X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=a9c98626980fa56bbf5995e2c0d186f342fddef2;hp=a069cf404be6d012a7ac129c4386b0c3a1721586;hb=e444e18d2bd75454e3bbd9e5667b2357a19e5388;hpb=47ee6d9fa4091aa05f6fedb62a2bb652b0422f08 diff --git a/src/position.cpp b/src/position.cpp index a069cf40..a9c98626 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -17,32 +17,25 @@ along with this program. If not, see . */ - -//// -//// Includes -//// - #include #include #include +#include #include +#include #include "bitcount.h" -#include "mersenne.h" #include "movegen.h" -#include "movepick.h" #include "position.h" #include "psqtab.h" -#include "san.h" +#include "rkiss.h" +#include "thread.h" #include "tt.h" #include "ucioption.h" using std::string; - - -//// -//// Variables -//// +using std::cout; +using std::endl; Key Position::zobrist[2][8][64]; Key Position::zobEp[64]; @@ -52,10 +45,69 @@ Key Position::zobExclusion; Score Position::PieceSquareTable[16][64]; -static bool RequestPending = false; +// Material values arrays, indexed by Piece +const Value Position::PieceValueMidgame[17] = { + VALUE_ZERO, + PawnValueMidgame, KnightValueMidgame, BishopValueMidgame, + RookValueMidgame, QueenValueMidgame, VALUE_ZERO, + VALUE_ZERO, VALUE_ZERO, + PawnValueMidgame, KnightValueMidgame, BishopValueMidgame, + RookValueMidgame, QueenValueMidgame +}; + +const Value Position::PieceValueEndgame[17] = { + VALUE_ZERO, + PawnValueEndgame, KnightValueEndgame, BishopValueEndgame, + RookValueEndgame, QueenValueEndgame, VALUE_ZERO, + VALUE_ZERO, VALUE_ZERO, + PawnValueEndgame, KnightValueEndgame, BishopValueEndgame, + RookValueEndgame, QueenValueEndgame +}; + +// Material values array used by SEE, indexed by PieceType +const Value Position::seeValues[] = { + VALUE_ZERO, + PawnValueMidgame, KnightValueMidgame, BishopValueMidgame, + RookValueMidgame, QueenValueMidgame, QueenValueMidgame*10 +}; + + +namespace { + + // Bonus for having the side to move (modified by Joona Kiiski) + const Score TempoValue = make_score(48, 22); + + 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 { -/// Constructors + std::map::const_iterator it; + for (it = begin(); it != end(); ++it) + if (it->second == p) + return it->first; + + assert(false); + return 0; + } + }; + + PieceLetters pieceLetters; +} + + +/// CheckInfo c'tor CheckInfo::CheckInfo(const Position& pos) { @@ -78,18 +130,17 @@ CheckInfo::CheckInfo(const Position& pos) { /// 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(int th) : threadID(th) {} - 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; } -Position::Position(const string& fen, int th) { +Position::Position(const string& fen, bool isChess960, int th) { - from_fen(fen); + from_fen(fen, isChess960); threadID = th; } @@ -110,143 +161,102 @@ void Position::detach() { /// 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) { +void Position::from_fen(const string& fen, bool isChess960) { +/* + A FEN string defines a particular position using only the ASCII character set. + + A FEN string contains six fields. The separator between fields is a space. The fields are: + + 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. + + 2) Active color. "w" means white moves next, "b" means black. - static const string pieceLetters = "KQRBNPkqrbnp"; - static const Piece pieces[] = { WK, WQ, WR, WB, WN, WP, BK, BQ, BR, BB, BN, BP }; + 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; + int hmc, fmn; + std::istringstream ss(fen); + Square sq = SQ_A8; clear(); - // Board - Rank rank = RANK_8; - File file = FILE_A; - size_t i = 0; - for ( ; fen[i] != ' '; i++) + // 1. Piece placement field + while (ss.get(token) && token != ' ') { - if (isdigit(fen[i])) - { - // Skip the given number of files - file += (fen[i] - '1' + 1); - continue; - } - else if (fen[i] == '/') + if (pieceLetters.find(token) != pieceLetters.end()) { - file = FILE_A; - rank--; - continue; + put_piece(pieceLetters[token], sq); + sq++; } - 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); - file++; + else if (isdigit(token)) + sq += Square(token - '0'); // Skip the given number of files + else if (token == '/') + sq -= SQ_A3; // Jump back of 2 rows + else + goto incorrect_fen; } - // 