X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=826e847f09e11a11835422764628341cf164f0ce;hp=fbde810b503bc26f4574824bb9d4dd3e673236eb;hb=dd9609521437dc839236c36d35bdb8cb633ba19f;hpb=aec918a2b6ee931826ef19db1726950976da7ffe diff --git a/src/position.cpp b/src/position.cpp index fbde810b..826e847f 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -1,8 +1,6 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 - Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad - Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad + Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file) Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -50,41 +48,6 @@ const string PieceToChar(" PNBRQK pnbrqk"); constexpr Piece Pieces[] = { W_PAWN, W_KNIGHT, W_BISHOP, W_ROOK, W_QUEEN, W_KING, B_PAWN, B_KNIGHT, B_BISHOP, B_ROOK, B_QUEEN, B_KING }; - -// min_attacker() is a helper function used by see_ge() to locate the least -// valuable attacker for the side to move, remove the attacker we just found -// from the bitboards and scan for new X-ray attacks behind it. - -template -PieceType min_attacker(const Bitboard* byTypeBB, Square to, Bitboard stmAttackers, - Bitboard& occupied, Bitboard& attackers) { - - Bitboard b = stmAttackers & byTypeBB[Pt]; - if (!b) - return min_attacker(byTypeBB, to, stmAttackers, occupied, attackers); - - occupied ^= lsb(b); // Remove the attacker from occupied - - // Add any X-ray attack behind the just removed piece. For instance with - // rooks in a8 and a7 attacking a1, after removing a7 we add rook in a8. - // Note that new added attackers can be of any color. - if (Pt == PAWN || Pt == BISHOP || Pt == QUEEN) - attackers |= attacks_bb(to, occupied) & (byTypeBB[BISHOP] | byTypeBB[QUEEN]); - - if (Pt == ROOK || Pt == QUEEN) - attackers |= attacks_bb(to, occupied) & (byTypeBB[ROOK] | byTypeBB[QUEEN]); - - // X-ray may add already processed pieces because byTypeBB[] is constant: in - // the rook example, now attackers contains _again_ rook in a7, so remove it. - attackers &= occupied; - return Pt; -} - -template<> -PieceType min_attacker(const Bitboard*, Square, Bitboard, Bitboard&, Bitboard&) { - return KING; // No need to update bitboards: it is the last cycle -} - } // namespace @@ -99,10 +62,11 @@ std::ostream& operator<<(std::ostream& os, const Position& pos) { for (File f = FILE_A; f <= FILE_H; ++f) os << " | " << PieceToChar[pos.piece_on(make_square(f, r))]; - os << " |\n +---+---+---+---+---+---+---+---+\n"; + os << " | " << (1 + r) << "\n +---+---+---+---+---+---+---+---+\n"; } - os << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase + os << " a b c d e f g h\n" + << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase << std::setfill('0') << std::setw(16) << pos.key() << std::setfill(' ') << std::dec << "\nCheckers: "; @@ -113,6 +77,8 @@ std::ostream& operator<<(std::ostream& os, const Position& pos) { && !pos.can_castle(ANY_CASTLING)) { StateInfo st; + ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize); + Position p; p.set(pos.fen(), pos.is_chess960(), &st, pos.this_thread()); Tablebases::ProbeState s1, s2; @@ -139,8 +105,7 @@ Key cuckoo[8192]; Move cuckooMove[8192]; -/// Position::init() initializes at startup the various arrays used to compute -/// hash keys. +/// Position::init() initializes at startup the various arrays used to compute