return hidden_checkers<false>(c);
}
-/// Position::attacks_to() computes a bitboard containing all pieces which
+/// Position::attackers_to() computes a bitboard containing all pieces which
/// attacks a given square.
-Bitboard Position::attacks_to(Square s) const {
+Bitboard Position::attackers_to(Square s) const {
- return (pawn_attacks(BLACK, s) & pieces(PAWN, WHITE))
- | (pawn_attacks(WHITE, s) & pieces(PAWN, BLACK))
- | (piece_attacks<KNIGHT>(s) & pieces(KNIGHT))
- | (piece_attacks<ROOK>(s) & pieces(ROOK, QUEEN))
- | (piece_attacks<BISHOP>(s) & pieces(BISHOP, QUEEN))
- | (piece_attacks<KING>(s) & pieces(KING));
+ return (pawn_attacks_from(s, BLACK) & pieces(PAWN, WHITE))
+ | (pawn_attacks_from(s, WHITE) & pieces(PAWN, BLACK))
+ | (piece_attacks_from<KNIGHT>(s) & pieces(KNIGHT))
+ | (piece_attacks_from<ROOK>(s) & pieces(ROOK, QUEEN))
+ | (piece_attacks_from<BISHOP>(s) & pieces(BISHOP, QUEEN))
+ | (piece_attacks_from<KING>(s) & pieces(KING));
}
-/// Position::piece_attacks_square() tests whether the piece on square f
-/// attacks square t.
+/// Position::piece_attacks_from() computes a bitboard of all attacks
+/// of a given piece put in a given square.
-bool Position::piece_attacks_square(Piece p, Square f, Square t) const {
+Bitboard Position::piece_attacks_from(Piece p, Square s) const {
- assert(square_is_ok(f));
- assert(square_is_ok(t));
+ assert(square_is_ok(s));
switch (p)
{
- case WP: return pawn_attacks_square(WHITE, f, t);
- case BP: return pawn_attacks_square(BLACK, f, t);
- case WN: case BN: return piece_attacks_square<KNIGHT>(f, t);
- case WB: case BB: return piece_attacks_square<BISHOP>(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);
+ case WP: return pawn_attacks_from(s, WHITE);
+ case BP: return pawn_attacks_from(s, BLACK);
+ case WN: case BN: return piece_attacks_from<KNIGHT>(s);
+ case WB: case BB: return piece_attacks_from<BISHOP>(s);
+ case WR: case BR: return piece_attacks_from<ROOK>(s);
+ case WQ: case BQ: return piece_attacks_from<QUEEN>(s);
+ case WK: case BK: return piece_attacks_from<KING>(s);
default: break;
}
return false;
assert(square_is_occupied(f));
- if (piece_attacks_square(piece_on(f), t, s))
+ if (bit_is_set(piece_attacks_from(piece_on(f), t), s))
return true;
// Move the piece and scan for X-ray attacks behind it
// 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)));
+ return xray && (xray ^ (xray & piece_attacks_from<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
+/// currently works by calling Position::attackers_to, which is probably
/// inefficient. Consider rewriting this function to use the last move
/// played, like in non-bitboard versions of Glaurung.
void Position::find_checkers() {
Color us = side_to_move();
- st->checkersBB = attacks_to(king_square(us), opposite_color(us));
+ st->checkersBB = attackers_to(king_square(us)) & pieces_of_color(opposite_color(us));
}
// If the moving piece is a king, check whether the destination
// square is attacked by the opponent.
if (type_of_piece_on(from) == KING)
- return !(square_is_attacked(move_to(m), opposite_color(us)));
+ return !(attackers_to(move_to(m)) & pieces_of_color(opposite_color(us)));
// 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.
{
case PAWN:
- if (bit_is_set(pawn_attacks(them, ksq), to)) // Normal check?
