castleRightsMask[make_square(initialQRFile, RANK_8)] ^= BLACK_OOO;
find_checkers();
- find_hidden_checks();
st->key = compute_key();
st->pawnKey = compute_pawn_key();
}
+/// Position:pinned_pieces() returns a bitboard of all pinned (against the
+/// king) pieces for the given color.
+Bitboard Position::pinned_pieces(Color c) const {
+
+ Bitboard p;
+ Square ksq = king_square(c);
+ return hidden_checks<ROOK, true>(c, ksq, p) | hidden_checks<BISHOP, true>(c, ksq, p);
+}
+
+
+/// 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.
+
+Bitboard Position::discovered_check_candidates(Color c) const {
+
+ Bitboard p;
+ Square ksq = king_square(opposite_color(c));
+ return hidden_checks<ROOK, false>(c, ksq, p) | hidden_checks<BISHOP, false>(c, ksq, p);
+}
+
+
/// 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
st->checkersBB = attacks_to(king_square(us), opposite_color(us));
}
-/// Position:find_hidden_checks() computes the pinned, pinners and dcCandidates
-/// bitboards. There are two versions of this function. One takes a color and
-/// computes bitboards relative to that color only, the other computes both
-/// colors. Bitboard checkersBB must be already updated.
-
-void Position::find_hidden_checks(Color us) {
- Bitboard p1, p2;
- Color them = opposite_color(us);
- Square ksq = king_square(them);
- st->pinned[them] = hidden_checks<ROOK, true>(them, ksq, p1) | hidden_checks<BISHOP, true>(them, ksq, p2);
- st->pinners[them] = p1 | p2;
- st->dcCandidates[us] = hidden_checks<ROOK, false>(us, ksq, p1) | hidden_checks<BISHOP, false>(us, ksq, p2);
-}
+/// Position::pl_move_is_legal() tests whether a pseudo-legal move is legal
-void Position::find_hidden_checks() {
+bool Position::pl_move_is_legal(Move m) const {
- for (Color c = WHITE; c <= BLACK; c++)
- find_hidden_checks(c);
+ return pl_move_is_legal(m, pinned_pieces(side_to_move()));
}
-
-/// Position::pl_move_is_legal() tests whether a pseudo-legal move is legal
-
-bool Position::pl_move_is_legal(Move m) const {
+bool Position::pl_move_is_legal(Move m, Bitboard pinned) 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.
// 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.
- return ( !bit_is_set(pinned_pieces(us), from)
+ return ( !bit_is_set(pinned, from)
|| (direction_between_squares(from, ksq) == direction_between_squares(move_to(m), ksq)));
}
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 {
+
assert(is_ok());
assert(move_is_ok(m));
+ assert(dcCandidates == discovered_check_candidates(side_to_move()));
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) == piece_of_color_and_type(them, KING));
}
-/// Position::update_hidden_checks() udpates pinned, pinners and dcCandidates
-/// bitboards incrementally, given the move. It is called in do_move and is
-/// faster then find_hidden_checks().
-
-void Position::update_hidden_checks(Square from, Square to) {
-
- Color us = sideToMove;
- Color them = opposite_color(us);
- Square ksq = king_square(opposite_color(us));
-
- Bitboard moveSquares = EmptyBoardBB;
- set_bit(&moveSquares, from);
- set_bit(&moveSquares, to);
-
- // Our moving piece could have been a possible pinner or hidden checker behind a dcCandidates?
- bool checkerMoved = (st->dcCandidates[us] | st->pinners[them]) && (moveSquares & sliders());
-
- // If we are moving from/to an opponent king attack direction and we was a possible hidden checker
- // or there exsist some possible hidden checker on that line then recalculate the position
- // otherwise skip because our dcCandidates and opponent pinned pieces are not changed.
- if ( (moveSquares & RookPseudoAttacks[ksq]) && (checkerMoved || (rooks_and_queens(us) & RookPseudoAttacks[ksq]))
- || (moveSquares & BishopPseudoAttacks[ksq]) && (checkerMoved || (bishops_and_queens(us) & BishopPseudoAttacks[ksq])))
- find_hidden_checks(us);
-
- ksq = king_square(us);
-
- if (ksq == to)
- {
- find_hidden_checks(them);
- return;
- }
-
- // It is possible that we have captured an opponent hidden checker?
- Bitboard checkerCaptured = st->capture && (st->dcCandidates[them] || bit_is_set(st->pinners[us], to));
-
- // If we are moving from/to an our king attack direction and there was/is some possible
- // opponent hidden checker then calculate the position otherwise skip because opponent
- // dcCandidates and our pinned pieces are not changed.