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] != ' ') - { - std::cout << "Error in FEN at character " << i << std::endl; - return; - } + sideToMove = (token == 'w' ? WHITE : BLACK); - 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 (!ss.get(token) || token != ' ') + goto incorrect_fen; - // Skip blanks - while (fen[i] == ' ') - i++; + // 3. Castling availability + while (ss.get(token) && token != ' ') + if (!set_castling_rights(token)) + goto incorrect_fen; - // 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 + 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)); + st->epSquare = make_square(file_from_char(col), rank_from_char(row)); + + // Ignore if no capture is possible 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(st->epSquare, them) & pieces(PAWN, sideToMove))) + st->epSquare = SQ_NONE; } - // Various initialisation - for (Square sq = SQ_A1; sq <= SQ_H8; sq++) - castleRightsMask[sq] = ALL_CASTLES; + // 5. Halfmove clock + if (ss >> hmc) + st->rule50 = hmc; + + // 6. Fullmove number + if (ss >> fmn) + startPosPlyCounter = (fmn - 1) * 2 + int(sideToMove == BLACK); - 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; + chess960 = isChess960; find_checkers(); st->key = compute_key(); @@ -255,115 +265,158 @@ 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::to_fen() converts the position object to a FEN string. This is -/// probably only useful for debugging. +/// 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) + { + do_allow_oo(c); + initialKRFile = square_file(sq); + break; + } + } + else if (token == 'Q') + { + for (Square sq = sqA; sq <= sqH; sq++) + if (piece_on(sq) == rook) + { + do_allow_ooo(c); + initialQRFile = square_file(sq); + break; + } + } + else if (token >= 'A' && token <= 'H') + { + File rookFile = File(token - 'A') + FILE_A; + if (rookFile < initialKFile) + { + do_allow_ooo(c); + initialQRFile = rookFile; + } + else + { + do_allow_oo(c); + initialKRFile = rookFile; + } + } + else + return token == '-'; + + return true; +} + + +/// 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--) + for (Rank rank = RANK_8; rank >= RANK_1; rank--, fen += '/') { - 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)]; + if (emptyCnt != '0') + { + fen += emptyCnt; + emptyCnt = '0'; + } + fen += pieceLetters.from_piece(piece_on(sq)); + } else + emptyCnt++; } - if (skip > 0) - fen += (char)skip + '0'; - fen += (rank > RANK_1 ? '/' : ' '); + if (emptyCnt != '0') + { + fen += emptyCnt; + emptyCnt = '0'; + } } - fen += (sideToMove == WHITE ? "w " : "b "); - if (st->castleRights != NO_CASTLES) + + 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 += chess960 ? 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 += chess960 ? char(toupper(file_to_char(initialQRFile))) : 'Q'; + + if (can_castle_kingside(BLACK)) + fen += chess960 ? file_to_char(initialKRFile) : 'k'; + + if (can_castle_queenside(BLACK)) + fen += chess960 ? file_to_char(initialQRFile) : 'q'; + } else fen += '-'; + fen += (ep_square() == SQ_NONE ? " -" : " " + square_to_string(ep_square())); return fen; } /// 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 { +/// the standard output. If a move is given then also the san is printed. - static const string pieceLetters = " PNBRQK PNBRQK ."; +void Position::print(Move move) const { - // Check for reentrancy, as example when called from inside - // MovePicker that is used also here in move_to_san() - if (RequestPending) - return; - - RequestPending = true; + const char* dottedLine = "\n+---+---+---+---+---+---+---+---+\n"; - std::cout << std::endl; - if (m != MOVE_NONE) + if (move) { Position p(*this, thread()); - string col = (color_of_piece_on(move_from(m)) == BLACK ? ".." : ""); - std::cout << "Move is: " << col << move_to_san(p, m) << std::endl; + 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); 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; + + char c = (color_of_piece_on(sq) == BLACK ? '=' : ' '); + 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; } @@ -446,16 +499,24 @@ Bitboard Position::attacks_from(Piece p, Square s) const { switch (p) { - 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; + default: return StepAttacksBB[p][s]; + } +} + +Bitboard Position::attacks_from(Piece