/*
- Glaurung, a UCI chess playing engine.
- Copyright (C) 2004-2008 Tord Romstad
+ Stockfish, a UCI chess playing engine derived from Glaurung 2.1
+ Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
+ Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
- Glaurung is free software: you can redistribute it and/or modify
+ 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.
-
- Glaurung is distributed in the hope that it will be useful,
+
+ 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
GNU General Public License for more details.
-
+
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
-#if !defined MOVEPICK_H_INCLUDED
+#ifndef 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 "types.h"
-////
-//// Types
-////
+/// HistoryStats records how often quiet moves have been successful or unsuccessful
+/// during the current search, and is used for reduction and move ordering decisions.
+struct HistoryStats {
-/// 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 int Max = 1 << 28;
-class MovePicker {
+ int get(Color c, Move m) const { return table[c][from_sq(m)][to_sq(m)]; }
+ void clear() { std::memset(table, 0, sizeof(table)); }
+ void update(Color c, Move m, int v) {
-public:
+ Square from = from_sq(m);
+ Square to = to_sq(m);
+
+ const int denom = 324;
+
+ assert(abs(int(v)) <= denom); // Needed for stability.
- 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(Position &p, bool pvnode, Move ttm, Move mk, Move k1, Move k2,
- Depth dpth);
- 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();
+ table[c][from][to] -= table[c][from][to] * abs(int(v)) / denom;
+ table[c][from][to] += int(v) * 32;
+ }
private:
- void score_captures();
- void score_noncaptures();
- void score_evasions();
- void score_qcaptures();
- Move pick_move_from_list();
-
- 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;
+ int table[COLOR_NB][SQUARE_NB][SQUARE_NB];
};
-////
-//// Inline functions
-////
+/// A template struct, used to generate MoveStats and CounterMoveHistoryStats:
+/// MoveStats store the move that refute a previous one.
+/// CounterMoveHistoryStats is like HistoryStats, but with two consecutive moves.
+/// Entries are stored using only the moving piece and destination square, hence
+/// two moves with different origin but same destination and piece will be
+/// considered identical.
+template<typename T>
+struct Stats {
+ const T* operator[](Piece pc) const { return table[pc]; }
+ T* operator[](Piece pc) { return table[pc]; }
+ void clear() { std::memset(table, 0, sizeof(table)); }
+ void fill(const int& v) { std::fill(&table[0][0], &table[PIECE_NB-1][SQUARE_NB-1]+1, v); };
+ void update(Piece pc, Square to, Move m) { table[pc][to] = m; }
+ void update(Piece pc, Square to, int v) {
+
+ const int denom = 936;
+
+ assert(abs(int(v)) <= denom); // Needed for stability.
-/// MovePicker::discovered_check_candidates() returns a bitboard containing
-/// all pieces which can possibly give discovered check. This bitboard is
-/// computed by the constructor function.
+ table[pc][to] -= table[pc][to] * abs(int(v)) / denom;
+ table[pc][to] += int(v) * 32;
+ }
+
+private:
+ T table[PIECE_NB][SQUARE_NB];
+};
-inline Bitboard MovePicker::discovered_check_candidates() const {
- return dc;
-}
+typedef Stats<Move> MoveStats;
+typedef Stats<int> CounterMoveStats;
+typedef Stats<CounterMoveStats> CounterMoveHistoryStats;
+
+
+/// 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.
+namespace Search { struct Stack; }
+
+class MovePicker {
+public:
+ MovePicker(const MovePicker&) = delete;
+ MovePicker& operator=(const MovePicker&) = delete;
+
+ MovePicker(const Position&, Move, Value);
+ MovePicker(const Position&, Move, Depth, Square);
+ MovePicker(const Position&, Move, Depth, Search::Stack*);
+
+ Move next_move(bool skipQuiets = false);
+
+private:
+ template<GenType> void score();
+ ExtMove* begin() { return cur; }
+ ExtMove* end() { return endMoves; }
+
+ const Position& pos;
+ const Search::Stack* ss;
+ Move countermove;
+ Depth depth;
+ Move ttMove;
+ Square recaptureSquare;
+ Value threshold;
+ int stage;
+ ExtMove *cur, *endMoves, *endBadCaptures;
+ ExtMove moves[MAX_MOVES];
+};
-#endif // !defined(MOVEPICK_H_INCLUDED)
+#endif // #ifndef MOVEPICK_H_INCLUDED
projects / stockfish / blobdiff