X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=cb63cf9537775848cdc222856a87dfdddc445ef3;hp=09daeba04ae10c6af40d68bee1b2697af24d7b32;hb=a28f4a56d31c9e7f7c5ce28a93e2b2b9ca9be5e5;hpb=6716337f407ad6586b636aca72ee673655822137 diff --git a/src/position.cpp b/src/position.cpp index 09daeba0..cb63cf95 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -22,10 +22,13 @@ //// Includes //// +#include #include #include #include +#include #include +#include #include "bitcount.h" #include "mersenne.h" @@ -38,12 +41,46 @@ #include "ucioption.h" using std::string; +using std::cout; +using std::endl; + +static inline bool isZero(char c) { return c == '0'; } + +struct PieceLetters : public std::map { + + PieceLetters() { + + operator[]('K') = WK; operator[]('k') = BK; + operator[]('Q') = WQ; operator[]('q') = BQ; + operator[]('R') = WR; operator[]('r') = BR; + operator[]('B') = WB; operator[]('b') = BB; + operator[]('N') = WN; operator[]('n') = BN; + operator[]('P') = WP; operator[]('p') = BP; + operator[](' ') = PIECE_NONE; operator[]('.') = PIECE_NONE_DARK_SQ; + } + + char from_piece(Piece p) const { + + std::map::const_iterator it; + for (it = begin(); it != end(); ++it) + if (it->second == p) + return it->first; + + assert(false); + return 0; + } +}; //// -//// Variables +//// Constants and variables //// +/// Bonus for having the side to move (modified by Joona Kiiski) + +static const Score TempoValue = make_score(48, 22); + + Key Position::zobrist[2][8][64]; Key Position::zobEp[64]; Key Position::zobCastle[16]; @@ -52,7 +89,13 @@ Key Position::zobExclusion; Score Position::PieceSquareTable[16][64]; -static bool RequestPending = false; +static PieceLetters pieceLetters; + +// Material values used by SEE, indexed by PieceType +const Value Position::seeValues[] = { + VALUE_ZERO, PawnValueMidgame, KnightValueMidgame, BishopValueMidgame, + RookValueMidgame, QueenValueMidgame, QueenValueMidgame*10 +}; /// Constructors @@ -74,23 +117,23 @@ CheckInfo::CheckInfo(const Position& pos) { } -/// 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 c'tors. Here we always create a copy of the original position +/// or the FEN string, we want the new born Position object do not depend +/// on any external data so we detach state pointer from the source one. -Position::Position() {} +Position::Position(int th) : threadID(th) {} -Position::Position(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; } -Position::Position(const string& fen) { +Position::Position(const string& fen, int th) { from_fen(fen); + threadID = th; } @@ -111,142 +154,108 @@ void Position::detach() { /// correct (this is assumed to be the responsibility of the GUI). void Position::from_fen(const string& fen) { +/* + A FEN string defines a particular position using only the ASCII character set. - static const string pieceLetters = "KQRBNPkqrbnp"; - static const Piece pieces[] = { WK, WQ, WR, WB, WN, WP, BK, BQ, BR, BB, BN, BP }; + A FEN string contains six fields. The separator between fields is a space. The fields are: - clear(); + 1) Piece placement (from white's perspective). Each rank is described, starting with rank 8 and ending + with rank 1; within each rank, the contents of each square are described from file a through file h. + Following the Standard Algebraic Notation (SAN), each piece is identified by a single letter taken + from the standard English names. White pieces are designated using upper-case letters ("PNBRQK") + while Black take lowercase ("pnbrqk"). Blank squares are noted using digits 1 through 8 (the number + of blank squares), and "/" separate ranks. - // Board + 2) Active color. "w" means white moves next, "b" means black. + + 3) Castling availability. If neither side can castle, this is "-". Otherwise, this has one or more + letters: "K" (White can castle kingside), "Q" (White can castle queenside), "k" (Black can castle + kingside), and/or "q" (Black can castle queenside). + + 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 + regardless of whether there is a pawn in position to make an en passant capture. + + 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 