- if ( (moveSquares & RookPseudoAttacks[ksq]) && (checkerCaptured || (rooks_and_queens(them) & RookPseudoAttacks[ksq]))
- || (moveSquares & BishopPseudoAttacks[ksq]) && (checkerCaptured || (bishops_and_queens(them) & BishopPseudoAttacks[ksq])))
- find_hidden_checks(them);
-}
-
-
/// Position::do_move() makes a move, and saves all information necessary
/// to a StateInfo 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, StateInfo& newSt) {
+ do_move(m, newSt, discovered_check_candidates(side_to_move()));
+}
+
+void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) {
+
assert(is_ok());
assert(move_is_ok(m));
- // Get now the current (before to move) dc candidates that we will use
- // in update_checkers().
- Bitboard oldDcCandidates = discovered_check_candidates(side_to_move());
-
// Copy some fields of old state to our new StateInfo object (except the
// captured piece, which is taken care of later) and switch state pointer
// to point to the new, ready to be updated, state.
Square ksq = king_square(them);
switch (piece)
{
- case PAWN: update_checkers<PAWN>(&st->checkersBB, ksq, from, to, oldDcCandidates); break;
- case KNIGHT: update_checkers<KNIGHT>(&st->checkersBB, ksq, from, to, oldDcCandidates); break;
- case BISHOP: update_checkers<BISHOP>(&st->checkersBB, ksq, from, to, oldDcCandidates); break;
- case ROOK: update_checkers<ROOK>(&st->checkersBB, ksq, from, to, oldDcCandidates); break;
- case QUEEN: update_checkers<QUEEN>(&st->checkersBB, ksq, from, to, oldDcCandidates); break;
- case KING: update_checkers<KING>(&st->checkersBB, ksq, from, to, oldDcCandidates); break;
+ case PAWN: update_checkers<PAWN>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
+ case KNIGHT: update_checkers<KNIGHT>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
+ case BISHOP: update_checkers<BISHOP>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
+ case ROOK: update_checkers<ROOK>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
+ case QUEEN: update_checkers<QUEEN>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
+ case KING: update_checkers<KING>(&(st->checkersBB), ksq, from, to, dcCandidates); break;
default: assert(false); break;
}
-
- update_hidden_checks(from, to);
}
// Finish
// Update checkers BB
st->checkersBB = attacks_to(king_square(them), us);
-
- // Update hidden checks
- find_hidden_checks();
}
// Update checkers BB
st->checkersBB = attacks_to(king_square(them), us);
-
- // Update hidden checks
- find_hidden_checks();
}
// Update checkers BB
st->checkersBB = attacks_to(king_square(them), us);
-
- // Update hidden checks
- find_hidden_checks();
}
Color us = (from != SQ_NONE ? color_of_piece_on(from) : opposite_color(color_of_piece_on(to)));
Color them = opposite_color(us);
- // Initialize pinned and pinners bitboards
- Bitboard pinned[2], pinners[2];
- pinned[us] = pinned_pieces(us, pinners[us]);
- pinned[them] = pinned_pieces(them, pinners[them]);
-
// Initialize pieces
Piece piece = piece_on(from);
Piece capture = piece_on(to);
| (pawn_attacks(WHITE, to) & pawns(BLACK))
| (pawn_attacks(BLACK, to) & pawns(WHITE));
- // Remove our pinned pieces from attacks if the captured piece is not
- // a pinner, otherwise we could remove a valid "capture the pinner" attack.
- if (pinned[us] != EmptyBoardBB && !bit_is_set(pinners[us], to))
- attackers &= ~pinned[us];
-
- // Remove opponent pinned pieces from attacks if the moving piece is not
- // a pinner, otherwise we could remove a piece that is no more pinned
- // due to our pinner piece is moving away.
- if (pinned[them] != EmptyBoardBB && !bit_is_set(pinners[them], from))
- attackers &= ~pinned[them];
-
if (from != SQ_NONE)
break;
lastCapturingPieceValue = seeValues[pt];
c = opposite_color(c);
- // Remove pinned pieces from attackers
- if ( pinned[c] != EmptyBoardBB
- && !bit_is_set(pinners[c], to)
- && !(pinners[c] & attackers))
- attackers &= ~pinned[c];
-
// Stop after a king capture
if (pt == KING && (attackers & pieces_of_color(c)))
{
projects / stockfish / blobdiff