Tweak check extension condition

[stockfish] / src / position.h

diff --git a/src/position.h b/src/position.h
index d44ed009e5d2405d8cb0826241b936724e6df488..b2538e96b5cf9316dc2907bbfe43aec9d929dcc3 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>
@@ -77,7 +78,8 @@ struct StateInfo {
   StateInfo* previous;
 };
 
-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
@@ -129,6 +131,7 @@ 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 target, Bitboard sliders, Square s) const;
 
   // Properties of moves
   bool legal(Move m, Bitboard pinned) const;
@@ -184,7 +187,6 @@ private:
   void set_state(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 +311,11 @@ inline Bitboard Position::checkers() const {
 }
 
 inline Bitboard Position::discovered_check_candidates() const {
-  return check_blockers(sideToMove, ~sideToMove);
+  return slider_blockers(pieces(sideToMove), pieces(sideToMove), square<KING>(~sideToMove));
 }
 
 inline Bitboard Position::pinned_pieces(Color c) const {
-  return check_blockers(c, c);
+  return slider_blockers(pieces(c), pieces(~c), square<KING>(c));
 }
 
 inline bool Position::pawn_passed(Color c, Square s) const {