fifty-move rule. + + 6) Fullmove number: The number of the full move. It starts at 1, and is incremented after Black's move. +*/ + + char token; + std::istringstream ss(fen); Rank rank = RANK_8; File file = FILE_A; - size_t i = 0; - for ( ; fen[i] != ' '; i++) + + clear(); + + // 1. Piece placement field + while (ss.get(token) && token != ' ') { - if (isdigit(fen[i])) + if (isdigit(token)) { - // Skip the given number of files - file += (fen[i] - '1' + 1); + file += File(token - '0'); // Skip the given number of files continue; } - else if (fen[i] == '/') + else if (token == '/') { file = FILE_A; rank--; continue; } - size_t idx = pieceLetters.find(fen[i]); - if (idx == string::npos) - { - std::cout << "Error in FEN at character " << i << std::endl; - return; - } - Square square = make_square(file, rank); - put_piece(pieces[idx], square); + + if (pieceLetters.find(token) == pieceLetters.end()) + goto incorrect_fen; + + put_piece(pieceLetters[token], make_square(file, rank)); file++; } - // Side to move - i++; - if (fen[i] != 'w' && fen[i] != 'b') - { - std::cout << "Error in FEN at character " << i << std::endl; - return; - } - sideToMove = (fen[i] == 'w' ? WHITE : BLACK); + // 2. Active color + if (!ss.get(token) || (token != 'w' && token != 'b')) + goto incorrect_fen; - // Castling rights - i++; - if (fen[i] != ' ') + sideToMove = (token == 'w' ? WHITE : BLACK); + + if (!ss.get(token) || token != ' ') + goto incorrect_fen; + + // 3. Castling availability + while (ss.get(token) && token != ' ') { - std::cout << "Error in FEN at character " << i << std::endl; - return; - } + if (token == '-') + continue; - 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; - } - } - 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 { - std::cout << "Error in FEN at character " << i << std::endl; - return; - } - i++; + if (!set_castling_rights(token)) + goto incorrect_fen; } - // Skip blanks - while (fen[i] == ' ') - i++; - - // 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')) + // 4. En passant square -- ignore if no capture is possible + char col, row; + if ( (ss.get(col) && (col >= 'a' && col <= 'h')) + && (ss.get(row) && (row == '3' || row == '6'))) { - Square fenEpSquare = square_from_string(fen.substr(i, 2)); + Square fenEpSquare = make_square(file_from_char(col), rank_from_char(row)); Color them = opposite_color(sideToMove); - if (attacks_from(fenEpSquare, them) & this->pieces(PAWN, sideToMove)) - st->epSquare = square_from_string(fen.substr(i, 2)); + + if (attacks_from(fenEpSquare, them) & pieces(PAWN, sideToMove)) + st->epSquare = fenEpSquare; } - // Various initialisation - for (Square sq = SQ_A1; sq <= SQ_H8; sq++) - castleRightsMask[sq] = ALL_CASTLES; + // 5-6. Halfmove clock and fullmove number are not parsed - castleRightsMask[make_square(initialKFile, RANK_1)] ^= (WHITE_OO|WHITE_OOO); - castleRightsMask[make_square(initialKFile, RANK_8)] ^= (BLACK_OO|BLACK_OOO); + // Various initialisations + castleRightsMask[make_square(initialKFile, RANK_1)] ^= WHITE_OO | WHITE_OOO; + castleRightsMask[make_square(initialKFile, RANK_8)] ^= BLACK_OO | BLACK_OOO; castleRightsMask[make_square(initialKRFile, RANK_1)] ^= WHITE_OO; castleRightsMask[make_square(initialKRFile, RANK_8)] ^= BLACK_OO; castleRightsMask[make_square(initialQRFile, RANK_1)] ^= WHITE_OOO; castleRightsMask[make_square(initialQRFile, RANK_8)] ^= BLACK_OOO; + isChess960 = initialKFile != FILE_E + || initialQRFile != FILE_A + || initialKRFile != FILE_H; + find_checkers(); st->key = compute_key(); @@ -255,70 +264,119 @@ void Position::from_fen(const string& fen) { st->value = compute_value(); st->npMaterial[WHITE] = compute_non_pawn_material(WHITE); st->npMaterial[BLACK] = compute_non_pawn_material(BLACK); + return; + +incorrect_fen: + cout << "Error in FEN string: " << fen << endl; +} + + +/// Position::set_castling_rights() sets castling parameters castling avaiability. +/// This function is compatible with 3 standards: Normal FEN standard, Shredder-FEN +/// that uses the letters of the columns on which the rooks began the game instead +/// of