Never clear stats

[stockfish] / src / movepick.h

diff --git a/src/movepick.h b/src/movepick.h
index fdbd834e43742e63edea39f16cd0bc77a793657f..423a6a1805e34a233844024940bd8d66839fb74b 100644 (file)
--- a/src/movepick.h
+++ b/src/movepick.h
@@ -1,7 +1,7 @@
 /*
   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
 
   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 +17,95 @@
   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 <algorithm> // For std::max
+
+#include "movegen.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 Stats struct stores moves statistics. According to the template parameter
+/// the class can store History, Gains 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.
+/// Countermoves store the move that refute a previous one. Entries are stored
+/// 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>
+struct Stats {
 
-class MovePicker {
+  static const Value Max = Value(250);
+
+  const T* operator[](Piece pc) const { return table[pc]; }
+  T* operator[](Piece pc) { return table[pc]; }
+
+  void update(Piece pc, Square to, Move m) {
+
+    if (m != table[pc][to])
+        table[pc][to] = m;
+  }
+
+  void update(Piece pc, Square to, Value v) {
+
+    if (Gain)
+        table[pc][to] = std::max(v, table[pc][to] - 1);
+
+    else if (abs(table[pc][to] + v) < Max)
+        table[pc][to] +=  v;
+  }
+
+private:
+  T table[PIECE_NB][SQUARE_NB];
+};
+
+typedef Stats< true, Value> GainsStats;
+typedef Stats<false, Value> HistoryStats;
+typedef Stats<false, Move> MovesStats;
+typedef Stats<false, HistoryStats> CounterMovesHistoryStats;
 
-  MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC
 
+/// 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, Depth, const HistoryStats&, const CounterMovesHistoryStats&, Square);
+  MovePicker(const Position&, Move, const HistoryStats&, const CounterMovesHistoryStats&, PieceType);
+  MovePicker(const Position&, Move, Depth, const HistoryStats&, const CounterMovesHistoryStats&, Move, Search::Stack*);
+
+  template<bool SpNode> Move next_move();
 
 private:
-  void score_captures();
-  void score_noncaptures();
-  void score_evasions();
-  void go_next_phase();
+  template<GenType> void score();
+  void generate_next_stage();
+  ExtMove* begin() { return moves; }
+  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 HistoryStats& history;
+  const CounterMovesHistoryStats& counterMovesHistory;
+  Search::Stack* ss;
+  Move countermove;
+  Depth depth;
+  Move ttMove;
+  ExtMove killers[3];
+  Square recaptureSquare;
+  Value captureThreshold;
+  int stage;
+  ExtMove *endQuiets, *endBadCaptures;
+  ExtMove moves[MAX_MOVES], *cur = moves, *endMoves = moves;
 };
 
-#endif // !defined(MOVEPICK_H_INCLUDED)
+#endif // #ifndef MOVEPICK_H_INCLUDED