/*
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) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+ Copyright (C) 2004-2022 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 <string>
#include "bitboard.h"
+#include "evaluate.h"
+#include "psqt.h"
#include "types.h"
+#include "nnue/nnue_accumulator.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
// 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
+ Eval::NNUE::Accumulator accumulator;
+ DirtyPiece dirtyPiece;
};
+
/// 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
// 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() const;
Bitboard pieces(PieceType pt) const;
Bitboard pieces(PieceType pt1, PieceType pt2) const;
Bitboard pieces(Color c) 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;
- int semiopen_file(Color c, File f) const;
+ bool is_on_semiopen_file(Color c, Square s) const;
// Castling
- int castling_rights(Color c) const;
- bool 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;
// Checking
Bitboard checkers() const;
Bitboard blockers_for_king(Color c) const;
Bitboard check_squares(PieceType pt) 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 attacks_from(PieceType pt, 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;
+ 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 gives_check(Move m) const;
- bool advanced_pawn_push(Move m) const;
Piece moved_piece(Move m) const;
Piece captured_piece() const;
bool has_repeated() const;
int rule50_count() const;
Score psq_score() const;
+ Value psq_eg_stm() const;
Value non_pawn_material(Color c) const;
Value non_pawn_material() const;
bool pos_is_ok() const;
void flip();
+ // Used by NNUE
+ StateInfo* state() 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_check_info(StateInfo* si) const;
// Other helpers
- void put_piece(Piece pc, Square s);
- void remove_piece(Piece pc, Square s);
- void move_piece(Piece pc, Square from, Square to);
+ void move_piece(Square from, Square to);
template<bool Do>
void do_castling(Color us, Square from, Square& to, Square& rfrom, Square& rto);
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];
+ Thread* thisThread;
+ StateInfo* st;
int gamePly;
Color sideToMove;
Score psq;
- Thread* thisThread;
- StateInfo* st;
bool chess960;
};
-namespace PSQT {
- extern Score psq[PIECE_NB][SQUARE_NB];
-}
-
extern std::ostream& operator<<(std::ostream& os, const Position& pos);
inline Color Position::side_to_move() const {
return sideToMove;
}
-inline bool Position::empty(Square s) const {
- return board[s] == NO_PIECE;
-}
-
inline Piece Position::piece_on(Square s) const {
+ assert(is_ok(s));
return board[s];
}
-inline Piece Position::moved_piece(Move m) const {
- return board[from_sq(m)];
+inline bool Position::empty(Square s) const {
+ return piece_on(s) == NO_PIECE;
}
-inline Bitboard Position::pieces() const {
- return byTypeBB[ALL_PIECES];
+inline Piece Position::moved_piece(Move m) const {
+ return piece_on(from_sq(m));
}
-inline Bitboard Position::pieces(PieceType pt) const {
+inline Bitboard Position::pieces(PieceType pt = ALL_PIECES) const {
return byTypeBB[pt];
}
inline Bitboard Position::pieces(PieceType pt1, PieceType pt2) const {
- return byTypeBB[pt1] | byTypeBB[pt2];
+ return pieces(pt1) | pieces(pt2);
}
inline Bitboard Position::pieces(Color c) const {
}
inline Bitboard Position::pieces(Color c, PieceType pt) const {
- return byColorBB[c] & byTypeBB[pt];
+ return pieces(c) & pieces(pt);
}
inline Bitboard Position::pieces(Color c, PieceType pt1, PieceType pt2) const {
- return byColorBB[c] & (byTypeBB[pt1] | byTypeBB[pt2]);
+ return pieces(c) & (pieces(pt1) | pieces(pt2));
}
template<PieceType Pt> inline int Position::count(Color c) const {
}
template<PieceType Pt> inline int Position::count() const {
- return pieceCount[make_piece(WHITE, Pt)] + pieceCount[make_piece(BLACK, Pt)];
-}
-
-template<PieceType Pt> inline const Square* Position::squares(Color c) const {
- return pieceList[make_piece(c, Pt)];
+ return count<Pt>(WHITE) + count<Pt>(BLACK);
}
template<PieceType Pt> inline Square Position::square(Color c) const {
- assert(pieceCount[make_piece(c, Pt)] == 1);
- return pieceList[make_piece(c, Pt)][0];
+ assert(count<Pt>(c) == 1);
+ return lsb(pieces(c, Pt));
}
inline Square Position::ep_square() const {
return st->epSquare;
}
-inline int Position::semiopen_file(Color c, File f) const {
