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;
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++)
{
} // 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<int Pt> 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<BISHOP>(to, occupied) & (bb[BISHOP] | bb[QUEEN]);
+
+ if (Pt == ROOK || Pt == QUEEN)
+ attackers |= attacks_bb<ROOK>(to, occupied) & (bb[ROOK] | bb[QUEEN]);
+
+ return (PieceType)Pt;
+ }
+ return next_attacker<Pt+1>(bb, to, stmAttackers, occupied, attackers);
+}
+
+template<> FORCE_INLINE
+PieceType next_attacker<KING>(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) {
}
-/// Position::from_fen() initializes the position object with the given FEN
-/// string. This function is not very robust - make sure that input FENs are
-/// correct (this is assumed to be the responsibility of the GUI).
+/// Position::set() initializes the position object with the given FEN 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& fenStr, bool isChess960, Thread* th) {
+void Position::set(const string& fenStr, bool isChess960, Thread* th) {
/*
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 fen(fenStr);
+ std::istringstream ss(fenStr);
clear();
- fen >> std::noskipws;
+ ss >> std::noskipws;
// 1. Piece placement
- while ((fen >> token) && !isspace(token))
+ while ((ss >> token) && !isspace(token))
{
if (isdigit(token))
sq += Square(token - '0'); // Advance the given number of files
}
// 2. Active color
- fen >> token;
+ ss >> token;
sideToMove = (token == 'w' ? WHITE : BLACK);
- fen >> token;
+ ss >> token;
// 3. Castling availability. Compatible with 3 standards: Normal FEN standard,
// Shredder-FEN that uses the letters of the columns on which the rooks began
// the game instead of KQkq and also X-FEN standard that, in case of Chess960,
// if an inner rook is associated with the castling right, the castling tag is
// replaced by the file letter of the involved rook, as for the Shredder-FEN.
- while ((fen >> token) && !isspace(token))
+ while ((ss >> token) && !isspace(token))
{
Square rsq;
Color c = islower(token) ? BLACK : WHITE;
}
// 4. En passant square. Ignore if no pawn capture is possible
- if ( ((fen >> col) && (col >= 'a' && col <= 'h'))
- && ((fen >> row) && (row == '3' || row == '6')))
+ if ( ((ss >> col) && (col >= 'a' && col <= 'h'))
+ && ((ss >> row) && (row == '3' || row == '6')))
{
st->epSquare = File(col - 'a') | Rank(row - '1');
}
// 5-6. Halfmove clock and fullmove number
- fen >> std::skipws >> st->rule50 >> startPosPly;
+ ss >> std::skipws >> st->rule50 >> startPosPly;
// Convert from fullmove starting from 1 to ply starting from 0,
// handle also common incorrect FEN with fullmove = 0.
}
-/// Position::to_fen() returns a FEN representation of the position. In case
+/// Position::fen() returns a FEN representation of the position. In case
/// of Chess960 the Shredder-FEN notation is used. Mainly a debugging function.
-const string Position::to_fen() const {
+const string Position::fen() const {
- std::ostringstream fen;
+ std::ostringstream ss;
Square sq;
int emptyCnt;
{
if (emptyCnt > 0)
{
- fen << emptyCnt;
+ ss << emptyCnt;
emptyCnt = 0;
}
- fen << PieceToChar[piece_on(sq)];
+ ss << PieceToChar[piece_on(sq)];
}
}
if (emptyCnt > 0)
- fen << emptyCnt;
+ ss << emptyCnt;
if (rank > RANK_1)
- fen << '/';
+ ss << '/';
}
- fen << (sideToMove == WHITE ? " w " : " b ");
+ ss << (sideToMove == WHITE ? " w " : " b ");
if (can_castle(WHITE_OO))
- fen << (chess960 ? char(toupper(file_to_char(file_of(castle_rook_square(WHITE, KING_SIDE))))) : 'K');
+ ss << (chess960 ? char(toupper(file_to_char(file_of(castle_rook_square(WHITE, KING_SIDE))))) : 'K');
if (can_castle(WHITE_OOO))
- fen << (chess960 ? char(toupper(file_to_char(file_of(castle_rook_square(WHITE, QUEEN_SIDE))))) : 'Q');
+ ss << (chess960 ? char(toupper(file_to_char(file_of(castle_rook_square(WHITE, QUEEN_SIDE))))) : 'Q');
if (can_castle(BLACK_OO))
- fen << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK, KING_SIDE))) : 'k');
+ ss << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK, KING_SIDE))) : 'k');
if (can_castle(BLACK_OOO))
- fen << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK, QUEEN_SIDE))) : 'q');
+ ss << (chess960 ? file_to_char(file_of(castle_rook_square(BLACK, QUEEN_SIDE))) : 'q');
if (st->castleRights == CASTLES_NONE)
- fen << '-';
+ ss << '-';
- fen << (ep_square() == SQ_NONE ? " - " : " " + square_to_string(ep_square()) + " ")
+ ss << (ep_square() == SQ_NONE ? " - " : " " + square_to_string(ep_square()) + " ")
<< st->rule50 << " " << 1 + (startPosPly - int(sideToMove == BLACK)) / 2;
- return fen.str();
+ return ss.str();
}
-/// Position::print() prints an ASCII representation of the position to
-/// the standard output. If a move is given then also the san is printed.
