X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.h;h=5b40ded8e0b5911636e9651f0b81d380e186d198;hp=6c73629916a01afdbb24a29f25f1f352f80ca9e3;hb=08d615cc9500713d89bd20dd0963258932abf627;hpb=cf71efc34bc6528a3a980aa0b9eec27770095eb8

diff --git a/src/movepick.h b/src/movepick.h
index 6c736299..5b40ded8 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) 2008-2009 Marco Costalba
+  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
@@ -17,83 +17,82 @@
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-
 #if !defined MOVEPICK_H_INCLUDED
 #define MOVEPICK_H_INCLUDED
 
-////
-//// Includes
-////
+#include <algorithm> // For std::max
+#include <cstring>   // For memset
 
-#include "depth.h"
-#include "history.h"
-#include "lock.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 both History and Gains type statistics. 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. 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.
+template<bool Gain>
+struct Stats {
 
-struct SearchStack;
+  static const Value Max = Value(2000);
 
-/// 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 Value* operator[](Piece p) const { return &table[p][0]; }
+  void clear() { memset(table, 0, sizeof(table)); }
 
-class MovePicker {
+  void update(Piece p, Square to, Value v) {
 
-  MovePicker& operator=(const MovePicker&); // silence a warning under MSVC
+    if (Gain)
+        table[p][to] = std::max(v, table[p][to] - 1);
 
-public:
-  MovePicker(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss = NULL);
-  Move get_next_move();
-  Move get_next_move(Lock& lock);
-  int number_of_evasions() const;
-  Bitboard discovered_check_candidates() const;
+    else if (abs(table[p][to] + v) < Max)
+        table[p][to] +=  v;
+  }
 
 private:
-  void score_captures();
-  void score_noncaptures();
-  void score_evasions();
-  void go_next_phase();
-
-  const Position& pos;
-  const History& H;
-  MoveStack ttMoves[2], killers[2];
-  bool finished;
-  int phase;
-  const uint8_t* phasePtr;
-  MoveStack *curMove, *lastMove, *lastBadCapture;
-  Bitboard dc, pinned;
-  MoveStack moves[256], badCaptures[64];
+  Value table[PIECE_NB][SQUARE_NB];
 };
 
+typedef Stats<false> History;
+typedef Stats<true> Gains;
+
 
-////
-//// 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
 
-inline int MovePicker::number_of_evasions() const {
-  return int(lastMove - moves);
-}
+public:
+  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();
 
-/// MovePicker::discovered_check_candidates() returns a bitboard containing
-/// all pieces which can possibly give discovered check. This bitboard is
-/// computed by the constructor function.
+private:
+  template<GenType> void score();
+  void generate_next();
 
-inline Bitboard MovePicker::discovered_check_candidates() const {
-  return dc;
-}
+  const Position& pos;
+  const History& Hist;
+  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)