X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=922a96fd8bdee8e23c4df7e1382ca486985a961c;hp=690ca59bb4789319d53cce58b573ae01e6f159ac;hb=eabba1119f45f2ac8a3a6248bd1c1d9868d7af5c;hpb=f25582d4b8860ff9fbe7dcf9873ed2986b1a7ed2 diff --git a/src/position.cpp b/src/position.cpp index 690ca59b..922a96fd 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -30,7 +30,6 @@ #include "rkiss.h" #include "thread.h" #include "tt.h" -#include "ucioption.h" using std::string; using std::cout; @@ -78,12 +77,11 @@ namespace { CheckInfo::CheckInfo(const Position& pos) { - Color us = pos.side_to_move(); - Color them = opposite_color(us); + Color them = opposite_color(pos.side_to_move()); Square ksq = pos.king_square(them); - dcCandidates = pos.discovered_check_candidates(us); - pinned = pos.pinned_pieces(us); + pinned = pos.pinned_pieces(); + dcCandidates = pos.discovered_check_candidates(); checkSq[PAWN] = pos.attacks_from(ksq, them); checkSq[KNIGHT] = pos.attacks_from(ksq); @@ -101,9 +99,10 @@ CheckInfo::CheckInfo(const Position& pos) { Position::Position(const Position& pos, int th) { memcpy(this, &pos, sizeof(Position)); - detach(); // Always detach() in copy c'tor to avoid surprises threadID = th; nodes = 0; + + assert(is_ok()); } Position::Position(const string& fen, bool isChess960, int th) { @@ -113,23 +112,11 @@ Position::Position(const string& fen, bool isChess960, int th) { } -/// 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). -void Position::from_fen(const string& fen, bool isChess960) { +void Position::from_fen(const string& fenStr, bool isChess960) { /* A FEN string defines a particular position using only the ASCII character set. @@ -161,13 +148,13 @@ void Position::from_fen(const string& fen, bool isChess960) { char col, row, token; size_t p; Square sq = SQ_A8; - std::istringstream ss(fen); + std::istringstream fen(fenStr); clear(); - ss >> std::noskipws; + fen >> std::noskipws; // 1. Piece placement - while ((ss >> token) && !isspace(token)) + while ((fen >> token) && !isspace(token)) { if (token == '/') sq -= Square(16); // Jump back of 2 rows @@ -183,17 +170,17 @@ void Position::from_fen(const string& fen, bool isChess960) { } // 2. Active color - ss >> token; + fen >> token; sideToMove = (token == 'w' ? WHITE : BLACK); - ss >> token; + fen >> token; // 3. Castling availability - while ((ss >> token) && !isspace(token)) + while ((fen >> token) && !isspace(token)) set_castling_rights(token); // 4. En passant square. Ignore if no pawn capture is possible - if ( ((ss >> col) && (col >= 'a' && col <= 'h')) - && ((ss >> row) && (row == '3' || row == '6'))) + if ( ((fen >> col) && (col >= 'a' && col <= 'h')) + && ((fen >> row) && (row == '3' || row == '6'))) { st->epSquare = make_square(File(col - 'a'), Rank(row - '1')); Color them = opposite_color(sideToMove); @@ -203,7 +190,11 @@ void Position::from_fen(const string& fen, bool isChess960) { } // 5-6. Halfmove clock and fullmove number - ss >> std::skipws >> st->rule50 >> fullMoves; + fen >> std::skipws >> st->rule50 >> startPosPly; + + // Convert from fullmove starting from 1 to ply starting from 0, + // handle also common incorrect FEN with fullmove = 0. + startPosPly = Max(2 * (startPosPly - 1), 0) + int(sideToMove == BLACK); // Various initialisations chess960 = isChess960; @@ -215,6 +206,8 @@ void Position::from_fen(const string& fen, bool isChess960) { st->value = compute_value(); st->npMaterial[WHITE] = compute_non_pawn_material(WHITE); st->npMaterial[BLACK] = compute_non_pawn_material(BLACK); + + assert(is_ok()); } @@ -270,13 +263,13 @@ void Position::set_castling_rights(char token) { const string Position::to_fen() const { - string fen; + std::ostringstream fen; Square sq; - char emptyCnt; + int emptyCnt; - for (Rank rank = RANK_8; rank >= RANK_1; rank--, fen += '/') + for (Rank rank = RANK_8; rank >= RANK_1; rank--) { - emptyCnt = '0'; + emptyCnt = 0; for (File file = FILE_A; file <= FILE_H; file++) { @@ -284,40 +277,46 @@ const string Position::to_fen() const { if (!square_is_empty(sq)) { - if (emptyCnt != '0') + if (emptyCnt) { - fen += emptyCnt; - emptyCnt = '0'; + fen << emptyCnt; + emptyCnt = 0; } - fen += PieceToChar[piece_on(sq)]; - } else + fen << PieceToChar[piece_on(sq)]; + } + else emptyCnt++; } - if (emptyCnt != '0') - fen += emptyCnt; + if (emptyCnt) + fen << emptyCnt; + + if (rank > RANK_1) + fen << '/'; } - fen += (sideToMove == WHITE ? " w " : " b "); + fen << (sideToMove == WHITE ? " w " : " b "); if (st->castleRights != CASTLES_NONE) { if (can_castle(WHITE_OO)) - fen += chess960 ? char(toupper(file_to_char(square_file(castle_rook_square(WHITE_OO))))) : 'K'; + fen << (chess960 ? char(toupper(file_to_char(square_file(castle_rook_square(WHITE_OO))))) : 'K'); if (can_castle(WHITE_OOO)) - fen += chess960 ? char(toupper(file_to_char(square_file(castle_rook_square(WHITE_OOO))))) : 'Q'; + fen << (chess960 ? char(toupper(file_to_char(square_file(castle_rook_square(WHITE_OOO))))) : 'Q'); if (can_castle(BLACK_OO)) - fen += chess960 ? file_to_char(square_file(castle_rook_square(BLACK_OO))) : 'k'; + fen << (chess960 ? file_to_char(square_file(castle_rook_square(BLACK_OO))) : 'k'); if (can_castle(BLACK_OOO)) - fen += chess960 ? file_to_char(square_file(castle_rook_square(BLACK_OOO))) : 'q'; + fen << (chess960 ? file_to_char(square_file(castle_rook_square(BLACK_OOO))) : 'q'); } else - fen += '-'; + fen << '-'; - fen += (ep_square() == SQ_NONE ? " -" : " " + square_to_string(ep_square())); - return fen; + fen << (ep_square() == SQ_NONE ? " -" : " " + square_to_string(ep_square())) + << " " << st->rule50 << " " << 1 + (startPosPly - int(sideToMove == BLACK)) / 2; + + return fen.str(); } @@ -331,7 +330,7 @@ void Position::print(Move move) const { if (move) { Position p(*this, thread()); - string dd = (piece_color(piece_on(move_from(move))) == BLACK ? ".." : ""); + string dd = (sideToMove == BLACK ? ".." : ""); cout << "\nMove is: " << dd << move_to_san(p, move); } @@ -355,36 +354,28 @@ void Position::print(Move move) const { /// 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. -/// Bitboard checkersBB must be already updated when looking for pinners. +/// king) pieces for the given color. Or, when template parameter FindPinned is +/// false, the function return the pieces of the given color candidate for a +/// discovery check against the enemy king. template -Bitboard Position::hidden_checkers(Color c) const { - - Bitboard result = EmptyBoardBB; - Bitboard pinners = pieces(FindPinned ? opposite_color(c) : c); +Bitboard Position::hidden_checkers() const { - // Pinned pieces protect our king, dicovery checks attack - // the enemy king. - Square ksq = king_square(FindPinned ? c : opposite_color(c)); + // Pinned pieces protect our king, dicovery checks attack the enemy king + Bitboard b, result = EmptyBoardBB; + Bitboard pinners = pieces(FindPinned ? opposite_color(sideToMove) : sideToMove); + Square ksq = king_square(FindPinned ? sideToMove : opposite_color(sideToMove)); - // 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; + // Pinners are sliders, that give check when candidate pinned is removed + pinners &= (pieces(ROOK, QUEEN) & RookPseudoAttacks[ksq]) + | (pieces(BISHOP, QUEEN) & BishopPseudoAttacks[ksq]); while (pinners) { - Square s = pop_1st_bit(&pinners); - Bitboard b = squares_between(s, ksq) & occupied_squares(); - - assert(b); + b = squares_between(ksq, pop_1st_bit(&pinners)) & occupied_squares(); - if ( !(b & (b - 1)) // Only one bit set? - && (b & pieces(c))) // Is an our piece? + // Only one bit set and is an our piece? + if (b && !