X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=2508db669dfb2241ed0e4c322fbfb6fbd8d0cfe0;hp=2b50ff2ae258df7a49eb0d892b79511d41e31908;hb=cfe59de27ddc42ac555187ae68879f2bc7bd7936;hpb=9e4befe3f1ea324bece88aee2e97b38659411c52 diff --git a/src/position.cpp b/src/position.cpp index 2b50ff2a..2508db66 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -51,27 +51,77 @@ Key Position::zobEp[64]; Key Position::zobCastle[16]; Key Position::zobMaterial[2][8][16]; Key Position::zobSideToMove; +Key Position::zobExclusion; -Value Position::MgPieceSquareTable[16][64]; -Value Position::EgPieceSquareTable[16][64]; +Score Position::PieceSquareTable[16][64]; static bool RequestPending = false; -//// -//// Functions -//// /// Constructors +CheckInfo::CheckInfo(const Position& pos) { + + Color us = pos.side_to_move(); + Color them = opposite_color(us); + + ksq = pos.king_square(them); + dcCandidates = pos.discovered_check_candidates(us); + + checkSq[PAWN] = pos.attacks_from(ksq, them); + checkSq[KNIGHT] = pos.attacks_from(ksq); + checkSq[BISHOP] = pos.attacks_from(ksq); + checkSq[ROOK] = pos.attacks_from(ksq); + checkSq[QUEEN] = checkSq[BISHOP] | checkSq[ROOK]; + checkSq[KING] = EmptyBoardBB; +} + + +/// Position c'tors. Here we always create a slower but safer copy of +/// the original position or the FEN string, we want the new born Position +/// object do not depend on any external data. Instead if we know what we +/// are doing and we need speed we can create a position with default +/// c'tor Position() and then use just fast_copy(). + +Position::Position() {} + Position::Position(const Position& pos) { - copy(pos); + + fast_copy(pos); + detach(); // Always detach() in copy c'tor to avoid surprises } Position::Position(const string& fen) { + from_fen(fen); } +/// Position::fast_copy() creates a partial copy of the given position, +/// only data that changes with a do_move() / undo_move() cycle is copied, +/// in particular for stateInfo are copied only the pointers, so that the +/// actual data remains stored in the parent Position. This is not a problem +/// if the parent Position is known not to be destroyed while we are still alive, +/// as is the common case, see detach() otherwise. + +void Position::fast_copy(const Position& pos) { + + memcpy(this, &pos, sizeof(Position)); +} + + +/// Position::detach() copies the content of the current state and castling +/// masks inside the position itself. This is needed when the st pointee could +/// become stale, as example because the caller is about to going out of scope. + +void Position::detach() { + + startState = *st; + st = &startState; + st->previous = NULL; // as a safe guard +} + + /// Position::from_fen() initializes the position object with the given 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). @@ -130,72 +180,77 @@ void Position::from_fen(const string& fen) { } i++; - while(strchr("KQkqabcdefghABCDEFGH-", fen[i])) { - if (fen[i] == '-') - { - i++; - break; - } - else if(fen[i] == 'K') allow_oo(WHITE); - else if(fen[i] == 'Q') allow_ooo(WHITE); - else if(fen[i] == 'k') allow_oo(BLACK); - else if(fen[i] == 'q') allow_ooo(BLACK); - else if(fen[i] >= 'A' && fen[i] <= 'H') { - File rookFile, kingFile = FILE_NONE; - for(Square square = SQ_B1; square <= SQ_G1; square++) - if(piece_on(square) == WK) - kingFile = square_file(square); - if(kingFile == FILE_NONE) { - std::cout << "Error in FEN at character " << i << std::endl; - return; - } - initialKFile = kingFile; - rookFile = File(fen[i] - 'A') + FILE_A; - if(rookFile < initialKFile) { - allow_ooo(WHITE); - initialQRFile = rookFile; - } - else { - allow_oo(WHITE); - initialKRFile = rookFile; + while (strchr("KQkqabcdefghABCDEFGH-", fen[i])) { + if (fen[i] == '-') + { + i++; + break; } - } - else if(fen[i] >= 'a' && fen[i] <= 'h') { - File rookFile, kingFile = FILE_NONE; - for(Square square = SQ_B8; square <= SQ_G8; square++) - if(piece_on(square) == BK) - kingFile = square_file(square); - if(kingFile == FILE_NONE) { - std::cout << "Error in FEN at character " << i << std::endl; - return; + else if (fen[i] == 'K') allow_oo(WHITE); + else if (fen[i] == 'Q') allow_ooo(WHITE); + else if (fen[i] == 'k') allow_oo(BLACK); + else if (fen[i] == 'q') allow_ooo(BLACK); + else if (fen[i] >= 'A' && fen[i] <= 'H') { + File rookFile, kingFile = FILE_NONE; + for (Square square = SQ_B1; square <= SQ_G1; square++) + if (piece_on(square) == WK) + kingFile = square_file(square); + if (kingFile == FILE_NONE) { + std::cout << "Error in FEN at character " << i << std::endl; + return; + } + initialKFile = kingFile; + rookFile = File(fen[i] - 'A') + FILE_A; + if (rookFile < initialKFile) { + allow_ooo(WHITE); + initialQRFile = rookFile; + } + else { + allow_oo(WHITE); + initialKRFile = rookFile; + } } - initialKFile = kingFile; - rookFile = File(fen[i] - 'a') + FILE_A; - if(rookFile < initialKFile) { - allow_ooo(BLACK); - initialQRFile = rookFile; + else if (fen[i] >= 'a' && fen[i] <= 'h') { + File rookFile, kingFile = FILE_NONE; + for (Square square = SQ_B8; square <= SQ_G8; square++) + if (piece_on(square) == BK) + kingFile = square_file(square); + if (kingFile == FILE_NONE) { + std::cout << "Error in FEN at character " << i << std::endl; + return; + } + initialKFile = kingFile; + rookFile = File(fen[i] - 'a') + FILE_A; + if (rookFile < initialKFile) { + allow_ooo(BLACK); + initialQRFile = rookFile; + } + else { + allow_oo(BLACK); + initialKRFile = rookFile; + } } else { - allow_oo(BLACK); - initialKRFile = rookFile; + std::cout << "Error in FEN at character " << i << std::endl; + return; } - } - else { - std::cout << "Error in FEN at character " << i << std::endl; - return; - } - i++; + i++; } // Skip blanks while (fen[i] == ' ') i++; - // En passant square + // En passant square -- ignore if no capture is possible if ( i <= fen.length() - 2 && (fen[i] >= 'a' && fen[i] <= 'h') && (fen[i+1] == '3' || fen[i+1] == '6')) - st->epSquare = square_from_string(fen.substr(i, 2)); + { + Square fenEpSquare = square_from_string(fen.substr(i, 2)); + Color them = opposite_color(sideToMove); + if (attacks_from(fenEpSquare, them) & this->pieces(PAWN, sideToMove)) + st->epSquare = square_from_string(fen.substr(i, 2)); + } // Various initialisation for (Square sq = SQ_A1; sq <= SQ_H8; sq++) @@ -213,8 +268,7 @@ void Position::from_fen(const string& fen) { st->key = compute_key(); st->pawnKey = compute_pawn_key(); st->materialKey = compute_material_key(); - st->mgValue = compute_value(); - st->egValue = compute_value(); + st->value = compute_value(); st->npMaterial[WHITE] = compute_non_pawn_material(WHITE); st->npMaterial[BLACK] = compute_non_pawn_material(BLACK); } @@ -254,10 +308,24 @@ const string Position::to_fen() const { fen += (sideToMove == WHITE ? "w " : "b "); if (st->castleRights != NO_CASTLES) { - if (can_castle_kingside(WHITE)) fen += 'K'; - if (can_castle_queenside(WHITE)) fen += 'Q'; - if (can_castle_kingside(BLACK)) fen += 'k'; - if (can_castle_queenside(BLACK)) fen += 'q'; + if (initialKFile == FILE_E && initialQRFile == FILE_A && initialKRFile == FILE_H) + { + if (can_castle_kingside(WHITE)) fen += 'K'; + if (can_castle_queenside(WHITE)) fen += 'Q'; + if (can_castle_kingside(BLACK)) fen += 'k'; + if (can_castle_queenside(BLACK)) fen += 'q'; + } + else + { + if (can_castle_kingside(WHITE)) + fen += char(toupper(file_to_char(initialKRFile))); + if (can_castle_queenside(WHITE)) + fen += char(toupper(file_to_char(initialQRFile))); + if (can_castle_kingside(BLACK)) + fen += file_to_char(initialKRFile); + if (can_castle_queenside(BLACK)) + fen += file_to_char(initialQRFile); + } } else fen += '-'; @@ -288,8 +356,9 @@ void Position::print(Move m) const { std::cout << std::endl; if (m != MOVE_NONE) { + Position p(*this); string col = (color_of_piece_on(move_from(m)) == BLACK ? ".." : ""); - std::cout << "Move is: " << col << move_to_san(*this, m) << std::endl; + std::cout << "Move is: " << col << move_to_san(p, m) << std::endl; } for (Rank rank = RANK_8; rank >= RANK_1; rank--) { @@ -314,34 +383,24 @@ void Position::print(Move m) const { } -/// Position::copy() creates a copy of the input position. - -void Position::copy(const Position& pos) { - - memcpy(this, &pos, sizeof(Position)); - saveState(); // detach and copy state info -} - - /// Position:hidden_checkers<>() returns a bitboard of all pinned (against the /// king) pieces for the given color and for the given pinner type. Or, when /// template parameter FindPinned is false, the pieces of the given color /// candidate for a discovery check against the enemy king. -/// Note that checkersBB bitboard must be already updated. +/// Bitboard checkersBB must be already updated when looking for pinners. template Bitboard Position::hidden_checkers(Color c) const { - Bitboard pinners, result = EmptyBoardBB; + Bitboard result = EmptyBoardBB; + Bitboard pinners = pieces_of_color(FindPinned ? opposite_color(c) : c); // Pinned pieces protect our king, dicovery checks attack // the enemy king. Square ksq = king_square(FindPinned ? c : opposite_color(c)); - // Pinners are sliders, not checkers, that give check when - // candidate pinned is removed. - pinners = (rooks_and_queens(FindPinned ? opposite_color(c) : c) & RookPseudoAttacks[ksq]) - | (bishops_and_queens(FindPinned ? opposite_color(c) : c) & BishopPseudoAttacks[ksq]); + // Pinners are sliders, not checkers, that give check when candidate pinned is removed + pinners &= (pieces(ROOK, QUEEN) & RookPseudoAttacks[ksq]) | (pieces(BISHOP, QUEEN) & BishopPseudoAttacks[ksq]); if (FindPinned && pinners) pinners &= ~st->checkersBB; @@ -362,7 +421,8 @@ Bitboard Position::hidden_checkers(Color c) const { /// Position:pinned_pieces() returns a bitboard of all pinned (against the -/// king) pieces for the given color. +/// king) pieces for the given color. Note that checkersBB bitboard must +/// be already updated. Bitboard Position::pinned_pieces(Color c) const { @@ -372,43 +432,43 @@ Bitboard Position::pinned_pieces(Color c) const { /// Position:discovered_check_candidates() returns a bitboard containing all /// pieces for the given side which are candidates for giving a discovered -/// check. +/// check. Contrary to pinned_pieces() here there is no need of checkersBB +/// to be already updated. Bitboard Position::discovered_check_candidates(Color c) const { return hidden_checkers(c); } -/// Position::attacks_to() computes a bitboard containing all pieces which +/// Position::attackers_to() computes a bitboard containing all pieces which /// attacks a given square. -Bitboard Position::attacks_to(Square s) const { +Bitboard Position::attackers_to(Square s) const { - return (pawn_attacks(BLACK, s) & pawns(WHITE)) - | (pawn_attacks(WHITE, s) & pawns(BLACK)) - | (piece_attacks(s) & pieces_of_type(KNIGHT)) - | (piece_attacks(s) & rooks_and_queens()) - | (piece_attacks(s) & bishops_and_queens()) - | (piece_attacks(s) & pieces_of_type(KING)); + return (attacks_from(s, BLACK) & pieces(PAWN, WHITE)) + | (attacks_from(s, WHITE) & pieces(PAWN, BLACK)) + | (attacks_from(s) & pieces(KNIGHT)) + | (attacks_from(s) & pieces(ROOK, QUEEN)) + | (attacks_from(s) & pieces(BISHOP, QUEEN)) + | (attacks_from(s) & pieces(KING)); } -/// Position::piece_attacks_square() tests whether the piece on square f -/// attacks square t. +/// Position::attacks_from() computes a bitboard of all attacks +/// of a given piece put in a given square. -bool Position::piece_attacks_square(Piece p, Square f, Square t) const { +Bitboard Position::attacks_from(Piece p, Square s) const { - assert(square_is_ok(f)); - assert(square_is_ok(t)); + assert(square_is_ok(s)); switch (p) { - case WP: return pawn_attacks_square(WHITE, f, t); - case BP: return pawn_attacks_square(BLACK, f, t); - case WN: case BN: return piece_attacks_square(f, t); - case WB: case BB: return piece_attacks_square(f, t); - case WR: case BR: return piece_attacks_square(f, t); - case WQ: case BQ: return piece_attacks_square(f, t); - case WK: case BK: return piece_attacks_square(f, t); + case