X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=97581e126316ecb79757388fe8ca66701a6b24ea;hp=46e5d78b9ae567a0c2846528ea059259e62430cf;hb=d558f8a673b56b32ab6da8050f41b9e02fe1758b;hpb=84f3e867903f62480c33243dd0ecbffd342796fc diff --git a/src/position.cpp b/src/position.cpp index 46e5d78b..97581e12 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -1,6 +1,6 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 - Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file) + 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 @@ -34,6 +34,8 @@ using std::string; +namespace Stockfish { + namespace Zobrist { Key psq[PIECE_NB][SQUARE_NB]; @@ -71,12 +73,14 @@ std::ostream& operator<<(std::ostream& os, const Position& pos) { << std::setfill(' ') << std::dec << "\nCheckers: "; for (Bitboard b = pos.checkers(); b; ) - os << UCI::square(pop_lsb(&b)) << " "; + os << UCI::square(pop_lsb(b)) << " "; if ( int(Tablebases::MaxCardinality) >= popcount(pos.pieces()) && !pos.can_castle(ANY_CASTLING)) { StateInfo st; + ASSERT_ALIGNED(&st, Eval::NNUE::CacheLineSize); + Position p; p.set(pos.fen(), pos.is_chess960(), &st, pos.this_thread()); Tablebases::ProbeState s1, s2; @@ -195,12 +199,8 @@ 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; - // Each piece on board gets a unique ID used to track the piece later - PieceId piece_id, next_piece_id = PIECE_ID_ZERO; - ss >> std::noskipws; // 1. Piece placement @@ -212,21 +212,8 @@ 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) - { - auto pc = Piece(idx); - put_piece(pc, sq); - - if (Eval::useNNUE) - { - // Kings get a fixed ID, other pieces get ID in order of placement - piece_id = - (idx == W_KING) ? PIECE_ID_WKING : - (idx == B_KING) ? PIECE_ID_BKING : - next_piece_id++; - evalList.put_piece(piece_id, sq, pc); - } - + else if ((idx = PieceToChar.find(token)) != string::npos) { + put_piece(Piece(idx), sq); ++sq; } } @@ -296,8 +283,6 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th thisThread = th; set_state(st); - assert(pos_is_ok()); - return *this; } @@ -318,7 +303,7 @@ void Position::set_castling_right(Color c, Square rfrom) { 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) + castlingPath[cr] = (between_bb(rfrom, rto) | between_bb(kfrom, kto)) & ~(kfrom | rfrom); } @@ -357,7 +342,7 @@ void Position::set_state(StateInfo* si) const { for (Bitboard b = pieces(); b; ) { - Square s = pop_lsb(&b); + Square s = pop_lsb(b); Piece pc = piece_on(s); si->key ^= Zobrist::psq[pc][s]; @@ -408,7 +393,7 @@ Position& Position::set(const string& code, Color c, StateInfo* si) { /// Position::fen() returns a FEN representation of the position. In case of /// Chess960 the Shredder-FEN notation is used. This is mainly a debugging function. -const string Position::fen() const { +string Position::fen() const { int emptyCnt; std::ostringstream ss; @@ -474,7 +459,7 @@ Bitboard Position::slider_blockers(Bitboard sliders, Square s, Bitboard& pinners while (snipers) { - Square sniperSq = pop_lsb(&snipers); + Square sniperSq = pop_lsb(snipers); Bitboard b = between_bb(s, sniperSq) & occupancy; if (b && !more_than_one(b)) @@ -518,7 +503,7 @@ 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); @@ -546,22 +531,20 @@ 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 // attacked by the opponent. if (type_of(piece_on(from)) == KING) - return !(attackers_to(to) & pieces(~us)); + return !(attackers_to(to, pieces() ^ from) & pieces(~us)); // 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 !(blockers_for_king(us) & from) - || aligned(from, to, square(us)); + return !(blockers_for_king(us) & from) + || aligned(from, to, square(us)); } @@ -577,8 +560,10 @@ 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) @@ -623,8 +608,8 @@ bool Position::pseudo_legal(const Move m) const { if (more_than_one(checkers())) return false; - // Our move must be a blocking evasion or a capture of the checking piece - if (!((between_bb(lsb(checkers()), square(us)) | checkers()) & to)) + // Our move must be a blocking interposition or a capture of the checking piece + if (!