Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
-class Position;
-struct Thread;
-
-/// CheckInfo struct is initialized at c'tor time and keeps info used to detect
-/// if a move gives check.
-
-struct CheckInfo {
-
- explicit CheckInfo(const Position&);
-
- Bitboard dcCandidates;
- Bitboard pinned;
- Bitboard checkSq[PIECE_TYPE_NB];
- Square ksq;
-};
+#include "nnue/nnue_accumulator.h"
/// 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
/// 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
+/// A list to keep track of the position states along the setup moves (from the
+/// start position to the position just before the search starts). Needed by
+/// 'draw by repetition' detection. Use a std::deque because pointers to
+/// elements are not invalidated upon list 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
/// do_move() and undo_move(), used by the search to update node info when
/// traversing the search tree.
/// Position class stores information regarding the board representation as
/// pieces, side to move, hash keys, castling info, etc. Important methods are
/// do_move() and undo_move(), used by the search to update node info when
/// traversing the search tree.
- 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;
- void set(const std::string& fenStr, bool isChess960, Thread* th);
- const std::string fen() const;
+ Position& set(const std::string& fenStr, bool isChess960, StateInfo* si, Thread* th);
+ Position& set(const std::string& code, Color c, StateInfo* si);
+ std::string fen() const;
Bitboard pieces(PieceType pt) const;
Bitboard pieces(PieceType pt1, PieceType pt2) const;
Bitboard pieces(Color c) const;
Bitboard pieces(Color c, PieceType pt) const;
Bitboard pieces(Color c, PieceType pt1, PieceType pt2) const;
Piece piece_on(Square s) const;
Bitboard pieces(PieceType pt) const;
Bitboard pieces(PieceType pt1, PieceType pt2) const;
Bitboard pieces(Color c) const;
Bitboard pieces(Color c, PieceType pt) const;
Bitboard pieces(Color c, PieceType pt1, PieceType pt2) const;
Piece piece_on(Square s) const;
Square ep_square() const;
bool empty(Square s) const;
template<PieceType Pt> int count(Color c) const;
Square ep_square() const;
bool empty(Square s) const;
template<PieceType Pt> int count(Color c) const;
- template<PieceType Pt> const Square* list(Color c) const;
+ template<PieceType Pt> int count() const;
+ template<PieceType Pt> Square square(Color c) const;
+ bool is_on_semiopen_file(Color c, Square s) const;
- int can_castle(Color c) const;
- int can_castle(CastlingRight cr) const;
- bool castling_impeded(CastlingRight cr) const;
- Square castling_rook_square(CastlingRight cr) const;
+ CastlingRights castling_rights(Color c) const;
+ bool can_castle(CastlingRights cr) const;
+ bool castling_impeded(CastlingRights cr) const;
+ Square castling_rook_square(CastlingRights cr) const;
- Bitboard discovered_check_candidates() const;
- Bitboard pinned_pieces(Color c) const;
+ Bitboard blockers_for_king(Color c) const;
+ Bitboard check_squares(PieceType pt) const;
+ Bitboard pinners(Color c) const;
+ bool is_discovered_check_on_king(Color c, Move m) const;
// Attacks to/from a given square
Bitboard attackers_to(Square s) const;
Bitboard attackers_to(Square s, Bitboard occupied) const;
// Attacks to/from a given square
Bitboard attackers_to(Square s) const;
Bitboard attackers_to(Square s, Bitboard occupied) const;
- 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, Bitboard& pinners) const;
bool pseudo_legal(const Move m) const;
bool capture(Move m) const;
bool capture_or_promotion(Move m) const;