KQkq and also X-FEN standard that, in case of Chess960, if an inner Rook is +/// associated with the castling right, the traditional castling tag will be replaced +/// by the file letter of the involved rook as for the Shredder-FEN. + +bool Position::set_castling_rights(char token) { + + Color c = token >= 'a' ? BLACK : WHITE; + Square sqA = (c == WHITE ? SQ_A1 : SQ_A8); + Square sqH = (c == WHITE ? SQ_H1 : SQ_H8); + Piece rook = (c == WHITE ? WR : BR); + + initialKFile = square_file(king_square(c)); + token = char(toupper(token)); + + if (token == 'K') + { + for (Square sq = sqH; sq >= sqA; sq--) + if (piece_on(sq) == rook) + { + allow_oo(c); + initialKRFile = square_file(sq); + break; + } + } + else if (token == 'Q') + { + for (Square sq = sqA; sq <= sqH; sq++) + if (piece_on(sq) == rook) + { + allow_ooo(c); + initialQRFile = square_file(sq); + break; + } + } + else if (token >= 'A' && token <= 'H') + { + File rookFile = File(token - 'A') + FILE_A; + if (rookFile < initialKFile) + { + allow_ooo(c); + initialQRFile = rookFile; + } + else + { + allow_oo(c); + initialKRFile = rookFile; + } + } + else return false; + + return true; } -/// Position::to_fen() converts the position object to a FEN string. This is -/// probably only useful for debugging. +/// Position::to_fen() returns a FEN representation of the position. In case +/// of Chess960 the Shredder-FEN notation is used. Mainly a debugging function. const string Position::to_fen() const { - static const string pieceLetters = " PNBRQK pnbrqk"; string fen; - int skip; + Square sq; + char emptyCnt = '0'; for (Rank rank = RANK_8; rank >= RANK_1; rank--) { - skip = 0; for (File file = FILE_A; file <= FILE_H; file++) { - Square sq = make_square(file, rank); - if (!square_is_occupied(sq)) - { skip++; - continue; - } - if (skip > 0) + sq = make_square(file, rank); + + if (square_is_occupied(sq)) { - fen += (char)skip + '0'; - skip = 0; - } - fen += pieceLetters[piece_on(sq)]; + fen += emptyCnt; + fen += pieceLetters.from_piece(piece_on(sq)); + emptyCnt = '0'; + } else + emptyCnt++; } - if (skip > 0) - fen += (char)skip + '0'; - - fen += (rank > RANK_1 ? '/' : ' '); + fen += emptyCnt; + fen += '/'; + emptyCnt = '0'; } - fen += (sideToMove == WHITE ? "w " : "b "); - if (st->castleRights != NO_CASTLES) + + fen.erase(std::remove_if(fen.begin(), fen.end(), isZero), fen.end()); + fen.erase(--fen.end()); + fen += (sideToMove == WHITE ? " w " : " b "); + + if (st->castleRights != CASTLES_NONE) { - 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 += '-'; + if (can_castle_kingside(WHITE)) + fen += isChess960 ? char(toupper(file_to_char(initialKRFile))) : 'K'; - fen += ' '; - if (ep_square() != SQ_NONE) - fen += square_to_string(ep_square()); - else + if (can_castle_queenside(WHITE)) + fen += isChess960 ? char(toupper(file_to_char(initialQRFile))) : 'Q'; + + if (can_castle_kingside(BLACK)) + fen += isChess960 ? file_to_char(initialKRFile) : 'k'; + + if (can_castle_queenside(BLACK)) + fen += isChess960 ? file_to_char(initialQRFile) : 'q'; + } else fen += '-'; + fen += (ep_square() == SQ_NONE ? " -" : " " + square_to_string(ep_square())); return fen; } @@ -326,44 +384,42 @@ const string Position::to_fen() const { /// Position::print() prints an ASCII representation of the position to /// the standard output. If a move is given then also the san is print. -void Position::print(Move m) const { +void Position::print(Move move) const { - static const string pieceLetters = " PNBRQK PNBRQK ."; + const char* dottedLine = "\n+---+---+---+---+---+---+---+---+\n"; + static bool requestPending = false; // Check for reentrancy, as example when called from inside // MovePicker that is used also here in move_to_san() - if (RequestPending) + if (requestPending) return; - RequestPending = true; + requestPending = true; - std::cout << std::endl; - if (m != MOVE_NONE) + if (move) { - Position p(*this); - string col = (color_of_piece_on(move_from(m)) == BLACK ? ".." : ""); - std::cout << "Move is: " << col << move_to_san(p, m) << std::endl; + Position p(*this, thread()); + string dd = (color_of_piece_on(move_from(move)) == BLACK ? ".." : ""); + cout << "\nMove is: " << dd << move_to_san(p, move); } + for (Rank rank = RANK_8; rank >= RANK_1; rank--) { - std::cout << "+---+---+---+---+---+---+---+---+" << std::endl; + cout << dottedLine << '|'; for (File file = FILE_A; file <= FILE_H; file++) { Square sq = make_square(file, rank); + char c = (color_of_piece_on(sq) == BLACK ? '=' : ' '); Piece piece = piece_on(sq); - if (piece == EMPTY && square_color(sq) == WHITE) - piece = NO_PIECE; - char col = (color_of_piece_on(sq) == BLACK ? '=' : ' '); - std::cout << '|' << col << pieceLetters[piece] << col; + if (piece == PIECE_NONE && square_color(sq) == DARK) + piece = PIECE_NONE_DARK_SQ; + + cout << c << pieceLetters.from_piece(piece) << c << '|'; } - std::cout << '|' << std::endl; } - std::cout << "+---+---+---+---+---+---+---+---+" << std::endl - << "Fen is: " << to_fen() << std::endl - << "Key is: " << st->key << std::endl; - - RequestPending = false; + cout << dottedLine << "Fen is: " << to_fen() << "\nKey is: " << st->key << endl; + requestPending = false; } @@ -533,7 +589,7 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { assert(to == ep_square()); assert(piece_on(from) == piece_of_color_and_type(us, PAWN)); assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN)); - assert(piece_on(to) == EMPTY); + assert(piece_on(to) == PIECE_NONE); clear_bit(&b, from); clear_bit(&b, capsq); @@ -641,10 +697,10 @@ bool Position::move_is_check(Move m, const CheckInfo& ci) const { } } - // En passant capture with check? We have already handled the case + // 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. + // 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)); @@ -703,7 +759,7 @@ 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, ply, pliesFromNull; + int castleRights, rule50, gamePly, pliesFromNull; Square epSquare; Score value; Value npMaterial[2]; @@ -715,7 +771,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI // Save the current key to the history[] array, in order to be able to // detect repetition draws. - history[st->ply++] = key; + history[st->gamePly++] = key; // Update side to move key ^= zobSideToMove; @@ -772,7 +828,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI } // Prefetch TT access as soon as we know key is updated - TT.prefetch(key); + prefetch((char*)TT.first_entry(key)); // Move the piece Bitboard move_bb = make_move_bb(from, to); @@ -781,7 +837,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares board[to] = board[from]; - board[from] = EMPTY; + board[from] = PIECE_NONE; // Update piece lists, note that index[from] is not updated and // becomes stale. This works as long as index[] is accessed just @@ -795,8 +851,9 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI // Reset rule 50 draw counter st->rule50 = 0; - // Update pawn hash key + // Update pawn hash key and prefetch in L1/L2 cache st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; + prefetchPawn(st->pawnKey, threadID); // Set en passant square, only if moved pawn can be captured if ((to ^ from) == 16) @@ -845,7 +902,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI st->value += pst(us, promotion, to); // Update material - st->npMaterial[us] += piece_value_midgame(promotion); + st->npMaterial[us] += PieceValueMidgame[promotion]; } } @@ -853,7 +910,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI st->value += pst_delta(piece, from, to); // Set capture piece - st->capture = capture; + st->capturedType = capture; // Update the key with the final value st->key = key; @@ -910,15 +967,15 @@ void Position::do_capture_move(Key& key, PieceType capture, Color them, Square t assert(to == st->epSquare); assert(relative_rank(opposite_color(them), to) == RANK_6); - assert(piece_on(to) == EMPTY); + assert(piece_on(to) == PIECE_NONE); assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN)); - board[capsq] = EMPTY; + board[capsq] = PIECE_NONE; } st->pawnKey ^= zobrist[them][PAWN][capsq]; } else - st->npMaterial[them] -= piece_value_midgame(capture); + st->npMaterial[them] -= PieceValueMidgame[capture]; // Remove captured