Update copyright years

[stockfish] / src / movepick.h

diff --git a/src/movepick.h b/src/movepick.h
index aaff388f641c0d61f239a722bb11d9b2f2808bb6..90f60b8a9619df11279489dd032eb19eb79fc281 100644 (file)
--- a/src/movepick.h
+++ b/src/movepick.h
@@ -1,8 +1,6 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
-  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2004-2023 The Stockfish developers (see AUTHORS file)
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -29,6 +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
@@ -86,13 +86,8 @@ 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, 10692, 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;
+/// (~11 elo)
+typedef Stats<int16_t, 7183, 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
@@ -107,15 +102,16 @@ typedef Stats<int16_t, 29952, PIECE_NB, SQUARE_NB> PieceToHistory;
 /// ContinuationHistory is the combined history of a given pair of moves, usually
 /// the current one given a previous one. The nested history table is based on
 /// PieceToHistory instead of ButterflyBoards.
+/// (~63 elo)
 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
+/// 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.
+/// 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.
 class MovePicker {
 
   enum PickType { Next, Best };
@@ -123,20 +119,20 @@ 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);
 
+  Bitboard threatenedPieces;
+
 private:
   template<PickType T, typename Pred> Move select(Pred);
   template<GenType> void score();
@@ -145,7 +141,6 @@ private:
 
   const Position& pos;
   const ButterflyHistory* mainHistory;
-  const LowPlyHistory* lowPlyHistory;
   const CapturePieceToHistory* captureHistory;
   const PieceToHistory** continuationHistory;
   Move ttMove;
@@ -154,8 +149,9 @@ private:
   Square recaptureSquare;
   Value threshold;
   Depth depth;
-  int ply;
   ExtMove moves[MAX_MOVES];
 };
 
+} // namespace Stockfish
+
 #endif // #ifndef MOVEPICK_H_INCLUDED