(b & (b - 1)) && (b & pieces(sideToMove))) result |= b; } return result; @@ -392,23 +383,21 @@ Bitboard Position::hidden_checkers(Color c) const { /// Position:pinned_pieces() returns a bitboard of all pinned (against the -/// king) pieces for the given color. Note that checkersBB bitboard must -/// be already updated. +/// king) pieces for the side to move. -Bitboard Position::pinned_pieces(Color c) const { +Bitboard Position::pinned_pieces() const { - return hidden_checkers(c); + return hidden_checkers(); } /// Position:discovered_check_candidates() returns a bitboard containing all -/// pieces for the given side which are candidates for giving a discovered -/// check. Contrary to pinned_pieces() here there is no need of checkersBB -/// to be already updated. +/// pieces for the side to move which are candidates for giving a discovered +/// check. -Bitboard Position::discovered_check_candidates(Color c) const { +Bitboard Position::discovered_check_candidates() const { - return hidden_checkers(c); + return hidden_checkers(); } /// Position::attackers_to() computes a bitboard containing all pieces which @@ -497,9 +486,8 @@ bool Position::move_attacks_square(Move m, Square s) const { 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(pinned == pinned_pieces()); Color us = side_to_move(); Square from = move_from(m); @@ -507,14 +495,14 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { assert(piece_color(piece_on(from)) == us); assert(piece_on(king_square(us)) == make_piece(us, KING)); - // 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 + // 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)) { Color them = opposite_color(us); Square to = move_to(m); - Square capsq = make_square(square_file(to), square_rank(from)); + Square capsq = to + pawn_push(them); Square ksq = king_square(us); Bitboard b = occupied_squares(); @@ -545,20 +533,14 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { } -/// Position::move_is_pl_slow() takes a move and tests whether the move -/// is pseudo legal. This version is not very fast and should be used -/// only in non time-critical paths. - -bool Position::move_is_pl_slow(const Move m) const { +/// Position::move_is_legal() takes a move and tests whether the move +/// is legal. This version is not very fast and should be used only +/// in non time-critical paths. - MoveStack mlist[MAX_MOVES]; - MoveStack *cur, *last; +bool Position::move_is_legal(const Move m) const { - last = in_check() ? generate(*this, mlist) - : generate(*this, mlist); - - for (cur = mlist; cur != last; cur++) - if (cur->move == m) + for (MoveList ml(*this); !ml.end(); ++ml) + if (ml.move() == m) return true; return false; @@ -570,8 +552,6 @@ bool Position::move_is_pl_slow(const Move m) const { bool Position::move_is_pl(const Move m) const { - assert(is_ok()); - Color us = sideToMove; Color them = opposite_color(sideToMove); Square from = move_from(m); @@ -580,7 +560,7 @@ bool Position::move_is_pl(const Move m) const { // Use a slower but simpler function for uncommon cases if (move_is_special(m)) - return move_is_pl_slow(m); + return move_is_legal(m); // Is not a promotion, so promotion piece must be empty if (promotion_piece_type(m) - 2 != PIECE_TYPE_NONE) @@ -694,9 +674,8 @@ bool Position::move_is_pl(const Move m) const { bool Position::move_gives_check(Move m, const CheckInfo& ci) const { - assert(is_ok()); assert(move_is_ok(m)); - assert(ci.dcCandidates == discovered_check_candidates(side_to_move())); + assert(ci.dcCandidates == discovered_check_candidates()); assert(piece_color(piece_on(move_from(m))) == side_to_move()); Square from = move_from(m); @@ -784,30 +763,6 @@ bool Position::move_gives_check(Move m, const CheckInfo& ci) const { } -/// Position::do_setup_move() makes a permanent move on the board. It should -/// be used when setting up a position on board. You can't undo the move. - -void Position::do_setup_move(Move m) { - - StateInfo newSt; - - // Update the number of full moves after black's move - if (sideToMove == BLACK) - fullMoves++; - - do_move(m, newSt); - - // Reset "game ply" in case we made a non-reversible move. - // "game ply" is used for repetition detection. - if (st->rule50 == 0) - st->gamePly = 0; - - // Our StateInfo newSt is about going out of scope so copy - // its content before it disappears. - detach(); -} - - /// Position::do_move() makes a move, and saves all information necessary /// to a StateInfo object. The move is assumed to be legal. Pseudo-legal /// moves should be filtered out before this function is called. @@ -820,7 +775,6 @@ void Position::do_move(Move m, StateInfo& newSt) { void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveIsCheck) { - assert(is_ok()); assert(move_is_ok(m)); assert(&newSt != st); @@ -832,10 +786,10 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI // pointer to point to the new, ready to be updated, state. struct ReducedStateInfo { Key pawnKey, materialKey; - int castleRights, rule50, gamePly, pliesFromNull; - Square epSquare; - Score value; Value npMaterial[2]; + int castleRights, rule50, pliesFromNull; + Score value; + Square epSquare; }; memcpy(&newSt, st, sizeof(ReducedStateInfo)); @@ -843,10 +797,6 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI newSt.previous = st; st = &newSt; - // Save the current key to the history[] array, in order to be able to - // detect repetition draws. - history[st->gamePly++] = key; - // Update side to move key ^= zobSideToMove; @@ -905,9 +855,9 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI // Move the piece Bitboard move_bb = make_move_bb(from, to); - do_move_bb(&(byColorBB[us]), move_bb); - do_move_bb(&(byTypeBB[pt]), move_bb); - do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares + do_move_bb(&byColorBB[us], move_bb); + do_move_bb(&byTypeBB[pt], move_bb); + do_move_bb(&byTypeBB[0], move_bb); // HACK: byTypeBB[0] == occupied squares board[to] = board[from]; board[from] = PIECE_NONE; @@ -930,7 +880,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI // Set en passant square, only if moved pawn can be captured if ((to ^ from) == 16) { - if (attacks_from(from + (us == WHITE ? DELTA_N : DELTA_S), us) & pieces(PAWN, them)) + if (attacks_from(from + pawn_push(us), us) & pieces(PAWN, them)) { st->epSquare = Square((int(from) + int(to)) / 2); key ^= zobEp[st->epSquare]; @@ -944,8 +894,8 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI assert(promotion >= KNIGHT && promotion <= QUEEN); // Insert promoted piece instead of pawn - clear_bit(&(byTypeBB[PAWN]), to); - set_bit(&(byTypeBB[promotion]), to); + clear_bit(&byTypeBB[PAWN], to); + set_bit(&byTypeBB[promotion], to); board[to] = make_piece(us, promotion); // Update piece counts @@ -1039,7 +989,7 @@ void Position::do_capture_move(Key& key, PieceType capture, Color them, Square t { if (ep) // en passant ? { - capsq = (them == BLACK)? (to - DELTA_N) : (to - DELTA_S); + capsq = to + pawn_push(them); assert(to == st->epSquare); assert(relative_rank(opposite_color(them), to) == RANK_6); @@ -1054,9 +1004,9 @@ void Position::do_capture_move(Key& key, PieceType capture, Color them, Square t st->npMaterial[them] -= PieceValueMidgame[capture]; // Remove captured piece - clear_bit(&(byColorBB[them]), capsq); - clear_bit(&(byTypeBB[capture]), capsq); - clear_bit(&(byTypeBB[0]), capsq); + clear_bit(&byColorBB[them], capsq); + clear_bit(&byTypeBB[capture], capsq); + clear_bit(&byTypeBB[0], capsq); // Update hash key key ^= zobrist[them][capture][capsq]; @@ -1100,12 +1050,9 @@ void Position::do_castle_move(Move m) { Color us = side_to_move(); Color them = opposite_color(us); - // Reset capture field - st->capturedType = PIECE_TYPE_NONE; - // Find source squares for king and rook Square kfrom = move_from(m); - Square rfrom = move_to(m); // HACK: See comment at