#include "movepick.h"
#include "position.h"
#include "psqtab.h"
+#include "san.h"
#include "ucioption.h"
//// Variables
////
+extern SearchStack EmptySearchStack;
+
int Position::castleRightsMask[64];
Key Position::zobrist[2][8][64];
Value Position::MgPieceSquareTable[16][64];
Value Position::EgPieceSquareTable[16][64];
+static bool RequestPending = false;
////
//// Functions
/// Constructors
-Position::Position(const Position &pos) {
+Position::Position(const Position& pos) {
copy(pos);
}
-Position::Position(const std::string &fen) {
+Position::Position(const std::string& fen) {
from_fen(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 std::string &fen) {
+void Position::from_fen(const std::string& fen) {
static const std::string pieceLetters = "KQRBNPkqrbnp";
static const Piece pieces[] = { WK, WQ, WR, WB, WN, WP, BK, BQ, BR, BB, BN, BP };
}
sideToMove = (fen[i] == 'w' ? WHITE : BLACK);
- // Castling rights:
+ // Castling rights
i++;
if (fen[i] != ' ')
{
i++;
while(strchr("KQkqabcdefghABCDEFGH-", fen[i])) {
- if(fen[i] == '-') {
- i++; break;
+ if (fen[i] == '-')
+ {
+ i++;
+ break;
}
else if(fen[i] == 'K') allow_oo(WHITE);
else if(fen[i] == 'Q') allow_ooo(WHITE);
fen += (char)skip + '0';
skip = 0;
}
- fen += pieceLetters[piece_on(sq)];
+ fen += pieceLetters[piece_on(sq)];
}
if (skip > 0)
fen += (char)skip + '0';
fen += (rank > RANK_1 ? '/' : ' ');
}
- fen += (sideToMove == WHITE ? 'w' : 'b') + ' ';
+ fen += (sideToMove == WHITE ? "w " : "b ");
if (castleRights != NO_CASTLES)
{
if (can_castle_kingside(WHITE)) fen += 'K';
/// Position::print() prints an ASCII representation of the position to
-/// the standard output.
-
-void Position::print() const {
- char pieceStrings[][8] =
- {"| ? ", "| P ", "| N ", "| B ", "| R ", "| Q ", "| K ", "| ? ",
- "| ? ", "|=P=", "|=N=", "|=B=", "|=R=", "|=Q=", "|=K="
- };
-
- for(Rank rank = RANK_8; rank >= RANK_1; rank--) {
- std::cout << "+---+---+---+---+---+---+---+---+\n";
- for(File file = FILE_A; file <= FILE_H; file++) {
- Square sq = make_square(file, rank);
- Piece piece = piece_on(sq);
- if(piece == EMPTY)
- std::cout << ((square_color(sq) == WHITE)? "| " : "| . ");
- else
- std::cout << pieceStrings[piece];
- }
- std::cout << "|\n";
+/// the standard output. If a move is given then also the san is print.
+
+void Position::print(Move m) const {
+
+ static const std::string pieceLetters = " PNBRQK PNBRQK .";
+
+ // Check for reentrancy, as example when called from inside
+ // MovePicker that is used also here in move_to_san()
+ if (RequestPending)
+ return;
+
+ RequestPending = true;
+
+ std::cout << std::endl;
+ if (m != MOVE_NONE)
+ {
+ std::string col = (color_of_piece_on(move_from(m)) == BLACK ? ".." : "");
+ std::cout << "Move is: " << col << move_to_san(*this, m) << std::endl;
}
- std::cout << "+---+---+---+---+---+---+---+---+\n";
- std::cout << to_fen() << std::endl;
- std::cout << key << std::endl;
+ for (Rank rank = RANK_8; rank >= RANK_1; rank--)
+ {
+ std::cout << "+---+---+---+---+---+---+---+---+" << std::endl;
+ for (File file = FILE_A; file <= FILE_H; file++)
+ {
+ Square sq = make_square(file, rank);
+ Piece piece = piece_on(sq);
+ if (piece == EMPTY && square_color(sq) == WHITE)
+ piece = NO_PIECE;
+
+ char col = (color_of_piece_on(sq) == BLACK ? '=' : ' ');
+ std::cout << '|' << col << pieceLetters[piece] << col;
+ }
+ std::cout << '|' << std::endl;
+ }
+ std::cout << "+---+---+---+---+---+---+---+---+" << std::endl
+ << "Fen is: " << to_fen() << std::endl
+ << "Key is: " << key << std::endl;
+
+ RequestPending = false;
}
/// king) pieces for the given color.
Bitboard Position::pinned_pieces(Color c) const {
+ if (pinned[c] != ~EmptyBoardBB)
+ return pinned[c];
+
+ Bitboard p1, p2;
Square ksq = king_square(c);
- return hidden_checks<ROOK, true>(c, ksq) | hidden_checks<BISHOP, true>(c, ksq);
+ pinned[c] = hidden_checks<ROOK, true>(c, ksq, p1) | hidden_checks<BISHOP, true>(c, ksq, p2);
+ pinners[c] = p1 | p2;
+ return pinned[c];
}
+Bitboard Position::pinned_pieces(Color c, Bitboard& p) const {
+
+ if (pinned[c] == ~EmptyBoardBB)
+ pinned_pieces(c);
-/// Position:discovered_check_candidates() returns a bitboard containing all
-/// pieces for the given side which are candidates for giving a discovered
-/// check. The code is almost the same as the function for finding pinned
-/// pieces.
