/// ordering decisions. It uses ButterflyBoards as backing store.
struct ButterflyHistory : public ButterflyBoards {
- void update(Color c, Move m, int v) {
+ void update(Color c, Move m, int bonus) {
const int D = 324;
auto& entry = (*this)[c][from_to(m)];
- assert(abs(v) <= D); // Consistency check for below formula
+ assert(abs(bonus) <= D); // Consistency check for below formula
- entry += v * 32 - entry * abs(v) / D;
+ entry += bonus * 32 - entry * abs(bonus) / D;
assert(abs(entry) <= 32 * D);
}
/// PieceToHistory is like ButterflyHistory, but is based on PieceToBoards
struct PieceToHistory : public PieceToBoards {
- void update(Piece pc, Square to, int v) {
+ void update(Piece pc, Square to, int bonus) {
const int D = 936;
auto& entry = (*this)[pc][to];
- assert(abs(v) <= D); // Consistency check for below formula
+ assert(abs(bonus) <= D); // Consistency check for below formula
- entry += v * 32 - entry * abs(v) / D;
+ entry += bonus * 32 - entry * abs(bonus) / D;
assert(abs(entry) <= 32 * D);
}
};
-/// CounterMoveStat stores counter moves indexed by [piece][to] of the previous
+/// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous
/// move, see chessprogramming.wikispaces.com/Countermove+Heuristic
-typedef StatBoards<PIECE_NB, SQUARE_NB, Move> CounterMoveStat;
+typedef StatBoards<PIECE_NB, SQUARE_NB, Move> CounterMoveHistory;
-/// CounterMoveHistoryStat is like CounterMoveStat but instead of a move it
-/// stores a full history (based on PieceTo boards instead of ButterflyBoards).
-typedef StatBoards<PIECE_NB, SQUARE_NB, PieceToHistory> CounterMoveHistoryStat;
+/// ContinuationHistory is the history of a given pair of moves, usually the
+/// current one given a previous one. History table is based on PieceToBoards
+/// instead of ButterflyBoards.
+typedef StatBoards<PIECE_NB, SQUARE_NB, PieceToHistory> ContinuationHistory;
/// MovePicker class is used to pick one pseudo legal move at a time from the
/// 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*);
-
+ MovePicker(const Position&, Move, Depth, const ButterflyHistory*, const PieceToHistory**, Square);
+ MovePicker(const Position&, Move, Depth, const ButterflyHistory*, const PieceToHistory**, Move, Move*);
Move next_move(bool skipQuiets = false);
private:
ExtMove* end() { return endMoves; }
const Position& pos;
- const Search::Stack* ss;
- Move killers[2];
- Move countermove;
- Depth depth;
- Move ttMove;
+ const ButterflyHistory* mainHistory;
+ const PieceToHistory** contHistory;
+ Move ttMove, countermove, killers[2];
+ ExtMove *cur, *endMoves, *endBadCaptures;
+ int stage;
Square recaptureSquare;
Value threshold;
- int stage;
- ExtMove *cur, *endMoves, *endBadCaptures;
+ Depth depth;
ExtMove moves[MAX_MOVES];
};