Remove Capture history pruning

[stockfish] / src / movepick.h

diff --git a/src/movepick.h b/src/movepick.h
index 5232ee4d4865db20e104edfe2d6b2aeb01c41ec0..426bac89bd9b232d5d9b58f7221270bdcdf5e2da 100644 (file)
--- a/src/movepick.h
+++ b/src/movepick.h
@@ -27,6 +27,8 @@
 #include "position.h"
 #include "types.h"
 
+namespace Stockfish {
+
 /// StatsEntry stores the stat table value. It is usually a number but could
 /// be a move or even a nested history. We use a class instead of naked value
 /// to directly call history update operator<<() on the entry so to use stats
@@ -84,13 +86,7 @@ enum StatsType { NoCaptures, Captures };
 /// unsuccessful during the current search, and is used for reduction and move
 /// ordering decisions. It uses 2 tables (one for each color) indexed by
 /// the move's from and to squares, see www.chessprogramming.org/Butterfly_Boards
-typedef Stats<int16_t, 13365, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyHistory;
-
-/// At higher depths LowPlyHistory records successful quiet moves near the root
-/// and quiet moves which are/were in the PV (ttPv). It is cleared with each new
-/// search and filled during iterative deepening.
-constexpr int MAX_LPH = 4;
-typedef Stats<int16_t, 10692, MAX_LPH, int(SQUARE_NB) * int(SQUARE_NB)> LowPlyHistory;
+typedef Stats<int16_t, 14365, COLOR_NB, int(SQUARE_NB) * int(SQUARE_NB)> ButterflyHistory;
 
 /// CounterMoveHistory stores counter moves indexed by [piece][to] of the previous
 /// move, see www.chessprogramming.org/Countermove_Heuristic
@@ -111,9 +107,9 @@ typedef Stats<PieceToHistory, NOT_USED, PIECE_NB, SQUARE_NB> ContinuationHistory
 /// 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.
+/// 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 {
 
   enum PickType { Next, Best };
@@ -121,18 +117,16 @@ class MovePicker {
 public:
   MovePicker(const MovePicker&) = delete;
   MovePicker& operator=(const MovePicker&) = delete;
-  MovePicker(const Position&, Move, Value, const CapturePieceToHistory*);
   MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
                                            const CapturePieceToHistory*,
                                            const PieceToHistory**,
-                                           Square);
+                                           Move,
+                                           const Move*);
   MovePicker(const Position&, Move, Depth, const ButterflyHistory*,
-                                           const LowPlyHistory*,
                                            const CapturePieceToHistory*,
                                            const PieceToHistory**,
-                                           Move,
-                                           const Move*,
-                                           int);
+                                           Square);
+  MovePicker(const Position&, Move, Value, const CapturePieceToHistory*);
   Move next_move(bool skipQuiets = false);
 
 private:
@@ -143,7 +137,6 @@ private:
 
   const Position& pos;
   const ButterflyHistory* mainHistory;
-  const LowPlyHistory* lowPlyHistory;
   const CapturePieceToHistory* captureHistory;
   const PieceToHistory** continuationHistory;
   Move ttMove;
@@ -152,8 +145,9 @@ private:
   Square recaptureSquare;
   Value threshold;
   Depth depth;
-  int ply;
   ExtMove moves[MAX_MOVES];
 };
 
+} // namespace Stockfish
+
 #endif // #ifndef MOVEPICK_H_INCLUDED