X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=60bdeafb4ca7d6b4e2d5db620b61cdf76f852ab9;hp=4d3f32a4d984d3b8edc5c92a3aff05d808098078;hb=7c8b7222f5eea024ab480abb2d9289fd1e42da9c;hpb=ec9038b7b4cb2701c3a3b8be56632e7f08e461ac diff --git a/src/position.cpp b/src/position.cpp index 4d3f32a4..60bdeafb 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -36,13 +36,8 @@ using std::string; using std::cout; using std::endl; -Key Position::zobrist[2][8][64]; -Key Position::zobEp[8]; -Key Position::zobCastle[16]; -Key Position::zobSideToMove; -Key Position::zobExclusion; - -Score Position::pieceSquareTable[16][64]; +// To convert a Piece to and from a FEN char +static const string PieceToChar(" PNBRQK pnbrqk"); // Material values arrays, indexed by Piece const Value PieceValueMidgame[17] = { @@ -63,8 +58,62 @@ const Value PieceValueEndgame[17] = { RookValueEndgame, QueenValueEndgame }; -// To convert a Piece to and from a FEN char -static const string PieceToChar(" PNBRQK pnbrqk"); +CACHE_LINE_ALIGNMENT + +Score pieceSquareTable[16][64]; + +namespace Zobrist { + +Key psq[2][8][64]; // [color][pieceType][square]/[piece count] +Key enpassant[8]; // [file] +Key castle[16]; // [castleRight] +Key side; +Key exclusion; + +/// init() initializes at startup the various arrays used to compute hash keys +/// and the piece square tables. The latter is a two-step operation: First, the +/// white halves of the tables are copied from PSQT[] tables. Second, the black +/// halves of the tables are initialized by flipping and changing the sign of +/// the white scores. + +void init() { + + RKISS rk; + + for (Color c = WHITE; c <= BLACK; c++) + for (PieceType pt = PAWN; pt <= KING; pt++) + for (Square s = SQ_A1; s <= SQ_H8; s++) + psq[c][pt][s] = rk.rand(); + + for (File f = FILE_A; f <= FILE_H; f++) + enpassant[f] = rk.rand(); + + for (int cr = CASTLES_NONE; cr <= ALL_CASTLES; cr++) + { + Bitboard b = cr; + while (b) + { + Key k = castle[1ULL << pop_lsb(&b)]; + castle[cr] ^= k ? k : rk.rand(); + } + } + + side = rk.rand(); + exclusion = rk.rand(); + + for (PieceType pt = PAWN; pt <= KING; pt++) + { + Score v = make_score(PieceValueMidgame[pt], PieceValueEndgame[pt]); + + for (Square s = SQ_A1; s <= SQ_H8; s++) + { + pieceSquareTable[make_piece(WHITE, pt)][ s] = (v + PSQT[pt][s]); + pieceSquareTable[make_piece(BLACK, pt)][~s] = -(v + PSQT[pt][s]); + } + } +} + +} // namespace Zobrist /// CheckInfo c'tor @@ -709,7 +758,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI st = &newSt; // Update side to move - k ^= zobSideToMove; + k ^= Zobrist::side; // Increment the 50 moves rule draw counter. Resetting it to zero in the // case of a capture or a pawn move is taken care of later. @@ -756,7 +805,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI board[capsq] = NO_PIECE; } - st->pawnKey ^= zobrist[them][PAWN][capsq]; + st->pawnKey ^= Zobrist::psq[them][PAWN][capsq]; } else st->npMaterial[them] -= PieceValueMidgame[capture]; @@ -779,8 +828,8 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI pieceList[them][capture][pieceCount[them][capture]] = SQ_NONE; // Update hash keys - k ^= zobrist[them][capture][capsq]; - st->materialKey ^= zobrist[them][capture][pieceCount[them][capture]]; + k ^= Zobrist::psq[them][capture][capsq]; + st->materialKey ^= Zobrist::psq[them][capture][pieceCount[them][capture]]; // Update incremental scores st->psqScore -= pieceSquareTable[make_piece(them, capture)][capsq]; @@ -790,12 +839,12 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI } // Update hash key - k ^= zobrist[us][pt][from] ^ zobrist[us][pt][to]; + k ^= Zobrist::psq[us][pt][from] ^ Zobrist::psq[us][pt][to]; // Reset en passant square if (st->epSquare != SQ_NONE) { - k ^= zobEp[file_of(st->epSquare)]; + k ^= Zobrist::enpassant[file_of(st->epSquare)]; st->epSquare = SQ_NONE; } @@ -803,7 +852,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI if (st->castleRights && (castleRightsMask[from] | castleRightsMask[to])) { int cr = castleRightsMask[from] | castleRightsMask[to]; - k ^= zobCastle[st->castleRights & cr]; + k ^= Zobrist::castle[st->castleRights & cr]; st->castleRights &= ~cr; } @@ -832,7 +881,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI && (attacks_from(from + pawn_push(us), us) & pieces(them, PAWN))) { st->epSquare = Square((from + to) / 2); - k ^= zobEp[file_of(st->epSquare)]; + k ^= Zobrist::enpassant[file_of(st->epSquare)]; } if (type_of(m) == PROMOTION) @@ -857,10 +906,10 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI pieceList[us][promotion][index[to]] = to; // Update hash keys - k ^= zobrist[us][PAWN][to] ^ zobrist[us][promotion][to]; - st->pawnKey ^= zobrist[us][PAWN][to]; - st->materialKey ^= zobrist[us][promotion][pieceCount[us][promotion]++] - ^ zobrist[us][PAWN][pieceCount[us][PAWN]]; + k ^= Zobrist::psq[us][PAWN][to] ^ Zobrist::psq[us][promotion][to]; + st->pawnKey ^= Zobrist::psq[us][PAWN][to]; + st->materialKey ^= Zobrist::psq[us][promotion][pieceCount[us][promotion]++] + ^ Zobrist::psq[us][PAWN][pieceCount[us][PAWN]]; // Update incremental score st->psqScore += pieceSquareTable[make_piece(us, promotion)][to] @@ -871,7 +920,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI } // Update pawn hash key - st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; + st->pawnKey ^= Zobrist::psq[us][PAWN][from] ^ Zobrist::psq[us][PAWN][to]; // Reset rule 50 draw counter st->rule50 = 0; @@ -1089,18 +1138,18 @@ void Position::do_castle_move(Move m) { st->psqScore += psq_delta(rook, rfrom, rto); // Update hash key - st->key ^= zobrist[us][KING][kfrom] ^ zobrist[us][KING][kto]; - st->key ^= zobrist[us][ROOK][rfrom] ^ zobrist[us][ROOK][rto]; + st->key ^= Zobrist::psq[us][KING][kfrom] ^ Zobrist::psq[us][KING][kto]; + st->key ^= Zobrist::psq[us][ROOK][rfrom] ^ Zobrist::psq[us][ROOK][rto]; // Clear en passant square if (st->epSquare != SQ_NONE) { - st->key ^= zobEp[file_of(st->epSquare)]; + st->key ^= Zobrist::enpassant[file_of(st->epSquare)]; st->epSquare = SQ_NONE; } // Update castling rights - st->key ^= zobCastle[st->castleRights & castleRightsMask[kfrom]]; + st->key ^= Zobrist::castle[st->castleRights & castleRightsMask[kfrom]]; st->castleRights &= ~castleRightsMask[kfrom]; // Update checkers BB @@ -1141,9 +1190,9 @@ void Position::do_null_move(StateInfo& backupSt) { if (Do) { if (st->epSquare != SQ_NONE) - st->key ^= zobEp[file_of(st->epSquare)]; + st->key ^= Zobrist::enpassant[file_of(st->epSquare)]; - st->key ^= zobSideToMove; + st->key ^= Zobrist::side; prefetch((char*)TT.first_entry(st->key)); st->epSquare = SQ_NONE; @@ -1320,19 +1369,19 @@ void Position::put_piece(Piece p, Square s) { Key Position::compute_key() const { - Key k = zobCastle[st->castleRights]; + Key k = Zobrist::castle[st->castleRights]; for (Bitboard b = pieces(); b; ) { Square s = pop_lsb(&b); - k ^= zobrist[color_of(piece_on(s))][type_of(piece_on(s))][s]; + k ^= Zobrist::psq[color_of(piece_on(s))][type_of(piece_on(s))][s]; } if (ep_square() != SQ_NONE) - k ^= zobEp[file_of(ep_square())]; + k ^= Zobrist::enpassant[file_of(ep_square())]; if (sideToMove == BLACK) - k ^= zobSideToMove; + k ^= Zobrist::side; return k; } @@ -1351,7 +1400,7 @@ Key Position::compute_pawn_key() const { for (Bitboard b = pieces(PAWN); b; ) { Square s = pop_lsb(&b); - k ^= zobrist[color_of(piece_on(s))][PAWN][s]; + k ^= Zobrist::psq[color_of(piece_on(s))][PAWN][s]; } return k; @@ -1371,7 +1420,7 @@ Key Position::compute_material_key() const { for (Color c = WHITE; c <= BLACK; c++) for (PieceType pt = PAWN; pt <= QUEEN; pt++) for (int cnt = 0; cnt < piece_count(c, pt); cnt++) - k ^= zobrist[c][pt][cnt]; + k ^= Zobrist::psq[c][pt][cnt]; return k; } @@ -1455,50 +1504,6 @@ template bool Position::is_draw() const; template bool Position::is_draw() const; -/// Position::init() is a static member function which initializes at startup -/// the various arrays used to compute hash keys and the piece square tables. -/// The latter is a two-step operation: First, the white halves of the tables -/// are copied from PSQT[] tables. Second, the black halves of the tables are -/// initialized by flipping and changing the sign of the white scores. - -void Position::init() { - - RKISS rk; - - for (Color c = WHITE; c <= BLACK; c++) - for (PieceType pt = PAWN; pt <= KING; pt++) - for (Square s = SQ_A1; s <= SQ_H8; s++) - zobrist[c][pt][s] = rk.rand(); - - for (File f = FILE_A; f <= FILE_H; f++) - zobEp[f] = rk.rand(); - - for (int cr = CASTLES_NONE; cr <= ALL_CASTLES; cr++) - { - Bitboard b = cr; - while (b) - { - Key k = zobCastle[1ULL << pop_lsb(&b)]; - zobCastle[cr] ^= k ? k : rk.rand(); - } - } - - zobSideToMove = rk.rand(); - zobExclusion = rk.rand(); - - for (PieceType pt = PAWN; pt <= KING; pt++) - { - Score v = make_score(PieceValueMidgame[pt], PieceValueEndgame[pt]); - - for (Square s = SQ_A1; s <= SQ_H8; s++) - { - pieceSquareTable[make_piece(WHITE, pt)][ s] = (v + PSQT[pt][s]); - pieceSquareTable[make_piece(BLACK, pt)][~s] = -(v + PSQT[pt][s]); - } - } -} - - /// Position::flip() flips position with the white and black sides reversed. This /// is only useful for debugging especially for finding evaluation symmetry bugs.