X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=004d6994731ca106e0dd3d7afd6fb5f5b31fd719;hp=9be0fe600b7080375b0b28f75a23a282e2c6e9cf;hb=e3b03278129e4d7f130826aef209668b3268aa94;hpb=fde0b9e701a6bfac05e56f6bffdc29943be56120 diff --git a/src/position.cpp b/src/position.cpp index 9be0fe60..004d6994 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -40,16 +40,16 @@ static const string PieceToChar(" PNBRQK pnbrqk"); CACHE_LINE_ALIGNMENT -Score pieceSquareTable[16][64]; // [piece][square] -Value PieceValue[2][18] = { // [Mg / Eg][piece / pieceType] +Score pieceSquareTable[PIECE_NB][SQUARE_NB]; +Value PieceValue[PHASE_NB][PIECE_NB] = { { VALUE_ZERO, PawnValueMg, KnightValueMg, BishopValueMg, RookValueMg, QueenValueMg }, { VALUE_ZERO, PawnValueEg, KnightValueEg, BishopValueEg, RookValueEg, QueenValueEg } }; namespace Zobrist { -Key psq[2][8][64]; // [color][pieceType][square / piece count] -Key enpassant[8]; // [file] -Key castle[16]; // [castleRight] +Key psq[COLOR_NB][PIECE_TYPE_NB][SQUARE_NB]; +Key enpassant[FILE_NB]; +Key castle[CASTLE_RIGHT_NB]; Key side; Key exclusion; @@ -86,10 +86,10 @@ void init() { for (PieceType pt = PAWN; pt <= KING; pt++) { - PieceValue[Mg][make_piece(BLACK, pt)] = PieceValue[Mg][pt]; - PieceValue[Eg][make_piece(BLACK, pt)] = PieceValue[Eg][pt]; + PieceValue[MG][make_piece(BLACK, pt)] = PieceValue[MG][pt]; + PieceValue[EG][make_piece(BLACK, pt)] = PieceValue[EG][pt]; - Score v = make_score(PieceValue[Mg][pt], PieceValue[Eg][pt]); + Score v = make_score(PieceValue[MG][pt], PieceValue[EG][pt]); for (Square s = SQ_A1; s <= SQ_H8; s++) { @@ -102,6 +102,40 @@ void init() { } // namespace Zobrist +namespace { + +/// next_attacker() is an helper function used by see() to locate the least +/// valuable attacker for the side to move, remove the attacker we just found +/// from the 'occupied' bitboard and scan for new X-ray attacks behind it. + +template FORCE_INLINE +PieceType next_attacker(const Bitboard* bb, const Square& to, const Bitboard& stmAttackers, + Bitboard& occupied, Bitboard& attackers) { + + if (stmAttackers & bb[Pt]) + { + Bitboard b = stmAttackers & bb[Pt]; + occupied ^= b & ~(b - 1); + + if (Pt == PAWN || Pt == BISHOP || Pt == QUEEN) + attackers |= attacks_bb(to, occupied) & (bb[BISHOP] | bb[QUEEN]); + + if (Pt == ROOK || Pt == QUEEN) + attackers |= attacks_bb(to, occupied) & (bb[ROOK] | bb[QUEEN]); + + return (PieceType)Pt; + } + return next_attacker(bb, to, stmAttackers, occupied, attackers); +} + +template<> FORCE_INLINE +PieceType next_attacker(const Bitboard*, const Square&, const Bitboard&, Bitboard&, Bitboard&) { + return KING; // No need to update bitboards, it is the last cycle +} + +} // namespace + + /// CheckInfo c'tor CheckInfo::CheckInfo(const Position& pos) { @@ -363,17 +397,17 @@ void Position::print(Move move) const { string brd = twoRows + twoRows + twoRows + twoRows + dottedLine; + sync_cout; + if (move) - { - Position p(*this); - cout << "\nMove is: " << (sideToMove == BLACK ? ".." : "") << move_to_san(p, move); - } + cout << "\nMove is: " << (sideToMove == BLACK ? ".." : "") + << move_to_san(*const_cast(this), move); for (Square sq = SQ_A1; sq <= SQ_H8; sq++) if (piece_on(sq) != NO_PIECE) brd[513 - 68*rank_of(sq) + 4*file_of(sq)] = PieceToChar[piece_on(sq)]; - cout << brd << "\nFen is: " << to_fen() << "\nKey is: " << st->key << endl; + cout << brd << "\nFen is: " << to_fen() << "\nKey is: " << st->key << sync_endl; } @@ -439,37 +473,6 @@ Bitboard Position::attacks_from(Piece p, Square s, Bitboard occ) { } -/// Position::move_attacks_square() tests whether a move from the current -/// position attacks a given square. - -bool Position::move_attacks_square(Move m, Square s) const { - - assert(is_ok(m)); - assert(is_ok(s)); - - Bitboard occ, xray; - Square from = from_sq(m); - Square to = to_sq(m); - Piece piece = piece_moved(m); - - assert(!is_empty(from)); - - // Update occupancy as if the piece is moving - occ = pieces() ^ from ^ to; - - // The piece moved in 'to' attacks the square 's' ? - if (attacks_from(piece, to, occ) & s) - return true; - - // Scan for possible X-ray attackers behind the moved piece - xray = (attacks_bb< ROOK>(s, occ) & pieces(color_of(piece), QUEEN, ROOK)) - | (attacks_bb(s, occ) & pieces(color_of(piece), QUEEN, BISHOP)); - - // Verify attackers are triggered by our move and not already existing - return xray && (xray ^ (xray & attacks_from(s))); -} - - /// Position::pl_move_is_legal() tests whether a pseudo-legal move is legal bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { @@ -736,9 +739,9 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI Key k = st->key; // Copy some fields of old state to our new StateInfo object except the ones - // which are recalculated from scratch anyway, then switch our state pointer - // to point to the new, ready to be updated, state. - memcpy(&newSt, st, sizeof(ReducedStateInfo)); + // which are going to be recalculated from scratch anyway, then switch our state + // pointer to point to the new, ready to be updated, state. + memcpy(&newSt, st, StateCopySize64 * sizeof(uint64_t)); newSt.previous = st; st = &newSt; @@ -794,7 +797,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI st->pawnKey ^= Zobrist::psq[them][PAWN][capsq]; } else - st->npMaterial[them] -= PieceValue[Mg][capture]; + st->npMaterial[them] -= PieceValue[MG][capture]; // Remove the captured piece byTypeBB[ALL_PIECES] ^= capsq; @@ -902,7 +905,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI - pieceSquareTable[make_piece(us, PAWN)][to]; // Update material - st->npMaterial[us] += PieceValue[Mg][promotion]; + st->npMaterial[us] += PieceValue[MG][promotion]; } // Update pawn hash key @@ -1207,7 +1210,7 @@ int Position::see_sign(Move m) const { // 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 (PieceValue[Mg][piece_on(to_sq(m))] >= PieceValue[Mg][piece_moved(m)]) + if (PieceValue[MG][piece_on(to_sq(m))] >= PieceValue[MG][piece_moved(m)]) return 1; return see(m); @@ -1216,47 +1219,45 @@ int Position::see_sign(Move m) const { int Position::see(Move m) const { Square from, to; - Bitboard occ, attackers, stmAttackers, b; + Bitboard occupied, attackers, stmAttackers; int swapList[32], slIndex = 1; - PieceType capturedType, pt; + PieceType captured; Color stm; assert(is_ok(m)); - // As castle moves are implemented as capturing the rook, they have - // SEE == RookValueMidgame most of the times (unless the rook is under - // attack). - if (type_of(m) == CASTLE) - return 0; - from = from_sq(m); to = to_sq(m); - capturedType = type_of(piece_on(to)); - occ = pieces(); + captured = type_of(piece_on(to)); + occupied = pieces() ^ from; // Handle en passant moves if (type_of(m) == ENPASSANT) { Square capQq = to - pawn_push(sideToMove); - assert(!capturedType); + assert(!captured); assert(type_of(piece_on(capQq)) == PAWN); // Remove the captured pawn - occ ^= capQq; - capturedType = PAWN; + occupied ^= capQq; + captured = PAWN; } + else if (type_of(m) == CASTLE) + // Castle moves are implemented as king capturing the rook so cannot be + // handled correctly. Simply return 0 that is always the correct value + // unless the rook is ends up under attack. + return 0; // Find all attackers to the destination square, with the moving piece // removed, but possibly an X-ray attacker added behind it. - occ ^= from; - attackers = attackers_to(to, occ); + attackers = attackers_to(to, occupied); // If the opponent has no attackers we are finished stm = ~color_of(piece_on(from)); stmAttackers = attackers & pieces(stm); if (!stmAttackers) - return PieceValue[Mg][capturedType]; + return PieceValue[MG][captured]; // The destination square is defended, which makes things rather more // difficult