X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=57f731d4f257b9cd26deb0842042423bc7953ab0;hp=09a574a5c23d901f4d10f73d9f04463235459422;hb=a24f28be8567c2527b154ef981090368a2bd8f76;hpb=9cb1f9f2655cd378eec9d88fd57a039a04396aae;ds=inline diff --git a/src/position.cpp b/src/position.cpp index 09a574a5..57f731d4 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -64,10 +64,11 @@ std::ostream& operator<<(std::ostream& os, const Position& pos) { for (File f = FILE_A; f <= FILE_H; ++f) os << " | " << PieceToChar[pos.piece_on(make_square(f, r))]; - os << " |\n +---+---+---+---+---+---+---+---+\n"; + os << " | " << (1 + r) << "\n +---+---+---+---+---+---+---+---+\n"; } - os << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase + os << " a b c d e f g h\n" + << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase << std::setfill('0') << std::setw(16) << pos.key() << std::setfill(' ') << std::dec << "\nCheckers: "; @@ -104,8 +105,7 @@ Key cuckoo[8192]; Move cuckooMove[8192]; -/// Position::init() initializes at startup the various arrays used to compute -/// hash keys. +/// Position::init() initializes at startup the various arrays used to compute hash keys void Position::init() { @@ -119,15 +119,7 @@ void Position::init() { Zobrist::enpassant[f] = rng.rand(); for (int cr = NO_CASTLING; cr <= ANY_CASTLING; ++cr) - { - Zobrist::castling[cr] = 0; - Bitboard b = cr; - while (b) - { - Key k = Zobrist::castling[1ULL << pop_lsb(&b)]; - Zobrist::castling[cr] ^= k ? k : rng.rand(); - } - } + Zobrist::castling[cr] = rng.rand(); Zobrist::side = rng.rand(); Zobrist::noPawns = rng.rand(); @@ -139,7 +131,7 @@ void Position::init() { for (Piece pc : Pieces) for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1) for (Square s2 = Square(s1 + 1); s2 <= SQ_H8; ++s2) - if (PseudoAttacks[type_of(pc)][s1] & s2) + if ((type_of(pc) != PAWN) && (attacks_bb(type_of(pc), s1, 0) & s2)) { Move move = make_move(s1, s2); Key key = Zobrist::psq[pc][s1] ^ Zobrist::psq[pc][s2] ^ Zobrist::side; @@ -186,9 +178,9 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th 4) En passant target square (in algebraic notation). If there's no en passant target square, this is "-". If a pawn has just made a 2-square move, this - is the position "behind" the pawn. This is recorded only if there is a pawn - in position to make an en passant capture, and if there really is a pawn - that might have advanced two squares. + is the position "behind" the pawn. Following X-FEN standard, this is recorded only + if there is a pawn in position to make an en passant capture, and if there really + is a pawn that might have advanced two squares. 5) Halfmove clock. This is the number of halfmoves since the last pawn advance or capture. This is used to determine if a draw can be claimed under the @@ -259,17 +251,25 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th set_castling_right(c, rsq); } - // 4. En passant square. Ignore if no pawn capture is possible + // 4. En passant square. + // Ignore if square is invalid or not on side to move relative rank 6. + bool enpassant = false; + if ( ((ss >> col) && (col >= 'a' && col <= 'h')) - && ((ss >> row) && (row == '3' || row == '6'))) + && ((ss >> row) && (row == (sideToMove == WHITE ? '6' : '3')))) { st->epSquare = make_square(File(col - 'a'), Rank(row - '1')); - if ( !(attackers_to(st->epSquare) & pieces(sideToMove, PAWN)) - || !(pieces(~sideToMove, PAWN) & (st->epSquare + pawn_push(~sideToMove)))) - st->epSquare = SQ_NONE; + // En passant square will be considered only if + // a) side to move have a pawn threatening epSquare + // b) there is an enemy pawn in front of epSquare + // c) there is no piece on epSquare or behind epSquare + enpassant = pawn_attacks_bb(~sideToMove, st->epSquare) & pieces(sideToMove, PAWN) + && (pieces(~sideToMove, PAWN) & (st->epSquare + pawn_push(~sideToMove))) + && !