hash keys void Position::init() { @@ -154,15 +119,7 @@ void Position::init() { Zobrist::enpassant[f] = rng.rand(); for (int cr = NO_CASTLING; cr <= ANY_CASTLING; ++cr) - { - Zobrist::castling[cr] = 0; - Bitboard b = cr; - while (b) - { - Key k = Zobrist::castling[1ULL << pop_lsb(&b)]; - Zobrist::castling[cr] ^= k ? k : rng.rand(); - } - } + Zobrist::castling[cr] = rng.rand(); Zobrist::side = rng.rand(); Zobrist::noPawns = rng.rand(); @@ -174,7 +131,7 @@ void Position::init() { for (Piece pc : Pieces) for (Square s1 = SQ_A1; s1 <= SQ_H8; ++s1) for (Square s2 = Square(s1 + 1); s2 <= SQ_H8; ++s2) - if (PseudoAttacks[type_of(pc)][s1] & s2) + if ((type_of(pc) != PAWN) && (attacks_bb(type_of(pc), s1, 0) & s2)) { Move move = make_move(s1, s2); Key key = Zobrist::psq[pc][s1] ^ Zobrist::psq[pc][s2] ^ Zobrist::side; @@ -221,9 +178,9 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th 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 only if there is a pawn - in position to make an en passant capture, and if there really is a pawn - that might have advanced two squares. + is the position "behind" the pawn. Following X-FEN standard, this is recorded only + if there is a pawn in position to make an en passant capture, and if there really + is a pawn that might have advanced two squares. 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 @@ -240,7 +197,6 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th std::memset(this, 0, sizeof(Position)); std::memset(si, 0, sizeof(StateInfo)); - std::fill_n(&pieceList[0][0], sizeof(pieceList) / sizeof(Square), SQ_NONE); st = si; ss >> std::noskipws; @@ -254,8 +210,7 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th else if (token == '/') sq += 2 * SOUTH; - else if ((idx = PieceToChar.find(token)) != string::npos) - { + else if ((idx = PieceToChar.find(token)) != string::npos) { put_piece(Piece(idx), sq); ++sq; } @@ -294,17 +249,25 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th set_castling_right(c, rsq); } - // 4. En passant square. Ignore if no pawn capture is possible + // 4. En passant square. + // Ignore if square is invalid or not on side to move relative rank 6. + bool enpassant = false; + if ( ((ss >> col) && (col >= 'a' && col <= 'h')) - && ((ss >> row) && (row == '3' || row == '6'))) + && ((ss >> row) && (row == (sideToMove == WHITE ? '6' : '3')))) { st->epSquare = make_square(File(col - 'a'), Rank(row - '1')); - if ( !(attackers_to(st->epSquare) & pieces(sideToMove, PAWN)) - || !(pieces(~sideToMove, PAWN) & (st->epSquare + pawn_push(~sideToMove)))) - st->epSquare = SQ_NONE; + // En passant square will be considered only if + // a) side to move have a pawn threatening epSquare + // b) there is an enemy pawn in front of epSquare + // c) there is no piece on epSquare or behind epSquare + enpassant = pawn_attacks_bb(~sideToMove, st->epSquare) & pieces(sideToMove, PAWN) + && (pieces(~sideToMove, PAWN) & (st->epSquare + pawn_push(~sideToMove))) + && !