X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=97581e126316ecb79757388fe8ca66701a6b24ea;hp=a2ee64f81cc603e6e4a03dbbfbbc00afeb863aa6;hb=d558f8a673b56b32ab6da8050f41b9e02fe1758b;hpb=7dcfc50bde9ed7499d43b469e12ba7f456bf0d25 diff --git a/src/position.cpp b/src/position.cpp index a2ee64f8..97581e12 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -73,13 +73,13 @@ 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::kCacheLineSize); + ASSERT_ALIGNED(&st, Eval::NNUE::CacheLineSize); Position p; p.set(pos.fen(), pos.is_chess960(), &st, pos.this_thread()); @@ -251,8 +251,6 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th set_castling_right(c, rsq); } - set_state(st); - // 4. En passant square. // Ignore if square is invalid or not on side to move relative rank 6. bool enpassant = false; @@ -266,24 +264,12 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th // 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 - // d) enemy pawn didn't block a check of its own color by moving forward 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)))) - && ( file_of(square(sideToMove)) == file_of(st->epSquare) - || !(blockers_for_king(sideToMove) & (st->epSquare + pawn_push(~sideToMove)))); + && !(pieces() & (st->epSquare | (st->epSquare + pawn_push(sideToMove)))); } - // It's necessary for st->previous to be intialized in this way because legality check relies on its existence - if (enpassant) { - st->previous = new StateInfo(); - remove_piece(st->epSquare - pawn_push(sideToMove)); - st->previous->checkersBB = attackers_to(square(~sideToMove)) & pieces(sideToMove); - st->previous->blockersForKing[WHITE] = slider_blockers(pieces(BLACK), square(WHITE), st->previous->pinners[BLACK]); - st->previous->blockersForKing[BLACK] = slider_blockers(pieces(WHITE), square(BLACK), st->previous->pinners[WHITE]); - put_piece(make_piece(~sideToMove, PAWN), st->epSquare - pawn_push(sideToMove)); - } - else + if (!enpassant) st->epSquare = SQ_NONE; // 5-6. Halfmove clock and fullmove number @@ -295,8 +281,7 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th chess960 = isChess960; thisThread = th; - st->accumulator.state[WHITE] = Eval::NNUE::INIT; - st->accumulator.state[BLACK] = Eval::NNUE::INIT; + set_state(st); 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]; @@ -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)) @@ -515,11 +500,23 @@ bool Position::legal(Move m) const { assert(color_of(moved_piece(m)) == us); assert(piece_on(square(us)) == make_piece(us, KING)); - // st->previous->blockersForKing consider capsq as empty. - // If pinned, it has to move along the king ray. + // 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) == EN_PASSANT) - return !(st->previous->blockersForKing[sideToMove] & from) - || aligned(from, to, square(us)); + { + Square ksq = square(us); + Square capsq = to - pawn_push(us); + Bitboard occupied = (pieces() ^ from ^ capsq) | to; + + assert(to == ep_square()); + assert(moved_piece(m) == make_piece(us, PAWN)); + assert(piece_on(capsq) == make_piece(~us, PAWN)); + assert(piece_on(to) == NO_PIECE); + + return !(attacks_bb< ROOK>(ksq, occupied) & pieces(~us, QUEEN, ROOK)) + && !(attacks_bb(ksq, occupied) & pieces(~us, QUEEN, BISHOP)); + } // Castling moves generation does not check if the castling path is clear of // enemy attacks, it is delayed at a later time: now! @@ -542,7 +539,7 @@ bool Position::legal(Move m) const { // 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. @@ -611,8 +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 @@ -652,15 +649,18 @@ bool Position::gives_check(Move m) const { case PROMOTION: return attacks_bb(promotion_type(m), to, pieces() ^ from) & square(~sideToMove); - // The double-pushed pawn blocked a check? En Passant will remove the blocker. - // The only discovery check that wasn't handle is through capsq and fromsq - // So the King must be in the same rank as fromsq to consider this possibility. - // st->previous->blockersForKing consider capsq as empty. + // En passant capture with check? We have already handled the case + // 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 EN_PASSANT: - return st->previous->checkersBB - || ( rank_of(square(~sideToMove)) == rank_of(from) - && st->previous->blockersForKing[~sideToMove] & from); + { + Square capsq = make_square(file_of(to), rank_of(from)); + Bitboard b = (pieces() ^ from ^ capsq) | to; + return (attacks_bb< ROOK>(square(~sideToMove), b) & pieces(sideToMove, QUEEN, ROOK)) + | (attacks_bb(square(~sideToMove), b) & pieces(sideToMove, QUEEN, BISHOP)); + } default: //CASTLING { // Castling is encoded as 'king captures the rook' @@ -700,8 +700,8 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { ++st->pliesFromNull; // Used by NNUE - st->accumulator.state[WHITE] = Eval::NNUE::EMPTY; - st->accumulator.state[BLACK] = Eval::NNUE::EMPTY; + st->accumulator.computed[WHITE] = false; + st->accumulator.computed[BLACK] = false; auto& dp = st->dirtyPiece; dp.dirty_num = 1; @@ -986,7 +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) { @@ -1001,8 +1001,8 @@ void Position::do_null_move(StateInfo& 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; + st->accumulator.computed[WHITE] = false; + st->accumulator.computed[BLACK] = false; if (st->epSquare != SQ_NONE) { @@ -1025,6 +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()); @@ -1075,8 +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; @@ -1090,8 +1094,8 @@ 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. + // 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); @@ -1107,7 +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); } @@ -1116,7 +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))) @@ -1124,7 +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); } @@ -1133,7 +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); } @@ -1142,7 +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)); } @@ -1216,7 +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; @@ -1313,7 +1317,7 @@ bool Position::pos_is_ok() const { assert(0 && "pos_is_ok: Bitboards"); StateInfo si = *st; - ASSERT_ALIGNED(&si, Eval::NNUE::kCacheLineSize); + ASSERT_ALIGNED(&si, Eval::NNUE::CacheLineSize); set_state(&si); if (std::memcmp(&si, st, sizeof(StateInfo)))