/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file)
+ 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
#include <cassert>
#include <deque>
-#include <memory> // For std::unique_ptr
+#include <iosfwd>
+#include <memory>
#include <string>
#include "bitboard.h"
-#include "evaluate.h"
-#include "types.h"
-
#include "nnue/nnue_accumulator.h"
+#include "types.h"
+namespace Stockfish {
/// 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
struct StateInfo {
// Copied when making a move
- Key pawnKey;
Key materialKey;
Value nonPawnMaterial[COLOR_NB];
int castlingRights;
// Not copied when making a move (will be recomputed anyhow)
Key key;
Bitboard checkersBB;
- Piece capturedPiece;
StateInfo* previous;
Bitboard blockersForKing[COLOR_NB];
Bitboard pinners[COLOR_NB];
Bitboard checkSquares[PIECE_TYPE_NB];
+ Piece capturedPiece;
int repetition;
// Used by NNUE
/// 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;
+using StateListPtr = std::unique_ptr<std::deque<StateInfo>>;
/// Position class stores information regarding the board representation as
// FEN string input/output
Position& set(const std::string& fenStr, bool isChess960, StateInfo* si, Thread* th);
Position& set(const std::string& code, Color c, StateInfo* si);
- const std::string fen() const;
+ std::string fen() const;
// Position representation
- Bitboard pieces(PieceType pt) const;
- Bitboard pieces(PieceType pt1, PieceType pt2) const;
+ Bitboard pieces(PieceType pt = ALL_PIECES) const;
+ template<typename ...PieceTypes> Bitboard pieces(PieceType pt, PieceTypes... pts) const;
Bitboard pieces(Color c) const;
- Bitboard pieces(Color c, PieceType pt) const;
- Bitboard pieces(Color c, PieceType pt1, PieceType pt2) const;
+ template<typename ...PieceTypes> Bitboard pieces(Color c, PieceTypes... pts) const;
Piece piece_on(Square s) const;
Square ep_square() const;
bool empty(Square s) const;
template<PieceType Pt> int count(Color c) const;
template<PieceType Pt> int count() const;
- template<PieceType Pt> const Square* squares(Color c) const;
template<PieceType Pt> Square square(Color c) const;
- bool is_on_semiopen_file(Color c, Square s) const;
// Castling
CastlingRights castling_rights(Color c) const;
Bitboard checkers() const;
Bitboard blockers_for_king(Color c) const;
Bitboard check_squares(PieceType pt) const;
- bool is_discovery_check_on_king(Color c, Move m) const;
+ Bitboard pinners(Color c) const;
// Attacks to/from a given square
Bitboard attackers_to(Square s) const;
Bitboard attackers_to(Square s, Bitboard occupied) const;
- Bitboard slider_blockers(Bitboard sliders, Square s, Bitboard& pinners) const;
+ void update_slider_blockers(Color c) const;
+ template<PieceType Pt> Bitboard attacks_by(Color c) const;
// Properties of moves
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 capture_stage(Move m) const;
bool gives_check(Move m) const;
- bool advanced_pawn_push(Move m) const;
Piece moved_piece(Move m) const;
Piece captured_piece() const;
- // Piece specific
- bool pawn_passed(Color c, Square s) const;
- bool opposite_bishops() const;
- int pawns_on_same_color_squares(Color c, Square s) const;
-
// Doing and undoing moves
void do_move(Move m, StateInfo& newSt);
void do_move(Move m, StateInfo& newSt, bool givesCheck);
// Static Exchange Evaluation
bool see_ge(Move m, Value threshold = VALUE_ZERO) const;
+ bool see_ge(Move m, Bitboard& occupied, Value threshold = VALUE_ZERO) const;
// Accessing hash keys
Key key() const;
Key key_after(Move m) const;
Key material_key() const;
- Key pawn_key() const;
// Other properties of the position
Color side_to_move() const;
bool has_game_cycle(int ply) const;
bool has_repeated() const;
int rule50_count() const;
- Score psq_score() const;
Value non_pawn_material(Color c) const;
Value non_pawn_material() const;