+ p = pinners[c];
+ return pinned[c];
+}
Bitboard Position::discovered_check_candidates(Color c) const {
+ if (dcCandidates[c] != ~EmptyBoardBB)
+ return dcCandidates[c];
+
+ Bitboard dummy;
Square ksq = king_square(opposite_color(c));
- return hidden_checks<ROOK, false>(c, ksq) | hidden_checks<BISHOP, false>(c, ksq);
+ dcCandidates[c] = hidden_checks<ROOK, false>(c, ksq, dummy) | hidden_checks<BISHOP, false>(c, ksq, dummy);
+ return dcCandidates[c];
}
-
/// Position:hidden_checks<>() returns a bitboard of all pinned (against the
/// king) pieces for the given color and for the given pinner type. Or, when
/// template parameter FindPinned is false, the pinned pieces of opposite color
/// that are, indeed, the pieces candidate for a discovery check.
template<PieceType Piece, bool FindPinned>
-Bitboard Position::hidden_checks(Color c, Square ksq) const {
+Bitboard Position::hidden_checks(Color c, Square ksq, Bitboard& pinners) const {
Square s;
Bitboard sliders, result = EmptyBoardBB;
-
+
if (Piece == ROOK) // Resolved at compile time
sliders = rooks_and_queens(FindPinned ? opposite_color(c) : c) & RookPseudoAttacks[ksq];
else
// King blockers are candidate pinned pieces
Bitboard candidate_pinned = piece_attacks<Piece>(ksq) & pieces_of_color(c);
- // Pinners are sliders, not checkers, that give check when
+ // Pinners are sliders, not checkers, that give check when
// candidate pinned are removed.
- Bitboard pinners = (FindPinned ? sliders & ~checkersBB : sliders);
+ pinners = (FindPinned ? sliders & ~checkersBB : sliders);
if (Piece == ROOK)
pinners &= rook_attacks_bb(ksq, occupied_squares() ^ candidate_pinned);
// Finally for each pinner find the corresponding pinned piece (if same color of king)
// or discovery checker (if opposite color) among the candidates.
- while (pinners)
+ Bitboard p = pinners;
+ while (p)
{
- s = pop_1st_bit(&pinners);
+ s = pop_1st_bit(&p);
result |= (squares_between(s, ksq) & candidate_pinned);
}
}
- return result;
-}
-
-
-/// Position::square_is_attacked() checks whether the given side attacks the
-/// given square.
-
-bool Position::square_is_attacked(Square s, Color c) const {
+ else
+ pinners = EmptyBoardBB;
- return (pawn_attacks(opposite_color(c), s) & pawns(c))
- || (piece_attacks<KNIGHT>(s) & knights(c))
- || (piece_attacks<KING>(s) & kings(c))
- || (piece_attacks<ROOK>(s) & rooks_and_queens(c))
- || (piece_attacks<BISHOP>(s) & bishops_and_queens(c));
+ return result;
}
| (piece_attacks<KING>(s) & pieces_of_type(KING));
}
-Bitboard Position::attacks_to(Square s, Color c) const {
-
- return attacks_to(s) & pieces_of_color(c);
-}
-
-
/// Position::piece_attacks_square() tests whether the piece on square f
/// attacks square t.
-bool Position::piece_attacks_square(Square f, Square t) const {
+bool Position::piece_attacks_square(Piece p, Square f, Square t) const {
assert(square_is_ok(f));
assert(square_is_ok(t));
- switch (piece_on(f))
+ switch (p)
{
case WP: return pawn_attacks_square(WHITE, f, t);
case BP: return pawn_attacks_square(BLACK, f, t);
case WR: case BR: return piece_attacks_square<ROOK>(f, t);
case WQ: case BQ: return piece_attacks_square<QUEEN>(f, t);
case WK: case BK: return piece_attacks_square<KING>(f, t);
- default: return false;
+ default: break;
}
return false;
}
/// Position::move_attacks_square() tests whether a move from the current
-/// position attacks a given square. Only attacks by the moving piece are
-/// considered; the function does not handle X-ray attacks.
+/// position attacks a given square.
bool Position::move_attacks_square(Move m, Square s) const {
assert(square_is_occupied(f));
- switch (piece_on(f))
- {
- case WP: return pawn_attacks_square(WHITE, t, s);
- case BP: return pawn_attacks_square(BLACK, t, s);
- case WN: case BN: return piece_attacks_square<KNIGHT>(t, s);
- case WB: case BB: return piece_attacks_square<BISHOP>(t, s);
- case WR: case BR: return piece_attacks_square<ROOK>(t, s);
- case WQ: case BQ: return piece_attacks_square<QUEEN>(t, s);
- case WK: case BK: return piece_attacks_square<KING>(t, s);
- default: assert(false);
- }
- return false;
+ if (piece_attacks_square(piece_on(f), t, s))
+ return true;
+
+ // Move the piece and scan for X-ray attacks behind it
+ Bitboard occ = occupied_squares();
+ Color us = color_of_piece_on(f);
+ clear_bit(&occ, f);
+ set_bit(&occ, t);
+ Bitboard xray = ( (rook_attacks_bb(s, occ) & rooks_and_queens())
+ |(bishop_attacks_bb(s, occ) & bishops_and_queens())) & pieces_of_color(us);
+
+ // If we have attacks we need to verify that are caused by our move
+ // and are not already existent ones.