piece clear_bit(&(byColorBB[them]), capsq); @@ -968,7 +1025,7 @@ void Position::do_castle_move(Move m) { Color them = opposite_color(us); // Reset capture field - st->capture = NO_PIECE_TYPE; + st->capturedType = PIECE_TYPE_NONE; // Find source squares for king and rook Square kfrom = move_from(m); @@ -1007,7 +1064,7 @@ void Position::do_castle_move(Move m) { // Update board array Piece king = piece_of_color_and_type(us, KING); Piece rook = piece_of_color_and_type(us, ROOK); - board[kfrom] = board[rfrom] = EMPTY; + board[kfrom] = board[rfrom] = PIECE_NONE; board[kto] = king; board[rto] = rook; @@ -1116,35 +1173,35 @@ void Position::undo_move(Move m) { do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares board[from] = piece_of_color_and_type(us, pt); - board[to] = EMPTY; + board[to] = PIECE_NONE; // Update piece list index[from] = index[to]; pieceList[us][pt][index[from]] = from; - if (st->capture) + if (st->capturedType) { Square capsq = to; if (ep) capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S); - assert(st->capture != KING); + assert(st->capturedType != KING); assert(!ep || square_is_empty(capsq)); // Restore the captured piece set_bit(&(byColorBB[them]), capsq); - set_bit(&(byTypeBB[st->capture]), capsq); + set_bit(&(byTypeBB[st->capturedType]), capsq); set_bit(&(byTypeBB[0]), capsq); - board[capsq] = piece_of_color_and_type(them, st->capture); + board[capsq] = piece_of_color_and_type(them, st->capturedType); // Update piece count - pieceCount[them][st->capture]++; + pieceCount[them][st->capturedType]++; // Update piece list, add a new captured piece in capsq square - index[capsq] = pieceCount[them][st->capture] - 1; - pieceList[them][st->capture][index[capsq]] = capsq; + index[capsq] = pieceCount[them][st->capturedType] - 1; + pieceList[them][st->capturedType][index[capsq]] = capsq; } // Finally point our state pointer back to the previous state @@ -1204,7 +1261,7 @@ void Position::undo_castle_move(Move m) { set_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares // Update board - board[rto] = board[kto] = EMPTY; + board[rto] = board[kto] = PIECE_NONE; board[rfrom] = piece_of_color_and_type(us, ROOK); board[kfrom] = piece_of_color_and_type(us, KING); @@ -1243,14 +1300,14 @@ void Position::do_null_move(StateInfo& backupSt) { // Save the current key to the history[] array, in order to be able to // detect repetition draws. - history[st->ply++] = st->key; + history[st->gamePly++] = st->key; // Update the necessary information if (st->epSquare != SQ_NONE) st->key ^= zobEp[st->epSquare]; st->key ^= zobSideToMove; - TT.prefetch(st->key); + prefetch((char*)TT.first_entry(st->key)); sideToMove = opposite_color(sideToMove); st->epSquare = SQ_NONE; @@ -1278,7 +1335,7 @@ void Position::undo_null_move() { // Update the necessary information sideToMove = opposite_color(sideToMove); st->rule50--; - st->ply--; + st->gamePly--; } @@ -1288,12 +1345,6 @@ void Position::undo_null_move() { /// move, and one which takes a 'from' and a 'to' square. The function does /// not yet understand promotions captures. -int Position::see(Square to) const { - - assert(square_is_ok(to)); - return see(SQ_NONE, to); -} - int Position::see(Move m) const { assert(move_is_ok(m)); @@ -1307,93 +1358,61 @@ int Position::see_sign(Move m) const { Square from = move_from(m); Square to = move_to(m); - // Early return if SEE cannot be negative because capturing piece value - // is not bigger then captured one. - if ( midgame_value_of_piece_on(from) <= midgame_value_of_piece_on(to) - && type_of_piece_on(from) != KING) - return 1; + // Early return if SEE cannot be negative because captured piece value + // is not less then capturing one. Note that king moves always return + // here because king midgame value is set to 0. + if (midgame_value_of_piece_on(to) >= midgame_value_of_piece_on(from)) + return 1; return see(from, to); } int Position::see(Square from, Square to) const { - // Material values - static const int seeValues[18] = { - 0, PawnValueMidgame, KnightValueMidgame, BishopValueMidgame, - RookValueMidgame, QueenValueMidgame, QueenValueMidgame*10, 