WP: return attacks_from(s, WHITE); + case BP: return attacks_from(s, BLACK); + case WN: case BN: return attacks_from(s); + case WB: case BB: return attacks_from(s); + case WR: case BR: return attacks_from(s); + case WQ: case BQ: return attacks_from(s); + case WK: case BK: return attacks_from(s); default: break; } return false; @@ -427,7 +487,7 @@ bool Position::move_attacks_square(Move m, Square s) const { assert(square_is_occupied(f)); - if (piece_attacks_square(piece_on(f), t, s)) + if (bit_is_set(attacks_from(piece_on(f), t), s)) return true; // Move the piece and scan for X-ray attacks behind it @@ -435,43 +495,35 @@ bool Position::move_attacks_square(Move m, Square s) const { Color us = color_of_piece_on(f); clear_bit(&occ, f); set_bit(&occ, t); - Bitboard xray = ( (rook_attacks_bb(s, occ) & rooks_and_queens()) - |(bishop_attacks_bb(s, occ) & bishops_and_queens())) & pieces_of_color(us); + Bitboard xray = ( (rook_attacks_bb(s, occ) & pieces(ROOK, QUEEN)) + |(bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN))) & pieces_of_color(us); // If we have attacks we need to verify that are caused by our move // and are not already existent ones. - return xray && (xray ^ (xray & piece_attacks(s))); + return xray && (xray ^ (xray & attacks_from(s))); } /// Position::find_checkers() computes the checkersBB bitboard, which /// contains a nonzero bit for each checking piece (0, 1 or 2). It -/// currently works by calling Position::attacks_to, which is probably +/// currently works by calling Position::attackers_to, which is probably /// inefficient. Consider rewriting this function to use the last move /// played, like in non-bitboard versions of Glaurung. void Position::find_checkers() { Color us = side_to_move(); - st->checkersBB = attacks_to(king_square(us), opposite_color(us)); + st->checkersBB = attackers_to(king_square(us)) & pieces_of_color(opposite_color(us)); } /// Position::pl_move_is_legal() tests whether a pseudo-legal move is legal -bool Position::pl_move_is_legal(Move m) const { - - // If we're in check, all pseudo-legal moves are legal, because our - // check evasion generator only generates true legal moves. - return is_check() || pl_move_is_legal(m, pinned_pieces(side_to_move())); -} - bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { assert(is_ok()); assert(move_is_ok(m)); assert(pinned == pinned_pieces(side_to_move())); - assert(!is_check()); // Castling moves are checked for legality during move generation. if (move_is_castle(m)) @@ -479,12 +531,11 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { Color us = side_to_move(); Square from = move_from(m); - Square ksq = king_square(us); assert(color_of_piece_on(from) == us); - assert(piece_on(ksq) == piece_of_color_and_type(us, KING)); + assert(piece_on(king_square(us)) == piece_of_color_and_type(us, KING)); - // En passant captures are a tricky special case. Because they are + // En passant captures are a tricky special case. Because they are // rather uncommon, we do it simply by testing whether the king is attacked // after the move is made if (move_is_ep(m)) @@ -493,6 +544,7 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { Square to = move_to(m); Square capsq = make_square(square_file(to), square_rank(from)); Bitboard b = occupied_squares(); + Square ksq = king_square(us); assert(to == ep_square()); assert(piece_on(from) == piece_of_color_and_type(us, PAWN)); @@ -503,20 +555,46 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { clear_bit(&b, capsq); set_bit(&b, to); - return !(rook_attacks_bb(ksq, b) & rooks_and_queens(them)) - && !(bishop_attacks_bb(ksq, b) & bishops_and_queens(them)); + return !(rook_attacks_bb(ksq, b) & pieces(ROOK, QUEEN, them)) + && !(bishop_attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, them)); } // If the moving piece is a king, check whether the destination // square is attacked by the opponent. - if (from == ksq) - return !(square_is_attacked(move_to(m), opposite_color(us))); + if (type_of_piece_on(from) == KING) + return !(attackers_to(move_to(m)) & pieces_of_color(opposite_color(us))); // A non-king move is legal if and only if it is not pinned or it // is moving along the ray towards or away from the king. return ( !pinned || !bit_is_set(pinned, from) - || (direction_between_squares(from, ksq) == direction_between_squares(move_to(m), ksq))); + || (direction_between_squares(from, king_square(us)) == direction_between_squares(move_to(m), king_square(us)))); +} + + +/// Position::pl_move_is_evasion() tests whether a pseudo-legal move is a legal evasion + +bool Position::pl_move_is_evasion(Move m, Bitboard pinned) const +{ + assert(is_check()); + + Color us = side_to_move(); + Square from = move_from(m); + Square to = move_to(m); + + // King moves and en-passant captures are verified in pl_move_is_legal() + if (type_of_piece_on(from) == KING || move_is_ep(m)) + return pl_move_is_legal(m, pinned); + + Bitboard target = checkers(); + Square checksq = pop_1st_bit(&target); + + if (target) // double check ? + return false; + + // Our move must be a blocking evasion or a capture of the checking piece + target = squares_between(checksq, king_square(us)) | checkers(); + return bit_is_set(target, to) && pl_move_is_legal(m, pinned); } @@ -524,161 +602,98 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { bool Position::move_is_check(Move m) const { - Bitboard dc = discovered_check_candidates(side_to_move()); - return move_is_check(m, dc); + return move_is_check(m, CheckInfo(*this)); } -bool Position::move_is_check(Move m, Bitboard dcCandidates) const { +bool Position::move_is_check(Move m, const CheckInfo& ci) const { assert(is_ok()); assert(move_is_ok(m)); - assert(dcCandidates == discovered_check_candidates(side_to_move())); + assert(ci.dcCandidates == discovered_check_candidates(side_to_move())); + assert(color_of_piece_on(move_from(m)) == side_to_move()); + assert(piece_on(ci.ksq) == piece_of_color_and_type(opposite_color(side_to_move()), KING)); - Color us = side_to_move(); - Color them = opposite_color(us); Square from = move_from(m); Square to = move_to(m); - Square ksq = king_square(them); + PieceType pt = type_of_piece_on(from); - assert(color_of_piece_on(from) == us); - assert(piece_on(ksq) == piece_of_color_and_type(them, KING)); + // Direct check ? + if (bit_is_set(ci.checkSq[pt], to)) + return true; - // Proceed according to the type of the moving piece - switch (type_of_piece_on(from)) + // Discovery check ? + if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from)) { - case PAWN: - - if (bit_is_set(pawn_attacks(them, ksq), to)) // Normal check? + // For pawn and king moves we need to verify also direction + if ( (pt != PAWN && pt != KING) + ||(direction_between_squares(from, ci.ksq) != direction_between_squares(to, ci.ksq))) return true; + } - if ( dcCandidates // Discovered check? - && bit_is_set(dcCandidates, from) - && (direction_between_squares(from, ksq) != direction_between_squares(to, ksq))) - return true; - - if (move_is_promotion(m)) // Promotion with check? - { - Bitboard b = occupied_squares(); - clear_bit(&b, from); - - switch (move_promotion_piece(m)) - { - case KNIGHT: - return bit_is_set(piece_attacks(to), ksq); - case BISHOP: - return bit_is_set(bishop_attacks_bb(to, b), ksq); - case ROOK: - return bit_is_set(rook_attacks_bb(to, b), ksq); - case QUEEN: - return bit_is_set(queen_attacks_bb(to, b), ksq); - default: - assert(false); - } - } - // En passant capture with check? We have already handled the case - // of direct checks and ordinary discovered check, the only case we - // need to handle is the unusual case of a discovered check through the - // captured pawn. - else if (move_is_ep(m)) - { - Square capsq = make_square(square_file(to), square_rank(from)); - Bitboard b = occupied_squares(); - clear_bit(&b, from); - clear_bit(&b, capsq); - set_bit(&b, to); - return (rook_attacks_bb(ksq, b) & rooks_and_queens(us)) - ||(bishop_attacks_bb(ksq, b) & bishops_and_queens(us)); - } + // Can we skip the ugly special cases ? + if (!move_is_special(m)) return false; - // Test discovered check and normal check according to piece type - case KNIGHT: - return (dcCandidates && bit_is_set(dcCandidates, from)) - || bit_is_set(piece_attacks(ksq), to); - - case BISHOP: - return (dcCandidates && bit_is_set(dcCandidates, from)) - || (direction_is_diagonal(ksq, to) && bit_is_set(piece_attacks(ksq), to)); - - case ROOK: - return (dcCandidates && bit_is_set(dcCandidates, from)) - || (direction_is_straight(ksq, to) && bit_is_set(piece_attacks(ksq), to)); - - case QUEEN: - // Discovered checks are impossible! - assert(!bit_is_set(dcCandidates, from)); - return ( (direction_is_straight(ksq, to) && bit_is_set(piece_attacks(ksq), to)) - || (direction_is_diagonal(ksq, to) && bit_is_set(piece_attacks(ksq), to))); - - case KING: - // Discovered check? - if ( bit_is_set(dcCandidates, from) - && (direction_between_squares(from, ksq) != direction_between_squares(to, ksq))) - return true; + Color us = side_to_move(); + Bitboard b = occupied_squares(); - // Castling with check? - if (move_is_castle(m)) - { - Square kfrom, kto, rfrom, rto; - Bitboard b = occupied_squares(); - kfrom = from; - rfrom = to; + // Promotion with check ? + if (move_is_promotion(m)) + { + clear_bit(&b, from); - if (rfrom > kfrom) - { - kto = relative_square(us, SQ_G1); - rto = relative_square(us, SQ_F1); - } else { - kto = relative_square(us, SQ_C1); - rto = relative_square(us, SQ_D1); - } - clear_bit(&b, kfrom); - clear_bit(&b, rfrom); - set_bit(&b, rto); - set_bit(&b, kto); - return bit_is_set(rook_attacks_bb(rto, b), ksq); + switch (move_promotion_piece(m)) + { + case KNIGHT: + return bit_is_set(attacks_from(to), ci.ksq); + case BISHOP: + return bit_is_set(bishop_attacks_bb(to, b), ci.ksq); + case ROOK: + return bit_is_set(rook_attacks_bb(to, b), ci.ksq); + case QUEEN: + return bit_is_set(queen_attacks_bb(to, b), ci.ksq); + default: + assert(false); } - return false; - - default: // NO_PIECE_TYPE - break; } - assert(false); - return false; -} - -/// Position::update_checkers() udpates chekers info given the move. It is called -/// in do_move() and is faster then find_checkers(). - -template -inline void Position::update_checkers(Bitboard* pCheckersBB, Square ksq, Square from, - Square to, Bitboard dcCandidates) { - - const bool Bishop = (Piece == QUEEN || Piece == BISHOP); - const bool Rook = (Piece == QUEEN || Piece == ROOK); - const bool Slider = Bishop || Rook; - - // Direct checks - if ( ( (Bishop && bit_is_set(BishopPseudoAttacks[ksq], to)) - || (Rook && bit_is_set(RookPseudoAttacks[ksq], to))) - && bit_is_set(piece_attacks(ksq), to)) // slow, try to early skip - set_bit(pCheckersBB, to); - - else if ( Piece != KING - && !Slider - && bit_is_set(piece_attacks(ksq), to)) - set_bit(pCheckersBB, to); + // En passant capture with check? We have already handled the case + // of direct checks and ordinary discovered check, the only case we + // need to handle is the unusual case of a discovered check through the + // captured pawn. + if (move_is_ep(m)) + { + Square capsq = make_square(square_file(to), square_rank(from)); + clear_bit(&b, from); + clear_bit(&b, capsq); + set_bit(&b, to); + return (rook_attacks_bb(ci.ksq, b) & pieces(ROOK, QUEEN, us)) + ||(bishop_attacks_bb(ci.ksq, b) & pieces(BISHOP, QUEEN, us)); + } - // Discovery checks - if (Piece != QUEEN && bit_is_set(dcCandidates, from)) + // Castling with check ? + if (move_is_castle(m)) { - if (Piece != ROOK) - (*pCheckersBB) |= (piece_attacks(ksq) & rooks_and_queens(side_to_move())); + Square kfrom, kto, rfrom, rto; + kfrom = from; + rfrom = to; - if (Piece != BISHOP) - (*pCheckersBB) |= (piece_attacks(ksq) & bishops_and_queens(side_to_move())); + if (rfrom > kfrom) + { + kto = relative_square(us, SQ_G1); + rto = relative_square(us, SQ_F1); + } else { + kto = relative_square(us, SQ_C1); + rto = relative_square(us, SQ_D1); + } + clear_bit(&b, kfrom); + clear_bit(&b, rfrom); + set_bit(&b, rto); + set_bit(&b, kto); + return