- return !(pieces(c, PAWN) & file_bb(f));
+inline bool Position::is_on_semiopen_file(Color c, Square s) const {
+ return !(pieces(c, PAWN) & file_bb(s));
}
-inline bool Position::can_castle(CastlingRight cr) const {
+inline bool Position::can_castle(CastlingRights cr) const {
return st->castlingRights & cr;
}
-inline int Position::castling_rights(Color c) const {
- return st->castlingRights & (c == WHITE ? WHITE_CASTLING : BLACK_CASTLING);
+inline CastlingRights Position::castling_rights(Color c) const {
+ return c & CastlingRights(st->castlingRights);
}
-inline bool Position::castling_impeded(CastlingRight cr) const {
- return byTypeBB[ALL_PIECES] & castlingPath[cr];
-}
+inline bool Position::castling_impeded(CastlingRights cr) const {
+ assert(cr == WHITE_OO || cr == WHITE_OOO || cr == BLACK_OO || cr == BLACK_OOO);
-inline Square Position::castling_rook_square(CastlingRight cr) const {
- return castlingRookSquare[cr];
+ return pieces() & castlingPath[cr];
}
-template<PieceType Pt>
-inline Bitboard Position::attacks_from(Square s) const {
- assert(Pt != PAWN);
- return Pt == BISHOP || Pt == ROOK ? attacks_bb<Pt>(s, byTypeBB[ALL_PIECES])
- : Pt == QUEEN ? attacks_from<ROOK>(s) | attacks_from<BISHOP>(s)
- : PseudoAttacks[Pt][s];
-}
+inline Square Position::castling_rook_square(CastlingRights cr) const {
+ assert(cr == WHITE_OO || cr == WHITE_OOO || cr == BLACK_OO || cr == BLACK_OOO);
-template<>
-inline Bitboard Position::attacks_from<PAWN>(Square s, Color c) const {
- return PawnAttacks[c][s];
+ return castlingRookSquare[cr];
}
-inline Bitboard Position::attacks_from(PieceType pt, Square s) const {
- return attacks_bb(pt, s, byTypeBB[ALL_PIECES]);
+inline Bitboard Position::attackers_to(Square s) const {
+ return attackers_to(s, pieces());
}
-inline Bitboard Position::attackers_to(Square s) const {
- return attackers_to(s, byTypeBB[ALL_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->blockersForKing[c];
}
+inline Bitboard Position::pinners(Color c) const {
+ return st->pinners[c];
+}
+
inline Bitboard Position::check_squares(PieceType pt) const {
return st->checkSquares[pt];
}
return !(pieces(~c, PAWN) & passed_pawn_span(c, s));
}
-inline bool Position::advanced_pawn_push(Move m) const {
- return type_of(moved_piece(m)) == PAWN
- && relative_rank(sideToMove, from_sq(m)) > RANK_4;
-}
-
inline int Position::pawns_on_same_color_squares(Color c, Square s) const {
return popcount(pieces(c, PAWN) & ((DarkSquares & s) ? DarkSquares : ~DarkSquares));
}
inline Key Position::key() const {
- return st->key;
+ return st->rule50 < 14 ? st->key
+ : st->key ^ make_key((st->rule50 - 14) / 8);
}
inline Key Position::pawn_key() const {
return psq;
}
+inline Value Position::psq_eg_stm() const {
+ return (sideToMove == WHITE ? 1 : -1) * eg_value(psq);
+}
+
inline Value Position::non_pawn_material(Color c) const {
return st->nonPawnMaterial[c];
}
inline Value Position::non_pawn_material() const {
- return st->nonPawnMaterial[WHITE] + st->nonPawnMaterial[BLACK];
+ return non_pawn_material(WHITE) + non_pawn_material(BLACK);
}
inline int Position::game_ply() const {
}
inline bool Position::opposite_bishops() const {
- return pieceCount[W_BISHOP] == 1
- && pieceCount[B_BISHOP] == 1
+ return count<BISHOP>(WHITE) == 1
+ && count<BISHOP>(BLACK) == 1
&& opposite_colors(square<BISHOP>(WHITE), square<BISHOP>(BLACK));
}
return chess960;
}
-inline bool Position::capture_or_promotion(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 {
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 (!empty(to_sq(m)) && type_of(m) != CASTLING) || type_of(m) == EN_PASSANT;
}
inline Piece Position::captured_piece() const {
inline void Position::put_piece(Piece pc, Square s) {
board[s] = pc;
- byTypeBB[ALL_PIECES] |= s;
- byTypeBB[type_of(pc)] |= s;
+ 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(Piece pc, Square 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(Piece pc, Square from, Square to) {
+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.
- Bitboard fromTo = square_bb(from) | square_bb(to);
+ Piece pc = board[from];
+ Bitboard fromTo = from | to;
byTypeBB[ALL_PIECES] ^= fromTo;
byTypeBB[type_of(pc)] ^= 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];
}
do_move(m, newSt, gives_check(m));
}
+inline StateInfo* Position::state() const {
+
+ return st;
+}
+
+} // namespace Stockfish
+
#endif // #ifndef POSITION_H_INCLUDED