+ return xray && (xray ^ (xray & piece_attacks<QUEEN>(s)));
}
/// 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::attacks_to, which is probably
-/// inefficient. Consider rewriting this function to use the last move
+/// inefficient. Consider rewriting this function to use the last move
/// played, like in non-bitboard versions of Glaurung.
void Position::find_checkers() {
- checkersBB = attacks_to(king_square(side_to_move()),opposite_color(side_to_move()));
+ Color us = side_to_move();
+ checkersBB = attacks_to(king_square(us), opposite_color(us));
}
-/// Position::move_is_legal() tests whether a pseudo-legal move is legal.
-/// There are two versions of this function: One which takes only a
-/// move as input, and one which takes a move and a bitboard of pinned
-/// pieces. The latter function is faster, and should always be preferred
-/// when a pinned piece bitboard has already been computed.
+/// Position::pl_move_is_legal() tests whether a pseudo-legal move is legal
-bool Position::move_is_legal(Move m) const {
-
- return move_is_legal(m, pinned_pieces(side_to_move()));
-}
-
-bool Position::move_is_legal(Move m, Bitboard pinned) const {
-
- Color us, them;
- Square ksq, from;
+bool Position::pl_move_is_legal(Move m) const {
assert(is_ok());
assert(move_is_ok(m));
- assert(pinned == pinned_pieces(side_to_move()));
// If we're in check, all pseudo-legal moves are legal, because our
// check evasion generator only generates true legal moves.
if (move_is_castle(m))
return true;
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- ksq = king_square(us);
+ Color us = side_to_move();
+ Color them = opposite_color(us);
+ Square from = move_from(m);
+ Square ksq = king_square(us);
assert(color_of_piece_on(from) == us);
- assert(piece_on(ksq) == king_of_color(us));
+ assert(piece_on(ksq) == piece_of_color_and_type(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
Bitboard b = occupied_squares();
assert(to == ep_square());
- assert(piece_on(from) == pawn_of_color(us));
- assert(piece_on(capsq) == pawn_of_color(them));
+ assert(piece_on(from) == piece_of_color_and_type(us, PAWN));
+ assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN));
assert(piece_on(to) == EMPTY);
clear_bit(&b, from);
// 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.
- if ( !bit_is_set(pinned, from)
- || (direction_between_squares(from, ksq) == direction_between_squares(move_to(m), ksq)))
- return true;
-
- return false;
+ return ( !bit_is_set(pinned_pieces(us), from)
+ || (direction_between_squares(from, ksq) == direction_between_squares(move_to(m), ksq)));
}
-/// Position::move_is_check() tests whether a pseudo-legal move is a check.
-/// There are two versions of this function: One which takes only a move as
-/// input, and one which takes a move and a bitboard of discovered check
-/// candidates. The latter function is faster, and should always be preferred
-/// when a discovered check candidates bitboard has already been computed.
+/// Position::move_is_check() tests whether a pseudo-legal move is a check
bool Position::move_is_check(Move m) const {
- Bitboard dc = discovered_check_candidates(side_to_move());
- return move_is_check(m, dc);
-}
-
-bool Position::move_is_check(Move m, Bitboard dcCandidates) const {
-
- Color us, them;
- Square ksq, from, to;
-
assert(is_ok());
assert(move_is_ok(m));
- assert(dcCandidates == discovered_check_candidates(side_to_move()));
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- to = move_to(m);
- ksq = king_square(them);
+ Color us = side_to_move();
+ Color them = opposite_color(us);
+ Square from = move_from(m);
+ Square to = move_to(m);
+ Square ksq = king_square(them);
+ Bitboard dcCandidates = discovered_check_candidates(us);
assert(color_of_piece_on(from) == us);
- assert(piece_on(ksq) == king_of_color(them));
+ assert(piece_on(ksq) == piece_of_color_and_type(them, KING));
// Proceed according to the type of the moving piece
switch (type_of_piece_on(from))
{
case PAWN:
-
+
if (bit_is_set(pawn_attacks(them, ksq), to)) // Normal check?
return true;
-
+
if ( bit_is_set(dcCandidates, from) // Discovered check?
&& (direction_between_squares(from, ksq) != direction_between_squares(to, ksq)))
return true;
-
+
if (move_promotion(m)) // Promotion with check?
{
Bitboard b = occupied_squares();
}
return false;
- case KNIGHT:
+ case KNIGHT:
return bit_is_set(dcCandidates, from) // Discovered check?
|| bit_is_set(piece_attacks<KNIGHT>(ksq), to); // Normal check?
case QUEEN:
// Discovered checks are impossible!
- assert(!bit_is_set(dcCandidates, from));
+ assert(!bit_is_set(dcCandidates, from));
return bit_is_set(piece_attacks<QUEEN>(ksq), to); // Normal check?
case KING:
}
return false;
- default:
- assert(false);
+ default: // NO_PIECE_TYPE
+ break;
}
assert(false);
return false;
/// Position::move_is_capture() tests whether a move from the current
-/// position is a capture.
