X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.h;h=928366bcf4307036d579ccd1cfd814a28f79e242;hp=21ab63fe1d898867aacc7c3fca91ec14d12b86ad;hb=1188141aa78d01c361582daaa73de5154b6d09b1;hpb=f3cd7002aaf30d4d2c26be21e318fbc15bcba0cb diff --git a/src/position.h b/src/position.h index 21ab63fe..928366bc 100644 --- a/src/position.h +++ b/src/position.h @@ -1,8 +1,6 @@ /* 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 + Copyright (C) 2004-2021 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 @@ -27,8 +25,11 @@ #include #include "bitboard.h" +#include "evaluate.h" #include "types.h" +#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 @@ -43,7 +44,6 @@ struct StateInfo { int castlingRights; int rule50; int pliesFromNull; - Score psq; Square epSquare; // Not copied when making a move (will be recomputed anyhow) @@ -52,11 +52,20 @@ struct StateInfo { Piece capturedPiece; StateInfo* previous; Bitboard blockersForKing[COLOR_NB]; - Bitboard pinnersForKing[COLOR_NB]; + Bitboard pinners[COLOR_NB]; Bitboard checkSquares[PIECE_TYPE_NB]; + int repetition; + + // Used by NNUE + Eval::NNUE::Accumulator accumulator; + DirtyPiece dirtyPiece; }; -// In a std::deque references to elements are unaffected upon resizing + +/// 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> StateListPtr; @@ -80,7 +89,6 @@ public: 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; @@ -90,27 +98,26 @@ public: Square ep_square() const; bool empty(Square s) const; template int count(Color c) const; - template const Square* squares(Color c) const; + template int count() const; template Square square(Color c) const; + bool is_on_semiopen_file(Color c, Square s) const; // Castling - 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; // Checking Bitboard checkers() 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; - Bitboard attacks_from(Piece pc, Square s) const; - template Bitboard attacks_from(Square s) const; - template Bitboard attacks_from(Square s, Color c) const; Bitboard slider_blockers(Bitboard sliders, Square s, Bitboard& pinners) const; // Properties of moves @@ -126,15 +133,17 @@ public: // 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); void undo_move(Move m); void do_null_move(StateInfo& newSt); void undo_null_move(); // Static Exchange Evaluation - bool see_ge(Move m, Value value) const; + bool see_ge(Move m, Value threshold = VALUE_ZERO) const; // Accessing hash keys Key key() const; @@ -144,20 +153,24 @@ public: // Other properties of the position Color side_to_move() const; - Phase game_phase() const; int game_ply() const; bool is_chess960() const; Thread* this_thread() const; - uint64_t nodes_searched() const; - bool is_draw() const; + bool is_draw(int ply) 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; // Position consistency check, for debugging - bool pos_is_ok(int* failedStep = nullptr) const; + bool pos_is_ok() const; void flip(); + // Used by NNUE + StateInfo* state() const; + private: // Initialization helpers (used while setting up a position) void set_castling_right(Color c, Square rfrom); @@ -166,8 +179,8 @@ private: // 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 remove_piece(Square s); + void move_piece(Square from, Square to); template void do_castling(Color us, Square from, Square& to, Square& rfrom, Square& rto); @@ -176,47 +189,46 @@ private: 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]; - uint64_t nodes; int gamePly; Color sideToMove; + Score psq; Thread* thisThread; StateInfo* st; bool chess960; }; -extern std::ostream& operator<<(std::ostream& os, Position& pos); +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 { @@ -224,93 +236,94 @@ 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 inline int Position::count(Color c) const { return pieceCount[make_piece(c, Pt)]; } -template inline const Square* Position::squares(Color c) const { - return pieceList[make_piece(c, Pt)]; +template inline int Position::count() const { + return count(WHITE) + count(BLACK); } template inline Square Position::square(Color c) const { - assert(pieceCount[make_piece(c, Pt)] == 1); - return pieceList[make_piece(c, Pt)][0]; + assert(count(c) == 1); + return lsb(pieces(c, Pt)); } inline Square Position::ep_square() const { return st->epSquare; } -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 -inline Bitboard Position::attacks_from(Square s) const { - return Pt == BISHOP || Pt == ROOK ? attacks_bb(s, byTypeBB[ALL_PIECES]) - : Pt == QUEEN ? attacks_from(s) | attacks_from(s) - : StepAttacksBB[Pt][s]; + return pieces() & castlingPath[cr]; } -template<> -inline Bitboard Position::attacks_from(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::attackers_to(Square s) const { - return attackers_to(s, byTypeBB[ALL_PIECES]); + return attackers_to(s, pieces()); } inline Bitboard Position::checkers() const { return st->checkersBB; } -inline Bitboard Position::discovered_check_candidates() const { - return st->blockersForKing[~sideToMove] & pieces(sideToMove); +inline Bitboard Position::blockers_for_king(Color c) const { + return st->blockersForKing[c]; } -inline Bitboard Position::pinned_pieces(Color c) const { - return st->blockersForKing[c] & pieces(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); +} + inline bool Position::pawn_passed(Color c, Square s) const { - return !(pieces(~c, PAWN) & passed_pawn_mask(c, s)); + 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; + && 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 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 { @@ -322,13 +335,17 @@ inline Key Position::material_key() const { } inline Score Position::psq_score() const { - return st->psq; + return psq; } inline Value Position::non_pawn_material(Color c) const { return st->nonPawnMaterial[c]; } +inline Value Position::non_pawn_material() const { + return non_pawn_material(WHITE) + non_pawn_material(BLACK); +} + inline int Position::game_ply() const { return gamePly; } @@ -337,13 +354,9 @@ inline int Position::rule50_count() const { return st->rule50; } -inline uint64_t Position::nodes_searched() const { - return nodes; -} - inline bool Position::opposite_bishops() const { - return pieceCount[W_BISHOP] == 1 - && pieceCount[B_BISHOP] == 1 + return count(WHITE) == 1 + && count(BLACK) == 1 && opposite_colors(square(WHITE), square(BLACK)); } @@ -359,7 +372,7 @@ inline bool Position::capture_or_promotion(Move m) const { 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 { @@ -373,43 +386,44 @@ inline Thread* Position::this_thread() 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; + 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 from_to_bb = SquareBB[from] ^ SquareBB[to]; - byTypeBB[ALL_PIECES] ^= from_to_bb; - byTypeBB[type_of(pc)] ^= from_to_bb; - byColorBB[color_of(pc)] ^= 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[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) { + do_move(m, newSt, gives_check(m)); +} + +inline StateInfo* Position::state() const { + + return st; } #endif // #ifndef POSITION_H_INCLUDED