Key Position::zobSideToMove;
Key Position::zobExclusion;
-Score Position::PieceSquareTable[16][64];
+Score Position::pieceSquareTable[16][64];
// Material values arrays, indexed by Piece
const Value PieceValueMidgame[17] = {
/// string. This function is not very robust - make sure that input FENs are
/// correct (this is assumed to be the responsibility of the GUI).
-void Position::from_fen(const string& fen, bool isChess960) {
+void Position::from_fen(const string& fenStr, bool isChess960) {
/*
A FEN string defines a particular position using only the ASCII character set.
char col, row, token;
size_t p;
Square sq = SQ_A8;
- std::istringstream ss(fen);
+ std::istringstream fen(fenStr);
clear();
- ss >> std::noskipws;
+ fen >> std::noskipws;
// 1. Piece placement
- while ((ss >> token) && !isspace(token))
+ while ((fen >> token) && !isspace(token))
{
if (token == '/')
sq -= Square(16); // Jump back of 2 rows
}
// 2. Active color
- ss >> token;
+ fen >> token;
sideToMove = (token == 'w' ? WHITE : BLACK);
- ss >> token;
+ fen >> token;
// 3. Castling availability
- while ((ss >> token) && !isspace(token))
+ while ((fen >> token) && !isspace(token))
set_castling_rights(token);
// 4. En passant square. Ignore if no pawn capture is possible
- if ( ((ss >> col) && (col >= 'a' && col <= 'h'))
- && ((ss >> row) && (row == '3' || row == '6')))
+ if ( ((fen >> col) && (col >= 'a' && col <= 'h'))
+ && ((fen >> row) && (row == '3' || row == '6')))
{
st->epSquare = make_square(File(col - 'a'), Rank(row - '1'));
Color them = opposite_color(sideToMove);
}
// 5-6. Halfmove clock and fullmove number
- ss >> std::skipws >> st->rule50 >> fullMoves;
+ fen >> std::skipws >> st->rule50 >> fullMoves;
// Various initialisations
chess960 = isChess960;
- find_checkers();
+ st->checkersBB = attackers_to(king_square(sideToMove)) & pieces(opposite_color(sideToMove));
st->key = compute_key();
st->pawnKey = compute_pawn_key();
Square sqH = relative_square(c, SQ_H1);
Square rsq, ksq = king_square(c);
- token = toupper(token);
+ token = char(toupper(token));
if (token == 'K')
for (rsq = sqH; piece_on(rsq) != make_piece(c, ROOK); rsq--) {}
const string Position::to_fen() const {
- string fen;
+ std::ostringstream fen;
Square sq;
- char emptyCnt;
+ int emptyCnt;
- for (Rank rank = RANK_8; rank >= RANK_1; rank--, fen += '/')
+ for (Rank rank = RANK_8; rank >= RANK_1; rank--)
{
- emptyCnt = '0';
+ emptyCnt = 0;
for (File file = FILE_A; file <= FILE_H; file++)
{
if (!square_is_empty(sq))
{
- if (emptyCnt != '0')
+ if (emptyCnt)
{
- fen += emptyCnt;
- emptyCnt = '0';
+ fen << emptyCnt;
+ emptyCnt = 0;
}
- fen += PieceToChar[piece_on(sq)];
- } else
+ fen << PieceToChar[piece_on(sq)];
+ }
+ else
emptyCnt++;
}
- if (emptyCnt != '0')
- fen += emptyCnt;
+ if (emptyCnt)
+ fen << emptyCnt;
+
+ if (rank > RANK_1)
+ fen << '/';
}
- fen += (sideToMove == WHITE ? " w " : " b ");
+ fen << (sideToMove == WHITE ? " w " : " b ");
if (st->castleRights != CASTLES_NONE)
{
if (can_castle(WHITE_OO))
- fen += chess960 ? char(toupper(file_to_char(square_file(castle_rook_square(WHITE_OO))))) : 'K';
+ fen << (chess960 ? char(toupper(file_to_char(square_file(castle_rook_square(WHITE_OO))))) : 'K');
if (can_castle(WHITE_OOO))
- fen += chess960 ? char(toupper(file_to_char(square_file(castle_rook_square(WHITE_OOO))))) : 'Q';
+ fen << (chess960 ? char(toupper(file_to_char(square_file(castle_rook_square(WHITE_OOO))))) : 'Q');
if (can_castle(BLACK_OO))
- fen += chess960 ? file_to_char(square_file(castle_rook_square(BLACK_OO))) : 'k';
+ fen << (chess960 ? file_to_char(square_file(castle_rook_square(BLACK_OO))) : 'k');
if (can_castle(BLACK_OOO))
- fen += chess960 ? file_to_char(square_file(castle_rook_square(BLACK_OOO))) : 'q';
+ fen << (chess960 ? file_to_char(square_file(castle_rook_square(BLACK_OOO))) : 'q');
} else
- fen += '-';
+ fen << '-';
+
+ fen << (ep_square() == SQ_NONE ? " -" : " " + square_to_string(ep_square()))
+ << " " << st->rule50 << " " << fullMoves;
- fen += (ep_square() == SQ_NONE ? " -" : " " + square_to_string(ep_square()));
- return fen;
+ return fen.str();
}
if (move)
{
Position p(*this, thread());
- string dd = (piece_color(piece_on(move_from(move))) == BLACK ? ".." : "");
+ string dd = (sideToMove == BLACK ? ".." : "");
cout << "\nMove is: " << dd << move_to_san(p, move);
}
Bitboard Position::hidden_checkers(Color c) const {
Bitboard result = EmptyBoardBB;
- Bitboard pinners = pieces_of_color(FindPinned ? opposite_color(c) : c);
+ Bitboard pinners = pieces(FindPinned ? opposite_color(c) : c);
// Pinned pieces protect our king, dicovery checks attack
// the enemy king.
