X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.h;h=b9d2594af114e447d987d39ec9edfc12a8cd8955;hp=93061ee6fc6a81c8aaf277b817dab41a0d02dd34;hb=b15dcd977487c58409de48016eb7680850481d5d;hpb=eed508b4445057cd26bfb95ab5cd754ac96629fd

diff --git a/src/movepick.h b/src/movepick.h
index 93061ee6..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) 2008-2013 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
@@ -30,41 +30,46 @@
 
 
 /// The Stats struct stores moves statistics. According to the template parameter
-/// the class can store History and Countermoves. History records how often
+/// 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.
+/// 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
-/// according only to moving piece and destination square, hence two moves with
+/// using only the moving piece and destination square, hence two moves with
 /// different origin but same destination and piece will be considered identical.
-template<typename T>
+template<bool Gain, typename T>
 struct Stats {
 
-  static const Value Max = Value(2000);
+  static const Value Max = Value(250);
 
-  const T* operator[](Piece p) const { return table[p]; }
+  const T* operator[](Piece pc) const { return table[pc]; }
   void clear() { std::memset(table, 0, sizeof(table)); }
 
-  void update(Piece p, Square to, Move m) {
+  void update(Piece pc, Square to, Move m) {
 
-    if (m == table[p][to].first)
+    if (m == table[pc][to].first)
         return;
 
-    table[p][to].second = table[p][to].first;
-    table[p][to].first = m;
+    table[pc][to].second = table[pc][to].first;
+    table[pc][to].first = m;
   }
 
-  void update(Piece p, Square to, Value v) {
+  void update(Piece pc, Square to, Value v) {
 
-    if (abs(table[p][to] + v) < Max)
-        table[p][to] +=  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<Value> HistoryStats;
-typedef Stats<std::pair<Move, Move> > CountermovesStats;
+typedef Stats< true, Value> GainsStats;
+typedef Stats<false, Value> HistoryStats;
+typedef Stats<false, std::pair<Move, Move> > MovesStats;
 
 
 /// MovePicker class is used to pick one pseudo legal move at a time from the
@@ -81,23 +86,25 @@ class MovePicker {
 public:
   MovePicker(const Position&, Move, Depth, const HistoryStats&, Square);
   MovePicker(const Position&, Move, const HistoryStats&, PieceType);
-  MovePicker(const Position&, Move, Depth, const HistoryStats&, Move*, Search::Stack*);
+  MovePicker(const Position&, Move, Depth, const HistoryStats&, Move*, Move*, Search::Stack*);
 
   template<bool SpNode> Move next_move();
 
 private:
   template<GenType> void score();
-  void generate_next();
+  void generate_next_stage();
 
   const Position& pos;
   const HistoryStats& history;
   Search::Stack* ss;
   Move* countermoves;
+  Move* followupmoves;
   Depth depth;
   Move ttMove;
-  ExtMove killers[4];
+  ExtMove killers[6];
   Square recaptureSquare;
-  int captureThreshold, stage;
+  Value captureThreshold;
+  int stage;
   ExtMove *cur, *end, *endQuiets, *endBadCaptures;
   ExtMove moves[MAX_MOVES];
 };