/*
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 "depth.h"
-#include "history.h"
#include "position.h"
+#include "search.h"
+#include "types.h"
-struct SearchStack;
-/// 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.
+/// 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
+ MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC
public:
- MovePicker(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss, Value beta);
- MovePicker(const Position& p, Move ttm, Depth d, const History& h);
- 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;
- Bitboard pinned;
- MoveStack ttMoves[2], killers[2];
- int badCaptureThreshold, phase;
- const uint8_t* phasePtr;
- MoveStack *curMove, *lastMove, *lastGoodNonCapture, *badCaptures;
- MoveStack moves[MOVES_MAX];
+ Search::Stack* ss;
+ Depth depth;
+ Move ttMove;
+ MoveStack killers[2];
+ Square recaptureSquare;
+ int captureThreshold, phase;
+ MoveStack *cur, *end, *endQuiets, *endBadCaptures;
+ MoveStack moves[MAX_MOVES];
};
#endif // !defined(MOVEPICK_H_INCLUDED)