assert(b);
if ( !(b & (b - 1)) // Only one bit set?
- && (b & pieces_of_color(c))) // Is an our piece?
+ && (b & pieces(c))) // Is an our piece?
result |= b;
}
return result;
do_move_bb(&occ, make_move_bb(f, t));
xray = ( (rook_attacks_bb(s, occ) & pieces(ROOK, QUEEN))
|(bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN)))
- & pieces_of_color(piece_color(piece_on(f)));
+ & pieces(piece_color(piece_on(f)));
// If we have attacks we need to verify that are caused by our move
// and are not already existent ones.
}
-/// Position::find_checkers() computes the checkersBB bitboard, which
-/// contains a nonzero bit for each checking piece (0, 1 or 2). It
-/// currently works by calling Position::attackers_to, which is probably
-/// inefficient. Consider rewriting this function to use the last move
-/// played, like in non-bitboard versions of Glaurung.
-
-void Position::find_checkers() {
-
- Color us = side_to_move();
- st->checkersBB = attackers_to(king_square(us)) & pieces_of_color(opposite_color(us));
-}
-
-
/// Position::pl_move_is_legal() tests whether a pseudo-legal move is legal
bool Position::pl_move_is_legal(Move m, Bitboard pinned) const {
assert(piece_color(piece_on(from)) == us);
assert(piece_on(king_square(us)) == make_piece(us, KING));
- // 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
+ // 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 (move_is_ep(m))
{
Color them = opposite_color(us);
Square to = move_to(m);
- Square capsq = make_square(square_file(to), square_rank(from));
+ Square capsq = to + pawn_push(them);
Square ksq = king_square(us);
Bitboard b = occupied_squares();
// square is attacked by the opponent. Castling moves are checked
// for legality during move generation.
if (piece_type(piece_on(from)) == KING)
- return move_is_castle(m) || !(attackers_to(move_to(m)) & pieces_of_color(opposite_color(us)));
+ return move_is_castle(m) || !(attackers_to(move_to(m)) & pieces(opposite_color(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.
}
-/// Position::move_is_pl_slow() takes a move and tests whether the move
-/// is pseudo legal. This version is not very fast and should be used
-/// only in non time-critical paths.
+/// Position::move_is_legal() takes a move and tests whether the move
+/// is legal. This version is not very fast and should be used only
+/// in non time-critical paths.