p, Square s, Bitboard occ) { + + assert(square_is_ok(s)); + + switch (p) + { + case WB: case BB: return bishop_attacks_bb(s, occ); + case WR: case BR: return rook_attacks_bb(s, occ); + case WQ: case BQ: return bishop_attacks_bb(s, occ) | rook_attacks_bb(s, occ); + default: return StepAttacksBB[p][s]; } - return false; } @@ -467,6 +528,7 @@ bool Position::move_attacks_square(Move m, Square s) const { assert(move_is_ok(m)); assert(square_is_ok(s)); + Bitboard occ, xray; Square f = move_from(m), t = move_to(m); assert(square_is_occupied(f)); @@ -475,12 +537,11 @@ bool Position::move_attacks_square(Move m, Square s) const { return true; // Move the piece and scan for X-ray attacks behind it - Bitboard occ = occupied_squares(); - Color us = color_of_piece_on(f); - clear_bit(&occ, f); - set_bit(&occ, t); - Bitboard xray = ( (rook_attacks_bb(s, occ) & pieces(ROOK, QUEEN)) - |(bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN))) & pieces_of_color(us); + occ = occupied_squares(); + do_move_bb(&occ, make_move_bb(f, t)); + xray = ( (rook_attacks_bb(s, occ) & pieces(ROOK, QUEEN)) + |(bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN))) + & pieces_of_color(color_of_piece_on(f)); // If we have attacks we need to verify that are caused by our move // and are not already existent ones. @@ -513,27 +574,23 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { if (move_is_castle(m)) return true; - Color us = side_to_move(); - Square from = move_from(m); - - assert(color_of_piece_on(from) == us); - assert(piece_on(king_square(us)) == piece_of_color_and_type(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 if (move_is_ep(m)) { + Color us = side_to_move(); Color them = opposite_color(us); + Square from = move_from(m); Square to = move_to(m); Square capsq = make_square(square_file(to), square_rank(from)); - Bitboard b = occupied_squares(); Square ksq = king_square(us); + Bitboard b = occupied_squares(); 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(from) == make_piece(us, PAWN)); + assert(piece_on(capsq) == make_piece(them, PAWN)); + assert(piece_on(to) == PIECE_NONE); clear_bit(&b, from); clear_bit(&b, capsq); @@ -543,6 +600,12 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { && !(bishop_attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, them)); } + Color us = side_to_move(); + Square from = move_from(m); + + assert(color_of_piece_on(from) == us); + assert(piece_on(king_square(us)) == make_piece(us, KING)); + // If the moving piece is a king, check whether the destination // square is attacked by the opponent. if (type_of_piece_on(from) == KING) @@ -550,9 +613,9 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { // 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, king_square(us)) == direction_between_squares(move_to(m), king_square(us)))); + return !pinned + || !bit_is_set(pinned, from) + || squares_aligned(from, move_to(m), king_square(us)); } @@ -560,7 +623,7 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { bool Position::pl_move_is_evasion(Move m, Bitboard pinned) const { - assert(is_check()); + assert(in_check()); Color us = side_to_move(); Square from = move_from(m); @@ -581,21 +644,130 @@ bool Position::pl_move_is_evasion(Move m, Bitboard pinned) const return bit_is_set(target, to) && pl_move_is_legal(m, pinned); } +/// Position::move_is_legal() takes a position and a (not necessarily pseudo-legal) +/// move and tests whether the move is legal. This version is not very fast and +/// should be used only in non time-critical paths. -/// Position::move_is_check() tests whether a pseudo-legal move is a check +bool Position::move_is_legal(const Move m) const { -bool Position::move_is_check(Move m) const { + MoveStack mlist[MAX_MOVES]; + MoveStack *cur, *last = generate(*this, mlist); - return move_is_check(m, CheckInfo(*this)); + for (cur = mlist; cur != last; cur++) + if (cur->move == m) + return pl_move_is_legal(m, pinned_pieces(sideToMove)); + + return false; } -bool Position::move_is_check(Move m, const CheckInfo& ci) const { + +/// Fast version of Position::move_is_legal() that takes a position a move and +/// a bitboard of pinned pieces as input, and tests whether the move is legal. + +bool