+ if (bit_is_set(pawn_attacks_from(ksq, them), to)) // Normal check?
return true;
if ( dcCandidates // Discovered check?
switch (move_promotion_piece(m))
{
case KNIGHT:
- return bit_is_set(piece_attacks<KNIGHT>(to), ksq);
+ return bit_is_set(piece_attacks_from<KNIGHT>(to), ksq);
case BISHOP:
return bit_is_set(bishop_attacks_bb(to, b), ksq);
case ROOK:
// Test discovered check and normal check according to piece type
case KNIGHT:
return (dcCandidates && bit_is_set(dcCandidates, from))
- || bit_is_set(piece_attacks<KNIGHT>(ksq), to);
+ || bit_is_set(piece_attacks_from<KNIGHT>(ksq), to);
case BISHOP:
return (dcCandidates && bit_is_set(dcCandidates, from))
- || (direction_is_diagonal(ksq, to) && bit_is_set(piece_attacks<BISHOP>(ksq), to));
+ || (direction_is_diagonal(ksq, to) && bit_is_set(piece_attacks_from<BISHOP>(ksq), to));
case ROOK:
return (dcCandidates && bit_is_set(dcCandidates, from))
- || (direction_is_straight(ksq, to) && bit_is_set(piece_attacks<ROOK>(ksq), to));
+ || (direction_is_straight(ksq, to) && bit_is_set(piece_attacks_from<ROOK>(ksq), to));
case QUEEN:
// Discovered checks are impossible!
assert(!bit_is_set(dcCandidates, from));
- return ( (direction_is_straight(ksq, to) && bit_is_set(piece_attacks<ROOK>(ksq), to))
- || (direction_is_diagonal(ksq, to) && bit_is_set(piece_attacks<BISHOP>(ksq), to)));
+ return ( (direction_is_straight(ksq, to) && bit_is_set(piece_attacks_from<ROOK>(ksq), to))
+ || (direction_is_diagonal(ksq, to) && bit_is_set(piece_attacks_from<BISHOP>(ksq), to)));
case KING:
// Discovered check?
// Direct checks
if ( ( (Bishop && bit_is_set(BishopPseudoAttacks[ksq], to))
|| (Rook && bit_is_set(RookPseudoAttacks[ksq], to)))
- && bit_is_set(piece_attacks<Piece>(ksq), to)) // slow, try to early skip
+ && bit_is_set(piece_attacks_from<Piece>(ksq), to)) // slow, try to early skip
set_bit(pCheckersBB, to);
else if ( Piece != KING
&& !Slider
- && bit_is_set(piece_attacks<Piece>(ksq), to))
+ && bit_is_set(Piece == PAWN ? pawn_attacks_from(ksq, opposite_color(sideToMove))
+ : piece_attacks_from<Piece>(ksq), to))
set_bit(pCheckersBB, to);
// Discovery checks
if (Piece != QUEEN && bit_is_set(dcCandidates, from))
{
if (Piece != ROOK)
- (*pCheckersBB) |= (piece_attacks<ROOK>(ksq) & pieces(ROOK, QUEEN, side_to_move()));
+ (*pCheckersBB) |= (piece_attacks_from<ROOK>(ksq) & pieces(ROOK, QUEEN, side_to_move()));
if (Piece != BISHOP)
- (*pCheckersBB) |= (piece_attacks<BISHOP>(ksq) & pieces(BISHOP, QUEEN, side_to_move()));
+ (*pCheckersBB) |= (piece_attacks_from<BISHOP>(ksq) & pieces(BISHOP, QUEEN, side_to_move()));
}
}
struct ReducedStateInfo {
Key key, pawnKey, materialKey;
int castleRights, rule50;
- Square epSquare;
+ Square kingSquare[2], epSquare;
Value mgValue, egValue;
Value npMaterial[2];
};
// If the moving piece was a king, update the king square
if (pt == KING)
- kingSquare[us] = to;
+ st->kingSquare[us] = to;
// Update piece lists, note that index[from] is not updated and
// becomes stale. This works as long as index[] is accessed just
// Set en passant square, only if moved pawn can be captured