bool pseudo_legal(const Move m) const;
bool capture(Move m) const;
bool capture_or_promotion(Move m) const;
- void do_move(Move m, StateInfo& st);
- void do_move(Move m, StateInfo& st, const CheckInfo& ci, bool givesCheck);
+ void do_move(Move m, StateInfo& newSt);
+ void do_move(Move m, StateInfo& newSt, bool givesCheck);
- // Static exchange evaluation
- Value see(Move m) const;
- Value see_sign(Move m) const;
+ // Static Exchange Evaluation
+ bool see_ge(Move m, Value threshold = VALUE_ZERO) const;
Key material_key() const;
Key pawn_key() const;
// Other properties of the position
Color side_to_move() const;
Key material_key() const;
Key pawn_key() const;
// Other properties of the position
Color side_to_move() const;
- uint64_t nodes_searched() const;
- void set_nodes_searched(uint64_t n);
- bool is_draw() const;
+ bool is_draw(int ply) const;
+ bool has_game_cycle(int ply) const;
+ bool has_repeated() const;
void set_castling_right(Color c, Square rfrom);
void set_state(StateInfo* si) const;
void set_castling_right(Color c, Square rfrom);
void set_state(StateInfo* si) const;
- 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);
+ void put_piece(Piece pc, Square s);
+ void remove_piece(Square s);
+ void move_piece(Square from, Square to);
template<bool Do>
void do_castling(Color us, Square from, Square& to, Square& rfrom, Square& rto);
template<bool Do>
void do_castling(Color us, Square from, Square& to, Square& rfrom, Square& rto);
int castlingRightsMask[SQUARE_NB];
Square castlingRookSquare[CASTLING_RIGHT_NB];
Bitboard castlingPath[CASTLING_RIGHT_NB];
int castlingRightsMask[SQUARE_NB];
Square castlingRookSquare[CASTLING_RIGHT_NB];
Bitboard castlingPath[CASTLING_RIGHT_NB];
-template<PieceType Pt> inline const Square* Position::list(Color c) const {
- return pieceList[c][Pt];
+template<PieceType Pt> inline int Position::count() const {
+ return count<Pt>(WHITE) + count<Pt>(BLACK);
-inline Square Position::king_square(Color c) const {
- return pieceList[c][KING][0];
+template<PieceType Pt> inline Square Position::square(Color c) const {
+ assert(count<Pt>(c) == 1);
+ return lsb(pieces(c, Pt));
-inline int Position::can_castle(CastlingRight cr) const {
- return st->castlingRights & cr;
+inline bool Position::is_on_semiopen_file(Color c, Square s) const {
+ return !(pieces(c, PAWN) & file_bb(s));
-inline int Position::can_castle(Color c) const {
- return st->castlingRights & ((WHITE_OO | WHITE_OOO) << (2 * c));
+inline bool Position::can_castle(CastlingRights cr) const {
+ return st->castlingRights & cr;
-inline bool Position::castling_impeded(CastlingRight cr) const {
- return byTypeBB[ALL_PIECES] & castlingPath[cr];
+inline CastlingRights Position::castling_rights(Color c) const {
+ return c & CastlingRights(st->castlingRights);
-inline Square Position::castling_rook_square(CastlingRight cr) const {
- return castlingRookSquare[cr];
-}
+inline bool Position::castling_impeded(CastlingRights cr) const {
+ assert(cr == WHITE_OO || cr == WHITE_OOO || cr == BLACK_OO || cr == BLACK_OOO);
-template<PieceType Pt>
-inline Bitboard Position::attacks_from(Square s) const {
- return Pt == BISHOP || Pt == ROOK ? attacks_bb<Pt>(s, byTypeBB[ALL_PIECES])
- : Pt == QUEEN ? attacks_from<ROOK>(s) | attacks_from<BISHOP>(s)
- : StepAttacksBB[Pt][s];
+ return pieces() & castlingPath[cr];
-template<>
-inline Bitboard Position::attacks_from<PAWN>(Square s, Color c) const {
- return StepAttacksBB[make_piece(c, PAWN)][s];
-}
+inline Square Position::castling_rook_square(CastlingRights cr) const {
+ assert(cr == WHITE_OO || cr == WHITE_OOO || cr == BLACK_OO || cr == BLACK_OOO);
