Retire linear imbalance

[stockfish] / src / position.h

diff --git a/src/position.h b/src/position.h
index d44ed009e5d2405d8cb0826241b936724e6df488..7fce1dbb79f6415d5b4ecfca87a7723e44a83785 100644 (file)
--- a/src/position.h
+++ b/src/position.h
@@ -23,6 +23,7 @@
 
 #include <cassert>
 #include <cstddef>  // For offsetof()
+#include <deque>
 #include <memory>   // For std::unique_ptr
 #include <string>
 #include <vector>
@@ -40,19 +41,6 @@ namespace PSQT {
   void init();
 }
 
-/// CheckInfo struct is initialized at constructor time and keeps info used to
-/// detect if a move gives check.
-
-struct CheckInfo {
-
-  explicit CheckInfo(const Position&);
-
-  Bitboard dcCandidates;
-  Bitboard pinned;
-  Bitboard checkSquares[PIECE_TYPE_NB];
-  Square   ksq;
-};
-
 
 /// StateInfo struct stores information needed to restore a Position object to
 /// its previous state when we retract a move. Whenever a move is made on the
@@ -75,9 +63,12 @@ struct StateInfo {
   Bitboard   checkersBB;
   PieceType  capturedType;
   StateInfo* previous;
+  Bitboard   blockersForKing[COLOR_NB];
+  Bitboard   checkSquares[PIECE_TYPE_NB];
 };
 
-typedef std::unique_ptr<std::vector<StateInfo>> StateListPtr;
+// In a std::deque references to elements are unaffected upon resizing
+typedef std::unique_ptr<std::deque<StateInfo>> StateListPtr;
 
 
 /// Position class stores information regarding the board representation as
@@ -122,6 +113,7 @@ public:
   Bitboard checkers() const;
   Bitboard discovered_check_candidates() const;
   Bitboard pinned_pieces(Color c) const;
+  Bitboard check_squares(PieceType pt) const;
 
   // Attacks to/from a given square
   Bitboard attackers_to(Square s) const;
@@ -129,13 +121,14 @@ public:
   Bitboard attacks_from(Piece pc, Square s) const;
   template<PieceType> Bitboard attacks_from(Square s) const;
   template<PieceType> Bitboard attacks_from(Square s, Color c) const;
+  Bitboard slider_blockers(Bitboard sliders, Square s) const;
 
   // Properties of moves
-  bool legal(Move m, Bitboard pinned) const;
+  bool legal(Move m) const;
   bool pseudo_legal(const Move m) const;
   bool capture(Move m) const;
   bool capture_or_promotion(Move m) const;
-  bool gives_check(Move m, const CheckInfo& ci) const;
+  bool gives_check(Move m) const;
   bool advanced_pawn_push(Move m) const;
   Piece moved_piece(Move m) const;
   PieceType captured_piece_type() const;
@@ -182,9 +175,9 @@ private:
   // Initialization helpers (used while setting up a position)
   void set_castling_right(Color c, Square rfrom);
   void set_state(StateInfo* si) const;
+  void set_check_info(StateInfo* si) const;
 
   // Other helpers
-  Bitboard check_blockers(Color c, Color kingColor) const;
   void put_piece(Color c, PieceType pt, Square s);
   void remove_piece(Color c, PieceType pt, Square s);
   void move_piece(Color c, PieceType pt, Square from, Square to);
@@ -309,11 +302,15 @@ inline Bitboard Position::checkers() const {
 }
 
 inline Bitboard Position::discovered_check_candidates() const {
-  return check_blockers(sideToMove, ~sideToMove);
+  return st->blockersForKing[~sideToMove] & pieces(sideToMove);
 }
 
 inline Bitboard Position::pinned_pieces(Color c) const {
-  return check_blockers(c, c);
+  return st->blockersForKing[c] & pieces(c);
+}
+
+inline Bitboard Position::check_squares(PieceType pt) const {
+  return st->checkSquares[pt];
 }
 
 inline bool Position::pawn_passed(Color c, Square s) const {