X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=ed7510101de89fbbd38270113019d82b710d8b7a;hp=abac6efc1ef56e4b57a22734558c5d1c3564348a;hb=a188a047ab79a742e55f157f29e30299baafa7d0;hpb=08265aef81d63b1ccf22e1e1818d0edb64e0528e diff --git a/src/position.cpp b/src/position.cpp index abac6efc..ed751010 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -52,6 +52,7 @@ Key Position::zobSideToMove; Value Position::MgPieceSquareTable[16][64]; Value Position::EgPieceSquareTable[16][64]; +static bool RequestPending = false; //// //// Functions @@ -59,11 +60,11 @@ Value Position::EgPieceSquareTable[16][64]; /// Constructors -Position::Position(const Position &pos) { +Position::Position(const Position& pos) { copy(pos); } -Position::Position(const std::string &fen) { +Position::Position(const std::string& fen) { from_fen(fen); } @@ -72,7 +73,7 @@ Position::Position(const std::string &fen) { /// string. This function is not very robust - make sure that input FENs are /// correct (this is assumed to be the responsibility of the GUI). -void Position::from_fen(const std::string &fen) { +void Position::from_fen(const std::string& fen) { static const std::string pieceLetters = "KQRBNPkqrbnp"; static const Piece pieces[] = { WK, WQ, WR, WB, WN, WP, BK, BQ, BR, BB, BN, BP }; @@ -272,6 +273,13 @@ void Position::print(Move m) const { static const std::string pieceLetters = " PNBRQK PNBRQK ."; + // Check for reentrancy, as example when called from inside + // MovePicker that is used also here in move_to_san() + if (RequestPending) + return; + + RequestPending = true; + std::cout << std::endl; if (m != MOVE_NONE) { @@ -296,6 +304,8 @@ void Position::print(Move m) const { std::cout << "+---+---+---+---+---+---+---+---+" << std::endl << "Fen is: " << to_fen() << std::endl << "Key is: " << key << std::endl; + + RequestPending = false; } @@ -307,6 +317,25 @@ void Position::copy(const Position &pos) { } +/// Position::update_checkers() updates checkers info, used in do_move() +template +inline void Position::update_checkers(Bitboard* pCheckersBB, Square ksq, Square from, + Square to, Bitboard dcCandidates) { + + if (Piece != KING && bit_is_set(piece_attacks(ksq), to)) + set_bit(pCheckersBB, to); + + if (Piece != QUEEN && bit_is_set(dcCandidates, from)) + { + if (Piece != ROOK) + (*pCheckersBB) |= (piece_attacks(ksq) & rooks_and_queens(side_to_move())); + + if (Piece != BISHOP) + (*pCheckersBB) |= (piece_attacks(ksq) & bishops_and_queens(side_to_move())); + } +} + + /// Position:pinned_pieces() returns a bitboard of all pinned (against the /// king) pieces for the given color. Bitboard Position::pinned_pieces(Color c) const { @@ -369,19 +398,6 @@ Bitboard Position::hidden_checks(Color c, Square ksq) const { } -/// Position::square_is_attacked() checks whether the given side attacks the -/// given square. - -bool Position::square_is_attacked(Square s, Color c) const { - - return (pawn_attacks(opposite_color(c), s) & pawns(c)) - || (piece_attacks(s) & knights(c)) - || (piece_attacks(s) & kings(c)) - || (piece_attacks(s) & rooks_and_queens(c)) - || (piece_attacks(s) & bishops_and_queens(c)); -} - - /// Position::attacks_to() computes a bitboard containing all pieces which /// attacks a given square. There are two versions of this function: One /// which finds attackers of both colors, and one which only finds the @@ -397,12 +413,6 @@ Bitboard Position::attacks_to(Square s) const { | (piece_attacks(s) & pieces_of_type(KING)); } -Bitboard Position::attacks_to(Square s, Color c) const { - - return attacks_to(s) & pieces_of_color(c); -} - - /// Position::piece_attacks_square() tests whether the piece on square f /// attacks square t. @@ -665,10 +675,12 @@ bool Position::move_is_check(Move m, Bitboard dcCandidates) const { /// Position::move_is_capture() tests