X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.h;h=03305ebdd8eab7cf02ce27fbdb56af2c22ada3e2;hp=5455a3df6a6db3e2f3372a4301e54e5452951a95;hb=9c35b9365d75a3522cee47536419534b1de91f48;hpb=4b232f5ddc7d8a05b7e6e3267bcb7a4119ffdc25

diff --git a/src/movepick.h b/src/movepick.h
index 5455a3df..db0ba3c4 100644
--- a/src/movepick.h
+++ b/src/movepick.h
@@ -1,7 +1,8 @@
 /*
   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) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, 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
@@ -17,47 +18,101 @@
   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 "history.h"
-#include "move.h"
+#include <array>
+
+#include "movegen.h"
 #include "position.h"
 #include "types.h"
 
-struct SearchStack;
+/// StatBoards is a generic 2-dimensional array used to store various statistics
+template<int Size1, int Size2, typename T = int16_t>
+struct StatBoards : public std::array<std::array<T, Size2>, Size1> {
 
-/// 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::get_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 get a cut-off first.
+  void fill(const T& v) {
+    T* p = &(*this)[0][0];
+    std::fill(p, p + sizeof(*this) / sizeof(*p), v);
+  }
 
-class MovePicker {
+  void update(T& entry, int bonus, const int D) {
+
+    assert(abs(bonus) <= D); // Ensure range is [-32 * D, 32 * D]
+    assert(abs(32 * D) < INT16_MAX); // Ensure we don't overflow
+
+    entry += bonus * 32 - entry * abs(bonus) / D;
+
+    assert(abs(entry) <= 32 * D);
+  }
+};
+
+/// ButterflyBoards are 2 tables (one for each color) indexed by the move's from
+/// and to squares, see chessprogramming.wikispaces.com/Butterfly+Boards
+typedef StatBoards<COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyBoards;
+
+/// PieceToBoards are addressed by a move's [piece][to] information
+typedef StatBoards<PIECE_NB, SQUARE_NB> PieceToBoards;
+
+/// ButterflyHistory records how often quiet moves have been successful or
+/// unsuccessful during the current search, and is used for reduction and move
+/// ordering decisions. It uses ButterflyBoards as backing store.
+struct ButterflyHistory : public ButterflyBoards {
 
-  MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC
+  void update(Color c, Move m, int bonus) {
+    StatBoards::update((*this)[c][from_to(m)], bonus, 324);
+  }
+};
+
+/// PieceToHistory is like ButterflyHistory, but is based on PieceToBoards
+struct PieceToHistory : public PieceToBoards {
+
+  void update(Piece pc, Square to, int bonus) {
+    StatBoards::update((*this)[pc][to], bonus, 936);
+  }
+};
+
+/// 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> CounterMoveHistory;
 
+/// 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
+/// 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 {
 public:
-  MovePicker(const Position&, Move, Depth, const History&, SearchStack*, Value);
-  MovePicker(const Position&, Move, Depth, const History&);
-  Move get_next_move();
-  bool isBadCapture() const;
+  MovePicker(const MovePicker&) = delete;
+  MovePicker& operator=(const MovePicker&) = delete;
+  MovePicker(const Position&, Move, Value);
+  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:
-  void score_captures();
-  void score_noncaptures();
-  void score_evasions();
-  void go_next_phase();
+  template<GenType> void score();
+  ExtMove* begin() { return cur; }
+  ExtMove* end() { return endMoves; }
 
   const Position& pos;
-  const History& H;
-  MoveStack ttMoves[2], killers[2];
-  int badCaptureThreshold, phase;
-  const uint8_t* phasePtr;
-  MoveStack *curMove, *lastMove, *lastGoodNonCapture, *badCaptures;
-  MoveStack moves[MAX_MOVES];
+  const ButterflyHistory* mainHistory;
+  const PieceToHistory** contHistory;
+  Move ttMove, countermove, killers[2];
+  ExtMove *cur, *endMoves, *endBadCaptures;
+  int stage;
+  Square recaptureSquare;
+  Value threshold;
+  Depth depth;
+  ExtMove moves[MAX_MOVES];
 };
 
-#endif // !defined(MOVEPICK_H_INCLUDED)
+#endif // #ifndef MOVEPICK_H_INCLUDED