+/// Position::pretty() returns an ASCII representation of the position to be
+/// printed to the standard output together with the move's san notation.
-void Position::print(Move move) const {
+const string Position::pretty(Move move) const {
const string dottedLine = "\n+---+---+---+---+---+---+---+---+";
const string twoRows = dottedLine + "\n| | . | | . | | . | | . |"
string brd = twoRows + twoRows + twoRows + twoRows + dottedLine;
- sync_cout;
+ std::ostringstream ss;
if (move)
- {
- Position p(*this);
- cout << "\nMove is: " << (sideToMove == BLACK ? ".." : "") << move_to_san(p, move);
- }
+ ss << "\nMove is: " << (sideToMove == BLACK ? ".." : "")
+ << move_to_san(*const_cast<Position*>(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 << sync_endl;
+ ss << brd << "\nFen is: " << fen() << "\nKey is: " << st->key;
+ return ss.str();
}
}
-/// 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<BISHOP>(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<QUEEN>(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 {
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;
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;
- pieceSquareTable[make_piece(us, PAWN)][to];
// Update material
- st->npMaterial[us] += PieceValue[Mg][promotion];
+ st->npMaterial[us] += PieceValue[MG][promotion];
}
// Update pawn hash key
// 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);
int Position::see(Move m) const {
Square from, to;
- Bitboard occupied, attackers, stmAttackers, b;
+ Bitboard occupied, attackers, stmAttackers;
int swapList[32], slIndex = 1;
PieceType captured;
Color stm;
stm = ~color_of(piece_on(from));
stmAttackers = attackers & pieces(stm);
if (!stmAttackers)
- return PieceValue[Mg][captured];
+ 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
// 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][captured];
+ swapList[0] = PieceValue[MG][captured];
captured = type_of(piece_on(from));
do {
assert(slIndex < 32);
// Add the new entry to the swap list
- swapList[slIndex] = -swapList[slIndex - 1] + PieceValue[Mg][captured];
+ swapList[slIndex] = -swapList[slIndex - 1] + PieceValue[MG][captured];
slIndex++;
- // 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 (captured = PAWN; (b = stmAttackers & pieces(captured)) == 0; captured++)
- assert(captured < KING);
-
- // Remove the attacker we just found from the 'occupied' bitboard,
- // and scan for new X-ray attacks behind the attacker.
- occupied ^= (b & (~b + 1));
- attackers |= (attacks_bb<ROOK>(to, occupied) & pieces(ROOK, QUEEN))
- | (attacks_bb<BISHOP>(to, occupied) & pieces(BISHOP, QUEEN));
+ // Locate and remove from 'occupied' the next least valuable attacker
+ captured = next_attacker<PAWN>(byTypeBB, to, stmAttackers, occupied, attackers);
- attackers &= occupied; // Cut out pieces we've already done
+ attackers &= occupied; // Remove the just found attacker
stm = ~stm;
stmAttackers = attackers & pieces(stm);
- // Stop before processing a king capture
- if (captured == 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;
}
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;
}
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;
}
/// 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<bool SkipRepetition>
+template<bool CheckRepetition, bool CheckThreeFold>
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<LEGAL>(*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);
+ }
}
}
}
// Explicit template instantiations
-template bool Position::is_draw<false>() const;
-template bool Position::is_draw<true>() const;
+template bool Position::is_draw<true, true>() const;
+template bool Position::is_draw<true, false>() const;
+template bool Position::is_draw<false,false>() const;
/// Position::flip() flips position with the white and black sides reversed. This
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)
projects / stockfish / blobdiff