whether a move from the current -/// position is a capture. +/// position is a capture. Move must not be MOVE_NONE. bool Position::move_is_capture(Move m) const { + assert(m != MOVE_NONE); + return ( !square_is_empty(move_to(m)) && (color_of_piece_on(move_to(m)) == opposite_color(side_to_move())) ) @@ -796,33 +808,34 @@ void Position::do_move(Move m, UndoInfo& u, Bitboard dcCandidates) { if (piece == KING) kingSquare[us] = to; - // If the move was a double pawn push, set the en passant square. - // This code is a bit ugly right now, and should be cleaned up later. - // FIXME + // Reset en passant square if (epSquare != SQ_NONE) { key ^= zobEp[epSquare]; epSquare = SQ_NONE; } + + // If the moving piece was a pawn do some special extra work if (piece == PAWN) { + // Reset rule 50 draw counter + rule50 = 0; + + // Update pawn hash key + pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; + + // Set en passant square, only if moved pawn can be captured if (abs(int(to) - int(from)) == 16) { - if( ( us == WHITE - && (pawn_attacks(WHITE, from + DELTA_N) & pawns(BLACK))) - || ( us == BLACK - && (pawn_attacks(BLACK, from + DELTA_S) & pawns(WHITE)))) + if ( (us == WHITE && (pawn_attacks(WHITE, from + DELTA_N) & pawns(BLACK))) + || (us == BLACK && (pawn_attacks(BLACK, from + DELTA_S) & pawns(WHITE)))) { epSquare = Square((int(from) + int(to)) / 2); key ^= zobEp[epSquare]; } } - // Reset rule 50 draw counter - rule50 = 0; - - // Update pawn hash key - pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; } + // Update piece lists pieceList[us][piece][index[from]] = to; index[to] = index[from]; @@ -833,54 +846,33 @@ void Position::do_move(Move m, UndoInfo& u, Bitboard dcCandidates) { castleRights &= castleRightsMask[to]; key ^= zobCastle[castleRights]; - // Update checkers bitboard + // Update checkers bitboard, piece must be already moved checkersBB = EmptyBoardBB; Square ksq = king_square(them); switch (piece) { case PAWN: - if (bit_is_set(pawn_attacks(them, ksq), to)) - set_bit(&checkersBB, to); - - if (bit_is_set(dcCandidates, from)) - checkersBB |= ( (piece_attacks(ksq) & rooks_and_queens(us)) - |(piece_attacks(ksq) & bishops_and_queens(us))); + update_checkers(&checkersBB, ksq, from, to, dcCandidates); break; case KNIGHT: - if (bit_is_set(piece_attacks(ksq), to)) - set_bit(&checkersBB, to); - - if (bit_is_set(dcCandidates, from)) - checkersBB |= ( (piece_attacks(ksq) & rooks_and_queens(us)) - |(piece_attacks(ksq) & bishops_and_queens(us))); + update_checkers(&checkersBB, ksq, from, to, dcCandidates); break; case BISHOP: - if (bit_is_set(piece_attacks(ksq), to)) - set_bit(&checkersBB, to); - - if (bit_is_set(dcCandidates, from)) - checkersBB |= (piece_attacks(ksq) & rooks_and_queens(us)); + update_checkers(&checkersBB, ksq, from, to, dcCandidates); break; case ROOK: - if (bit_is_set(piece_attacks(ksq), to)) - set_bit(&checkersBB, to); - - if (bit_is_set(dcCandidates, from)) - checkersBB |= (piece_attacks(ksq) & bishops_and_queens(us)); + update_checkers(&checkersBB, ksq, from, to, dcCandidates); break; case QUEEN: - if (bit_is_set(piece_attacks(ksq), to)) - set_bit(&checkersBB, to); + update_checkers(&checkersBB, ksq, from, to, dcCandidates); break; case KING: - if (bit_is_set(dcCandidates, from)) - checkersBB |= ( (piece_attacks(ksq) & rooks_and_queens(us)) - |(piece_attacks(ksq) & bishops_and_queens(us))); + update_checkers(&checkersBB, ksq, from, to, dcCandidates); break; default: @@ -900,7 +892,6 @@ void Position::do_move(Move m, UndoInfo& u, Bitboard dcCandidates) { assert(is_ok()); } - /// Position::do_capture_move() is a private method used to update captured /// piece info. It is called from the main Position::do_move function. @@ -1570,10 +1561,16 @@ void Position::undo_null_move(const UndoInfo &u) { /// Position::see() is