(pieces() & (st->epSquare | (st->epSquare + pawn_push(sideToMove)))); } - else + + if (!enpassant) st->epSquare = SQ_NONE; // 5-6. Halfmove clock and fullmove number @@ -304,7 +304,7 @@ void Position::set_castling_right(Color c, Square rfrom) { Square rto = relative_square(c, cr & KING_SIDE ? SQ_F1 : SQ_D1); castlingPath[cr] = (between_bb(rfrom, rto) | between_bb(kfrom, kto) | rto | kto) - & ~(square_bb(kfrom) | rfrom); + & ~(kfrom | rfrom); } @@ -317,10 +317,10 @@ void Position::set_check_info(StateInfo* si) const { Square ksq = square(~sideToMove); - si->checkSquares[PAWN] = attacks_from(ksq, ~sideToMove); - si->checkSquares[KNIGHT] = attacks_from(ksq); - si->checkSquares[BISHOP] = attacks_from(ksq); - si->checkSquares[ROOK] = attacks_from(ksq); + si->checkSquares[PAWN] = pawn_attacks_bb(~sideToMove, ksq); + si->checkSquares[KNIGHT] = attacks_bb(ksq); + si->checkSquares[BISHOP] = attacks_bb(ksq, pieces()); + si->checkSquares[ROOK] = attacks_bb(ksq, pieces()); si->checkSquares[QUEEN] = si->checkSquares[BISHOP] | si->checkSquares[ROOK]; si->checkSquares[KING] = 0; } @@ -373,11 +373,13 @@ void Position::set_state(StateInfo* si) const { Position& Position::set(const string& code, Color c, StateInfo* si) { - assert(code.length() > 0 && code.length() < 8); assert(code[0] == 'K'); string sides[] = { code.substr(code.find('K', 1)), // Weak - code.substr(0, code.find('K', 1)) }; // Strong + code.substr(0, std::min(code.find('v'), code.find('K', 1))) }; // Strong + + assert(sides[0].length() > 0 && sides[0].length() < 8); + assert(sides[1].length() > 0 && sides[1].length() < 8); std::transform(sides[c].begin(), sides[c].end(), sides[c].begin(), tolower); @@ -451,8 +453,8 @@ Bitboard Position::slider_blockers(Bitboard sliders, Square s, Bitboard& pinners pinners = 0; // Snipers are sliders that attack 's' when a piece and other snipers are removed - Bitboard snipers = ( (PseudoAttacks[ ROOK][s] & pieces(QUEEN, ROOK)) - | (PseudoAttacks[BISHOP][s] & pieces(QUEEN, BISHOP))) & sliders; + Bitboard snipers = ( (attacks_bb< ROOK>(s) & pieces(QUEEN, ROOK)) + | (attacks_bb(s) & pieces(QUEEN, BISHOP))) & sliders; Bitboard occupancy = pieces() ^ snipers; while (snipers) @@ -476,12 +478,12 @@ Bitboard Position::slider_blockers(Bitboard sliders, Square s, Bitboard& pinners Bitboard Position::attackers_to(Square s, Bitboard occupied) const { - return (attacks_from(s, BLACK) & pieces(WHITE, PAWN)) - | (attacks_from(s, WHITE) & pieces(BLACK, PAWN)) - | (attacks_from(s) & pieces(KNIGHT)) + return (pawn_attacks_bb(BLACK, s) & pieces(WHITE, PAWN)) + | (pawn_attacks_bb(WHITE, s) & pieces(BLACK, PAWN)) + | (attacks_bb(s) & pieces(KNIGHT)) | (attacks_bb< ROOK>(s, occupied) & pieces( ROOK, QUEEN)) | (attacks_bb(s, occupied) & pieces(BISHOP, QUEEN)) - | (attacks_from(s) & pieces(KING)); + | (attacks_bb(s) & pieces(KING)); } @@ -584,15 +586,15 @@ bool Position::pseudo_legal(const Move m) const { if ((Rank8BB | Rank1BB) & to) return false; - if ( !(attacks_from(from, us) & pieces(~us) & to) // Not a capture + if ( !(pawn_attacks_bb(us, from) & pieces(~us) & to) // Not a capture && !((from + pawn_push(us) == to) && empty(to)) // Not a single push && !( (from + 2 * pawn_push(us) == to) // Not a double push - && (rank_of(from) == relative_rank(us, RANK_2)) + && (relative_rank(us, from) == RANK_2) && empty(to) && empty(to - pawn_push(us)))) return false; } - else if (!(attacks_from(type_of(pc), from) & to)) + else if (!(attacks_bb(type_of(pc), from, pieces()) & to)) return false; // Evasions generator already takes care to avoid some kind of illegal moves @@ -631,11 +633,11 @@ bool Position::gives_check(Move m) const { Square to = to_sq(m); // Is there a direct check? - if (st->checkSquares[type_of(piece_on(from))] & to) + if (check_squares(type_of(piece_on(from))) & to) return true; // Is there a discovered check? - if ( (st->blockersForKing[~sideToMove] & from) + if ( (blockers_for_king(~sideToMove) & from) && !aligned(from, to, square(~sideToMove))) return true; @@ -662,11 +664,11 @@ bool Position::gives_check(Move m) const { case CASTLING: { Square kfrom = from; - Square rfrom = to; // Castling is encoded as 'King captures the rook' + Square rfrom = to; // Castling is encoded as 'king captures the rook' Square kto = relative_square(sideToMove, rfrom > kfrom ? SQ_G1 : SQ_C1); Square rto = relative_square(sideToMove, rfrom > kfrom ? SQ_F1 : SQ_D1); - return (PseudoAttacks[ROOK][rto] & square(~sideToMove)) + return (attacks_bb(rto) & square(~sideToMove)) && (attacks_bb(rto, (pieces() ^ kfrom ^ rfrom) | rto | kto) & square(~sideToMove)); } default: @@ -741,8 +743,6 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { assert(relative_rank(us, to) == RANK_6); assert(piece_on(to) == NO_PIECE); assert(piece_on(capsq) == make_piece(them, PAWN)); - - board[capsq] = NO_PIECE; // Not done by remove_piece() } st->pawnKey ^= Zobrist::psq[captured][capsq]; @@ -751,7 +751,10 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { st->nonPawnMaterial[them] -= PieceValue[MG][captured]; // Update board and piece lists - remove_piece(captured, capsq); + remove_piece(capsq); + + if (type_of(m) == ENPASSANT) + board[capsq] = NO_PIECE; // Update material hash key and prefetch access to materialTable k ^= Zobrist::psq[captured][capsq]; @@ -775,21 +778,21 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { // Update castling rights if needed if (st->castlingRights && (castlingRightsMask[from] | castlingRightsMask[to])) { - int cr = castlingRightsMask[from] | castlingRightsMask[to]; - k ^= Zobrist::castling[st->castlingRights & cr]; - st->castlingRights &= ~cr; + k ^= Zobrist::castling[st->castlingRights]; + st->castlingRights &= ~(castlingRightsMask[from] | castlingRightsMask[to]); + k ^= Zobrist::castling[st->castlingRights]; } // Move the piece. The tricky Chess960 castling is handled earlier if (type_of(m) != CASTLING) - move_piece(pc, from, to); + move_piece(from, to); // If the moving piece is a pawn do some special extra work if (type_of(pc) == PAWN) { // Set en-passant square if the moved pawn can be captured if ( (int(to) ^ int(from)) == 16 - && (attacks_from(to - pawn_push(us), us) & pieces(them, PAWN))) + && (pawn_attacks_bb(us, to - pawn_push(us)) & pieces(them, PAWN))) { st->epSquare = to - pawn_push(us); k ^= Zobrist::enpassant[file_of(st->epSquare)]; @@ -802,7 +805,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { assert(relative_rank(us, to) == RANK_8); assert(type_of(promotion) >= KNIGHT && type_of(promotion) <= QUEEN); - remove_piece(pc, to); + remove_piece(to); put_piece(promotion, to); // Update hash keys @@ -882,7 +885,7 @@ void Position::undo_move(Move m) { assert(type_of(pc) == promotion_type(m)); assert(type_of(pc) >= KNIGHT && type_of(pc) <= QUEEN); - remove_piece(pc, to); + remove_piece(to); pc = make_piece(us, PAWN); put_piece(pc, to); } @@ -894,7 +897,7 @@ void Position::undo_move(Move m) { } else { - move_piece(pc, to, from); // Put the piece back at the source square + move_piece(to, from); // Put the piece back at the source square if (st->capturedPiece) { @@ -934,9 +937,9 @@ void Position::do_castling(Color us, Square from, Square& to, Square& rfrom, Squ to = relative_square(us, kingSide ? SQ_G1 : SQ_C1); // Remove both pieces first since squares could overlap in Chess960 - remove_piece(make_piece(us, KING), Do ? from : to); - remove_piece(make_piece(us, ROOK), Do ? rfrom : rto); - board[Do ? from : to] = board[Do ? rfrom : rto] = NO_PIECE; // Since remove_piece doesn't do it for us + remove_piece(Do ? from : to); + remove_piece(Do ? rfrom : rto); + board[Do ? from : to] = board[Do ? rfrom : rto] = NO_PIECE; // Since remove_piece doesn't do this for us put_piece(make_piece(us, KING), Do ? to : from); put_piece(make_piece(us, ROOK), Do ? rto : rfrom); } @@ -1106,6 +1109,7 @@ bool Position::see_ge(Move m, Value threshold) const { return bool(res); } + /// Position::is_draw() tests whether the position is drawn by 50-move rule /// or by repetition. It does not detect stalemates. @@ -1116,10 +1120,7 @@ bool Position::is_draw(int ply) const { // Return a draw score if a position repeats once earlier but strictly // after the root, or repeats twice before or at the root. - if (st->repetition && st->repetition < ply) - return true; - - return false; + return st->repetition && st->repetition < ply; }