bit_is_set(rook_attacks_bb(rto, b), ci.ksq); } + + return false; } @@ -688,10 +703,11 @@ inline void Position::update_checkers(Bitboard* pCheckersBB, Square ksq, Square void Position::do_move(Move m, StateInfo& newSt) { - do_move(m, newSt, discovered_check_candidates(side_to_move())); + CheckInfo ci(*this); + do_move(m, newSt, ci, move_is_check(m, ci)); } -void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { +void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveIsCheck) { assert(is_ok()); assert(move_is_ok(m)); @@ -702,10 +718,10 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { // ones which are recalculated from scratch anyway, then switch our state // pointer to point to the new, ready to be updated, state. struct ReducedStateInfo { - Key key, pawnKey, materialKey; - int castleRights, rule50; + Key pawnKey, materialKey; + int castleRights, rule50, pliesFromNull; Square epSquare; - Value mgValue, egValue; + Score value; Value npMaterial[2]; }; @@ -724,6 +740,7 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { // Increment the 50 moves rule draw counter. Resetting it to zero in the // case of non-reversible moves is taken care of later. st->rule50++; + st->pliesFromNull++; if (move_is_castle(m)) { @@ -741,16 +758,15 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { Piece piece = piece_on(from); PieceType pt = type_of_piece(piece); + PieceType capture = ep ? PAWN : type_of_piece_on(to); assert(color_of_piece_on(from) == us); assert(color_of_piece_on(to) == them || square_is_empty(to)); assert(!(ep || pm) || piece == piece_of_color_and_type(us, PAWN)); assert(!pm || relative_rank(us, to) == RANK_8); - st->capture = ep ? PAWN : type_of_piece_on(to); - - if (st->capture) - do_capture_move(key, st->capture, them, to, ep); + if (capture) + do_capture_move(key, capture, them, to, ep); // Update hash key key ^= zobrist[us][pt][from] ^ zobrist[us][pt][to]; @@ -784,10 +800,6 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { board[to] = board[from]; board[from] = EMPTY; - // If the moving piece was a king, update the king square - if (pt == KING) - kingSquare[us] = to; - // Update piece lists, note that index[from] is not updated and // becomes stale. This works as long as index[] is accessed just // by known occupied squares. @@ -804,9 +816,9 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { st->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 ((to ^ from) == 16) { - if (pawn_attacks(us, from + (us == WHITE ? DELTA_N : DELTA_S)) & pawns(them)) + if (attacks_from(from + (us == WHITE ? DELTA_N : DELTA_S), us) & pieces(PAWN, them)) { st->epSquare = Square((int(from) + int(to)) / 2); key ^= zobEp[st->epSquare]; @@ -815,8 +827,10 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { } // Update incremental scores - st->mgValue += pst_delta(piece, from, to); - st->egValue += pst_delta(piece, from, to); + st->value += pst_delta(piece, from, to); + + // Set capture piece + st->capture = capture; if (pm) // promotion ? { @@ -842,6 +856,7 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { Square lastPawnSquare = pieceList[us][PAWN][pieceCount[us][PAWN]]; index[lastPawnSquare] = index[to]; pieceList[us][PAWN][index[lastPawnSquare]] = lastPawnSquare; + pieceList[us][PAWN][pieceCount[us][PAWN]] = SQ_NONE; index[to] = pieceCount[us][promotion] - 1; pieceList[us][promotion][index[to]] = to; @@ -850,10 +865,8 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { st->pawnKey ^= zobrist[us][PAWN][to]; // Partially revert and update incremental scores - st->mgValue -= pst(us, PAWN, to); - st->mgValue += pst(us, promotion, to); - st->egValue -= pst(us, PAWN, to); - st->egValue += pst(us, promotion, to); + st->value -= pst(us, PAWN, to); + st->value += pst(us, promotion, to); // Update material st->npMaterial[us] += piece_value_midgame(promotion); @@ -863,29 +876,33 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { st->key = key; // Update checkers bitboard, piece must be already moved - if (ep | pm) - st->checkersBB = attacks_to(king_square(them), us); - else + st->checkersBB = EmptyBoardBB; + + if (moveIsCheck) { - st->checkersBB = EmptyBoardBB; - Square ksq = king_square(them); - switch (pt) + if (ep | pm) + st->checkersBB = attackers_to(king_square(them)) & pieces_of_color(us); + else { - case PAWN: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case KNIGHT: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case BISHOP: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case ROOK: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case QUEEN: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case KING: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - default: assert(false); break; + // Direct checks + if (bit_is_set(ci.checkSq[pt], to)) + st->checkersBB = SetMaskBB[to]; + + // Discovery checks + if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from)) + { + if (pt != ROOK) + st->checkersBB |= (attacks_from(ci.ksq) & pieces(ROOK, QUEEN, us)); + + if (pt != BISHOP) + st->checkersBB |= (attacks_from(ci.ksq) & pieces(BISHOP, QUEEN, us)); + } } } // Finish sideToMove = opposite_color(sideToMove); - - st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; - st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; + st->value += (sideToMove == WHITE ? TempoValue : -TempoValue); assert(is_ok()); } @@ -920,16 +937,14 @@ void Position::do_capture_move(Bitboard& key, PieceType capture, Color them, Squ // Update hash key key ^= zobrist[them][capture][capsq]; - // If the captured piece was a pawn, update pawn hash key - if (capture == PAWN) - st->pawnKey ^= zobrist[them][PAWN][capsq]; - // Update incremental scores - st->mgValue -= pst(them, capture, capsq); - st->egValue -= pst(them, capture, capsq); + st->value -= pst(them, capture, capsq); - // Update material - if (capture != PAWN) + // If the captured piece was a pawn, update pawn hash key, + // otherwise update non-pawn material. + if (capture == PAWN) + st->pawnKey ^= zobrist[them][PAWN][capsq]; + else