X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.h;h=b9d2594af114e447d987d39ec9edfc12a8cd8955;hp=c656deaf44bc319ac06fd37bdc679d894ab03422;hb=b15dcd977487c58409de48016eb7680850481d5d;hpb=9f626725aeb770a38be093a9a47a461053cf7008

diff --git a/src/movepick.h b/src/movepick.h
index c656deaf..b9d2594a 100644
--- 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) 2008-2014 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
@@ -17,71 +17,96 @@
   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
 
-////
-//// Includes
-////
+#include <algorithm> // For std::max
+#include <cstring>   // For std::memset
 
-#include "depth.h"
-#include "history.h"
+#include "movegen.h"
 #include "position.h"
+#include "search.h"
+#include "types.h"
 
 
-////
-//// Types
-////
+/// 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 {
 
-struct SearchStack;
+  static const Value Max = Value(250);
 
-/// 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.
+  const T* operator[](Piece pc) const { return table[pc]; }
+  void clear() { std::memset(table, 0, sizeof(table)); }
 
-class MovePicker {
+  void update(Piece pc, Square to, Move m) {
 
-  MovePicker& operator=(const MovePicker&); // silence a warning under MSVC
+    if (m == table[pc][to].first)
+        return;
 
-public:
-  MovePicker(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss = NULL, Value beta = -VALUE_INFINITE);
-  Move get_next_move();
-  int number_of_evasions() const;
+    table[pc][to].second = table[pc][to].first;
+    table[pc][to].first = m;
+  }
 
-private:
-  void score_captures();
-  void score_noncaptures();
-  void score_evasions();
-  void go_next_phase();
+  void update(Piece pc, Square to, Value v) {
 
-  const Position& pos;
-  const History& H;
-  Bitboard pinned;
-  MoveStack ttMoves[2], killers[2];
-  int badCaptureThreshold, phase;
-  const int* phasePtr;
-  MoveStack *curMove, *lastMove, *lastGoodNonCapture, *badCaptures;
-  MoveStack moves[MOVES_MAX];
+    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, std::pair<Move, Move> > MovesStats;
+
 
-////
-//// Inline functions
-////
+/// 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.
 
-/// MovePicker::number_of_evasions() simply returns the number of moves in
-/// evasions phase. It is intended to be used in positions where the side to
-/// move is in check, for detecting checkmates or situations where there is
-/// only a single reply to check.
-/// WARNING: It works as long as PH_EVASIONS is the _only_ phase for evasions.
+class MovePicker {
+
+  MovePicker& operator=(const MovePicker&); // Silence a warning under MSVC
+
+public:
+  MovePicker(const Position&, Move, Depth, const HistoryStats&, Square);
+  MovePicker(const Position&, Move, const HistoryStats&, PieceType);
+  MovePicker(const Position&, Move, Depth, const HistoryStats&, Move*, Move*, Search::Stack*);
+
+  template<bool SpNode> Move next_move();
 
-inline int MovePicker::number_of_evasions() const {
-  return int(lastMove - moves);
-}
+private:
+  template<GenType> void score();
+  void generate_next_stage();
+
+  const Position& pos;
+  const HistoryStats& history;
+  Search::Stack* ss;
+  Move* countermoves;
+  Move* followupmoves;
+  Depth depth;
+  Move ttMove;
+  ExtMove killers[6];
+  Square recaptureSquare;
+  Value captureThreshold;
+  int stage;
+  ExtMove *cur, *end, *endQuiets, *endBadCaptures;
+  ExtMove moves[MAX_MOVES];
+};
 
-#endif // !defined(MOVEPICK_H_INCLUDED)
+#endif // #ifndef MOVEPICK_H_INCLUDED