a static exchange evaluator: It tries to estimate the -/// material gain or loss resulting from a move. There are two versions of -/// this function: One which takes a move as input, and one which takes a -/// 'from' and a 'to' square. The function does not yet understand promotions -/// or en passant captures. +/// material gain or loss resulting from a move. There are three versions of +/// this function: One which takes a destination square as input, one takes a +/// move, and one which takes a 'from' and a 'to' square. The function does +/// not yet understand promotions or en passant captures. + +int Position::see(Square to) const { + + assert(square_is_ok(to)); + return see(SQ_NONE, to); +} int Position::see(Move m) const { @@ -1583,18 +1580,22 @@ int Position::see(Move m) const { int Position::see(Square from, Square to) const { - // Approximate material values, with pawn = 1 + // Material values static const int seeValues[18] = { - 0, 1, 3, 3, 5, 10, 100, 0, 0, 1, 3, 3, 5, 10, 100, 0, 0, 0 + 0, PawnValueMidgame, KnightValueMidgame, BishopValueMidgame, + RookValueMidgame, QueenValueMidgame, QueenValueMidgame*10, 0, + 0, PawnValueMidgame, KnightValueMidgame, BishopValueMidgame, + RookValueMidgame, QueenValueMidgame, QueenValueMidgame*10, 0, + 0, 0 }; Bitboard attackers, occ, b; - assert(square_is_ok(from)); + assert(square_is_ok(from) || from == SQ_NONE); assert(square_is_ok(to)); // Initialize colors - Color us = color_of_piece_on(from); + Color us = (from != SQ_NONE ? color_of_piece_on(from) : opposite_color(color_of_piece_on(to))); Color them = opposite_color(us); // Initialize pieces @@ -1604,15 +1605,49 @@ int Position::see(Square from, Square to) const { // Find all attackers to the destination square, with the moving piece // removed, but possibly an X-ray attacker added behind it. occ = occupied_squares(); - clear_bit(&occ, from); - attackers = (rook_attacks_bb(to, occ) & rooks_and_queens()) - | (bishop_attacks_bb(to, occ) & bishops_and_queens()) - | (piece_attacks(to) & knights()) - | (piece_attacks(to) & kings()) - | (pawn_attacks(WHITE, to) & pawns(BLACK)) - | (pawn_attacks(BLACK, to) & pawns(WHITE)); - - // If the opponent has no attackers, we are finished + + // Handle enpassant moves + if (ep_square() == to && type_of_piece_on(from) == PAWN) + { + assert(capture == EMPTY); + + Square capQq = (side_to_move() == WHITE)? (to - DELTA_N) : (to - DELTA_S); + capture = piece_on(capQq); + + assert(type_of_piece_on(capQq) == PAWN); + + // Remove the captured pawn + clear_bit(&occ, capQq); + } + + while (true) + { + clear_bit(&occ, from); + attackers = (rook_attacks_bb(to, occ) & rooks_and_queens()) + | (bishop_attacks_bb(to, occ) & bishops_and_queens()) + | (piece_attacks(to) & knights()) + | (piece_attacks(to) & kings()) + | (pawn_attacks(WHITE, to) & pawns(BLACK)) + | (pawn_attacks(BLACK, to) & pawns(WHITE)); + + if (from != SQ_NONE) + break; + + // If we don't have any attacker we are finished + if ((attackers & pieces_of_color(us)) == EmptyBoardBB) + return 0; + + // Locate the least valuable attacker to the destination square + // and use it to initialize from square. + PieceType pt; + for (pt = PAWN; !(attackers & pieces_of_color_and_type(us, pt)); pt++) + assert(pt < KING); + + from = first_1(attackers & pieces_of_color_and_type(us, pt)); + piece = piece_on(from); + } + + // If the opponent has no attackers we are finished if ((attackers & pieces_of_color(them)) == EmptyBoardBB) return seeValues[capture]; @@ -1911,7 +1946,7 @@ Value Position::compute_non_pawn_material(Color c) const { /// side to move is checkmated. Note that this function is currently very /// slow, and shouldn't be used frequently inside the search. -bool Position::is_mate() { +bool Position::is_mate() const { if (is_check()) {