// Used by NNUE
StateInfo* state() const;
- const EvalList* eval_list() const;
+
+ void put_piece(Piece pc, Square s);
+ void remove_piece(Square s);
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;
+ void set_state() const;
+ void set_check_info() const;
// Other helpers
- 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);
-
- // ID of a piece on a given square
- PieceId piece_id_on(Square sq) const;
+ template<bool AfterMove>
+ Key adjust_key50(Key k) const;
// Data members
Piece board[SQUARE_NB];
Bitboard byTypeBB[PIECE_TYPE_NB];
Bitboard byColorBB[COLOR_NB];
int pieceCount[PIECE_NB];
- Square pieceList[PIECE_NB][16];
- int index[SQUARE_NB];
int castlingRightsMask[SQUARE_NB];
Square castlingRookSquare[CASTLING_RIGHT_NB];
Bitboard castlingPath[CASTLING_RIGHT_NB];
- int gamePly;
- Color sideToMove;
- Score psq;
Thread* thisThread;
StateInfo* st;
+ int gamePly;
+ Color sideToMove;
bool chess960;
-
- // List of pieces used in NNUE evaluation function
- EvalList evalList;
};
-namespace PSQT {
- extern Score psq[PIECE_NB][SQUARE_NB];
-}
-
-extern std::ostream& operator<<(std::ostream& os, const Position& pos);
+std::ostream& operator<<(std::ostream& os, const Position& pos);
inline Color Position::side_to_move() const {
return sideToMove;
return piece_on(from_sq(m));
}
-inline Bitboard Position::pieces(PieceType pt = ALL_PIECES) const {
+inline Bitboard Position::pieces(PieceType pt) const {
return byTypeBB[pt];
}
-inline Bitboard Position::pieces(PieceType pt1, PieceType pt2) const {
- return pieces(pt1) | pieces(pt2);
+template<typename ...PieceTypes>
+inline Bitboard Position::pieces(PieceType pt, PieceTypes... pts) const {
+ return pieces(pt) | pieces(pts...);
}
inline Bitboard Position::pieces(Color c) const {
return byColorBB[c];
}
-inline Bitboard Position::pieces(Color c, PieceType pt) const {
- return pieces(c) & pieces(pt);
-}
-
-inline Bitboard Position::pieces(Color c, PieceType pt1, PieceType pt2) const {
- return pieces(c) & (pieces(pt1) | pieces(pt2));
+template<typename ...PieceTypes>
+inline Bitboard Position::pieces(Color c, PieceTypes... pts) const {
+ return pieces(c) & pieces(pts...);
}
template<PieceType Pt> inline int Position::count(Color c) const {
return count<Pt>(WHITE) + count<Pt>(BLACK);
}
-template<PieceType Pt> inline const Square* Position::squares(Color c) const {
- return pieceList[make_piece(c, Pt)];
-}
-
template<PieceType Pt> inline Square Position::square(Color c) const {
- assert(pieceCount[make_piece(c, Pt)] == 1);
- return squares<Pt>(c)[0];
+ assert(count<Pt>(c) == 1);
+ return lsb(pieces(c, Pt));
}
inline Square Position::ep_square() const {
return st->epSquare;
}
-inline bool Position::is_on_semiopen_file(Color c, Square s) const {
- return !(pieces(c, PAWN) & file_bb(s));
-}
-
inline bool Position::can_castle(CastlingRights cr) const {
return st->castlingRights & cr;
}
return attackers_to(s, pieces());
}
+template<PieceType Pt>
+inline Bitboard Position::attacks_by(Color c) const {
+
+ if constexpr (Pt == PAWN)
+ return c == WHITE ? pawn_attacks_bb<WHITE>(pieces(WHITE, PAWN))
+ : pawn_attacks_bb<BLACK>(pieces(BLACK, PAWN));
+ else
+ {
+ Bitboard threats = 0;
+ Bitboard attackers = pieces(c, Pt);
+ while (attackers)
+ threats |= attacks_bb<Pt>(pop_lsb(attackers), pieces());
+ return threats;
+ }
+}
+
inline Bitboard Position::checkers() const {
return st->checkersBB;
}
return st->blockersForKing[c];
}
-inline Bitboard Position::check_squares(PieceType pt) const {
- return st->checkSquares[pt];
-}
-
-inline bool Position::is_discovery_check_on_king(Color c, Move m) const {
- return st->blockersForKing[c] & from_sq(m);
-}
-
-inline bool Position::pawn_passed(Color c, Square s) const {
- return !(pieces(~c, PAWN) & passed_pawn_span(c, s));