(pieces() & (st->epSquare | (st->epSquare + pawn_push(sideToMove)))); } - else + + if (!enpassant) st->epSquare = SQ_NONE; // 5-6. Halfmove clock and fullmove number @@ -317,6 +280,8 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th chess960 = isChess960; thisThread = th; set_state(st); + st->accumulator.state[WHITE] = Eval::NNUE::INIT; + st->accumulator.state[BLACK] = Eval::NNUE::INIT; assert(pos_is_ok()); @@ -330,19 +295,18 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th void Position::set_castling_right(Color c, Square rfrom) { Square kfrom = square(c); - CastlingSide cs = kfrom < rfrom ? KING_SIDE : QUEEN_SIDE; - CastlingRight cr = (c | cs); + CastlingRights cr = c & (kfrom < rfrom ? KING_SIDE: QUEEN_SIDE); st->castlingRights |= cr; castlingRightsMask[kfrom] |= cr; castlingRightsMask[rfrom] |= cr; castlingRookSquare[cr] = rfrom; - Square kto = relative_square(c, cs == KING_SIDE ? SQ_G1 : SQ_C1); - Square rto = relative_square(c, cs == KING_SIDE ? SQ_F1 : SQ_D1); + Square kto = relative_square(c, cr & KING_SIDE ? SQ_G1 : SQ_C1); + Square rto = relative_square(c, cr & KING_SIDE ? SQ_F1 : SQ_D1); castlingPath[cr] = (between_bb(rfrom, rto) | between_bb(kfrom, kto) | rto | kto) - & ~(square_bb(kfrom) | rfrom); + & ~(kfrom | rfrom); } @@ -355,10 +319,10 @@ void Position::set_check_info(StateInfo* si) const { Square ksq = square(~sideToMove); - si->checkSquares[PAWN] = attacks_from(ksq, ~sideToMove); - si->checkSquares[KNIGHT] = attacks_from(ksq); - si->checkSquares[BISHOP] = attacks_from(ksq); - si->checkSquares[ROOK] = attacks_from(ksq); + si->checkSquares[PAWN] = pawn_attacks_bb(~sideToMove, ksq); + si->checkSquares[KNIGHT] = attacks_bb(ksq); + si->checkSquares[BISHOP] = attacks_bb(ksq, pieces()); + si->checkSquares[ROOK] = attacks_bb(ksq, pieces()); si->checkSquares[QUEEN] = si->checkSquares[BISHOP] | si->checkSquares[ROOK]; si->checkSquares[KING] = 0; } @@ -411,11 +375,13 @@ void Position::set_state(StateInfo* si) const { Position& Position::set(const string& code, Color c, StateInfo* si) { - assert(code.length() > 0 && code.length() < 8); assert(code[0] == 'K'); string sides[] = { code.substr(code.find('K', 1)), // Weak - code.substr(0, code.find('K', 1)) }; // Strong + code.substr(0, std::min(code.find('v'), code.find('K', 1))) }; // Strong + + assert(sides[0].length() > 0 && sides[0].length() < 8); + assert(sides[1].length() > 0 && sides[1].length() < 8); std::transform(sides[c].begin(), sides[c].end(), sides[c].begin(), tolower); @@ -489,8 +455,8 @@ Bitboard Position::slider_blockers(Bitboard sliders, Square s, Bitboard& pinners pinners = 0; // Snipers are sliders that attack 's' when a piece and other snipers are removed - Bitboard snipers = ( (PseudoAttacks[ ROOK][s] & pieces(QUEEN, ROOK)) - | (PseudoAttacks[BISHOP][s] & pieces(QUEEN, BISHOP))) & sliders; + Bitboard snipers = ( (attacks_bb< ROOK>(s) & pieces(QUEEN, ROOK)) + | (attacks_bb(s) & pieces(QUEEN, BISHOP))) & sliders; Bitboard occupancy = pieces() ^ snipers; while (snipers) @@ -514,12 +480,12 @@ Bitboard Position::slider_blockers(Bitboard sliders, Square s, Bitboard& pinners Bitboard Position::attackers_to(Square s, Bitboard occupied) const { - return (attacks_from(s, BLACK) & pieces(WHITE, PAWN)) - | (attacks_from(s, WHITE) & pieces(BLACK, PAWN)) - | (attacks_from(s) & pieces(KNIGHT)) + return (pawn_attacks_bb(BLACK, s) & pieces(WHITE, PAWN)) + | (pawn_attacks_bb(WHITE, s) & pieces(BLACK, PAWN)) + | (attacks_bb(s) & pieces(KNIGHT)) | (attacks_bb< ROOK>(s, occupied) & pieces( ROOK, QUEEN)) | (attacks_bb(s, occupied) & pieces(BISHOP, QUEEN)) - | (attacks_from(s) & pieces(KING)); + | (attacks_bb(s) & pieces(KING)); } @@ -539,7 +505,7 @@ bool Position::legal(Move