-inline Bitboard Position::attacks_from(Piece pc, Square s) const {
- return attacks_bb(pc, s, byTypeBB[ALL_PIECES]);
+ return castlingRookSquare[cr];
-inline Bitboard Position::discovered_check_candidates() const {
- return check_blockers(sideToMove, ~sideToMove);
+inline Bitboard Position::blockers_for_king(Color c) const {
+ return st->blockersForKing[c];
-inline Bitboard Position::pinned_pieces(Color c) const {
- return check_blockers(c, c);
+inline Bitboard Position::pinners(Color c) const {
+ return st->pinners[c];
+}
+
+inline Bitboard Position::check_squares(PieceType pt) const {
+ return st->checkSquares[pt];
+}
+
+inline bool Position::is_discovered_check_on_king(Color c, Move m) const {
+ return st->blockersForKing[c] & from_sq(m);
- && relative_rank(sideToMove, from_sq(m)) > RANK_4;
+ && relative_rank(sideToMove, to_sq(m)) > RANK_5;
+}
+
+inline int Position::pawns_on_same_color_squares(Color c, Square s) const {
+ return popcount(pieces(c, PAWN) & ((DarkSquares & s) ? DarkSquares : ~DarkSquares));
- return pieceCount[WHITE][BISHOP] == 1
- && pieceCount[BLACK][BISHOP] == 1
- && opposite_colors(pieceList[WHITE][BISHOP][0], pieceList[BLACK][BISHOP][0]);
-}
-
-inline bool Position::pawn_on_7th(Color c) const {
- return pieces(c, PAWN) & rank_bb(relative_rank(c, RANK_7));
+ return count<BISHOP>(WHITE) == 1
+ && count<BISHOP>(BLACK) == 1
+ && opposite_colors(square<BISHOP>(WHITE), square<BISHOP>(BLACK));
assert(is_ok(m));
return type_of(m) != NORMAL ? type_of(m) != CASTLING : !empty(to_sq(m));
}
inline bool Position::capture(Move m) const {
assert(is_ok(m));
return type_of(m) != NORMAL ? type_of(m) != CASTLING : !empty(to_sq(m));
}
inline bool Position::capture(Move m) const {
- board[s] = make_piece(c, pt);
- byTypeBB[ALL_PIECES] |= s;
- byTypeBB[pt] |= s;
- byColorBB[c] |= s;
- index[s] = pieceCount[c][pt]++;
- pieceList[c][pt][index[s]] = s;
- pieceCount[c][ALL_PIECES]++;
+ board[s] = pc;
+ byTypeBB[ALL_PIECES] |= byTypeBB[type_of(pc)] |= s;
+ byColorBB[color_of(pc)] |= s;
+ pieceCount[pc]++;
+ pieceCount[make_piece(color_of(pc), ALL_PIECES)]++;
+ psq += PSQT::psq[pc][s];
- // WARNING: This is not a reversible operation. If we remove a piece in
- // do_move() and then replace it in undo_move() we will put it at the end of
- // the list and not in its original place, it means index[] and pieceList[]
- // are not guaranteed to be invariant to a do_move() + undo_move() sequence.
- Square lastSquare = pieceList[c][pt][--pieceCount[c][pt]];
- index[lastSquare] = index[s];
- pieceList[c][pt][index[lastSquare]] = lastSquare;
- pieceList[c][pt][pieceCount[c][pt]] = SQ_NONE;
- pieceCount[c][ALL_PIECES]--;
+ pieceCount[pc]--;
+ pieceCount[make_piece(color_of(pc), ALL_PIECES)]--;
+ psq -= PSQT::psq[pc][s];
- // index[from] is not updated and becomes stale. This works as long as index[]
- // is accessed just by known occupied squares.
- Bitboard from_to_bb = SquareBB[from] ^ SquareBB[to];
- byTypeBB[ALL_PIECES] ^= from_to_bb;
- byTypeBB[pt] ^= from_to_bb;
- byColorBB[c] ^= from_to_bb;
+ Piece pc = board[from];
+ Bitboard fromTo = from | to;
+ byTypeBB[ALL_PIECES] ^= fromTo;
+ byTypeBB[type_of(pc)] ^= fromTo;
+ byColorBB[color_of(pc)] ^= fromTo;
- board[to] = make_piece(c, pt);
- index[to] = index[from];
- pieceList[c][pt][index[to]] = to;
+ board[to] = pc;
+ psq += PSQT::psq[pc][to] - PSQT::psq[pc][from];
+inline void Position::do_move(Move m, StateInfo& newSt) {
+ do_move(m, newSt, gives_check(m));
+}
+
+inline StateInfo* Position::state() const {
+
+ return st;
+}
+
+} // namespace Stockfish
+