+inline Bitboard Position::pinners(Color c) const {
+ return st->pinners[c];
}
-inline bool Position::advanced_pawn_push(Move m) const {
- return type_of(moved_piece(m)) == PAWN
- && 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));
+inline Bitboard Position::check_squares(PieceType pt) const {
+ return st->checkSquares[pt];
}
inline Key Position::key() const {
- return st->key;
+ return adjust_key50<false>(st->key);
}
-inline Key Position::pawn_key() const {
- return st->pawnKey;
+template<bool AfterMove>
+inline Key Position::adjust_key50(Key k) const
+{
+ return st->rule50 < 14 - AfterMove
+ ? k : k ^ make_key((st->rule50 - (14 - AfterMove)) / 8);
}
inline Key Position::material_key() const {
return st->materialKey;
}
-inline Score Position::psq_score() const {
- return psq;
-}
-
inline Value Position::non_pawn_material(Color c) const {
return st->nonPawnMaterial[c];
}
return st->rule50;
}
-inline bool Position::opposite_bishops() const {
- return count<BISHOP>(WHITE) == 1
- && count<BISHOP>(BLACK) == 1
- && opposite_colors(square<BISHOP>(WHITE), square<BISHOP>(BLACK));
-}
-
inline bool Position::is_chess960() const {
return chess960;
}
-inline bool Position::capture_or_promotion(Move m) const {
+inline bool Position::capture(Move m) const {
assert(is_ok(m));
- return type_of(m) != NORMAL ? type_of(m) != CASTLING : !empty(to_sq(m));
+ return (!empty(to_sq(m)) && type_of(m) != CASTLING)
+ || type_of(m) == EN_PASSANT;
}
-inline bool Position::capture(Move m) const {
+// returns true if a move is generated from the capture stage
+// having also queen promotions covered, i.e. consistency with the capture stage move generation
+// is needed to avoid the generation of duplicate moves.
+inline bool Position::capture_stage(Move m) const {
assert(is_ok(m));
- // Castling is encoded as "king captures rook"
- return (!empty(to_sq(m)) && type_of(m) != CASTLING) || type_of(m) == ENPASSANT;
+ return capture(m) || promotion_type(m) == QUEEN;
}
inline Piece Position::captured_piece() const {
board[s] = pc;
byTypeBB[ALL_PIECES] |= byTypeBB[type_of(pc)] |= s;
byColorBB[color_of(pc)] |= s;
- index[s] = pieceCount[pc]++;
- pieceList[pc][index[s]] = s;
+ pieceCount[pc]++;
pieceCount[make_piece(color_of(pc), ALL_PIECES)]++;
- psq += PSQT::psq[pc][s];
}
inline void Position::remove_piece(Square 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 invariant to a do_move() + undo_move() sequence.
Piece pc = board[s];
byTypeBB[ALL_PIECES] ^= s;
byTypeBB[type_of(pc)] ^= s;
byColorBB[color_of(pc)] ^= s;
- /* board[s] = NO_PIECE; Not needed, overwritten by the capturing one */
- Square lastSquare = pieceList[pc][--pieceCount[pc]];
- index[lastSquare] = index[s];
- pieceList[pc][index[lastSquare]] = lastSquare;
- pieceList[pc][pieceCount[pc]] = SQ_NONE;
+ board[s] = NO_PIECE;
+ pieceCount[pc]--;
pieceCount[make_piece(color_of(pc), ALL_PIECES)]--;
- psq -= PSQT::psq[pc][s];
}
inline void Position::move_piece(Square from, Square to) {
- // index[from] is not updated and becomes stale. This works as long as index[]
- // is accessed just by known occupied squares.
Piece pc = board[from];
Bitboard fromTo = from | to;
byTypeBB[ALL_PIECES] ^= fromTo;
byColorBB[color_of(pc)] ^= fromTo;
board[from] = NO_PIECE;
board[to] = pc;
- index[to] = index[from];
- pieceList[pc][index[to]] = to;
- psq += PSQT::psq[pc][to] - PSQT::psq[pc][from];
}
inline void Position::do_move(Move m, StateInfo& newSt) {
return st;
}
-inline const EvalList* Position::eval_list() const {
-
- return &evalList;
-}
-
-inline PieceId Position::piece_id_on(Square sq) const
-{
-
- assert(piece_on(sq) != NO_PIECE);
-
- PieceId pid = evalList.piece_id_list[sq];
- assert(is_ok(pid));
-
- return pid;
-}
+} // namespace Stockfish
#endif // #ifndef POSITION_H_INCLUDED
projects / stockfish / blobdiff