+/// position is a capture. Move must not be MOVE_NONE.
bool Position::move_is_capture(Move m) const {
- return color_of_piece_on(move_to(m)) == opposite_color(side_to_move())
- || move_is_ep(m);
+ assert(m != MOVE_NONE);
+
+ return ( !square_is_empty(move_to(m))
+ && (color_of_piece_on(move_to(m)) != color_of_piece_on(move_from(m)))
+ )
+ || move_is_ep(m);
}
void Position::backup(UndoInfo& u) const {
u.castleRights = castleRights;
- u.epSquare = epSquare;
- u.checkersBB = checkersBB;
- u.key = key;
- u.pawnKey = pawnKey;
- u.materialKey = materialKey;
- u.rule50 = rule50;
- u.lastMove = lastMove;
- u.capture = NO_PIECE_TYPE;
- u.mgValue = mgValue;
- u.egValue = egValue;
+ u.epSquare = epSquare;
+ u.checkersBB = checkersBB;
+ u.key = key;
+ u.pawnKey = pawnKey;
+ u.materialKey = materialKey;
+ u.rule50 = rule50;
+ u.lastMove = lastMove;
+ u.mgValue = mgValue;
+ u.egValue = egValue;
+ u.capture = NO_PIECE_TYPE;
+
+ for (Color c = WHITE; c <= BLACK; c++)
+ {
+ u.pinners[c] = pinners[c];
+ u.pinned[c] = pinned[c];
+ u.dcCandidates[c] = dcCandidates[c];
+ }
}
void Position::restore(const UndoInfo& u) {
castleRights = u.castleRights;
- epSquare = u.epSquare;
- checkersBB = u.checkersBB;
- key = u.key;
- pawnKey = u.pawnKey;
- materialKey = u.materialKey;
- rule50 = u.rule50;
- lastMove = u.lastMove;
+ epSquare = u.epSquare;
+ checkersBB = u.checkersBB;
+ key = u.key;
+ pawnKey = u.pawnKey;
+ materialKey = u.materialKey;
+ rule50 = u.rule50;
+ lastMove = u.lastMove;
+ mgValue = u.mgValue;
+ egValue = u.egValue;
// u.capture is restored in undo_move()
- mgValue = u.mgValue;
- egValue = u.egValue;
+
+ for (Color c = WHITE; c <= BLACK; c++)
+ {
+ pinners[c] = u.pinners[c];
+ pinned[c] = u.pinned[c];
+ dcCandidates[c] = u.dcCandidates[c];
+ }
}
-/// Position::do_move() makes a move, and backs up all information necessary
-/// to undo the move to an UndoInfo object. The move is assumed to be legal.
-/// Pseudo-legal moves should be filtered out before this function is called.
-/// There are two versions of this function, one which takes only the move and
-/// the UndoInfo as input, and one which takes a third parameter, a bitboard of
-/// discovered check candidates. The second version is faster, because knowing
-/// the discovered check candidates makes it easier to update the checkersBB
-/// member variable in the position object.
+/// Position::update_checkers() is a private method to udpate chekers info
-void Position::do_move(Move m, UndoInfo& u) {
+template<PieceType Piece>
+inline void Position::update_checkers(Bitboard* pCheckersBB, Square ksq, Square from,
+ Square to, Bitboard dcCandidates) {
- do_move(m, u, discovered_check_candidates(side_to_move()));
+ if (Piece != KING && bit_is_set(piece_attacks<Piece>(ksq), to))
+ set_bit(pCheckersBB, to);
+
+ if (Piece != QUEEN && bit_is_set(dcCandidates, from))
+ {
+ if (Piece != ROOK)
+ (*pCheckersBB) |= (piece_attacks<ROOK>(ksq) & rooks_and_queens(side_to_move()));
+
+ if (Piece != BISHOP)
+ (*pCheckersBB) |= (piece_attacks<BISHOP>(ksq) & bishops_and_queens(side_to_move()));
+ }
}
-void Position::do_move(Move m, UndoInfo& u, Bitboard dcCandidates) {
+
+/// Position::do_move() makes a move, and backs up all information necessary
+/// to undo the move to an UndoInfo object. The move is assumed to be legal.
+/// Pseudo-legal moves should be filtered out before this function is called.
+
+void Position::do_move(Move m, UndoInfo& u) {
assert(is_ok());
assert(move_is_ok(m));
+ // Get now the current (pre-move) dc candidates that we will use
+ // in update_checkers().