-bool Position::move_is_pl_slow(const Move m) const {
+bool Position::move_is_legal(const Move m) const {
- MoveStack mlist[MAX_MOVES];
- MoveStack *cur, *last;
-
- last = in_check() ? generate<MV_EVASION>(*this, mlist)
- : generate<MV_NON_EVASION>(*this, mlist);
-
- for (cur = mlist; cur != last; cur++)
- if (cur->move == m)
+ for (MoveList<MV_LEGAL> ml(*this); !ml.end(); ++ml)
+ if (ml.move() == m)
return true;
return false;
// Use a slower but simpler function for uncommon cases
if (move_is_special(m))
- return move_is_pl_slow(m);
+ return move_is_legal(m);
// Is not a promotion, so promotion piece must be empty
if (promotion_piece_type(m) - 2 != PIECE_TYPE_NONE)
{
Bitboard b = occupied_squares();
clear_bit(&b, from);
- if (attackers_to(move_to(m), b) & pieces_of_color(opposite_color(us)))
+ if (attackers_to(move_to(m), b) & pieces(opposite_color(us)))
return false;
}
else
// Move the piece
Bitboard move_bb = make_move_bb(from, to);
- do_move_bb(&(byColorBB[us]), move_bb);
- do_move_bb(&(byTypeBB[pt]), move_bb);
- do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares
+ do_move_bb(&byColorBB[us], move_bb);
+ do_move_bb(&byTypeBB[pt], move_bb);
+ do_move_bb(&byTypeBB[0], move_bb); // HACK: byTypeBB[0] == occupied squares
board[to] = board[from];
board[from] = PIECE_NONE;
// Set en passant square, only if moved pawn can be captured
if ((to ^ from) == 16)
{
- if (attacks_from<PAWN>(from + (us == WHITE ? DELTA_N : DELTA_S), us) & pieces(PAWN, them))
+ if (attacks_from<PAWN>(from + pawn_push(us), us) & pieces(PAWN, them))
{
st->epSquare = Square((int(from) + int(to)) / 2);
key ^= zobEp[st->epSquare];
assert(promotion >= KNIGHT && promotion <= QUEEN);
// Insert promoted piece instead of pawn
- clear_bit(&(byTypeBB[PAWN]), to);
- set_bit(&(byTypeBB[promotion]), to);
+ clear_bit(&byTypeBB[PAWN], to);
+ set_bit(&byTypeBB[promotion], to);
board[to] = make_piece(us, promotion);
// Update piece counts
if (moveIsCheck)
{
if (ep | pm)
- st->checkersBB = attackers_to(king_square(them)) & pieces_of_color(us);
+ st->checkersBB = attackers_to(king_square(them)) & pieces(us);
else
{
// Direct checks
{
if (ep) // en passant ?
{
- capsq = (them == BLACK)? (to - DELTA_N) : (to - DELTA_S);
+ capsq = to + pawn_push(them);
assert(to == st->epSquare);
assert(relative_rank(opposite_color(them), to) == RANK_6);
st->npMaterial[them] -= PieceValueMidgame[capture];
// Remove captured piece
- clear_bit(&(byColorBB[them]), capsq);
- clear_bit(&(byTypeBB[capture]), capsq);
- clear_bit(&(byTypeBB[0]), capsq);
+ clear_bit(&byColorBB[them], capsq);
+ clear_bit(&byTypeBB[capture], capsq);
+ clear_bit(&byTypeBB[0], capsq);
// Update hash key
key ^= zobrist[them][capture][capsq];
Color us = side_to_move();
Color them = opposite_color(us);
- // Reset capture field
- st->capturedType = PIECE_TYPE_NONE;
-
// Find source squares for king and rook
Square kfrom = move_from(m);
- Square rfrom = move_to(m); // HACK: See comment at beginning of function
+ Square rfrom = move_to(m);
Square kto, rto;
assert(piece_on(kfrom) == make_piece(us, KING));
{
kto = relative_square(us, SQ_G1);
rto = relative_square(us, SQ_F1);
- } else { // O-O-O
+ }
+ else // O-O-O
+ {
kto = relative_square(us, SQ_C1);
rto = relative_square(us, SQ_D1);
}
- // Remove pieces from source squares:
- clear_bit(&(byColorBB[us]), kfrom);
- clear_bit(&(byTypeBB[KING]), kfrom);
- clear_bit(&(byTypeBB[0]), kfrom); // HACK: byTypeBB[0] == occupied squares
- clear_bit(&(byColorBB[us]), rfrom);
- clear_bit(&(byTypeBB[ROOK]), rfrom);
- clear_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares
-
- // Put pieces on destination squares:
- set_bit(&(byColorBB[us]), kto);
- set_bit(&(byTypeBB[KING]), kto);
- set_bit(&(byTypeBB[0]), kto); // HACK: byTypeBB[0] == occupied squares
- set_bit(&(byColorBB[us]), rto);
