It should help to avoid recalculating check squares
of sliding attackers for queen when already done for
bishops and rooks. Of course this helps when there are
bishop, rook and queen on the board !
Fixed also a subtle bug (use of same variable b in while
condition and in condition body) introduced recently by
revision
d655147e8c that triggers
in case we have at least 2 non-pawn discovered check pieces.
This is very rare that's why didn't show in the node count
verification where we actually have a case of 2 dc pieces
in position 14, but one is a pawn.
No functional change.
Signed-off-by: Marco Costalba <mcostalba@gmail.com>
- inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist, Color us,
- Bitboard dc, Square ksq) {
+ inline MoveStack* generate_direct_checks(const Position& pos, MoveStack* mlist,
+ Color us, const CheckInfo& ci) {
assert(Pt != KING && Pt != PAWN);
Bitboard checkSqs, b;
assert(Pt != KING && Pt != PAWN);
Bitboard checkSqs, b;
if ((from = *pl++) == SQ_NONE)
return mlist;
if ((from = *pl++) == SQ_NONE)
return mlist;
- checkSqs = pos.attacks_from<Pt>(ksq) & pos.empty_squares();
+ checkSqs = ci.checkSq[Pt] & pos.empty_squares();
|| (Pt == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
continue;
|| (Pt == BISHOP && !(BishopPseudoAttacks[from] & checkSqs)))
continue;
- if (dc && bit_is_set(dc, from))
+ if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from))
continue;
b = pos.attacks_from<Pt>(from) & checkSqs;
continue;
b = pos.attacks_from<Pt>(from) & checkSqs;
- FORCE_INLINE MoveStack* generate_direct_checks<PAWN>(const Position& p, MoveStack* m, Color us, Bitboard dc, Square ksq) {
+ FORCE_INLINE MoveStack* generate_direct_checks<PAWN>(const Position& p, MoveStack* m,
+ Color us, const CheckInfo& ci) {
- return us == WHITE ? generate_pawn_moves<WHITE, MV_NON_CAPTURE_CHECK>(p, m, dc, ksq)
- : generate_pawn_moves<BLACK, MV_NON_CAPTURE_CHECK>(p, m, dc, ksq);
+ return us == WHITE ? generate_pawn_moves<WHITE, MV_NON_CAPTURE_CHECK>(p, m, ci.dcCandidates, ci.ksq)
+ : generate_pawn_moves<BLACK, MV_NON_CAPTURE_CHECK>(p, m, ci.dcCandidates, ci.ksq);
- Bitboard b, dc;
- Square from;
- PieceType pt;
Color us = pos.side_to_move();
Color us = pos.side_to_move();
- Square ksq = pos.king_square(flip(us));
+ CheckInfo ci(pos);
+ Bitboard dc = ci.dcCandidates;
- assert(pos.piece_on(ksq) == make_piece(flip(us), KING));
-
- b = dc = pos.discovered_check_candidates();
-
- while (b)
- from = pop_1st_bit(&b);
- pt = type_of(pos.piece_on(from));
+ Square from = pop_1st_bit(&dc);
+ PieceType pt = type_of(pos.piece_on(from));
if (pt == PAWN)
continue; // Will be generated togheter with direct checks
if (pt == PAWN)
continue; // Will be generated togheter with direct checks
- b = pos.attacks_from(Piece(pt), from) & pos.empty_squares();
+ Bitboard b = pos.attacks_from(Piece(pt), from) & pos.empty_squares();
- b &= ~QueenPseudoAttacks[ksq];
+ b &= ~QueenPseudoAttacks[ci.ksq];
- mlist = generate_direct_checks<PAWN>(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks<KNIGHT>(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks<BISHOP>(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks<ROOK>(pos, mlist, us, dc, ksq);
- mlist = generate_direct_checks<QUEEN>(pos, mlist, us, dc, ksq);
+ mlist = generate_direct_checks<PAWN>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<KNIGHT>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<BISHOP>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<ROOK>(pos, mlist, us, ci);
+ mlist = generate_direct_checks<QUEEN>(pos, mlist, us, ci);
if (pos.can_castle(us))
{
if (pos.can_castle(us))
{
CheckInfo::CheckInfo(const Position& pos) {
Color them = flip(pos.side_to_move());
CheckInfo::CheckInfo(const Position& pos) {
Color them = flip(pos.side_to_move());
- Square ksq = pos.king_square(them);
+ ksq = pos.king_square(them);
pinned = pos.pinned_pieces();
dcCandidates = pos.discovered_check_candidates();
pinned = pos.pinned_pieces();
dcCandidates = pos.discovered_check_candidates();
Bitboard dcCandidates;
Bitboard pinned;
Bitboard checkSq[8];
Bitboard dcCandidates;
Bitboard pinned;
Bitboard checkSq[8];