beginning of function + Square rfrom = move_to(m); Square kto, rto; assert(piece_on(kfrom) == make_piece(us, KING)); @@ -1116,28 +1063,30 @@ void Position::do_castle_move(Move m) { { kto = relative_square(us, SQ_G1); rto = relative_square(us, SQ_F1); - } else { // O-O-O + } + else // O-O-O + { kto = relative_square(us, SQ_C1); rto = relative_square(us, SQ_D1); } - // 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 + // Remove pieces from source squares + clear_bit(&byColorBB[us], kfrom); + clear_bit(&byTypeBB[KING], kfrom); + clear_bit(&byTypeBB[0], kfrom); + clear_bit(&byColorBB[us], rfrom); + clear_bit(&byTypeBB[ROOK], rfrom); + clear_bit(&byTypeBB[0], rfrom); + + // Put pieces on destination squares + set_bit(&byColorBB[us], kto); + set_bit(&byTypeBB[KING], kto); + set_bit(&byTypeBB[0], kto); + set_bit(&byColorBB[us], rto); + set_bit(&byTypeBB[ROOK], rto); + set_bit(&byTypeBB[0], rto); + + // Update board Piece king = make_piece(us, KING); Piece rook = make_piece(us, ROOK); board[kfrom] = board[rfrom] = PIECE_NONE; @@ -1147,10 +1096,13 @@ void Position::do_castle_move(Move m) { // Update piece lists pieceList[us][KING][index[kfrom]] = kto; pieceList[us][ROOK][index[rfrom]] = rto; - int tmp = index[rfrom]; // In Chess960 could be rto == kfrom + int tmp = index[rfrom]; // In Chess960 could be kto == rfrom index[kto] = index[kfrom]; index[rto] = tmp; + // Reset capture field + st->capturedType = PIECE_TYPE_NONE; + // Update incremental scores st->value += pst_delta(king, kfrom, kto); st->value += pst_delta(rook, rfrom, rto); @@ -1190,7 +1142,6 @@ void Position::do_castle_move(Move m) { void Position::undo_move(Move m) { - assert(is_ok()); assert(move_is_ok(m)); sideToMove = opposite_color(sideToMove); @@ -1226,8 +1177,8 @@ void Position::undo_move(Move m) { assert(piece_on(to) == make_piece(us, promotion)); // Replace promoted piece with a pawn - clear_bit(&(byTypeBB[promotion]), to); - set_bit(&(byTypeBB[PAWN]), to); + clear_bit(&byTypeBB[promotion], to); + set_bit(&byTypeBB[PAWN], to); // Update piece counts pieceCount[us][promotion]--; @@ -1244,9 +1195,9 @@ void Position::undo_move(Move m) { // Put the piece back at the source square Bitboard move_bb = make_move_bb(to, from); - do_move_bb(&(byColorBB[us]), move_bb); - do_move_bb(&(byTypeBB[pt]), move_bb); - do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares + do_move_bb(&byColorBB[us], move_bb); + do_move_bb(&byTypeBB[pt], move_bb); + do_move_bb(&byTypeBB[0], move_bb); // HACK: byTypeBB[0] == occupied squares board[from] = make_piece(us, pt); board[to] = PIECE_NONE; @@ -1260,15 +1211,15 @@ void Position::undo_move(Move m) { Square capsq = to; if (ep) - capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S); + capsq = to - pawn_push(us); assert(st->capturedType != KING); assert(!ep || square_is_empty(capsq)); // Restore the captured piece - set_bit(&(byColorBB[them]), capsq); - set_bit(&(byTypeBB[st->capturedType]), capsq); - set_bit(&(byTypeBB[0]), capsq); + set_bit(&byColorBB[them], capsq); + set_bit(&byTypeBB[st->capturedType], capsq); + set_bit(&byTypeBB[0], capsq); board[capsq] = make_piece(them, st->capturedType); @@ -1298,13 +1249,13 @@ void Position::undo_castle_move(Move m) { assert(move_is_castle(m)); // When we have arrived here, some work has already been done by - // Position::undo_move. In particular, the side to move has been switched, + // Position::undo_move. In particular, the side to move has been switched, // so the code below is correct. Color us = side_to_move(); // Find source squares for king and rook Square kfrom = move_from(m); - Square rfrom = move_to(m); // HACK: See comment at beginning of function + Square rfrom = move_to(m); Square kto, rto; // Find destination squares for king and rook @@ -1312,7 +1263,9 @@ void Position::undo_castle_move(Move m) { { kto = relative_square(us, SQ_G1); rto = relative_square(us, SQ_F1); - } else { // O-O-O + } + else // O-O-O + { kto = relative_square(us, SQ_C1); rto = relative_square(us, SQ_D1); } @@ -1320,26 +1273,28 @@ void Position::undo_castle_move(Move m) { assert(piece_on(kto) == make_piece(us, KING)); assert(piece_on(rto) == make_piece(us, ROOK)); - // 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 + // Remove pieces from destination squares + clear_bit(&byColorBB[us], kto); + clear_bit(&byTypeBB[KING], kto); + clear_bit(&byTypeBB[0], kto); + clear_bit(&byColorBB[us], rto); + clear_bit(&byTypeBB[ROOK], rto); + clear_bit(&byTypeBB[0], rto); + + // Put pieces on source squares + set_bit(&byColorBB[us], kfrom); + set_bit(&byTypeBB[KING], kfrom); + set_bit(&byTypeBB[0], kfrom); + set_bit(&byColorBB[us], rfrom); + set_bit(&byTypeBB[ROOK], rfrom); + set_bit(&byTypeBB[0], rfrom); // Update board - board[rto] = board[kto] = PIECE_NONE; - board[rfrom] = make_piece(us, ROOK); - board[kfrom] = make_piece(us, KING); + Piece king = make_piece(us, KING); + Piece rook = make_piece(us, ROOK); + board[kto] = board[rto] = PIECE_NONE; + board[kfrom] = king; + board[rfrom] = rook; // Update piece lists pieceList[us][KING][index[kto]] = kfrom; @@ -1360,7 +1315,6 @@ void Position::undo_castle_move(Move m) { void Position::do_null_move(StateInfo& backupSt) { - assert(is_ok()); assert(!in_check()); // Back up the information necessary to undo the null move to the supplied @@ -1374,10 +1328,6 @@ void Position::do_null_move(StateInfo& backupSt) { backupSt.pliesFromNull = st->pliesFromNull; st->previous = &backupSt; - // Save the current key to the history[] array, in order to be able to - // detect repetition draws. - history[st->gamePly++] = st->key; - // Update the necessary information if (st->epSquare != SQ_NONE) st->key ^= zobEp[st->epSquare]; @@ -1390,6 +1340,8 @@ void Position::do_null_move(StateInfo& backupSt) { st->rule50++; st->pliesFromNull = 0; st->value += (sideToMove == WHITE) ? TempoValue : -TempoValue; + + assert(is_ok()); } @@ -1397,7 +1349,6 @@ void Position::do_null_move(StateInfo& backupSt) { void Position::undo_null_move() { - assert(is_ok()); assert(!in_check()); // Restore information from the our backup StateInfo object @@ -1411,7 +1362,8 @@ void Position::undo_null_move() { // Update the necessary information sideToMove = opposite_color(sideToMove); st->rule50--; - st->gamePly--; + + assert(is_ok()); } @@ -1461,7 +1413,7 @@ int Position::see(Move m) const { // Handle en passant moves if (st->epSquare == to && piece_type(piece_on(from)) == PAWN) { - Square capQq = (side_to_move() == WHITE ? to - DELTA_N : to - DELTA_S); + Square capQq = to - pawn_push(side_to_move()); assert(capturedType == PIECE_TYPE_NONE); assert(piece_type(piece_on(capQq)) == PAWN); @@ -1560,7 +1512,6 @@ void Position::clear() { castleRightsMask[sq] = ALL_CASTLES; } sideToMove = WHITE; - fullMoves = 1; nodes = 0; } @@ -1701,9 +1652,24 @@ bool Position::is_draw() const { // Draw by repetition? if (!SkipRepetition) - for (int i = 4, e = Min(Min(st->gamePly, st->rule50), st->pliesFromNull); i <= e; i += 2) - if (history[st->gamePly - i] == st->key) - return true; + { + int i = 4, e = Min(st->rule50, st->pliesFromNull); + + if (i <= e) + { + StateInfo* stp = st->previous->previous; + + do { + stp = stp->previous->previous; + + if (stp->key == st->key) + return true; + + i +=2; + + } while (i <= e); + } + } return false; } @@ -1718,8 +1684,7 @@ template bool Position::is_draw() const; bool Position::is_mate() const { - MoveStack moves[MAX_MOVES]; - return in_check() && generate(*this, moves) == moves; + return in_check() && !MoveList(*this).size(); } @@ -1763,8 +1728,6 @@ void Position::init() { void Position::flip() { - assert(is_ok()); - // Make a copy of current position before to start changing const Position pos(*this, threadID);