- set_bit(&(byTypeBB[ROOK]), rto);
- set_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares
-
- // Update board array
+ // Remove pieces from source squares
+ clear_bit(&byColorBB[us], kfrom);
+ clear_bit(&byTypeBB[KING], kfrom);
+ clear_bit(&byTypeBB[0], kfrom);
+ clear_bit(&byColorBB[us], rfrom);
+ clear_bit(&byTypeBB[ROOK], rfrom);
+ clear_bit(&byTypeBB[0], rfrom);
+
+ // Put pieces on destination squares
+ set_bit(&byColorBB[us], kto);
+ set_bit(&byTypeBB[KING], kto);
+ set_bit(&byTypeBB[0], kto);
+ set_bit(&byColorBB[us], rto);
+ set_bit(&byTypeBB[ROOK], rto);
+ set_bit(&byTypeBB[0], rto);
+
+ // Update board
Piece king = make_piece(us, KING);
Piece rook = make_piece(us, ROOK);
board[kfrom] = board[rfrom] = PIECE_NONE;
// Update piece lists
pieceList[us][KING][index[kfrom]] = kto;
pieceList[us][ROOK][index[rfrom]] = rto;
- int tmp = index[rfrom]; // In Chess960 could be rto == kfrom
+ int tmp = index[rfrom]; // In Chess960 could be kto == rfrom
index[kto] = index[kfrom];
index[rto] = tmp;
+ // Reset capture field
+ st->capturedType = PIECE_TYPE_NONE;
+
// Update incremental scores
st->value += pst_delta(king, kfrom, kto);
st->value += pst_delta(rook, rfrom, rto);
st->rule50 = 0;
// Update checkers BB
- st->checkersBB = attackers_to(king_square(them)) & pieces_of_color(us);
+ st->checkersBB = attackers_to(king_square(them)) & pieces(us);
// Finish
sideToMove = opposite_color(sideToMove);
assert(piece_on(to) == make_piece(us, promotion));
// Replace promoted piece with a pawn
- clear_bit(&(byTypeBB[promotion]), to);
- set_bit(&(byTypeBB[PAWN]), to);
+ clear_bit(&byTypeBB[promotion], to);
+ set_bit(&byTypeBB[PAWN], to);
// Update piece counts
pieceCount[us][promotion]--;
// Put the piece back at the source square
Bitboard move_bb = make_move_bb(to, from);
- do_move_bb(&(byColorBB[us]), move_bb);
- do_move_bb(&(byTypeBB[pt]), move_bb);
- do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares
+ do_move_bb(&byColorBB[us], move_bb);
+ do_move_bb(&byTypeBB[pt], move_bb);
+ do_move_bb(&byTypeBB[0], move_bb); // HACK: byTypeBB[0] == occupied squares
board[from] = make_piece(us, pt);
board[to] = PIECE_NONE;
Square capsq = to;
if (ep)
- capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S);
+ capsq = to - pawn_push(us);
assert(st->capturedType != KING);
assert(!ep || square_is_empty(capsq));
// Restore the captured piece
- set_bit(&(byColorBB[them]), capsq);
- set_bit(&(byTypeBB[st->capturedType]), capsq);
- set_bit(&(byTypeBB[0]), capsq);
+ set_bit(&byColorBB[them], capsq);
+ set_bit(&byTypeBB[st->capturedType], capsq);
+ set_bit(&byTypeBB[0], capsq);
board[capsq] = make_piece(them, st->capturedType);
assert(move_is_castle(m));
// When we have arrived here, some work has already been done by
- // Position::undo_move. In particular, the side to move has been switched,
+ // Position::undo_move. In particular, the side to move has been switched,
// so the code below is correct.
Color us = side_to_move();
// Find source squares for king and rook
Square kfrom = move_from(m);
- Square rfrom = move_to(m); // HACK: See comment at beginning of function
+ Square rfrom = move_to(m);
Square kto, rto;
// Find destination squares for king and rook
{
kto = relative_square(us, SQ_G1);
rto = relative_square(us, SQ_F1);
- } else { // O-O-O
+ }
+ else // O-O-O
+ {
kto = relative_square(us, SQ_C1);
rto = relative_square(us, SQ_D1);
}
assert(piece_on(kto) == make_piece(us, KING));
assert(piece_on(rto) == make_piece(us, ROOK));
- // Remove pieces from destination squares:
- clear_bit(&(byColorBB[us]), kto);
- clear_bit(&(byTypeBB[KING]), kto);
- clear_bit(&(byTypeBB[0]), kto); // HACK: byTypeBB[0] == occupied squares
- clear_bit(&(byColorBB[us]), rto);
- clear_bit(&(byTypeBB[ROOK]), rto);
- clear_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares
-