Position::move_is_legal(const Move m, Bitboard pinned) const { + + assert(is_ok()); + assert(pinned == pinned_pieces(sideToMove)); + + Color us = sideToMove; + Color them = opposite_color(sideToMove); + Square from = move_from(m); + Square to = move_to(m); + Piece pc = piece_on(from); + + // Use a slower but simpler function for uncommon cases + if (move_is_special(m)) + return move_is_legal(m); + + // If the from square is not occupied by a piece belonging to the side to + // move, the move is obviously not legal. + if (color_of_piece(pc) != us) + return false; + + // The destination square cannot be occupied by a friendly piece + if (color_of_piece_on(to) == us) + return false; + + // Handle the special case of a pawn move + if (type_of_piece(pc) == PAWN) + { + // Move direction must be compatible with pawn color + int direction = to - from; + if ((us == WHITE) != (direction > 0)) + return false; + + // We have already handled promotion moves, so destination + // cannot be on the 8/1th rank. + if (square_rank(to) == RANK_8 || square_rank(to) == RANK_1) + return false; + + // Proceed according to the square delta between the origin and + // destination squares. + switch (direction) + { + case DELTA_NW: + case DELTA_NE: + case DELTA_SW: + case DELTA_SE: + // Capture. The destination square must be occupied by an enemy + // piece (en passant captures was handled earlier). + if (color_of_piece_on(to) != them) + return false; + break; + + case DELTA_N: + case DELTA_S: + // Pawn push. The destination square must be empty. + if (!square_is_empty(to)) + return false; + break; + + case DELTA_NN: + // Double white pawn push. The destination square must be on the fourth + // rank, and both the destination square and the square between the + // source and destination squares must be empty. + if ( square_rank(to) != RANK_4 + || !square_is_empty(to) + || !square_is_empty(from + DELTA_N)) + return false; + break; + + case DELTA_SS: + // Double black pawn push. The destination square must be on the fifth + // rank, and both the destination square and the square between the + // source and destination squares must be empty. + if ( square_rank(to) != RANK_5 + || !square_is_empty(to) + || !square_is_empty(from + DELTA_S)) + return false; + break; + + default: + return false; + } + } + else if (!bit_is_set(attacks_from(pc, from), to)) + return false; + + // The move is pseudo-legal, check if it is also legal + return in_check() ? pl_move_is_evasion(m, pinned) : pl_move_is_legal(m, pinned); +} + + +/// Position::move_gives_check() tests whether a pseudo-legal move is a check + +bool Position::move_gives_check(Move m) const { + + return move_gives_check(m, CheckInfo(*this)); +} + +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(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)); + assert(piece_on(ci.ksq) == make_piece(opposite_color(side_to_move()), KING)); Square from = move_from(m); Square to = move_to(m); @@ -610,7 +782,7 @@ bool Position::move_is_check(Move m, const CheckInfo& ci) const { { // 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))) + || !squares_aligned(from, to, ci.ksq)) return true; } @@ -641,10 +813,10 @@ 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)); @@ -681,21 +853,46 @@ bool Position::move_is_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; + + 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; + + // Update the number of plies played from the starting position + startPosPlyCounter++; + + // 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. +/// to a StateInfo object. The move is assumed to be legal. Pseudo-legal +/// moves should be filtered out before this function is called. void Position::do_move(Move m, StateInfo& newSt) { CheckInfo ci(*this); - do_move(m, newSt, ci, move_is_check(m, ci)); + do_move(m, newSt, ci, move_gives_check(m, ci)); } void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveIsCheck) { assert(is_ok()); assert(move_is_ok(m)); + assert(&newSt != st); + nodes++; Key key = st->key; // Copy some fields of old state to our new StateInfo object except the @@ -710,6 +907,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI }; memcpy(&newSt, st, sizeof(ReducedStateInfo)); + newSt.previous = st; st = &newSt; @@ -745,7 +943,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI 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(!