p][to] += v;
+ }
+
+private:
+ T table[PIECE_NB][SQUARE_NB];
};
+typedef Stats< true, Value> GainsStats;
+typedef Stats<false, Value> HistoryStats;
+typedef Stats<false, std::pair<Move, Move> > CountermovesStats;
-////
-//// Inline functions
-////
-/// MovePicker::number_of_moves() simply returns the numOfMoves member
-/// variable. It is intended to be used in positions where the side to move
-/// is in check, for detecting checkmates or situations where there is only
-/// a single reply to check.
+/// MovePicker class is used to pick one pseudo legal move at a time from the
+/// current position. The most important method is next_move(), which returns a
+/// new pseudo legal move each time it is called, until there are no moves left,
+/// when MOVE_NONE is returned. In order to improve the efficiency of the alpha
+/// beta algorithm, MovePicker attempts to return the moves which are most likely
+/// to get a cut-off first.
-inline int MovePicker::number_of_moves() const {
+class MovePicker {
- return numOfMoves;
-}
+ MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC
-/// MovePicker::discovered_check_candidates() returns a bitboard containing
-/// all pieces which can possibly give discovered check. This bitboard is
-/// computed by the constructor function.
+public:
+ MovePicker(const Position&, Move, Depth, const HistoryStats&, Square);
+ MovePicker(const Position&, Move, const HistoryStats&, PieceType);
+ MovePicker(const Position&, Move, Depth, const HistoryStats&, Move*, Search::Stack*, Value);
-inline Bitboard MovePicker::discovered_check_candidates() const {
- return dc;
-}
+ template<bool SpNode> Move next_move();
+
+private:
+ template<GenType> void score();
+ void generate_next();
+
+ const Position& pos;
+ const HistoryStats& history;
+ Search::Stack* ss;
+ Move* countermoves;
+ Depth depth;
+ Move ttMove;
+ ExtMove killers[4];
+ Square recaptureSquare;
+ int captureThreshold, phase;
+ ExtMove *cur, *end, *endQuiets, *endBadCaptures;
+ ExtMove moves[MAX_MOVES];
+};
#endif // !defined(MOVEPICK_H_INCLUDED)
projects / stockfish / blobdiff