if (abs(int(to) - int(from)) == 16)
{
- if (pawn_attacks(us, from + (us == WHITE ? DELTA_N : DELTA_S)) & pieces(PAWN, them))
+ if (pawn_attacks_from(from + (us == WHITE ? DELTA_N : DELTA_S), us) & pieces(PAWN, them))
{
st->epSquare = Square((int(from) + int(to)) / 2);
key ^= zobEp[st->epSquare];
// Update checkers bitboard, piece must be already moved
if (ep | pm)
- st->checkersBB = attacks_to(king_square(them), us);
+ st->checkersBB = attackers_to(king_square(them)) & pieces_of_color(us);
else
{
st->checkersBB = EmptyBoardBB;
// Update hash key
key ^= zobrist[them][capture][capsq];
- // If the captured piece was a pawn, update pawn hash key
- if (capture == PAWN)
- st->pawnKey ^= zobrist[them][PAWN][capsq];
-
// Update incremental scores
st->mgValue -= pst<MidGame>(them, capture, capsq);
st->egValue -= pst<EndGame>(them, capture, capsq);
- // Update material
- if (capture != PAWN)
+ // If the captured piece was a pawn, update pawn hash key,
+ // otherwise update non-pawn material.
+ if (capture == PAWN)
+ st->pawnKey ^= zobrist[them][PAWN][capsq];
+ else
st->npMaterial[them] -= piece_value_midgame(capture);
// Update material hash key
board[rto] = rook;
// Update king square
- kingSquare[us] = kto;
+ st->kingSquare[us] = kto;
// Update piece lists
pieceList[us][KING][index[kfrom]] = kto;
st->rule50 = 0;
// Update checkers BB
- st->checkersBB = attacks_to(king_square(them), us);
+ st->checkersBB = attackers_to(king_square(them)) & pieces_of_color(us);
// Finish
sideToMove = opposite_color(sideToMove);
board[from] = piece_of_color_and_type(us, pt);
board[to] = EMPTY;
- // If the moving piece was a king, update the king square
- if (pt == KING)
- kingSquare[us] = from;
-
// Update piece list
index[from] = index[to];
pieceList[us][pt][index[from]] = from;
board[rfrom] = piece_of_color_and_type(us, ROOK);
board[kfrom] = piece_of_color_and_type(us, KING);
- // Update king square
- kingSquare[us] = kfrom;
-
// Update piece lists
pieceList[us][KING][index[kto]] = kfrom;
pieceList[us][ROOK][index[rto]] = rfrom;
while (true)
{
clear_bit(&occ, from);
- attackers = (rook_attacks_bb(to, occ) & pieces(ROOK, QUEEN))
- | (bishop_attacks_bb(to, occ) & pieces(BISHOP, QUEEN))
- | (piece_attacks<KNIGHT>(to) & pieces(KNIGHT))
- | (piece_attacks<KING>(to) & pieces(KING))
- | (pawn_attacks(WHITE, to) & pieces(PAWN, BLACK))
- | (pawn_attacks(BLACK, to) & pieces(PAWN, WHITE));
+ attackers = (rook_attacks_bb(to, occ) & pieces(ROOK, QUEEN))
+ | (bishop_attacks_bb(to, occ) & pieces(BISHOP, QUEEN))
+ | (piece_attacks_from<KNIGHT>(to) & pieces(KNIGHT))
+ | (piece_attacks_from<KING>(to) & pieces(KING))
+ | (pawn_attacks_from(to, WHITE) & pieces(PAWN, BLACK))
+ | (pawn_attacks_from(to, BLACK) & pieces(PAWN, WHITE));
if (from != SQ_NONE)
break;
pieceCount[c][pt]++;
if (pt == KING)
- kingSquare[c] = s;
+ st->kingSquare[c] = s;
}
Color us = side_to_move();
Color them = opposite_color(us);
Square ksq = king_square(them);
- if (square_is_attacked(ksq, us))
+ if (attackers_to(ksq) & pieces_of_color(us))
return false;
}