+ Bitboard oldDcCandidates = discovered_check_candidates(side_to_move());
+
// Back up the necessary information to our UndoInfo object (except the
// captured piece, which is taken care of later.
backup(u);
// case of non-reversible moves is taken care of later.
rule50++;
+ // Reset pinned bitboard and its friends
+ for (Color c = WHITE; c <= BLACK; c++)
+ pinners[c] = pinned[c] = dcCandidates[c] = ~EmptyBoardBB;
+
if (move_is_castle(m))
do_castle_move(m);
else if (move_promotion(m))
if (capture)
{
- assert(capture != KING);
-
- // Remove captured piece
- clear_bit(&(byColorBB[them]), to);
- clear_bit(&(byTypeBB[capture]), to);
-
- // Update hash key
- key ^= zobrist[them][capture][to];
-
- // If the captured piece was a pawn, update pawn hash key
- if (capture == PAWN)
- pawnKey ^= zobrist[them][PAWN][to];
-
- // Update incremental scores
- mgValue -= mg_pst(them, capture, to);
- egValue -= eg_pst(them, capture, to);
-
- // Update material
- if (capture != PAWN)
- npMaterial[them] -= piece_value_midgame(capture);
-
- // Update material hash key
- materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]];
-
- // Update piece count
- pieceCount[them][capture]--;
-
- // Update piece list
- pieceList[them][capture][index[to]] = pieceList[them][capture][pieceCount[them][capture]];
- index[pieceList[them][capture][index[to]]] = index[to];
-
- // Remember the captured piece, in order to be able to undo the move correctly
- u.capture = capture;
-
- // Reset rule 50 counter
- rule50 = 0;
+ u.capture = capture;
+ do_capture_move(m, capture, them, to);
}
// Move the piece
if (piece == KING)
kingSquare[us] = to;
- // If the move was a double pawn push, set the en passant square.
- // This code is a bit ugly right now, and should be cleaned up later.
- // FIXME
+ // Reset en passant square
if (epSquare != SQ_NONE)
{
key ^= zobEp[epSquare];
epSquare = SQ_NONE;
}
+
+ // If the moving piece was a pawn do some special extra work
if (piece == PAWN)
{
+ // Reset rule 50 draw counter
+ rule50 = 0;
+
+ // Update pawn hash key
+ pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
+
+ // Set en passant square, only if moved pawn can be captured
if (abs(int(to) - int(from)) == 16)
{
- if( ( us == WHITE
- && (pawn_attacks(WHITE, from + DELTA_N) & pawns(BLACK)))
- || ( us == BLACK
- && (pawn_attacks(BLACK, from + DELTA_S) & pawns(WHITE))))
+ if ( (us == WHITE && (pawn_attacks(WHITE, from + DELTA_N) & pawns(BLACK)))
+ || (us == BLACK && (pawn_attacks(BLACK, from + DELTA_S) & pawns(WHITE))))
{
epSquare = Square((int(from) + int(to)) / 2);
key ^= zobEp[epSquare];
}
}
- // Reset rule 50 draw counter
- rule50 = 0;
-
- // Update pawn hash key
- pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to];
}
+
// Update piece lists
pieceList[us][piece][index[from]] = to;
index[to] = index[from];
castleRights &= castleRightsMask[to];
key ^= zobCastle[castleRights];
- // Update checkers bitboard
+ // Update checkers bitboard, piece must be already moved
checkersBB = EmptyBoardBB;
Square ksq = king_square(them);
switch (piece)
{
- case PAWN:
- if (bit_is_set(pawn_attacks(them, ksq), to))
- set_bit(&checkersBB, to);
-
- if (bit_is_set(dcCandidates, from))
- checkersBB |= ( (piece_attacks<ROOK>(ksq) & rooks_and_queens(us))
- |(piece_attacks<BISHOP>(ksq) & bishops_and_queens(us)));
- break;
-
- case KNIGHT:
- if (bit_is_set(piece_attacks<KNIGHT>(ksq), to))
- set_bit(&checkersBB, to);
-
- if (bit_is_set(dcCandidates, from))
- checkersBB |= ( (piece_attacks<ROOK>(ksq) & rooks_and_queens(us))
- |(piece_attacks<BISHOP>(ksq) & bishops_and_queens(us)));
- break;
-
- case BISHOP:
- if (bit_is_set(piece_attacks<BISHOP>(ksq), to))
- set_bit(&checkersBB, to);
-
- if (bit_is_set(dcCandidates, from))
- checkersBB |= (piece_attacks<ROOK>(ksq) & rooks_and_queens(us));
- break;
-
- case ROOK:
- if (bit_is_set(piece_attacks<ROOK>(ksq), to))
- set_bit(&checkersBB, to);
-
- if (bit_is_set(dcCandidates, from))
- checkersBB |= (piece_attacks<BISHOP>(ksq) & bishops_and_queens(us));
- break;
-
- case QUEEN:
- if (bit_is_set(piece_attacks<QUEEN>(ksq), to))
- set_bit(&checkersBB, to);
- break;
-
- case KING:
- if (bit_is_set(dcCandidates, from))
- checkersBB |= ( (piece_attacks<ROOK>(ksq) & rooks_and_queens(us))
- |(piece_attacks<BISHOP>(ksq) & bishops_and_queens(us)));
- break;
-
- default:
- assert(false);
- break;
+ case PAWN: update_checkers<PAWN>(&checkersBB, ksq, from, to, oldDcCandidates); break;
+ case KNIGHT: update_checkers<KNIGHT>(&checkersBB, ksq, from, to, oldDcCandidates); break;
+ case BISHOP: update_checkers<BISHOP>(&checkersBB, ksq, from, to, oldDcCandidates); break;
+ case ROOK: update_checkers<ROOK>(&checkersBB, ksq, from, to, oldDcCandidates); break;
+ case QUEEN: update_checkers<QUEEN>(&checkersBB, ksq, from, to, oldDcCandidates); break;
+ case KING: update_checkers<KING>(&checkersBB, ksq, from, to, oldDcCandidates); break;
+ default: assert(false); break;
}
}
}
+/// Position::do_capture_move() is a private method used to update captured
+/// piece info. It is called from the main Position::do_move function.