(between_bb(square(us), lsb(checkers())) & to)) return false; } // In case of king moves under check we have to remove king so as to catch @@ -668,7 +653,7 @@ 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; @@ -676,19 +661,15 @@ 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 (attacks_bb(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; } } @@ -719,10 +700,8 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { ++st->pliesFromNull; // Used by NNUE - st->accumulator.computed_accumulation = false; - st->accumulator.computed_score = false; - PieceId dp0 = PIECE_ID_NONE; - PieceId dp1 = PIECE_ID_NONE; + st->accumulator.computed[WHITE] = false; + st->accumulator.computed[BLACK] = false; auto& dp = st->dirtyPiece; dp.dirty_num = 1; @@ -731,7 +710,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { 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)); @@ -757,7 +736,7 @@ 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); @@ -775,18 +754,16 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { if (Eval::useNNUE) { - dp.dirty_num = 2; // 2 pieces moved - dp1 = piece_id_on(capsq); - dp.pieceId[1] = dp1; - dp.old_piece[1] = evalList.piece_with_id(dp1); - evalList.put_piece(dp1, capsq, NO_PIECE); - dp.new_piece[1] = evalList.piece_with_id(dp1); + 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(capsq); - if (type_of(m) == ENPASSANT) + if (type_of(m) == EN_PASSANT) board[capsq] = NO_PIECE; // Update material hash key and prefetch access to materialTable @@ -821,11 +798,9 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { { if (Eval::useNNUE) { - dp0 = piece_id_on(from); - dp.pieceId[0] = dp0; - dp.old_piece[0] = evalList.piece_with_id(dp0); - evalList.put_piece(dp0, to, pc); - dp.new_piece[0] = evalList.piece_with_id(dp0); + dp.piece[0] = pc; + dp.from[0] = from; + dp.to[0] = to; } move_piece(from, to); @@ -834,7 +809,7 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { // 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 && (pawn_attacks_bb(us, to - pawn_push(us)) & pieces(them, PAWN))) { @@ -854,9 +829,12 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { if (Eval::useNNUE) { - dp0 = piece_id_on(to); - evalList.put_piece(dp0, to, promotion); - dp.new_piece[0] = evalList.piece_with_id(dp0); + // 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 @@ -950,17 +928,11 @@ void Position::undo_move(Move m) { { move_piece(to, from); // Put the piece back at the source square - if (Eval::useNNUE) - { - PieceId dp0 = st->dirtyPiece.pieceId[0]; - evalList.put_piece(dp0, from, pc); - } - if (st->capturedPiece) { Square capsq = to; - if (type_of(m) == ENPASSANT) + if (type_of(m) == EN_PASSANT) { capsq -= pawn_push(us); @@ -972,14 +944,6 @@ void Position::undo_move(Move m) { } put_piece(st->capturedPiece, capsq); // Restore the captured piece - - if (Eval::useNNUE) - { - PieceId dp1 = st->dirtyPiece.pieceId[1]; - assert(evalList.piece_with_id(dp1).from[WHITE] == PS_NONE); - assert(evalList.piece_with_id(dp1).from[BLACK] == PS_NONE); - evalList.put_piece(dp1, capsq, st->capturedPiece); - } } } @@ -1001,32 +965,16 @@ 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 (Eval::useNNUE) + if (Do && Eval::useNNUE) { - PieceId dp0, dp1; auto& dp = st->dirtyPiece; - dp.dirty_num = 2; // 2 pieces moved - - if (Do) - { - dp0 = piece_id_on(from); - dp1 = piece_id_on(rfrom); - dp.pieceId[0] = dp0; - dp.old_piece[0] = evalList.piece_with_id(dp0); - evalList.put_piece(dp0, to, make_piece(us, KING)); - dp.new_piece[0] = evalList.piece_with_id(dp0); - dp.pieceId[1] = dp1; - dp.old_piece[1] = evalList.piece_with_id(dp1); - evalList.put_piece(dp1, rto, make_piece(us, ROOK)); - dp.new_piece[1] = evalList.piece_with_id(dp1); - } - else - { - dp0 = piece_id_on(to); - dp1 = piece_id_on(rto); - evalList.put_piece(dp0, from, make_piece(us, KING)); - evalList.put_piece(dp1, rfrom, make_piece(us, ROOK)); - } + 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 @@ -1038,7 +986,7 @@ void Position::do_castling(Color us, Square from, Square& to, Square& rfrom, Squ } -/// Position::do(undo)_null_move() is used to do(undo) a "null move": it flips +/// Position::do_null_move() is used to do a "null move": it flips /// the side to move without executing any move on the board. void Position::do_null_move(StateInfo& newSt) { @@ -1046,17 +994,16 @@ void Position::do_null_move(StateInfo& newSt) { assert(!checkers()); assert(&newSt != st); - if (Eval::useNNUE) - { - std::memcpy(&newSt, st, sizeof(StateInfo)); - st->accumulator.computed_score = false; - } - else - std::memcpy(&newSt, st, offsetof(StateInfo, accumulator)); + 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.computed[WHITE] = false; + st->accumulator.computed[BLACK] = false; + if (st->epSquare != SQ_NONE) { st->key ^= Zobrist::enpassant[file_of(st->epSquare)]; @@ -1064,7 +1011,7 @@ 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; @@ -1078,6 +1025,9 @@ void Position::do_null_move(StateInfo& newSt) { assert(pos_is_ok()); } + +/// Position::undo_null_move() must be used to undo a "null move" + void Position::undo_null_move() { assert(!checkers()); @@ -1089,7 +1039,7 @@ 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 { @@ -1114,7 +1064,7 @@ 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; @@ -1128,8 +1078,9 @@ bool Position::see_ge(Move m, Value threshold) const { if (swap <= 0) return true; + assert(color_of(piece_on(from)) == sideToMove); Bitboard occupied = pieces() ^ from ^ to; - Color stm = color_of(piece_on(from)); + Color stm = sideToMove; Bitboard attackers = attackers_to(to, occupied); Bitboard stmAttackers, bb; int res = 1; @@ -1143,10 +1094,10 @@ bool Position::see_ge(Move m, Value threshold) const { if (!(stmAttackers = attackers & pieces(stm))) break; - // Don't allow pinned pieces to attack (except the king) as long as - // there are pinners on their original square. - if (st->pinners[~stm] & occupied) - stmAttackers &= ~st->blockersForKing[stm]; + // Don't allow pinned pieces to attack as long as there are + // pinners on their original square. + if (pinners(~stm) & occupied) + stmAttackers &= ~blockers_for_king(stm); if (!stmAttackers) break; @@ -1160,7 +1111,7 @@ bool Position::see_ge(Move m, Value threshold) const { if ((swap = PawnValueMg - swap) < res) break; - occupied ^= lsb(bb); + occupied ^= least_significant_square_bb(bb); attackers |= attacks_bb(to, occupied) & pieces(BISHOP, QUEEN); } @@ -1169,7 +1120,7 @@ bool Position::see_ge(Move m, Value threshold) const { if ((swap = KnightValueMg - swap) < res) break; - occupied ^= lsb(bb); + occupied ^= least_significant_square_bb(bb); } else if ((bb = stmAttackers & pieces(BISHOP))) @@ -1177,7 +1128,7 @@ bool Position::see_ge(Move m, Value threshold) const { if ((swap = BishopValueMg - swap) < res) break; - occupied ^= lsb(bb); + occupied ^= least_significant_square_bb(bb); attackers |= attacks_bb(to, occupied) & pieces(BISHOP, QUEEN); } @@ -1186,7 +1137,7 @@ bool Position::see_ge(Move m, Value threshold) const { if ((swap = RookValueMg - swap) < res) break; - occupied ^= lsb(bb); + occupied ^= least_significant_square_bb(bb); attackers |= attacks_bb(to, occupied) & pieces(ROOK, QUEEN); } @@ -1195,7 +1146,7 @@ bool Position::see_ge(Move m, Value threshold) const { if ((swap = QueenValueMg - swap) < res) break; - occupied ^= lsb(bb); + occupied ^= least_significant_square_bb(bb); attackers |= (attacks_bb(to, occupied) & pieces(BISHOP, QUEEN)) | (attacks_bb(to, occupied) & pieces(ROOK , QUEEN)); } @@ -1269,7 +1220,7 @@ bool Position::has_game_cycle(int ply) const { Square s1 = from_sq(move); Square s2 = to_sq(move); - if (!(between_bb(s1, s2) & pieces())) + if (!((between_bb(s1, s2) ^ s2) & pieces())) { if (ply > i) return true; @@ -1366,21 +1317,17 @@ bool Position::pos_is_ok() const { assert(0 && "pos_is_ok: Bitboards"); StateInfo si = *st; + ASSERT_ALIGNED(&si, Eval::NNUE::CacheLineSize); + 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 (CastlingRights cr : {c & KING_SIDE, c & QUEEN_SIDE}) { @@ -1395,3 +1342,5 @@ bool Position::pos_is_ok() const { return true; } + +} // namespace Stockfish