st->npMaterial[them] -= piece_value_midgame(capture); // Update material hash key @@ -939,9 +954,16 @@ void Position::do_capture_move(Bitboard& key, PieceType capture, Color them, Squ pieceCount[them][capture]--; // Update piece list, move the last piece at index[capsq] position + // + // WARNING: This is a not perfectly revresible operation. When we + // will reinsert the captured piece 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 guaranteed to be invariant to a + // do_move() + undo_move() sequence. Square lastPieceSquare = pieceList[them][capture][pieceCount[them][capture]]; index[lastPieceSquare] = index[capsq]; pieceList[them][capture][index[lastPieceSquare]] = lastPieceSquare; + pieceList[them][capture][pieceCount[them][capture]] = SQ_NONE; // Reset rule 50 counter st->rule50 = 0; @@ -982,16 +1004,21 @@ void Position::do_castle_move(Move m) { rto = relative_square(us, SQ_D1); } - // Move the pieces - Bitboard kmove_bb = make_move_bb(kfrom, kto); - do_move_bb(&(byColorBB[us]), kmove_bb); - do_move_bb(&(byTypeBB[KING]), kmove_bb); - do_move_bb(&(byTypeBB[0]), kmove_bb); // HACK: byTypeBB[0] == occupied squares - - Bitboard rmove_bb = make_move_bb(rfrom, rto); - do_move_bb(&(byColorBB[us]), rmove_bb); - do_move_bb(&(byTypeBB[ROOK]), rmove_bb); - do_move_bb(&(byTypeBB[0]), rmove_bb); // HACK: byTypeBB[0] == occupied squares + // Remove pieces from source squares: + clear_bit(&(byColorBB[us]), kfrom); + clear_bit(&(byTypeBB[KING]), kfrom); + clear_bit(&(byTypeBB[0]), kfrom); // HACK: byTypeBB[0] == occupied squares + clear_bit(&(byColorBB[us]), rfrom); + clear_bit(&(byTypeBB[ROOK]), rfrom); + clear_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares + + // Put pieces on destination squares: + set_bit(&(byColorBB[us]), kto); + set_bit(&(byTypeBB[KING]), kto); + set_bit(&(byTypeBB[0]), kto); // HACK: byTypeBB[0] == occupied squares + set_bit(&(byColorBB[us]), rto); + set_bit(&(byTypeBB[ROOK]), rto); + set_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares // Update board array Piece king = piece_of_color_and_type(us, KING); @@ -1000,9 +1027,6 @@ void Position::do_castle_move(Move m) { board[kto] = king; board[rto] = rook; - // Update king square - kingSquare[us] = kto; - // Update piece lists pieceList[us][KING][index[kfrom]] = kto; pieceList[us][ROOK][index[rfrom]] = rto; @@ -1011,10 +1035,8 @@ void Position::do_castle_move(Move m) { index[rto] = tmp; // Update incremental scores - st->mgValue += pst_delta(king, kfrom, kto); - st->egValue += pst_delta(king, kfrom, kto); - st->mgValue += pst_delta(rook, rfrom, rto); - st->egValue += pst_delta(rook, rfrom, rto); + st->value += pst_delta(king, kfrom, kto); + st->value += pst_delta(rook, rfrom, rto); // Update hash key st->key ^= zobrist[us][KING][kfrom] ^ zobrist[us][KING][kto]; @@ -1036,13 +1058,11 @@ void Position::do_castle_move(Move m) { st->rule50 = 0; // Update checkers BB - st->checkersBB = attacks_to(king_square(them), us); + st->checkersBB = attackers_to(king_square(them)) & pieces_of_color(us); // Finish sideToMove = opposite_color(sideToMove); - - st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; - st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; + st->value += (sideToMove == WHITE ? TempoValue : -TempoValue); assert(is_ok()); } @@ -1101,10 +1121,12 @@ void Position::undo_move(Move m) { Square lastPromotionSquare = pieceList[us][promotion][pieceCount[us][promotion]]; index[lastPromotionSquare] = index[to]; pieceList[us][promotion][index[lastPromotionSquare]] = lastPromotionSquare; + pieceList[us][promotion][pieceCount[us][promotion]] = SQ_NONE; index[to] = pieceCount[us][PAWN] - 1; pieceList[us][PAWN][index[to]] = to; } + // Put the piece back at the source square Bitboard move_bb = make_move_bb(to, from); do_move_bb(&(byColorBB[us]), move_bb); @@ -1114,10 +1136,6 @@ void Position::undo_move(Move m) { board[from] = piece_of_color_and_type(us, pt); board[to] = EMPTY; - // If the moving piece was a king, update the king square - if (pt == KING) - kingSquare[us] = from; - // Update piece list index[from] = index[to]; pieceList[us][pt][index[from]] = from; @@ -1187,25 +1205,27 @@ void Position::undo_castle_move(Move m) { assert(piece_on(kto) == piece_of_color_and_type(us, KING)); assert(piece_on(rto) == piece_of_color_and_type(us, ROOK)); - // Put the pieces back at the source square - Bitboard kmove_bb = make_move_bb(kto, kfrom); - do_move_bb(&(byColorBB[us]), kmove_bb); - do_move_bb(&(byTypeBB[KING]), kmove_bb); - do_move_bb(&(byTypeBB[0]), kmove_bb); // HACK: byTypeBB[0] == occupied squares - - Bitboard rmove_bb = make_move_bb(rto, rfrom); - do_move_bb(&(byColorBB[us]), rmove_bb); - do_move_bb(&(byTypeBB[ROOK]), rmove_bb); - do_move_bb(&(byTypeBB[0]), rmove_bb); // HACK: byTypeBB[0] == occupied squares + // Remove pieces from destination squares: + clear_bit(&(byColorBB[us]), kto); + clear_bit(&(byTypeBB[KING]), kto); + clear_bit(&(byTypeBB[0]), kto); // HACK: byTypeBB[0] == occupied squares + clear_bit(&(byColorBB[us]), rto); + clear_bit(&(byTypeBB[ROOK]), rto); + clear_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares + + // Put pieces on source squares: + set_bit(&(byColorBB[us]), kfrom); + set_bit(&(byTypeBB[KING]), kfrom); + set_bit(&(byTypeBB[0]), kfrom); // HACK: byTypeBB[0] == occupied squares + set_bit(&(byColorBB[us]), rfrom); + set_bit(&(byTypeBB[ROOK]), rfrom); + set_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares // Update board board[rto] = board[kto] = EMPTY; board[rfrom] = piece_of_color_and_type(us, ROOK); board[kfrom] = piece_of_color_and_type(us, KING); - // Update king square - kingSquare[us] = kfrom; - // Update piece lists pieceList[us][KING][index[kto]] = kfrom; pieceList[us][ROOK][index[rto]] = rfrom; @@ -1234,9 +1254,9 @@ void Position::do_null_move(StateInfo& backupSt) { // a backup storage not as a new state to be used. backupSt.key = st->key; backupSt.epSquare = st->epSquare; - backupSt.mgValue = st->mgValue; - backupSt.egValue = st->egValue; + backupSt.value = st->value; backupSt.previous = st->previous; + backupSt.pliesFromNull = st->pliesFromNull; st->previous = &backupSt; // Save the current key to the history[] array, in order to be able to @@ -1253,10 +1273,9 @@ void Position::do_null_move(StateInfo& backupSt) { sideToMove = opposite_color(sideToMove); st->epSquare = SQ_NONE; st->rule50++; + st->pliesFromNull = 0; + st->value += (sideToMove == WHITE) ? TempoValue : -TempoValue; gamePly++; - - st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; - st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; } @@ -1271,9 +1290,9 @@ void Position::undo_null_move() { StateInfo* backupSt = st->previous; st->key = backupSt->key; st->epSquare = backupSt->epSquare; - st->mgValue = backupSt->mgValue; - st->egValue = backupSt->egValue; + st->value = backupSt->value; st->previous = backupSt->previous; + st->pliesFromNull = backupSt->pliesFromNull; // Update the necessary information sideToMove = opposite_color(sideToMove); @@ -1282,6 +1301,11 @@ void Position::undo_null_move() { } +/// +PieceType Position::captured_piece() const { + return st->capture; +} + /// Position::see() is a static exchange evaluator: It tries to estimate the /// 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 @@ -1327,7 +1351,7 @@ int Position::see(Square from, Square to) const { 0, 0 }; - Bitboard attackers, stmAttackers, occ, b; + Bitboard attackers, stmAttackers, b; assert(square_is_ok(from) || from == SQ_NONE); assert(square_is_ok(to)); @@ -1339,10 +1363,11 @@ int Position::see(Square from, Square to) const { // Initialize pieces Piece piece = piece_on(from); Piece capture = piece_on(to); + Bitboard occ = occupied_squares(); - // Find all attackers to the destination square, with the moving piece - // removed, but possibly an X-ray attacker added behind it. - occ = occupied_squares(); + // King cannot be recaptured + if (type_of_piece(piece) == KING) + return seeValues[capture]; // Handle en passant moves if (st->epSquare == to && type_of_piece_on(from) == PAWN) @@ -1359,13 +1384,15 @@ int Position::see(Square from, Square to) const { while (true) { + // Find all attackers to the destination square, with the moving piece + // removed, but possibly an X-ray attacker added behind it. 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)); + attackers = (rook_attacks_bb(to, occ) & pieces(ROOK, QUEEN)) + | (bishop_attacks_bb(to, occ) & pieces(BISHOP, QUEEN)) + | (attacks_from(to) & pieces(KNIGHT)) + | (attacks_from(to) & pieces(KING)) + | (attacks_from(to, WHITE) & pieces(PAWN, BLACK)) + | (attacks_from(to, BLACK) & pieces(PAWN, WHITE)); if (from != SQ_NONE) break; @@ -1376,11 +1403,12 @@ int Position::see(Square from, Square to) const { // Locate the least valuable attacker to the destination square // and use it to initialize from square. + stmAttackers = attackers & pieces_of_color(us); PieceType pt; - for (pt = PAWN; !(attackers & pieces_of_color_and_type(us, pt)); pt++) + for (pt = PAWN; !(stmAttackers & pieces(pt)); pt++) assert(pt < KING); - from = first_1(attackers & pieces_of_color_and_type(us, pt)); + from = first_1(stmAttackers & pieces(pt)); piece = piece_on(from); } @@ -1408,15 +1436,15 @@ int Position::see(Square from, Square to) const { // Locate the least valuable attacker for the side to move. The loop // below looks like it is potentially infinite, but it isn't. We know // that the side to move still has at least one attacker left. - for (pt = PAWN; !(stmAttackers & pieces_of_type(pt)); pt++) + for (pt = PAWN; !(stmAttackers & pieces(pt)); pt++) assert(pt < KING); // Remove the attacker we just found from the 'attackers' bitboard, // and scan for new X-ray attacks behind the attacker. - b = stmAttackers & pieces_of_type(pt); + b = stmAttackers & pieces(pt); occ ^= (b & (~b + 1)); - attackers |= (rook_attacks_bb(to, occ) & rooks_and_queens()) - | (bishop_attacks_bb(to, occ) & bishops_and_queens()); + attackers |= (rook_attacks_bb(to, occ) & pieces(ROOK, QUEEN)) + | (bishop_attacks_bb(to, occ) & pieces(BISHOP, QUEEN)); attackers &= occ; @@ -1449,19 +1477,6 @@ int Position::see(Square from, Square to) const { } -/// Position::saveState() copies the content of the current state -/// inside startState and makes st point to it. This is needed -/// when the st pointee could become stale, as example because -/// the caller is about to going out of scope. - -void Position::saveState() { - - startState = *st; - st = &startState; - st->previous = NULL; // as a safe guard -} - - /// Position::clear() erases the position object to a pristine state, with an /// empty board, white to move, and no castling rights. @@ -1479,8 +1494,8 @@ void Position::clear() { for (int i = 0; i < 64; i++) board[i] = EMPTY; - for (int i = 0; i < 7; i++) - for (int j = 0; j < 8; j++) + for (int i = 0; i < 8; i++) + for (int j = 0; j < 16; j++) pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE; sideToMove = WHITE; @@ -1520,9 +1535,6 @@ void Position::put_piece(Piece p, Square s) { set_bit(&byTypeBB[0], s); // HACK: byTypeBB[0] contains all occupied squares. pieceCount[c][pt]++; - - if (pt == KING) - kingSquare[c] = s; } @@ -1582,8 +1594,8 @@ Key Position::compute_pawn_key() const { for (Color c = WHITE; c <= BLACK; c++) { - b = pawns(c); - while(b) + b = pieces(PAWN, c); + while (b) { s = pop_1st_bit(&b); result ^= zobrist[c][PAWN][s]; @@ -1617,27 +1629,25 @@ Key Position::compute_material_key() const { /// game and the endgame. These functions are used to initialize the incremental /// scores when a new position is set up, and to verify that the scores are correctly /// updated by do_move and undo_move when the program is running in debug mode. -template -Value Position::compute_value() const { +Score Position::compute_value() const { - Value result = Value(0); + Score result = make_score(0, 0); Bitboard b; Square s; for (Color c = WHITE; c <= BLACK; c++) for (PieceType pt = PAWN; pt <= KING; pt++) { - b = pieces_of_color_and_type(c, pt); - while(b) + b = pieces(pt, c); + while (b) { s = pop_1st_bit(&b); assert(piece_on(s) == piece_of_color_and_type(c, pt)); - result += pst(c, pt, s); + result += pst(c, pt, s); } } - const Value TempoValue = (Phase == MidGame ? TempoValueMidgame : TempoValueEndgame); - result += (side_to_move() == WHITE)? TempoValue / 2 : -TempoValue / 2; + result += (side_to_move() == WHITE ? TempoValue / 2 : -TempoValue / 2); return result; } @@ -1653,7 +1663,7 @@ Value Position::compute_non_pawn_material(Color c) const { for (PieceType pt = KNIGHT; pt <= QUEEN; pt++) { - Bitboard b = pieces_of_color_and_type(c, pt); + Bitboard b = pieces(pt, c); while (b) { assert(piece_on(first_1(b)) == piece_of_color_and_type(c, pt)); @@ -1672,7 +1682,7 @@ Value Position::compute_non_pawn_material(Color c) const { bool Position::is_draw() const { // Draw by material? - if ( !pawns() + if ( !pieces(PAWN) && (non_pawn_material(WHITE) + non_pawn_material(BLACK) <= BishopValueMidgame)) return true; @@ -1681,7 +1691,7 @@ bool Position::is_draw() const { return true; // Draw by repetition? - for (int i = 2; i < Min(gamePly, st->rule50); i += 2) + for (int i = 2; i < Min(Min(gamePly, st->rule50), st->pliesFromNull); i += 2) if (history[gamePly - i] == st->key) return true; @@ -1695,8 +1705,7 @@ bool Position::is_draw() const { bool Position::is_mate() const { MoveStack moves[256]; - - return is_check() && (generate_evasions(*this, moves, pinned_pieces(sideToMove)) == moves); + return is_check() && (generate_moves(*this, moves, false) == moves); } @@ -1717,11 +1726,10 @@ bool Position::has_mate_threat(Color c) { MoveStack mlist[120]; bool result = false; - Bitboard dc = discovered_check_candidates(sideToMove); Bitboard pinned = pinned_pieces(sideToMove); // Generate pseudo-legal non-capture and capture check moves - MoveStack* last = generate_non_capture_checks(*this, mlist, dc); + MoveStack* last = generate_non_capture_checks(*this, mlist); last = generate_captures(*this, last); // Loop through the moves, and see if one of them is mate @@ -1771,6 +1779,8 @@ void Position::init_zobrist() { for (int i = 0; i < 16; i++) zobMaterial[0][KING][i] = zobMaterial[1][KING][i] = Key(0ULL); + + zobExclusion = genrand_int64(); } @@ -1788,16 +1798,12 @@ void Position::init_piece_square_tables() { for (Piece p = WP; p <= WK; p++) { i = (r == 0)? 0 : (genrand_int32() % (r*2) - r); - MgPieceSquareTable[p][s] = Value(MgPST[p][s] + i); - EgPieceSquareTable[p][s] = Value(EgPST[p][s] + i); + PieceSquareTable[p][s] = make_score(MgPST[p][s] + i, EgPST[p][s] + i); } for (Square s = SQ_A1; s <= SQ_H8; s++) for (Piece p = BP; p <= BK; p++) - { - MgPieceSquareTable[p][s] = -MgPieceSquareTable[p-8][flip_square(s)]; - EgPieceSquareTable[p][s] = -EgPieceSquareTable[p-8][flip_square(s)]; - } + PieceSquareTable[p][s] = -PieceSquareTable[p-8][flip_square(s)]; } @@ -1852,8 +1858,7 @@ void Position::flipped_copy(const Position& pos) { st->materialKey = compute_material_key(); // Incremental scores - st->mgValue = compute_value(); - st->egValue = compute_value(); + st->value = compute_value(); // Material st->npMaterial[WHITE] = compute_non_pawn_material(WHITE); @@ -1880,6 +1885,7 @@ bool Position::is_ok(int* failedStep) const { static const bool debugNonPawnMaterial = false; static const bool debugPieceCounts = false; static const bool debugPieceList = false; + static const bool debugCastleSquares = false; if (failedStep) *failedStep = 1; @@ -1924,7 +1930,7 @@ bool Position::is_ok(int* failedStep) const { Color us = side_to_move(); Color them = opposite_color(us); Square ksq = king_square(them); - if (square_is_attacked(ksq, us)) + if (attackers_to(ksq) & pieces_of_color(us)) return false; } @@ -1949,7 +1955,7 @@ bool Position::is_ok(int* failedStep) const { // Separate piece type bitboards must have empty intersections for (PieceType p1 = PAWN; p1 <= KING; p1++) for (PieceType p2 = PAWN; p2 <= KING; p2++) - if (p1 != p2 && (pieces_of_type(p1) & pieces_of_type(p2))) + if (p1 != p2 && (pieces(p1) & pieces(p2))) return false; } @@ -1980,14 +1986,8 @@ bool Position::is_ok(int* failedStep) const { // Incremental eval OK? if (failedStep) (*failedStep)++; - if (debugIncrementalEval) - { - if (st->mgValue != compute_value()) - return false; - - if (st->egValue != compute_value()) - return false; - } + if (debugIncrementalEval && st->value != compute_value()) + return false; // Non-pawn material OK? if (failedStep) (*failedStep)++; @@ -2005,15 +2005,15 @@ bool Position::is_ok(int* failedStep) const { if (debugPieceCounts) for (Color c = WHITE; c <= BLACK; c++) for (PieceType pt = PAWN; pt <= KING; pt++) - if (pieceCount[c][pt] != count_1s(pieces_of_color_and_type(c, pt))) + if (pieceCount[c][pt] != count_1s(pieces(pt, c))) return false; if (failedStep) (*failedStep)++; if (debugPieceList) { - for(Color c = WHITE; c <= BLACK; c++) - for(PieceType pt = PAWN; pt <= KING; pt++) - for(int i = 0; i < pieceCount[c][pt]; i++) + for (Color c = WHITE; c <= BLACK; c++) + for (PieceType pt = PAWN; pt <= KING; pt++) + for (int i = 0; i < pieceCount[c][pt]; i++) { if (piece_on(piece_list(c, pt, i)) != piece_of_color_and_type(c, pt)) return false; @@ -2022,6 +2022,25 @@ bool Position::is_ok(int* failedStep) const { return false; } } + + if (failedStep) (*failedStep)++; + if (debugCastleSquares) { + for (Color c = WHITE; c <= BLACK; c++) { + if (can_castle_kingside(c) && piece_on(initial_kr_square(c)) != piece_of_color_and_type(c, ROOK)) + return false; + if (can_castle_queenside(c) && piece_on(initial_qr_square(c)) != piece_of_color_and_type(c, ROOK)) + return false; + } + if (castleRightsMask[initial_kr_square(WHITE)] != (ALL_CASTLES ^ WHITE_OO)) + return false; + if (castleRightsMask[initial_qr_square(WHITE)] != (ALL_CASTLES ^ WHITE_OOO)) + return false; + if (castleRightsMask[initial_kr_square(BLACK)] != (ALL_CASTLES ^ BLACK_OO)) + return false; + if (castleRightsMask[initial_qr_square(BLACK)] != (ALL_CASTLES ^ BLACK_OOO)) + return false; + } + if (failedStep) *failedStep = 0; return true; }