+
+void Position::do_capture_move(Move m, PieceType capture, Color them, Square to) {
+
+ assert(capture != KING);
+
+ // Remove captured piece
+ clear_bit(&(byColorBB[them]), to);
+ clear_bit(&(byTypeBB[capture]), to);
+
+ // Update hash key
+ key ^= zobrist[them][capture][to];
+
+ // If the captured piece was a pawn, update pawn hash key
+ if (capture == PAWN)
+ pawnKey ^= zobrist[them][PAWN][to];
+
+ // Update incremental scores
+ mgValue -= mg_pst(them, capture, to);
+ egValue -= eg_pst(them, capture, to);
+
+ assert(!move_promotion(m) || capture != PAWN);
+
+ // Update material
+ if (capture != PAWN)
+ npMaterial[them] -= piece_value_midgame(capture);
+
+ // Update material hash key
+ materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]];
+
+ // Update piece count
+ pieceCount[them][capture]--;
+
+ // Update piece list
+ pieceList[them][capture][index[to]] = pieceList[them][capture][pieceCount[them][capture]];
+ index[pieceList[them][capture][index[to]]] = index[to];
+
+ // Reset rule 50 counter
+ rule50 = 0;
+}
+
+
/// Position::do_castle_move() is a private method used to make a castling
-/// move. It is called from the main Position::do_move function. Note that
+/// move. It is called from the main Position::do_move function. Note that
/// castling moves are encoded as "king captures friendly rook" moves, for
/// instance white short castling in a non-Chess960 game is encoded as e1h1.
Square rfrom = move_to(m); // HACK: See comment at beginning of function
Square kto, rto;
- assert(piece_on(kfrom) == king_of_color(us));
- assert(piece_on(rfrom) == rook_of_color(us));
+ assert(piece_on(kfrom) == piece_of_color_and_type(us, KING));
+ assert(piece_on(rfrom) == piece_of_color_and_type(us, ROOK));
// Find destination squares for king and rook
if (rfrom > kfrom) // O-O
// Update board array
board[kfrom] = board[rfrom] = EMPTY;
- board[kto] = king_of_color(us);
- board[rto] = rook_of_color(us);
+ board[kto] = piece_of_color_and_type(us, KING);
+ board[rto] = piece_of_color_and_type(us, ROOK);
// Update king square
kingSquare[us] = kto;
key ^= zobrist[us][ROOK][rfrom] ^ zobrist[us][ROOK][rto];
// Clear en passant square
- if(epSquare != SQ_NONE)
+ if (epSquare != SQ_NONE)
{
key ^= zobEp[epSquare];
epSquare = SQ_NONE;
to = move_to(m);
assert(relative_rank(us, to) == RANK_8);
- assert(piece_on(from) == pawn_of_color(us));
+ assert(piece_on(from) == piece_of_color_and_type(us, PAWN));
assert(color_of_piece_on(to) == them || square_is_empty(to));
capture = type_of_piece_on(to);
if (capture)
{
- assert(capture != KING);
-
- // Remove captured piece
- clear_bit(&(byColorBB[them]), to);
- clear_bit(&(byTypeBB[capture]), to);
-
- // Update hash key
- key ^= zobrist[them][capture][to];
-
- // Update incremental scores
- mgValue -= mg_pst(them, capture, to);
- egValue -= eg_pst(them, capture, to);
-
- // Update material. Because our move is a promotion, we know that the
- // captured piece is not a pawn.
- assert(capture != PAWN);
- npMaterial[them] -= piece_value_midgame(capture);
-
- // Update material hash key
- materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]];
-
- // Update piece count
- pieceCount[them][capture]--;
-
- // Update piece list
- pieceList[them][capture][index[to]] = pieceList[them][capture][pieceCount[them][capture]];
- index[pieceList[them][capture][index[to]]] = index[to];
-
- // Remember the captured piece, in order to be able to undo the move correctly
u.capture = capture;
+ do_capture_move(m, capture, them, to);
}
// Remove pawn
assert(to == epSquare);
assert(relative_rank(us, to) == RANK_6);
assert(piece_on(to) == EMPTY);
- assert(piece_on(from) == pawn_of_color(us));
- assert(piece_on(capsq) == pawn_of_color(them));
+ assert(piece_on(from) == piece_of_color_and_type(us, PAWN));
+ assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN));
// Remove captured piece
clear_bit(&(byColorBB[them]), capsq);
}
-/// Position::undo_move() unmakes a move. When it returns, the position should
-/// be restored to exactly the same state as before the move was made. It is
+/// Position::undo_move() unmakes a move. When it returns, the position should
+/// be restored to exactly the same state as before the move was made. It is
/// important that Position::undo_move is called with the same move and UndoInfo
/// object as the earlier call to Position::do_move.
// Position::undo_move. In particular, the side to move has been switched,
// so the code below is correct.
