/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2015 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
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
#include <algorithm> // For std::max
/// The Stats struct stores moves statistics. According to the template parameter
-/// the class can store History, Gains and Countermoves. History records how often
+/// the class can store History 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.
+/// and is used for reduction and move ordering 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
+/// using only the 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>
+template<typename T, bool CM = false>
struct Stats {
- static const Value Max = Value(2000);
+ static const Value Max = Value(1 << 28);
- const T* operator[](Piece p) const { return table[p]; }
+ 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 update(Piece p, Square to, Move m) {
+ void update(Piece pc, Square to, Move m) {
- if (m == table[p][to].first)
- return;
-
- table[p][to].second = table[p][to].first;
- table[p][to].first = m;
+ if (m != table[pc][to])
+ table[pc][to] = m;
}
- void update(Piece p, Square to, Value v) {
+ void update(Piece pc, Square to, Value v) {
- if (Gain)
- table[p][to] = std::max(v, table[p][to] - 1);
+ if (abs(int(v)) >= 324)
+ return;
- else if (abs(table[p][to] + v) < Max)
- table[p][to] += v;
+ table[pc][to] -= table[pc][to] * abs(int(v)) / (CM ? 512 : 324);
+ table[pc][to] += int(v) * (CM ? 64 : 32);
}
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;
+typedef Stats<Move> MovesStats;
+typedef Stats<Value, false> HistoryStats;
+typedef Stats<Value, true> CounterMovesStats;
+typedef Stats<CounterMovesStats> CounterMovesHistoryStats;
/// MovePicker class is used to pick one pseudo legal move at a time from the
/// to get a cut-off first.
class MovePicker {
-
- MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC
-
public:
+ MovePicker(const MovePicker&) = delete;
+ MovePicker& operator=(const MovePicker&) = delete;
+
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);
+ MovePicker(const Position&, Move, const HistoryStats&, Value);
+ MovePicker(const Position&, Move, Depth, const HistoryStats&, const CounterMovesStats&, Move, Search::Stack*);
- template<bool SpNode> Move next_move();
+ Move next_move();
private:
template<GenType> void score();
- void generate_next();
+ void generate_next_stage();
+ ExtMove* begin() { return moves; }
+ ExtMove* end() { return endMoves; }
const Position& pos;
const HistoryStats& history;
+ const CounterMovesStats* counterMovesHistory;
Search::Stack* ss;
- Move* countermoves;
+ Move countermove;
Depth depth;
Move ttMove;
- MoveStack killers[4];
+ ExtMove killers[3];
Square recaptureSquare;
- int captureThreshold, phase;
- MoveStack *cur, *end, *endQuiets, *endBadCaptures;
- MoveStack moves[MAX_MOVES];
+ Value threshold;
+ int stage;
+ ExtMove *endQuiets, *endBadCaptures = moves + MAX_MOVES - 1;
+ ExtMove moves[MAX_MOVES], *cur = moves, *endMoves = moves;
};
-#endif // !defined(MOVEPICK_H_INCLUDED)
+#endif // #ifndef MOVEPICK_H_INCLUDED