(ep || pm) || piece == make_piece(us, PAWN)); assert(!pm || relative_rank(us, to) == RANK_8); if (capture) @@ -781,7 +979,7 @@ 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 @@ -795,7 +993,7 @@ 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]; // Set en passant square, only if moved pawn can be captured @@ -817,7 +1015,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI // Insert promoted piece instead of pawn clear_bit(&(byTypeBB[PAWN]), to); set_bit(&(byTypeBB[promotion]), to); - board[to] = piece_of_color_and_type(us, promotion); + board[to] = make_piece(us, promotion); // Update piece counts pieceCount[us][promotion]++; @@ -845,15 +1043,19 @@ 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]; } } + // Prefetch pawn and material hash tables + Threads[threadID].pawnTable.prefetch(st->pawnKey); + Threads[threadID].materialTable.prefetch(st->materialKey); + // Update incremental scores 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 +1112,15 @@ 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(capsq) == piece_of_color_and_type(them, PAWN)); + assert(piece_on(to) == PIECE_NONE); + assert(piece_on(capsq) == make_piece(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); @@ -968,15 +1170,15 @@ 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); Square rfrom = move_to(m); // HACK: See comment at beginning of function Square kto, rto; - assert(piece_on(kfrom) == piece_of_color_and_type(us, KING)); - assert(piece_on(rfrom) == piece_of_color_and_type(us, ROOK)); + assert(piece_on(kfrom) == make_piece(us, KING)); + assert(piece_on(rfrom) == make_piece(us, ROOK)); // Find destination squares for king and rook if (rfrom > kfrom) // O-O @@ -1005,9 +1207,9 @@ void Position::do_castle_move(Move m) { set_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares // 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; + Piece king = make_piece(us, KING); + Piece rook = make_piece(us, ROOK); + board[kfrom] = board[rfrom] = PIECE_NONE; board[kto] = king; board[rto] = rook; @@ -1082,7 +1284,7 @@ void Position::undo_move(Move m) { assert(!pm || relative_rank(us, to) == RANK_8); assert(!ep || to == st->previous->epSquare); assert(!ep || relative_rank(us, to) == RANK_6); - assert(!ep || piece_on(to) == piece_of_color_and_type(us, PAWN)); + assert(!ep || piece_on(to) == make_piece(us, PAWN)); if (pm) // promotion ? { @@ -1090,7 +1292,7 @@ void Position::undo_move(Move m) { pt = PAWN; assert(promotion >= KNIGHT && promotion <= QUEEN); - assert(piece_on(to) == piece_of_color_and_type(us, promotion)); + assert(piece_on(to) == make_piece(us, promotion)); // Replace promoted piece with a pawn clear_bit(&(byTypeBB[promotion]), to); @@ -1115,36 +1317,36 @@ void Position::undo_move(Move m) { do_move_bb(&(byTypeBB[pt]), move_bb); 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[from] = make_piece(us, pt); + 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] = make_piece(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 @@ -1184,8 +1386,8 @@ void Position::undo_castle_move(Move m) { rto = relative_square(us, SQ_D1); } - assert(piece_on(kto) == piece_of_color_and_type(us, KING)); - assert(piece_on(rto) == piece_of_color_and_type(us, ROOK)); + 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); @@ -1204,9 +1406,9 @@ 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[rfrom] = piece_of_color_and_type(us, ROOK); - board[kfrom] = piece_of_color_and_type(us, KING); + board[rto] = board[kto] = PIECE_NONE; + board[rfrom] = make_piece(us, ROOK); + board[kfrom] = make_piece(us, KING); // Update piece lists pieceList[us][KING][index[kto]] = kfrom; @@ -1228,7 +1430,7 @@ void Position::undo_castle_move(Move m) { void Position::do_null_move(StateInfo& backupSt) { assert(is_ok()); - assert(!is_check()); + assert(!in_check()); // Back up the information necessary to undo the null move to the supplied // StateInfo object. @@ -1265,7 +1467,7 @@ void Position::do_null_move(StateInfo& backupSt) { void Position::undo_null_move() { assert(is_ok()); - assert(!is_check()); + assert(!in_check()); // Restore