m) const { // 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 (type_of(m) == ENPASSANT) + if (type_of(m) == EN_PASSANT) { Square ksq = square(us); Square capsq = to - pawn_push(us); @@ -567,11 +533,9 @@ bool Position::legal(Move m) const { if (attackers_to(s) & pieces(~us)) return false; - // In case of Chess960, verify that when moving the castling rook we do - // not discover some hidden checker. + // In case of Chess960, verify if the Rook blocks some checks // For instance an enemy queen in SQ_A1 when castling rook is in SQ_B1. - return !chess960 - || !(attacks_bb(to, pieces() ^ to_sq(m)) & pieces(~us, ROOK, QUEEN)); + return !chess960 || !(blockers_for_king(us) & to_sq(m)); } // If the moving piece is a king, check whether the destination square is @@ -598,8 +562,10 @@ bool Position::pseudo_legal(const Move m) const { Piece pc = moved_piece(m); // Use a slower but simpler function for uncommon cases + // yet we skip the legality check of MoveList(). if (type_of(m) != NORMAL) - return MoveList(*this).contains(m); + return checkers() ? MoveList< EVASIONS>(*this).contains(m) + : MoveList(*this).contains(m); // Is not a promotion, so promotion piece must be empty if (promotion_type(m) - KNIGHT != NO_PIECE_TYPE) @@ -622,15 +588,15 @@ bool Position::pseudo_legal(const Move m) const { if ((Rank8BB | Rank1BB) & to) return false; - if ( !(attacks_from(from, us) & pieces(~us) & to) // Not a capture + if ( !(pawn_attacks_bb(us, from) & pieces(~us) & to) // Not a capture && !((from + pawn_push(us) == to) && empty(to)) // Not a single push && !( (from + 2 * pawn_push(us) == to) // Not a double push - && (rank_of(from) == relative_rank(us, RANK_2)) + && (relative_rank(us, from) == RANK_2) && empty(to) && empty(to - pawn_push(us)))) return false; } - else if (!(attacks_from(type_of(pc), from) & to)) + else if (!(attacks_bb(type_of(pc), from, pieces()) & to)) return false; // Evasions generator already takes care to avoid some kind of illegal moves @@ -669,11 +635,11 @@ bool Position::gives_check(Move m) const { Square to = to_sq(m); // Is there a direct check? - if (st->checkSquares[type_of(piece_on(from))] & to) + if (check_squares(type_of(piece_on(from))) & to) return true; // Is there a discovered check? - if ( (st->blockersForKing[~sideToMove] & from) + if ( (blockers_for_king(~sideToMove) & from) && !aligned(from, to, square(~sideToMove))) return true; @@ -689,7 +655,7 @@ bool Position::gives_check(Move m) const { // of direct checks and ordinary discovered check, so the only case we // need to handle is the unusual case of a discovered check through // the captured pawn. - case ENPASSANT: + case EN_PASSANT: { Square capsq = make_square(file_of(to), rank_of(from)); Bitboard b = (pieces() ^ from ^ capsq) | to; @@ -697,19 +663,15 @@ bool Position::gives_check(Move m) const { return (attacks_bb< ROOK>(square(~sideToMove), b) & pieces(sideToMove, QUEEN, ROOK)) | (attacks_bb(square(~sideToMove), b) & pieces(sideToMove, QUEEN, BISHOP)); } - case CASTLING: + default: //CASTLING { - Square kfrom = from; - Square rfrom = to; // Castling is encoded as 'King captures the rook' - Square kto = relative_square(sideToMove, rfrom > kfrom ? SQ_G1 : SQ_C1); - Square rto = relative_square(sideToMove, rfrom > kfrom ? SQ_F1 : SQ_D1); + // Castling is encoded as 'king captures the rook' + Square ksq = square(~sideToMove); + Square rto = relative_square(sideToMove, to > from ? SQ_F1 : SQ_D1); - return (PseudoAttacks[ROOK][rto] & square(~sideToMove)) - && (attacks_bb(rto, (pieces() ^ kfrom ^ rfrom) | rto | kto) & square(~sideToMove)); + return (attacks_bb(rto) & ksq) + && (attacks_bb(rto, pieces() ^ from ^ to) & ksq); } - default: - assert(false); - return false; } } @@ -739,12 +701,18 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { ++st->rule50; ++st->pliesFromNull; + // Used by NNUE + st->accumulator.state[WHITE] = Eval::NNUE::EMPTY; + st->accumulator.state[BLACK] = Eval::NNUE::EMPTY; + auto& dp = st->dirtyPiece; + dp.dirty_num = 1; + Color us = sideToMove; Color them = ~us; Square from = from_sq(m); Square to = to_sq(m); Piece pc = piece_on(from); - Piece captured = type_of(m) == ENPASSANT ? make_piece(them, PAWN) : piece_on(to); + Piece captured = type_of(m) == EN_PASSANT ? make_piece(them, PAWN) : piece_on(to); assert(color_of(pc) == us); assert(captured == NO_PIECE || color_of(captured) == (type_of(m) != CASTLING ? them : us)); @@ -770,7 +738,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { // update non-pawn material. if (type_of(captured) == PAWN) { - if (type_of(m) == ENPASSANT) + if (type_of(m) == EN_PASSANT) { capsq -= pawn_push(us); @@ -779,8 +747,6 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { assert(relative_rank(us, to) == RANK_6); assert(piece_on(to) == NO_PIECE); assert(piece_on(capsq) == make_piece(them, PAWN)); - - board[capsq] = NO_PIECE; // Not done by remove_piece() } st->pawnKey ^= Zobrist::psq[captured][capsq]; @@ -788,8 +754,19 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { else st->nonPawnMaterial[them] -= PieceValue[MG][captured]; + if (Eval::useNNUE) + { + dp.dirty_num = 2; // 1 piece moved, 1 piece captured + dp.piece[1] = captured; + dp.from[1] = capsq; + dp.to[1] = SQ_NONE; + } + // Update board and piece lists - remove_piece(captured, capsq); + remove_piece(capsq); + + if (type_of(m) == EN_PASSANT) + board[capsq] = NO_PIECE; // Update material hash key and prefetch access to materialTable k ^= Zobrist::psq[captured][capsq]; @@ -813,21 +790,30 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { // Update castling rights if needed if (st->castlingRights && (castlingRightsMask[from] | castlingRightsMask[to])) { - int cr = castlingRightsMask[from] | castlingRightsMask[to]; - k ^= Zobrist::castling[st->castlingRights & cr]; - st->castlingRights &= ~cr; + k ^= Zobrist::castling[st->castlingRights]; + st->castlingRights &= ~(castlingRightsMask[from] | castlingRightsMask[to]); + k ^= Zobrist::castling[st->castlingRights]; } // Move the piece. The tricky Chess960 castling is handled earlier if (type_of(m) != CASTLING) - move_piece(pc, from, to); + { + if (Eval::useNNUE) + { + dp.piece[0] = pc; + dp.from[0] = from; + dp.to[0] = to; + } + + move_piece(from, to); + } // If the moving piece is a pawn do some special extra work if (type_of(pc) == PAWN) { - // Set en-passant square if the moved pawn can be captured + // Set en passant square if the moved pawn can be captured if ( (int(to) ^ int(from)) == 16 - && (attacks_from(to - pawn_push(us), us) & pieces(them, PAWN))) + && (pawn_attacks_bb(us, to - pawn_push(us)) & pieces(them, PAWN))) { st->epSquare = to - pawn_push(us); k ^= Zobrist::enpassant[file_of(st->epSquare)]; @@ -840,9 +826,19 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { assert(relative_rank(us, to) == RANK_8); assert(type_of(promotion) >= KNIGHT && type_of(promotion) <= QUEEN); - remove_piece(pc, to); + remove_piece(to); put_piece(promotion, to); + if (Eval::useNNUE) + { + // Promoting pawn to SQ_NONE, promoted piece from SQ_NONE + dp.to[0] = SQ_NONE; + dp.piece[dp.dirty_num] = promotion; + dp.from[dp.dirty_num] = SQ_NONE; + dp.to[dp.dirty_num] = to; + dp.dirty_num++; + } + // Update hash keys k ^= Zobrist::psq[pc][to] ^ Zobrist::psq[promotion][to]; st->pawnKey ^= Zobrist::psq[pc][to]; @@ -853,7 +849,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { st->nonPawnMaterial[us] += PieceValue[MG][promotion]; } - // Update pawn hash key and prefetch access to pawnsTable + // Update pawn hash key st->pawnKey ^= Zobrist::psq[pc][from] ^ Zobrist::psq[pc][to]; // Reset rule 50 draw counter @@ -882,7 +878,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { if (end >= 4) { StateInfo* stp = st->previous->previous; - for (int i=4; i <= end; i += 2) + for (int i = 4; i <= end; i += 2) { stp = stp->previous->previous; if (stp->key == st->key) @@ -920,7 +916,7 @@ void Position::undo_move(Move m) { assert(type_of(pc) == promotion_type(m)); assert(type_of(pc) >= KNIGHT && type_of(pc) <= QUEEN); - remove_piece(pc, to); + remove_piece(to); pc = make_piece(us, PAWN); put_piece(pc, to); } @@ -932,13 +928,13 @@ void Position::undo_move(Move m) { } else { - move_piece(pc, to, from); // Put the piece back at the source square + move_piece(to, from); // Put the piece back at the source square if (st->capturedPiece) { Square capsq = to; - if (type_of(m) == ENPASSANT) + if (type_of(m) == EN_PASSANT) { capsq -= pawn_push(us); @@ -971,16 +967,28 @@ void Position::do_castling(Color us, Square from, Square& to, Square& rfrom, Squ rto = relative_square(us, kingSide ? SQ_F1 : SQ_D1); to = relative_square(us, kingSide ? SQ_G1 : SQ_C1); + if (Do && Eval::useNNUE) + { + auto& dp = st->dirtyPiece; + dp.piece[0] = make_piece(us, KING); + dp.from[0] = from; + dp.to[0] = to; + dp.piece[1] = make_piece(us, ROOK); + dp.from[1] = rfrom; + dp.to[1] = rto; + dp.dirty_num = 2; + } + // Remove both pieces first since squares could overlap in Chess960 - remove_piece(make_piece(us, KING), Do ? from : to); - remove_piece(make_piece(us, ROOK), Do ? rfrom : rto); - board[Do ? from : to] = board[Do ? rfrom : rto] = NO_PIECE; // Since remove_piece doesn't do it for us + remove_piece(Do ? from : to); + remove_piece(Do ? rfrom : rto); + board[Do ? from : to] = board[Do ? rfrom : rto] = NO_PIECE; // Since remove_piece doesn't do this for us put_piece(make_piece(us, KING), Do ? to : from); put_piece(make_piece(us, ROOK), Do ? rto : rfrom); } -/// Position::do(undo)_null_move() is used to do(undo) a "null move": It flips +/// Position::do(undo)_null_move() is used to do(undo) a "null move": it flips /// the side to move without executing any move on the board. void Position::do_null_move(StateInfo& newSt) { @@ -988,10 +996,16 @@ void Position::do_null_move(StateInfo& newSt) { assert(!checkers()); assert(&newSt != st); - std::memcpy(&newSt, st, sizeof(StateInfo)); + std::memcpy(&newSt, st, offsetof(StateInfo, accumulator)); + newSt.previous = st; st = &newSt; + st->dirtyPiece.dirty_num = 0; + st->dirtyPiece.piece[0] = NO_PIECE; // Avoid