/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2008-2012 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
#if !defined MOVEPICK_H_INCLUDED
#define MOVEPICK_H_INCLUDED
-#include "history.h"
#include "position.h"
+#include "search.h"
#include "types.h"
-struct SearchStack;
-/// MovePicker is a class which is used to pick one pseudo 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::get_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.
+/// The History class stores statistics about how often different moves
+/// have been successful or unsuccessful during the current search. These
+/// statistics are used for reduction and move ordering decisions. History
+/// entries are stored according only to moving piece and destination square,
+/// in particular two moves with different origin but same destination and
+/// same piece will be considered identical.
+
+class History {
+public:
+
+ static const Value Max = Value(2000);
+
+ const Value* operator[](Piece p) const { return &history[p][0]; }
+ Value gain(Piece p, Square to) const { return gains[p][to]; }
+
+ void clear();
+ void update(Piece p, Square to, Value bonus);
+ void update_gain(Piece p, Square to, Value gain);
+
+private:
+ Value history[PIECE_NB][SQUARE_NB];
+ Value gains[PIECE_NB][SQUARE_NB];
+};
+
+
+/// 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.
class MovePicker {
MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC
public:
- MovePicker(const Position&, Move, Depth, const History&, SearchStack*, Value);
- MovePicker(const Position&, Move, Depth, const History&, Square recaptureSq);
- MovePicker(const Position&, Move, const History&, PieceType parentCapture);
- Move get_next_move();
+ MovePicker(const Position&, Move, Depth, const History&, Search::Stack*, Value);
+ MovePicker(const Position&, Move, Depth, const History&, Square);
+ MovePicker(const Position&, Move, const History&, PieceType);
+ template<bool SpNode> Move next_move();
private:
void score_captures();
void score_noncaptures();
void score_evasions();
- void go_next_phase();
+ void generate_next();
const Position& pos;
const History& H;
+ Search::Stack* ss;
Depth depth;
Move ttMove;
MoveStack killers[2];
Square recaptureSquare;
int captureThreshold, phase;
- const uint8_t* phasePtr;
- MoveStack *curMove, *lastMove, *lastNonCapture, *badCaptures;
+ MoveStack *cur, *end, *endQuiets, *endBadCaptures;
MoveStack moves[MAX_MOVES];
};