0, - 0, PawnValueMidgame, KnightValueMidgame, BishopValueMidgame, - RookValueMidgame, QueenValueMidgame, QueenValueMidgame*10, 0, - 0, 0 - }; - - Bitboard attackers, stmAttackers, b; + Bitboard occ, attackers, stmAttackers, b; + int swapList[32], slIndex = 1; + PieceType capturedType, pt; + Color stm; - assert(square_is_ok(from) || from == SQ_NONE); + assert(square_is_ok(from)); assert(square_is_ok(to)); - // Initialize colors - Color us = (from != SQ_NONE ? color_of_piece_on(from) : opposite_color(color_of_piece_on(to))); - Color them = opposite_color(us); - - // Initialize pieces - Piece piece = piece_on(from); - Piece capture = piece_on(to); - Bitboard occ = occupied_squares(); + capturedType = type_of_piece_on(to); // King cannot be recaptured - if (type_of_piece(piece) == KING) - return seeValues[capture]; + if (capturedType == KING) + return seeValues[capturedType]; + + occ = occupied_squares(); // Handle en passant moves if (st->epSquare == to && type_of_piece_on(from) == PAWN) { - assert(capture == EMPTY); + Square capQq = (side_to_move() == WHITE) ? (to - DELTA_N) : (to - DELTA_S); - Square capQq = (side_to_move() == WHITE)? (to - DELTA_N) : (to - DELTA_S); - capture = piece_on(capQq); + assert(capturedType == PIECE_TYPE_NONE); assert(type_of_piece_on(capQq) == PAWN); // Remove the captured pawn clear_bit(&occ, capQq); + capturedType = PAWN; } - 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) & 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; - - // 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. - stmAttackers = attackers & pieces_of_color(us); - PieceType pt; - for (pt = PAWN; !(stmAttackers & pieces(pt)); pt++) - assert(pt < KING); - - from = first_1(stmAttackers & pieces(pt)); - piece = piece_on(from); - } + // 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) & 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 the opponent has no attackers we are finished - stmAttackers = attackers & pieces_of_color(them); + stm = opposite_color(color_of_piece_on(from)); + stmAttackers = attackers & pieces_of_color(stm); if (!stmAttackers) - return seeValues[capture]; - - attackers &= occ; // Remove the moving piece + return seeValues[capturedType]; // The destination square is defended, which makes things rather more // difficult to compute. We proceed by building up a "swap list" containing @@ -1401,12 +1420,8 @@ int Position::see(Square from, Square to) const { // destination square, where the sides alternately capture, and always // capture with the least valuable piece. After each capture, we look for // new X-ray attacks from behind the capturing piece. - int lastCapturingPieceValue = seeValues[piece]; - int swapList[32], n = 1; - Color c = them; - PieceType pt; - - swapList[0] = seeValues[capture]; + swapList[0] = seeValues[capturedType]; + capturedType = type_of_piece_on(from); do { // Locate the least valuable attacker for the side to move. The loop @@ -1419,35 +1434,35 @@ int Position::see(Square from, Square to) const { // and scan for new X-ray attacks behind the attacker. b = stmAttackers & pieces(pt); occ ^= (b & (~b + 1)); - attackers |= (rook_attacks_bb(to, occ) & pieces(ROOK, QUEEN)) + attackers |= (rook_attacks_bb(to, occ) & pieces(ROOK, QUEEN)) | (bishop_attacks_bb(to, occ) & pieces(BISHOP, QUEEN)); - attackers &= occ; + attackers &= occ; // Cut out pieces we've already done // Add the new entry to the swap list - assert(n < 32); - swapList[n] = -swapList[n - 1] + lastCapturingPieceValue; - n++; + assert(slIndex < 32); + swapList[slIndex] = -swapList[slIndex - 1] + seeValues[capturedType]; + slIndex++; // Remember the value of the capturing piece, and change the side to move // before beginning the next iteration - lastCapturingPieceValue = seeValues[pt]; - c = opposite_color(c); - stmAttackers = attackers & pieces_of_color(c); + capturedType = pt; + stm = opposite_color(stm); + stmAttackers = attackers & pieces_of_color(stm); // Stop after a king capture if (pt == KING && stmAttackers) { - assert(n < 32); - swapList[n++] = QueenValueMidgame*10; + assert(slIndex < 