Retire linear imbalance

[stockfish] / src / position.h

diff --git a/src/position.h b/src/position.h
index 0f1620b115600e0402705075e737bb43fbd96b6e..7fce1dbb79f6415d5b4ecfca87a7723e44a83785 100644 (file)
--- a/src/position.h
+++ b/src/position.h
@@ -2,6 +2,7 @@
   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) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -22,13 +23,16 @@
 
 #include <cassert>
 #include <cstddef>  // For offsetof()
+#include <deque>
+#include <memory>   // For std::unique_ptr
 #include <string>
+#include <vector>
 
 #include "bitboard.h"
 #include "types.h"
 
 class Position;
-struct Thread;
+class Thread;
 
 namespace PSQT {
 
@@ -37,19 +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
@@ -72,8 +63,13 @@ struct StateInfo {
   Bitboard   checkersBB;
   PieceType  capturedType;
   StateInfo* previous;
+  Bitboard   blockersForKing[COLOR_NB];
+  Bitboard   checkSquares[PIECE_TYPE_NB];
 };
 
+// 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
 /// pieces, side to move, hash keys, castling info, etc. Important methods are
@@ -85,14 +81,12 @@ class Position {
 public:
   static void init();
 
-  Position() = default; // To define the global object RootPos
+  Position() = default;
   Position(const Position&) = delete;
-  Position(const Position& pos, Thread* th) { *this = pos; thisThread = th; }
-  Position(const std::string& f, bool c960, Thread* th) { set(f, c960, th); }
-  Position& operator=(const Position&); // To assign RootPos from UCI
+  Position& operator=(const Position&) = delete;
 
   // FEN string input/output
-  void set(const std::string& fenStr, bool isChess960, Thread* th);
+  Position& set(const std::string& fenStr, bool isChess960, StateInfo* si, Thread* th);
   const std::string fen() const;
 
   // Position representation
@@ -119,6 +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;
@@ -126,13 +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;
@@ -177,12 +173,11 @@ public:
 
 private:
   // Initialization helpers (used while setting up a position)
-  void clear();
   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);
@@ -199,7 +194,6 @@ private:
   int castlingRightsMask[SQUARE_NB];
   Square castlingRookSquare[CASTLING_RIGHT_NB];
   Bitboard castlingPath[CASTLING_RIGHT_NB];
-  StateInfo startState;
   uint64_t nodes;
   int gamePly;
   Color sideToMove;
@@ -308,11 +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 {