- // Put pieces on source squares:
- set_bit(&(byColorBB[us]), kfrom);
- set_bit(&(byTypeBB[KING]), kfrom);
- set_bit(&(byTypeBB[0]), kfrom); // HACK: byTypeBB[0] == occupied squares
- set_bit(&(byColorBB[us]), rfrom);
- set_bit(&(byTypeBB[ROOK]), rfrom);
- set_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares
+ // Remove pieces from destination squares
+ clear_bit(&byColorBB[us], kto);
+ clear_bit(&byTypeBB[KING], kto);
+ clear_bit(&byTypeBB[0], kto);
+ clear_bit(&byColorBB[us], rto);
+ clear_bit(&byTypeBB[ROOK], rto);
+ clear_bit(&byTypeBB[0], rto);
+
+ // Put pieces on source squares
+ set_bit(&byColorBB[us], kfrom);
+ set_bit(&byTypeBB[KING], kfrom);
+ set_bit(&byTypeBB[0], kfrom);
+ set_bit(&byColorBB[us], rfrom);
+ set_bit(&byTypeBB[ROOK], rfrom);
+ set_bit(&byTypeBB[0], rfrom);
// Update board
- board[rto] = board[kto] = PIECE_NONE;
- board[rfrom] = make_piece(us, ROOK);
- board[kfrom] = make_piece(us, KING);
+ Piece king = make_piece(us, KING);
+ Piece rook = make_piece(us, ROOK);
+ board[kto] = board[rto] = PIECE_NONE;
+ board[kfrom] = king;
+ board[rfrom] = rook;
// Update piece lists
pieceList[us][KING][index[kto]] = kfrom;
// Handle en passant moves
if (st->epSquare == to && piece_type(piece_on(from)) == PAWN)
{
- Square capQq = (side_to_move() == WHITE ? to - DELTA_N : to - DELTA_S);
+ Square capQq = to - pawn_push(side_to_move());
assert(capturedType == PIECE_TYPE_NONE);
assert(piece_type(piece_on(capQq)) == PAWN);
// If the opponent has no attackers we are finished
stm = opposite_color(piece_color(piece_on(from)));
- stmAttackers = attackers & pieces_of_color(stm);
+ stmAttackers = attackers & pieces(stm);
if (!stmAttackers)
return PieceValueMidgame[capturedType];
// move before beginning the next iteration.
capturedType = pt;
stm = opposite_color(stm);
- stmAttackers = attackers & pieces_of_color(stm);
+ stmAttackers = attackers & pieces(stm);
// Stop before processing a king capture
if (capturedType == KING && stmAttackers)
bool Position::is_mate() const {
- MoveStack moves[MAX_MOVES];
- return in_check() && generate<MV_LEGAL>(*this, moves) == moves;
+ return in_check() && !MoveList<MV_LEGAL>(*this).size();
}
for (Square s = SQ_A1; s <= SQ_H8; s++)
for (Piece p = WP; p <= WK; p++)
- PieceSquareTable[p][s] = make_score(MgPST[p][s], EgPST[p][s]);
+ pieceSquareTable[p][s] = make_score(MgPST[p][s], EgPST[p][s]);
for (Square s = SQ_A1; s <= SQ_H8; s++)
for (Piece p = BP; p <= BK; p++)
- PieceSquareTable[p][s] = -PieceSquareTable[p-8][flip_square(s)];
+ pieceSquareTable[p][s] = -pieceSquareTable[p-8][flip_square(s)];
}
st->epSquare = flip_square(pos.st->epSquare);
// Checkers
- find_checkers();
+ st->checkersBB = attackers_to(king_square(sideToMove)) & pieces(opposite_color(sideToMove));
// Hash keys
st->key = compute_key();
Color us = side_to_move();
Color them = opposite_color(us);
Square ksq = king_square(them);
- if (attackers_to(ksq) & pieces_of_color(us))
+ if (attackers_to(ksq) & pieces(us))
return false;
}
if (debugBitboards)
{
// The intersection of the white and black pieces must be empty
- if ((pieces_of_color(WHITE) & pieces_of_color(BLACK)) != EmptyBoardBB)
+ if ((pieces(WHITE) & pieces(BLACK)) != EmptyBoardBB)
return false;
// The union of the white and black pieces must be equal to all
// occupied squares
- if ((pieces_of_color(WHITE) | pieces_of_color(BLACK)) != occupied_squares())
+ if ((pieces(WHITE) | pieces(BLACK)) != occupied_squares())
return false;
// Separate piece type bitboards must have empty intersections
for (PieceType pt = PAWN; pt <= KING; pt++)
for (int i = 0; i < pieceCount[c][pt]; i++)
{
- if (piece_on(piece_list(c, pt, i)) != make_piece(c, pt))
+ if (piece_on(piece_list(c, pt)[i]) != make_piece(c, pt))
return false;
- if (index[piece_list(c, pt, i)] != i)
+ if (index[piece_list(c, pt)[i]] != i)
return false;
}