32); + swapList[slIndex++] = QueenValueMidgame*10; break; } } while (stmAttackers); // Having built the swap list, we negamax through it to find the best // achievable score from the point of view of the side to move - while (--n) - swapList[n-1] = Min(-swapList[n], swapList[n-1]); + while (--slIndex) + swapList[slIndex-1] = Min(-swapList[slIndex], swapList[slIndex-1]); return swapList[0]; } @@ -1461,6 +1476,7 @@ void Position::clear() { st = &startState; memset(st, 0, sizeof(StateInfo)); st->epSquare = SQ_NONE; + startPosPlyCounter = 0; memset(byColorBB, 0, sizeof(Bitboard) * 2); memset(byTypeBB, 0, sizeof(Bitboard) * 8); @@ -1468,12 +1484,15 @@ void Position::clear() { memset(index, 0, sizeof(int) * 64); for (int i = 0; i < 64; i++) - board[i] = EMPTY; + board[i] = PIECE_NONE; for (int i = 0; i < 8; i++) for (int j = 0; j < 16; j++) pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE; + for (Square sq = SQ_A1; sq <= SQ_H8; sq++) + castleRightsMask[sq] = ALL_CASTLES; + sideToMove = WHITE; initialKFile = FILE_E; initialKRFile = FILE_H; @@ -1481,17 +1500,21 @@ void Position::clear() { } -/// Position::reset_ply() simply sets ply to 0. It is used from the +/// Position::reset_game_ply() simply sets gamePly to 0. It is used from the /// UCI interface code, whenever a non-reversible move is made in a /// 'position fen moves m1 m2 ...' command. This makes it possible /// for the program to handle games of arbitrary length, as long as the GUI /// handles draws by the 50 move rule correctly. -void Position::reset_ply() { +void Position::reset_game_ply() { - st->ply = 0; + st->gamePly = 0; } +void Position::inc_startpos_ply_counter() { + + startPosPlyCounter++; +} /// Position::put_piece() puts a piece on the given square of the board, /// updating the board array, bitboards, and piece counts. @@ -1606,7 +1629,7 @@ Key Position::compute_material_key() const { /// updated by do_move and undo_move when the program is running in debug mode. Score Position::compute_value() const { - Score result = make_score(0, 0); + Score result = SCORE_ZERO; Bitboard b; Square s; @@ -1634,7 +1657,7 @@ Score Position::compute_value() const { Value Position::compute_non_pawn_material(Color c) const { - Value result = Value(0); + Value result = VALUE_ZERO; for (PieceType pt = KNIGHT; pt <= QUEEN; pt++) { @@ -1642,8 +1665,9 @@ Value Position::compute_non_pawn_material(Color c) const { while (b) { assert(piece_on(first_1(b)) == piece_of_color_and_type(c, pt)); + pop_1st_bit(&b); - result += piece_value_midgame(pt); + result += PieceValueMidgame[pt]; } } return result; @@ -1653,7 +1677,6 @@ Value Position::compute_non_pawn_material(Color c) const { /// Position::is_draw() tests whether the position is drawn by material, /// repetition, or the 50 moves rule. It does not detect stalemates, this /// must be done by the search. -// FIXME: Currently we are not handling 50 move rule correctly when in check bool Position::is_draw() const { @@ -1663,14 +1686,12 @@ bool Position::is_draw() const { return true; // Draw by the 50 moves rule? - if (st->rule50 > 100 || (st->rule50 == 100 && !is_check())) + if (st->rule50 > 99 && (st->rule50 > 100 || !is_mate())) return true; - assert(st->ply >= st->rule50); - - // Draw by repetition? - for (int i = 4, e = Min(st->rule50, st->pliesFromNull); i <= e; i += 2) - if (history[st->ply - i] == st->key) + // Draw by repetition? + 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; return false; @@ -1683,92 +1704,85 @@ bool Position::is_draw() const { bool Position::is_mate() const { MoveStack moves[256]; - return is_check() && (generate_moves(*this, moves, false) == moves); + return is_check() && (generate_moves(*this, moves) == moves); } -/// Position::has_mate_threat() tests whether a given color has a mate in one -/// from the current position. +/// Position::has_mate_threat() tests whether the side to move is under +/// a threat of being mated in one from the current position. -bool Position::has_mate_threat(Color c) { +bool Position::has_mate_threat() { + MoveStack mlist[256], *last, *cur; StateInfo st1, st2; - Color stm = side_to_move(); + bool mateFound = false; + // If we are under check it's up to evasions to do the job if (is_check()) return false; - // If the input color is not equal to the side to move, do a null move - if (c != stm) - do_null_move(st1); - - MoveStack mlist[120]; - bool result = false; - Bitboard pinned = pinned_pieces(sideToMove); + // First pass the move to our opponent doing a null move + do_null_move(st1); - // Generate pseudo-legal non-capture and capture check moves - MoveStack* last = generate_non_capture_checks(*this, mlist); + // Then generate pseudo-legal moves that give check + last = generate_non_capture_checks(*this, mlist); last = generate_captures(*this, last); - // Loop through the moves, and see if one of them is mate - for (MoveStack* cur = mlist; cur != last; cur++) + // Loop through the moves, and see if one of them gives mate + Bitboard pinned = pinned_pieces(sideToMove); + CheckInfo ci(*this); + for (cur = mlist; cur != last && !mateFound; cur++) { Move move = cur->move; - if (!pl_move_is_legal(move, pinned)) + if ( !pl_move_is_legal(move, pinned) + || !move_is_check(move, ci)) continue; - do_move(move, st2); + do_move(move, st2, ci, true); + if (is_mate()) - result = true; + mateFound = true; undo_move(move); } - // Undo null move, if necessary - if (c != stm) - undo_null_move(); - - return result; + undo_null_move(); + return mateFound; } -/// Position::init_zobrist() is a static member function which initializes the -/// various arrays used to compute hash keys. +/// Position::init_zobrist() is a static member function which initializes at +/// startup the various arrays used to compute hash keys. void Position::init_zobrist() { - for (int i = 0; i < 2; i++) - for (int j = 0; j < 8; j++) - for (int k = 0; k < 64; k++) - zobrist[i][j][k] = Key(genrand_int64()); + int i,j, k; - for (int i = 0; i < 64; i++) + for (i = 0; i < 2; i++) for (j = 0; j < 8; j++) for (k = 0; k < 64; k++) + zobrist[i][j][k] = Key(genrand_int64()); + + for (i = 0; i < 64; i++) zobEp[i] = Key(genrand_int64()); - for (int i = 0; i < 16; i++) - zobCastle[i] = genrand_int64(); + for (i = 0; i < 16; i++) + zobCastle[i] = Key(genrand_int64()); - zobSideToMove = genrand_int64(); - zobExclusion = genrand_int64(); + zobSideToMove = Key(genrand_int64()); + zobExclusion = Key(genrand_int64()); } /// Position::init_piece_square_tables() initializes the piece square tables. -/// This is a two-step operation: First, the white halves of the tables are -/// copied from the MgPST[][] and EgPST[][] arrays, with a small random number -/// added to each entry if the "Randomness" UCI parameter is non-zero. -/// Second, the black halves of the tables are initialized by mirroring -/// and changing the sign of the corresponding white scores. +/// This is a two-step operation: First, the white halves of the tables are +/// copied from the MgPST[][] and EgPST[][] arrays. Second, the black halves +/// of the tables are initialized by mirroring and changing the sign of the +/// corresponding white scores. void Position::init_piece_square_tables() { - int r = get_option_value_int("Randomness"), i; for (Square s = SQ_A1; s <= SQ_H8; s++) for (Piece p = WP; p <= WK; p++) - { - i = (r == 0)? 0 : (genrand_int32() % (r*2) - r); - PieceSquareTable[p][s] = make_score(MgPST[p][s] + i, EgPST[p][s] + i); - } + PieceSquareTable[p][s] = make_score(MgPST[p][s], EgPST[p][s]); for (Square s = SQ_A1; s <= SQ_H8; s++) for (Piece p = BP; p <= BK; p++) @@ -1785,6 +1799,7 @@ void Position::flipped_copy(const Position& pos) { assert(pos.is_ok()); clear(); + threadID = pos.thread(); // Board for (Square s = SQ_A1; s <= SQ_H8; s++) @@ -1804,9 +1819,6 @@ void Position::flipped_copy(const Position& pos) { initialKRFile = pos.initialKRFile; initialQRFile = pos.initialQRFile; - for (Square sq = SQ_A1; sq <= SQ_H8; sq++) - castleRightsMask[sq] = ALL_CASTLES; - castleRightsMask[make_square(initialKFile, RANK_1)] ^= (WHITE_OO | WHITE_OOO); castleRightsMask[make_square(initialKFile, RANK_8)] ^= (BLACK_OO | BLACK_OOO); castleRightsMask[make_square(initialKRFile, RANK_1)] ^= WHITE_OO;