to compute. We proceed by building up a "swap list" containing @@ -1264,42 +1265,32 @@ int Position::see(Move m) 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. - swapList[0] = PieceValue[Mg][capturedType]; - capturedType = type_of(piece_on(from)); + swapList[0] = PieceValue[MG][captured]; + captured = type_of(piece_on(from)); do { - // Locate the least valuable attacker for the side to move. The loop - // below looks like it is potentially infinite, but it isn't. We know - // that the side to move still has at least one attacker left. - for (pt = PAWN; (b = stmAttackers & pieces(pt)) == 0; pt++) - assert(pt < KING); - - // Remove the attacker we just found from the 'occupied' bitboard, - // and scan for new X-ray attacks behind the attacker. - occ ^= (b & (~b + 1)); - attackers |= (attacks_bb(to, occ) & pieces(ROOK, QUEEN)) - | (attacks_bb(to, occ) & pieces(BISHOP, QUEEN)); - - attackers &= occ; // Cut out pieces we've already done + assert(slIndex < 32); // Add the new entry to the swap list - assert(slIndex < 32); - swapList[slIndex] = -swapList[slIndex - 1] + PieceValue[Mg][capturedType]; + swapList[slIndex] = -swapList[slIndex - 1] + PieceValue[MG][captured]; slIndex++; - // Remember the value of the capturing piece, and change the side to - // move before beginning the next iteration. - capturedType = pt; + // Locate and remove from 'occupied' the next least valuable attacker + captured = next_attacker(byTypeBB, to, stmAttackers, occupied, attackers); + + attackers &= occupied; // Remove the just found attacker stm = ~stm; stmAttackers = attackers & pieces(stm); - // Stop before processing a king capture - if (capturedType == KING && stmAttackers) + if (captured == KING) { - assert(slIndex < 32); - swapList[slIndex++] = QueenValueMg * 16; + // Stop before processing a king capture + if (stmAttackers) + swapList[slIndex++] = QueenValueMg * 16; + break; } + } while (stmAttackers); // Having built the swap list, we negamax through it to find the best @@ -1323,9 +1314,6 @@ void Position::clear() { 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++) - board[sq] = NO_PIECE; } @@ -1439,7 +1427,7 @@ Value Position::compute_non_pawn_material(Color c) const { Value value = VALUE_ZERO; for (PieceType pt = KNIGHT; pt <= QUEEN; pt++) - value += piece_count(c, pt) * PieceValue[Mg][pt]; + value += piece_count(c, pt) * PieceValue[MG][pt]; return value; } @@ -1448,36 +1436,31 @@ 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. -template +template bool Position::is_draw() const { - // Draw by material? if ( !pieces(PAWN) && (non_pawn_material(WHITE) + non_pawn_material(BLACK) <= BishopValueMg)) return true; - // Draw by the 50 moves rule? if (st->rule50 > 99 && (!in_check() || MoveList(*this).size())) return true; - // Draw by repetition? - if (!SkipRepetition) + if (CheckRepetition) { - int i = 4, e = std::min(st->rule50, st->pliesFromNull); + int i = 4, e = std::min(st->rule50, st->pliesFromNull), cnt; if (i <= e) { StateInfo* stp = st->previous->previous; - do { + for (cnt = 0; i <= e; i += 2) + { stp = stp->previous->previous; - if (stp->key == st->key) + if (stp->key == st->key && (!CheckThreeFold || ++cnt >= 2)) return true; - - i +=2; - - } while (i <= e); + } } } @@ -1485,8 +1468,9 @@ bool Position::is_draw() const { } // Explicit template instantiations -template bool Position::is_draw() const; -template bool Position::is_draw() const; +template bool Position::is_draw() const; +template bool Position::is_draw() const; +template bool Position::is_draw() const; /// Position::flip() flips position with the white and black sides reversed. This @@ -1569,7 +1553,7 @@ bool Position::pos_is_ok(int* failedStep) const { if ((*step)++, debugKingCount) { - int kingCount[2] = {}; + int kingCount[COLOR_NB] = {}; for (Square s = SQ_A1; s <= SQ_H8; s++) if (type_of(piece_on(s)) == KING)