information from the our backup StateInfo object StateInfo* backupSt = st->previous; @@ -1288,18 +1490,6 @@ 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)); - return see(move_from(m), move_to(m)); -} - int Position::see_sign(Move m) const { assert(move_is_ok(m)); @@ -1307,93 +1497,58 @@ 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); + return see(m); } -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; - - assert(square_is_ok(from) || from == SQ_NONE); - assert(square_is_ok(to)); +int Position::see(Move m) const { - // Initialize colors - Color us = (from != SQ_NONE ? color_of_piece_on(from) : opposite_color(color_of_piece_on(to))); - Color them = opposite_color(us); + Square from, to; + Bitboard occupied, attackers, stmAttackers, b; + int swapList[32], slIndex = 1; + PieceType capturedType, pt; + Color stm; - // Initialize pieces - Piece piece = piece_on(from); - Piece capture = piece_on(to); - Bitboard occ = occupied_squares(); + assert(move_is_ok(m)); - // King cannot be recaptured - if (type_of_piece(piece) == KING) - return seeValues[capture]; + from = move_from(m); + to = move_to(m); + capturedType = type_of_piece_on(to); + occupied = 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); + clear_bit(&occupied, 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(&occupied, from); + attackers = (rook_attacks_bb(to, occupied) & pieces(ROOK, QUEEN)) + | (bishop_attacks_bb(to, occupied)& 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 +1556,8 @@ 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 @@ -1415,39 +1566,39 @@ int Position::see(Square from, Square to) const { for (pt = PAWN; !(stmAttackers & pieces(pt)); pt++) assert(pt < KING); - // Remove the attacker we just found from the 'attackers' bitboard, + // Remove the attacker we just found from the 'occupied' bitboard, // 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)) - | (bishop_attacks_bb(to, occ) & pieces(BISHOP, QUEEN)); + occupied ^= (b & (~b + 1)); + attackers |= (rook_attacks_bb(to, occupied) & pieces(ROOK, QUEEN)) + | (bishop_attacks_bb(to, occupied) & pieces(BISHOP, QUEEN)); - attackers &= occ; + attackers &= occupied; // 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++; - - // 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); - - // Stop after a king capture - if (pt == KING && stmAttackers) + 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. + capturedType = pt; + stm = opposite_color(stm); + stmAttackers = attackers & pieces_of_color(stm); + + // Stop before processing a king capture + if (capturedType == 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]); + // achievable score from the point of view of the side to move. + while (--slIndex) + swapList[slIndex-1] = Min(-swapList[slIndex], swapList[slIndex-1]); return swapList[0]; } @@ -1461,6 +1612,8 @@ void Position::clear() { st = &startState; memset(st, 0, sizeof(StateInfo)); st->epSquare = SQ_NONE; + startPosPlyCounter = 0; + nodes = 0; memset(byColorBB, 0, sizeof(Bitboard) * 2); memset(byTypeBB, 0, sizeof(Bitboard) * 8); @@ -1468,12 +1621,15 @@ 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; @@ -1481,20 +1637,8 @@ void Position::clear() { } -/// 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_game_ply() { - - st->gamePly = 0; -} - - /// Position::put_piece() puts a piece on the given square of the board, -/// updating the board array, bitboards, and piece counts. +/// updating the board array, pieces list, bitboards, and piece counts. void Position::put_piece(Piece p, Square s) { @@ -1502,32 +1646,12 @@ void Position::put_piece(Piece p, Square s) { PieceType pt = type_of_piece(p); board[s] = p; - index[s] = pieceCount[c][pt]; + index[s] = pieceCount[c][pt]++; pieceList[c][pt][index[s]] = s; set_bit(&(byTypeBB[pt]), s); set_bit(&(byColorBB[c]), s); - set_bit(&byTypeBB[0], s); // HACK: byTypeBB[0] contains all occupied squares. - - pieceCount[c][pt]++; -} - - -/// Position::allow_oo() gives the given side the right to castle kingside. -/// Used when setting castling rights during parsing of FEN strings. - -void Position::allow_oo(Color c) { - - st->castleRights |= (1 + int(c)); -} - - -/// Position::allow_ooo() gives the given side