Color us = side_to_move();
- Color them = opposite_color(us);
// Find source squares for king and rook
Square kfrom = move_from(m);
rto = relative_square(us, SQ_D1);
}
- assert(piece_on(kto) == king_of_color(us));
- assert(piece_on(rto) == rook_of_color(us));
+ assert(piece_on(kto) == piece_of_color_and_type(us, KING));
+ assert(piece_on(rto) == piece_of_color_and_type(us, ROOK));
// Remove pieces from destination squares
clear_bit(&(byColorBB[us]), kto);
// Update board
board[rto] = board[kto] = EMPTY;
- board[rfrom] = rook_of_color(us);
- board[kfrom] = king_of_color(us);
+ board[rfrom] = piece_of_color_and_type(us, ROOK);
+ board[kfrom] = piece_of_color_and_type(us, KING);
// Update king square
kingSquare[us] = kfrom;
/// Position::do_move, is used to put back the captured piece (if any).
void Position::undo_promotion_move(Move m, const UndoInfo &u) {
-
+
Color us, them;
Square from, to;
PieceType capture, promotion;
set_bit(&(byColorBB[us]), from);
set_bit(&(byTypeBB[PAWN]), from);
set_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares
- board[from] = pawn_of_color(us);
+ board[from] = piece_of_color_and_type(us, PAWN);
// Update material
npMaterial[us] -= piece_value_midgame(promotion);
assert(to == ep_square());
assert(relative_rank(us, to) == RANK_6);
- assert(piece_on(to) == pawn_of_color(us));
+ assert(piece_on(to) == piece_of_color_and_type(us, PAWN));
assert(piece_on(from) == EMPTY);
assert(piece_on(capsq) == EMPTY);
set_bit(&(byColorBB[them]), capsq);
set_bit(&(byTypeBB[PAWN]), capsq);
set_bit(&(byTypeBB[0]), capsq);
- board[capsq] = pawn_of_color(them);
+ board[capsq] = piece_of_color_and_type(them, PAWN);
// Remove moving piece from destination square
clear_bit(&(byColorBB[us]), to);
set_bit(&(byColorBB[us]), from);
set_bit(&(byTypeBB[PAWN]), from);
set_bit(&(byTypeBB[0]), from);
- board[from] = pawn_of_color(us);
+ board[from] = piece_of_color_and_type(us, PAWN);
// Update piece list:
pieceList[us][PAWN][index[to]] = from;
/// Position::do_null_move makes() a "null move": It switches the side to move
/// and updates the hash key without executing any move on the board.
-void Position::do_null_move(UndoInfo &u) {
+void Position::do_null_move(UndoInfo& u) {
assert(is_ok());
assert(!is_check());
}
-/// Position::see() is a static exchange evaluator: It tries to estimate the
-/// material gain or loss resulting from a move. There are two versions of
-/// this function: One which takes a move as input, and one which takes a
-/// 'from' and a 'to' square. The function does not yet understand promotions
-/// or en passant captures.
+/// Position::see() is a static exchange evaluator: It tries to estimate the
+/// material gain or loss resulting from a move. There are three versions of
+/// this function: One which takes a destination square as input, one takes a
+/// move, and one which takes a 'from' and a 'to' square. The function does
+/// not yet understand promotions captures.
+
+int Position::see(Square to) const {
+
+ assert(square_is_ok(to));
+ return see(SQ_NONE, to);
+}
int Position::see(Move m) const {
int Position::see(Square from, Square to) const {
- // Approximate material values, with pawn = 1
+ // Material values
static const int seeValues[18] = {
- 0, 1, 3, 3, 5, 10, 100, 0, 0, 1, 3, 3, 5, 10, 100, 0, 0, 0
+ 0, PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
+ RookValueMidgame, QueenValueMidgame, QueenValueMidgame*10, 0,
+ 0, PawnValueMidgame, KnightValueMidgame, BishopValueMidgame,
+ RookValueMidgame, QueenValueMidgame, QueenValueMidgame*10, 0,
+ 0, 0
};
Bitboard attackers, occ, b;
- assert(square_is_ok(from));
+ assert(square_is_ok(from) || from == SQ_NONE);
assert(square_is_ok(to));
// Initialize colors
- Color us = color_of_piece_on(from);
+ Color us = (from != SQ_NONE ? color_of_piece_on(from) : opposite_color(color_of_piece_on(to)));
Color them = opposite_color(us);
// Initialize pieces
// Find all attackers to the destination square, with the moving piece
// removed, but possibly an X-ray attacker added behind it.
