X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.h;h=3c285c983ca52f195ad31d767d6b48611b4b346b;hp=5010ee627f41ef8b94464dd07c15a24c2ee79325;hb=e14046517ed0a690c0969b3ca8d1b0e25ac9fb9e;hpb=1d5eaba5735e24c3afdeb07a5108d7ebf9e3ff57

diff --git a/src/movepick.h b/src/movepick.h
index 5010ee62..3c285c98 100644
--- a/src/movepick.h
+++ b/src/movepick.h
@@ -30,14 +30,13 @@
 
 
 /// The Stats struct stores moves statistics. According to the template parameter
-/// the class can store History, Gains and Countermoves. History records how often
+/// the class can store History 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.
+/// and is used for reduction and move ordering 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>
+template<typename T>
 struct Stats {
 
   static const Value Max = Value(250);
@@ -48,19 +47,13 @@ struct Stats {
 
   void update(Piece pc, Square to, Move m) {
 
-    if (m == table[pc][to].first)
-        return;
-
-    table[pc][to].second = table[pc][to].first;
-    table[pc][to].first = 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)
+    if (abs(table[pc][to] + v) < Max)
         table[pc][to] +=  v;
   }
 
@@ -68,10 +61,9 @@ 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;
-typedef Stats<false, HistoryStats> CounterMovesHistoryStats;
+typedef Stats<Value> HistoryStats;
+typedef Stats<Move> MovesStats;
+typedef Stats<HistoryStats> CounterMovesHistoryStats;
 
 
 /// MovePicker class is used to pick one pseudo legal move at a time from the
@@ -88,7 +80,7 @@ public:
 
   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*);
+  MovePicker(const Position&, Move, Depth, const HistoryStats&, const CounterMovesHistoryStats&, Move, Search::Stack*);
 
   template<bool SpNode> Move next_move();
 
@@ -102,10 +94,10 @@ private:
   const HistoryStats& history;
   const CounterMovesHistoryStats& counterMovesHistory;
   Search::Stack* ss;
-  Move* countermoves;
+  Move countermove;
   Depth depth;
   Move ttMove;
-  ExtMove killers[4];
+  ExtMove killers[3];
   Square recaptureSquare;
   Value captureThreshold;
   int stage;