the right to castle queenside. -/// Used when setting castling rights during parsing of FEN strings. - -void Position::allow_ooo(Color c) { - - st->castleRights |= (4 + 4*int(c)); + set_bit(&(byTypeBB[0]), s); // HACK: byTypeBB[0] contains all occupied squares. } @@ -1538,7 +1662,7 @@ void Position::allow_ooo(Color c) { Key Position::compute_key() const { - Key result = Key(0ULL); + Key result = zobCastle[st->castleRights]; for (Square s = SQ_A1; s <= SQ_H8; s++) if (square_is_occupied(s)) @@ -1547,7 +1671,6 @@ Key Position::compute_key() const { if (ep_square() != SQ_NONE) result ^= zobEp[ep_square()]; - result ^= zobCastle[st->castleRights]; if (side_to_move() == BLACK) result ^= zobSideToMove; @@ -1563,18 +1686,14 @@ Key Position::compute_key() const { Key Position::compute_pawn_key() const { - Key result = Key(0ULL); Bitboard b; - Square s; + Key result = 0; for (Color c = WHITE; c <= BLACK; c++) { b = pieces(PAWN, c); while (b) - { - s = pop_1st_bit(&b); - result ^= zobrist[c][PAWN][s]; - } + result ^= zobrist[c][PAWN][pop_1st_bit(&b)]; } return result; } @@ -1588,11 +1707,13 @@ Key Position::compute_pawn_key() const { Key Position::compute_material_key() const { - Key result = Key(0ULL); + int count; + Key result = 0; + for (Color c = WHITE; c <= BLACK; c++) for (PieceType pt = PAWN; pt <= QUEEN; pt++) { - int count = piece_count(c, pt); + count = piece_count(c, pt); for (int i = 0; i < count; i++) result ^= zobrist[c][pt][i]; } @@ -1606,20 +1727,15 @@ 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); Bitboard b; - Square s; + Score result = SCORE_ZERO; for (Color c = WHITE; c <= BLACK; c++) for (PieceType pt = PAWN; pt <= KING; pt++) { 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, pop_1st_bit(&b)); } result += (side_to_move() == WHITE ? TempoValue / 2 : -TempoValue / 2); @@ -1628,24 +1744,17 @@ Score Position::compute_value() const { /// Position::compute_non_pawn_material() computes the total non-pawn middle -/// game material score for the given side. Material scores are updated +/// game material value for the given side. Material values are updated /// incrementally during the search, this function is only used while /// initializing a new Position object. Value Position::compute_non_pawn_material(Color c) const { - Value result = Value(0); + Value result = VALUE_ZERO; for (PieceType pt = KNIGHT; pt <= QUEEN; pt++) - { - Bitboard b = pieces(pt, c); - 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 += piece_count(c, pt) * PieceValueMidgame[pt]; + return result; } @@ -1653,7 +1762,6 @@ 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 { @@ -1663,7 +1771,7 @@ 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 && !is_mate()) return true; // Draw by repetition? @@ -1680,93 +1788,44 @@ bool Position::is_draw() const { bool Position::is_mate() const { - MoveStack moves[256]; - return is_check() && (generate_moves(*this, moves, false) == moves); + MoveStack moves[MAX_MOVES]; + return in_check() && generate(*this, moves) == moves; } -/// Position::has_mate_threat() tests whether a given color has a mate in one -/// from the current position. - -bool Position::has_mate_threat(Color c) { - - StateInfo st1, st2; - Color stm = side_to_move(); - - 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); - - // Generate pseudo-legal non-capture and capture check moves - 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 - for (MoveStack* cur = mlist; cur != last; cur++) - { - Move move = cur->move; - if (!pl_move_is_legal(move, pinned)) - continue; - - do_move(move, st2); - if (is_mate()) - result = true; - - undo_move(move); - } - - // Undo null move, if necessary - if (c != stm) - undo_null_move(); - - return result; -} - - -/// 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; + RKISS rk; - for (int i = 0; i < 64; i++) - zobEp[i] = Key(genrand_int64()); + for (i = 0; i < 2; i++) for (j = 0; j < 8; j++) for (k = 0; k < 64; k++) + zobrist[i][j][k] = rk.rand(); - for (int i = 0; i < 16; i++) - zobCastle[i] = genrand_int64(); + for (i = 0; i < 64; i++) + zobEp[i] = rk.rand(); - zobSideToMove = genrand_int64(); - zobExclusion = genrand_int64(); + for (i = 0; i < 16; i++) + zobCastle[i] = rk.rand(); + + zobSideToMove = rk.rand(); + zobExclusion = rk.rand(); } /// 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++) @@ -1774,13 +1833,15 @@ void Position::init_piece_square_tables() { } -/// Position::flipped_copy() makes a copy of the input position, but with -/// the white and black sides reversed. This is only useful for debugging, -/// especially for finding evaluation symmetry bugs. +/// Position::flip() flips position with the white and black sides reversed. This +/// is only useful for debugging especially for finding evaluation symmetry bugs. + +void Position::flip() { -void Position::flipped_copy(const Position& pos) { + assert(is_ok()); - assert(pos.is_ok()); + // Make a copy of current position before to start changing + const Position pos(*this, threadID); clear(); threadID = pos.thread(); @@ -1788,24 +1849,21 @@ void Position::flipped_copy(const Position& pos) { // Board for (Square s = SQ_A1; s <= SQ_H8; s++) if (!pos.square_is_empty(s)) - put_piece(Piece(int(pos.piece_on(s)) ^ 8), flip_square(s)); + put_piece(Piece(pos.piece_on(s) ^ 8), flip_square(s)); // Side to move sideToMove = opposite_color(pos.side_to_move()); // Castling rights - if (pos.can_castle_kingside(WHITE)) allow_oo(BLACK); - if (pos.can_castle_queenside(WHITE)) allow_ooo(BLACK); - if (pos.can_castle_kingside(BLACK)) allow_oo(WHITE); - if (pos.can_castle_queenside(BLACK)) allow_ooo(WHITE); + if (pos.can_castle_kingside(WHITE)) do_allow_oo(BLACK); + if (pos.can_castle_queenside(WHITE)) do_allow_ooo(BLACK); + if (pos.can_castle_kingside(BLACK)) do_allow_oo(WHITE); + if (pos.can_castle_queenside(BLACK)) do_allow_ooo(WHITE); initialKFile = pos.initialKFile; 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; @@ -1842,18 +1900,20 @@ void Position::flipped_copy(const Position& pos) { bool Position::is_ok(int* failedStep) const { // What features of the position should be verified? - static const bool debugBitboards = false; - static const bool debugKingCount = false; - static const bool debugKingCapture = false; - static const bool debugCheckerCount = false; - static const bool debugKey = false; - static const bool debugMaterialKey = false; - static const bool debugPawnKey = false; - static const bool debugIncrementalEval = false; - static const bool debugNonPawnMaterial = false; - static const bool debugPieceCounts = false; - static const bool debugPieceList = false; - static const bool debugCastleSquares = false; + const bool debugAll = false; + + const bool debugBitboards = debugAll || false; + const bool debugKingCount = debugAll || false; + const bool debugKingCapture = debugAll || false; + const bool debugCheckerCount = debugAll || false; + const bool debugKey = debugAll || false; + const bool debugMaterialKey = debugAll || false; + const bool debugPawnKey = debugAll || false; + const bool debugIncrementalEval = debugAll || false; + const bool debugNonPawnMaterial = debugAll || false; + const bool debugPieceCounts = debugAll || false; + const bool debugPieceList = debugAll || false; + const bool debugCastleSquares = debugAll || false; if (failedStep) *failedStep = 1; @@ -1904,7 +1964,7 @@ bool Position::is_ok(int* failedStep) const { // Is there more than 2 checkers? if (failedStep) (*failedStep)++; - if (debugCheckerCount && count_1s(st->checkersBB) > 2) + if (debugCheckerCount && count_1s(st->checkersBB) > 2) return false; // Bitboards OK? @@ -1973,30 +2033,31 @@ 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(pt, c))) + 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++) { - if (piece_on(piece_list(c, pt, i)) != piece_of_color_and_type(c, pt)) + if (piece_on(piece_list(c, pt, i)) != make_piece(c, pt)) return false; if (index[piece_list(c, pt, i)] != i) 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)) + if (debugCastleSquares) + { + for (Color c = WHITE; c <= BLACK; c++) + { + if (can_castle_kingside(c) && piece_on(initial_kr_square(c)) != make_piece(c, ROOK)) return false; - if (can_castle_queenside(c) && piece_on(initial_qr_square(c)) != piece_of_color_and_type(c, ROOK)) + + if (can_castle_queenside(c) && piece_on(initial_qr_square(c)) != make_piece(c, ROOK)) return false; } if (castleRightsMask[initial_kr_square(WHITE)] != (ALL_CASTLES ^ WHITE_OO))