occ = occupied_squares();
- clear_bit(&occ, from);
- attackers = (rook_attacks_bb(to, occ) & rooks_and_queens())
- | (bishop_attacks_bb(to, occ) & bishops_and_queens())
- | (piece_attacks<KNIGHT>(to) & knights())
- | (piece_attacks<KING>(to) & kings())
- | (pawn_attacks(WHITE, to) & pawns(BLACK))
- | (pawn_attacks(BLACK, to) & pawns(WHITE));
- attackers &= occ; // Re-add removed piece
+ // Handle en passant moves
+ if (epSquare == to && type_of_piece_on(from) == PAWN)
+ {
+ assert(capture == EMPTY);
+
+ Square capQq = (side_to_move() == WHITE)? (to - DELTA_N) : (to - DELTA_S);
+ capture = piece_on(capQq);
+
+ assert(type_of_piece_on(capQq) == PAWN);
- // If the opponent has no attackers, we are finished
+ // Remove the captured pawn
+ clear_bit(&occ, capQq);
+ }
+
+ while (true)
+ {
+ clear_bit(&occ, from);
+ attackers = (rook_attacks_bb(to, occ) & rooks_and_queens())
+ | (bishop_attacks_bb(to, occ) & bishops_and_queens())
+ | (piece_attacks<KNIGHT>(to) & knights())
+ | (piece_attacks<KING>(to) & kings())
+ | (pawn_attacks(WHITE, to) & pawns(BLACK))
+ | (pawn_attacks(BLACK, to) & pawns(WHITE));
+
+ if (from != SQ_NONE)
+ break;
+
+ // If we don't have any attacker we are finished
+ if ((attackers & pieces_of_color(us)) == EmptyBoardBB)
+ return 0;
+
+ // Locate the least valuable attacker to the destination square
+ // and use it to initialize from square.
+ PieceType pt;
+ for (pt = PAWN; !(attackers & pieces_of_color_and_type(us, pt)); pt++)
+ assert(pt < KING);
+
+ from = first_1(attackers & pieces_of_color_and_type(us, pt));
+ piece = piece_on(from);
+ }
+
+ // If the opponent has no attackers we are finished
if ((attackers & pieces_of_color(them)) == EmptyBoardBB)
return seeValues[capture];
+ attackers &= occ; // Remove the moving piece
+
// The destination square is defended, which makes things rather more
// difficult to compute. We proceed by building up a "swap list" containing
// the material gain or loss at each stop in a sequence of captures to the
- // destianation square, where the sides alternately capture, and always
+ // 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.
int lastCapturingPieceValue = seeValues[piece];
}
checkersBB = EmptyBoardBB;
+ for (Color c = WHITE; c <= BLACK; c++)
+ pinners[c] = pinned[c] = dcCandidates[c] = ~EmptyBoardBB;
lastMove = MOVE_NONE;
}
-/// Position::reset_game_ply() simply sets gamePly to 0. It is used from the
+/// Position::reset_game_ply() simply sets gamePly to 0. It is used from the
/// UCI interface code, whenever a non-reversible move is made in a
/// 'position fen <fen> moves m1 m2 ...' command. This makes it possible
/// for the program to handle games of arbitrary length, as long as the GUI
}
-/// Position::compute_pawn_key() computes the hash key of the position. The
+/// Position::compute_pawn_key() computes the hash key of the position. The
/// hash key is usually updated incrementally as moves are made and unmade,
/// the compute_pawn_key() function is only used when a new position is set
/// up, and to verify the correctness of the pawn hash key when running in
/// Position::compute_mg_value() and Position::compute_eg_value() compute the
-/// incremental scores for the middle game and the endgame. These functions
+/// incremental scores for the middle game and the endgame. These functions
/// are used to initialize the incremental scores when a new position is set
/// up, and to verify that the scores are correctly updated by do_move
/// and undo_move when the program is running in debug mode.
/// Position::compute_non_pawn_material() computes the total non-pawn middle
-/// game material score for the given side. Material scores are updated
+/// game material score for the given side. Material scores are updated
/// incrementally during the search, this function is only used while
/// initializing a new Position object.
/// side to move is checkmated. Note that this function is currently very
/// slow, and shouldn't be used frequently inside the search.
-bool Position::is_mate() {
+bool Position::is_mate() const {
if (is_check())
{
- MovePicker mp = MovePicker(*this, false, MOVE_NONE, MOVE_NONE,
- MOVE_NONE, MOVE_NONE, Depth(0));
+ MovePicker mp = MovePicker(*this, false, MOVE_NONE, EmptySearchStack, Depth(0));
return mp.get_next_move() == MOVE_NONE;
}
return false;
/// Position::is_draw() tests whether the position is drawn by material,
-/// repetition, or the 50 moves rule. It does not detect stalemates, this
+/// repetition, or the 50 moves rule. It does not detect stalemates, this
/// must be done by the search.
bool Position::is_draw() const {
/// Position::flipped_copy() makes a copy of the input position, but with
-/// the white and black sides reversed. This is only useful for debugging,
+/// the white and black sides reversed. This is only useful for debugging,
/// especially for finding evaluation symmetry bugs.
void Position::flipped_copy(const Position &pos) {
if (type_of_piece_on(s) == KING)
kingCount[color_of_piece_on(s)]++;
- if(kingCount[0] != 1 || kingCount[1] != 1)
+ if (kingCount[0] != 1 || kingCount[1] != 1)
return false;
}
{
if (mgValue != compute_mg_value())
return false;
-
+
if (egValue != compute_eg_value())
return false;
}
if (failedStep) (*failedStep)++;
if (debugNonPawnMaterial)
{
- if(npMaterial[WHITE] != compute_non_pawn_material(WHITE))
+ if (npMaterial[WHITE] != compute_non_pawn_material(WHITE))
return false;
- if(npMaterial[BLACK] != compute_non_pawn_material(BLACK))
+ if (npMaterial[BLACK] != compute_non_pawn_material(BLACK))
return false;
}
projects / stockfish / blobdiff