checks in UpdateAccumulator() + st->accumulator.state[WHITE] = Eval::NNUE::EMPTY; + st->accumulator.state[BLACK] = Eval::NNUE::EMPTY; + if (st->epSquare != SQ_NONE) { st->key ^= Zobrist::enpassant[file_of(st->epSquare)]; @@ -999,7 +1013,7 @@ void Position::do_null_move(StateInfo& newSt) { } st->key ^= Zobrist::side; - prefetch(TT.first_entry(st->key)); + prefetch(TT.first_entry(key())); ++st->rule50; st->pliesFromNull = 0; @@ -1024,7 +1038,7 @@ void Position::undo_null_move() { /// Position::key_after() computes the new hash key after the given move. Needed /// for speculative prefetch. It doesn't recognize special moves like castling, -/// en-passant and promotions. +/// en passant and promotions. Key Position::key_after(Move m) const { @@ -1049,79 +1063,99 @@ bool Position::see_ge(Move m, Value threshold) const { assert(is_ok(m)); - // Only deal with normal moves, assume others pass a simple see + // Only deal with normal moves, assume others pass a simple SEE if (type_of(m) != NORMAL) return VALUE_ZERO >= threshold; - Bitboard stmAttackers; Square from = from_sq(m), to = to_sq(m); - PieceType nextVictim = type_of(piece_on(from)); - Color us = color_of(piece_on(from)); - Color stm = ~us; // First consider opponent's move - Value balance; // Values of the pieces taken by us minus opponent's ones - // The opponent may be able to recapture so this is the best result - // we can hope for. - balance = PieceValue[MG][piece_on(to)] - threshold; - - if (balance < VALUE_ZERO) + int swap = PieceValue[MG][piece_on(to)] - threshold; + if (swap < 0) return false; - // Now assume the worst possible result: that the opponent can - // capture our piece for free. - balance -= PieceValue[MG][nextVictim]; - - // If it is enough (like in PxQ) then return immediately. Note that - // in case nextVictim == KING we always return here, this is ok - // if the given move is legal. - if (balance >= VALUE_ZERO) + swap = PieceValue[MG][piece_on(from)] - swap; + if (swap <= 0) return true; - // Find all attackers to the destination square, with the moving piece - // removed, but possibly an X-ray attacker added behind it. Bitboard occupied = pieces() ^ from ^ to; - Bitboard attackers = attackers_to(to, occupied) & occupied; + Color stm = color_of(piece_on(from)); + Bitboard attackers = attackers_to(to, occupied); + Bitboard stmAttackers, bb; + int res = 1; while (true) { - stmAttackers = attackers & pieces(stm); + stm = ~stm; + attackers &= occupied; + + // If stm has no more attackers then give up: stm loses + if (!(stmAttackers = attackers & pieces(stm))) + break; // Don't allow pinned pieces to attack (except the king) as long as - // any pinners are on their original square. - if (st->pinners[~stm] & occupied) - stmAttackers &= ~st->blockersForKing[stm]; + // there are pinners on their original square. + if (pinners(~stm) & occupied) + stmAttackers &= ~blockers_for_king(stm); - // If stm has no more attackers then give up: stm loses if (!stmAttackers) break; + res ^= 1; + // Locate and remove the next least valuable attacker, and add to - // the bitboard 'attackers' the possibly X-ray attackers behind it. - nextVictim = min_attacker(byTypeBB, to, stmAttackers, occupied, attackers); + // the bitboard 'attackers' any X-ray attackers behind it. + if ((bb = stmAttackers & pieces(PAWN))) + { + if ((swap = PawnValueMg - swap) < res) + break; - stm = ~stm; // Switch side to move + occupied ^= lsb(bb); + attackers |= attacks_bb(to, occupied) & pieces(BISHOP, QUEEN); + } - // Negamax the balance with alpha = balance, beta = balance+1 and - // add nextVictim's value. - // - // (balance, balance+1) -> (-balance-1, -balance) - // - assert(balance < VALUE_ZERO); + else if ((bb = stmAttackers & pieces(KNIGHT))) + { + if ((swap = KnightValueMg - swap) < res) + break; - balance = -balance - 1 - PieceValue[MG][nextVictim]; + occupied ^= lsb(bb); + } - // If balance is still non-negative after giving away nextVictim then we - // win. The only thing to be careful about it is that we should revert - // stm if we captured with the king when the opponent still has attackers. - if (balance >= VALUE_ZERO) + else if ((bb = stmAttackers & pieces(BISHOP))) { - if (nextVictim == KING && (attackers & pieces(stm))) - stm = ~stm; - break; + if ((swap = BishopValueMg - swap) < res) + break; + + occupied ^= lsb(bb); + attackers |= attacks_bb(to, occupied) & pieces(BISHOP, QUEEN); } - assert(nextVictim != KING); + + else if ((bb = stmAttackers & pieces(ROOK))) + { + if ((swap = RookValueMg - swap) < res) + break; + + occupied ^= lsb(bb); + attackers |= attacks_bb(to, occupied) & pieces(ROOK, QUEEN); + } + + else if ((bb = stmAttackers & pieces(QUEEN))) + { + if ((swap = QueenValueMg - swap) < res) + break; + + occupied ^= lsb(bb); + attackers |= (attacks_bb(to, occupied) & pieces(BISHOP, QUEEN)) + | (attacks_bb(to, occupied) & pieces(ROOK , QUEEN)); + } + + else // KING + // If we "capture" with the king but opponent still has attackers, + // reverse the result. + return (attackers & ~pieces(stm)) ? res ^ 1 : res; } - return us != stm; // We break the above loop when stm loses + + return bool(res); } @@ -1135,10 +1169,7 @@ bool Position::is_draw(int ply) const { // Return a draw score if a position repeats once earlier but strictly // after the root, or repeats twice before or at the root. - if (st->repetition && st->repetition < ply) - return true; - - return false; + return st->repetition && st->repetition < ply; } @@ -1284,30 +1315,26 @@ bool Position::pos_is_ok() const { assert(0 && "pos_is_ok: Bitboards"); StateInfo si = *st; + ASSERT_ALIGNED(&si, Eval::NNUE::kCacheLineSize); + set_state(&si); if (std::memcmp(&si, st, sizeof(StateInfo))) assert(0 && "pos_is_ok: State"); for (Piece pc : Pieces) - { if ( pieceCount[pc] != popcount(pieces(color_of(pc), type_of(pc))) || pieceCount[pc] != std::count(board, board + SQUARE_NB, pc)) assert(0 && "pos_is_ok: Pieces"); - for (int i = 0; i < pieceCount[pc]; ++i) - if (board[pieceList[pc][i]] != pc || index[pieceList[pc][i]] != i) - assert(0 && "pos_is_ok: Index"); - } - for (Color c : { WHITE, BLACK }) - for (CastlingSide s : {KING_SIDE, QUEEN_SIDE}) + for (CastlingRights cr : {c & KING_SIDE, c & QUEEN_SIDE}) { - if (!can_castle(c | s)) + if (!can_castle(cr)) continue; - if ( piece_on(castlingRookSquare[c | s]) != make_piece(c, ROOK) - || castlingRightsMask[castlingRookSquare[c | s]] != (c | s) - || (castlingRightsMask[square(c)] & (c | s)) != (c | s)) + if ( piece_on(castlingRookSquare[cr]) != make_piece(c, ROOK) + || castlingRightsMask[castlingRookSquare[cr]] != cr + || (castlingRightsMask[square(c)] & cr) != cr) assert(0 && "pos_is_ok: Castling"); }