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Update pinned bitboards and friends in do_move()

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Probably is slightly slow, but code is surely better
in this way. We will optimize later for speed.

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
This commit is contained in:
Marco Costalba 2009-02-23 11:37:31 +01:00
parent 4324276419
commit 0bf45823da
2 changed files with 37 additions and 39 deletions
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62
src/position.cpp
View file

@ -206,6 +206,7 @@ void Position::from_fen(const std::string& fen) {
castleRightsMask[make_square(initialQRFile, RANK_8)] ^= BLACK_OOO;
find_checkers();
find_pinned();
st->key = compute_key();
st->pawnKey = compute_pawn_key();
@ -319,44 +320,11 @@ void Position::copy(const Position &pos) {
}
/// Position:pinned_pieces() returns a bitboard of all pinned (against the
/// king) pieces for the given color.
Bitboard Position::pinned_pieces(Color c) const {
if (st->pinned[c] != ~EmptyBoardBB)
return st->pinned[c];
Bitboard p1, p2;
Square ksq = king_square(c);
st->pinned[c] = hidden_checks<ROOK, true>(c, ksq, p1) | hidden_checks<BISHOP, true>(c, ksq, p2);
st->pinners[c] = p1 | p2;
return st->pinned[c];
}
Bitboard Position::pinned_pieces(Color c, Bitboard& p) const {
if (st->pinned[c] == ~EmptyBoardBB)
pinned_pieces(c);
p = st->pinners[c];
return st->pinned[c];
}
Bitboard Position::discovered_check_candidates(Color c) const {
if (st->dcCandidates[c] != ~EmptyBoardBB)
return st->dcCandidates[c];
Bitboard dummy;
Square ksq = king_square(opposite_color(c));
st->dcCandidates[c] = hidden_checks<ROOK, false>(c, ksq, dummy) | hidden_checks<BISHOP, false>(c, ksq, dummy);
return st->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.
/// Note that checkersBB bitboard must be already updated.
template<PieceType Piece, bool FindPinned>
Bitboard Position::hidden_checks(Color c, Square ksq, Bitboard& pinners) const {
@ -466,7 +434,7 @@ bool Position::move_attacks_square(Move m, Square s) const {
/// Position::find_checkers() computes the checkersBB bitboard, which
/// contains a nonzero bit for each checking piece (0, 1 or 2). It
/// 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
/// played, like in non-bitboard versions of Glaurung.
@ -478,6 +446,25 @@ void Position::find_checkers() {
}
/// Position:find_pinned() computes the pinned, pinners and dcCandidates
/// bitboards for both colors. Bitboard checkersBB must be already updated.
void Position::find_pinned() {
Bitboard p1, p2;
Square ksq;
for (Color c = WHITE; c <= BLACK; c++)
{
ksq = king_square(c);
st->pinned[c] = hidden_checks<ROOK, true>(c, ksq, p1) | hidden_checks<BISHOP, true>(c, ksq, p2);
st->pinners[c] = p1 | p2;
ksq = king_square(opposite_color(c));
st->dcCandidates[c] = hidden_checks<ROOK, false>(c, ksq, p1) | hidden_checks<BISHOP, false>(c, ksq, p2);
}
}
/// Position::pl_move_is_legal() tests whether a pseudo-legal move is legal
bool Position::pl_move_is_legal(Move m) const {
@ -719,10 +706,6 @@ void Position::do_move(Move m, StateInfo& newSt) {
// case of non-reversible moves is taken care of later.
st->rule50++;
// Reset pinned bitboard and its friends
for (Color c = WHITE; c <= BLACK; c++)
st->pinned[c] = st->dcCandidates[c] = ~EmptyBoardBB;
if (move_is_castle(m))
do_castle_move(m);
else if (move_promotion(m))
@ -823,6 +806,7 @@ void Position::do_move(Move m, StateInfo& newSt) {
}
// Finish
find_pinned();
st->key ^= zobSideToMove;
sideToMove = opposite_color(sideToMove);
gamePly++;

14
src/position.h
View file

@ -302,6 +302,7 @@ private:
void undo_promotion_move(Move m);
void undo_ep_move(Move m);
void find_checkers();
void find_pinned();
template<PieceType Piece>
void update_checkers(Bitboard* pCheckersBB, Square ksq, Square from, Square to, Bitboard dcCandidates);
@ -556,6 +557,19 @@ inline Bitboard Position::piece_attacks<KING>(Square s) const {
return StepAttackBB[KING][s];
}
inline Bitboard Position::pinned_pieces(Color c) const {
return st->pinned[c];
}
inline Bitboard Position::pinned_pieces(Color c, Bitboard& p) const {
p = st->pinners[c];
return st->pinned[c];
}
inline Bitboard Position::discovered_check_candidates(Color c) const {
return st->dcCandidates[c];
}
inline Bitboard Position::checkers() const {
return st->checkersBB;
}