using std::endl;
Key Position::zobrist[2][8][64];
-Key Position::zobEp[64];
+Key Position::zobEp[8];
Key Position::zobCastle[16];
Key Position::zobSideToMove;
Key Position::zobExclusion;
/// Position::set_castle_right() is an helper function used to set castling
/// rights given the corresponding color and the rook starting square.
-void Position::set_castle_right(Color c, Square rsq) {
+void Position::set_castle_right(Color c, Square rfrom) {
- int f = (rsq < king_square(c) ? WHITE_OOO : WHITE_OO) << c;
+ Square kfrom = king_square(c);
+ bool kingSide = kfrom < rfrom;
+ int cr = (kingSide ? WHITE_OO : WHITE_OOO) << c;
- st->castleRights |= f;
- castleRightsMask[king_square(c)] ^= f;
- castleRightsMask[rsq] ^= f;
- castleRookSquare[f] = rsq;
+ st->castleRights |= cr;
+ castleRightsMask[kfrom] |= cr;
+ castleRightsMask[rfrom] |= cr;
+ castleRookSquare[cr] = rfrom;
+
+ Square kto = relative_square(c, kingSide ? SQ_G1 : SQ_C1);
+ Square rto = relative_square(c, kingSide ? SQ_F1 : SQ_D1);
+
+ for (Square s = std::min(rfrom, rto); s <= std::max(rfrom, rto); s++)
+ if (s != kfrom && s != rfrom)
+ castlePath[cr] |= s;
+
+ for (Square s = std::min(kfrom, kto); s <= std::max(kfrom, kto); s++)
+ if (s != kfrom && s != rfrom)
+ castlePath[cr] |= s;
}
return (attacks_from<PAWN>(s, BLACK) & pieces(PAWN, WHITE))
| (attacks_from<PAWN>(s, WHITE) & pieces(PAWN, BLACK))
| (attacks_from<KNIGHT>(s) & pieces(KNIGHT))
- | (rook_attacks_bb(s, occ) & pieces(ROOK, QUEEN))
- | (bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN))
+ | (attacks_bb<ROOK>(s, occ) & pieces(ROOK, QUEEN))
+ | (attacks_bb<BISHOP>(s, occ) & pieces(BISHOP, QUEEN))
| (attacks_from<KING>(s) & pieces(KING));
}
switch (type_of(p))
{
- case BISHOP: return bishop_attacks_bb(s, occ);
- case ROOK : return rook_attacks_bb(s, occ);
- case QUEEN : return bishop_attacks_bb(s, occ) | rook_attacks_bb(s, occ);
+ case BISHOP: return attacks_bb<BISHOP>(s, occ);
+ case ROOK : return attacks_bb<ROOK>(s, occ);
+ case QUEEN : return attacks_bb<BISHOP>(s, occ) | attacks_bb<ROOK>(s, occ);
default : return StepAttacksBB[p][s];
}
}
Bitboard occ, xray;
Square from = from_sq(m);
Square to = to_sq(m);
- Piece piece = piece_on(from);
+ Piece piece = piece_moved(m);
assert(!square_is_empty(from));
// Update occupancy as if the piece is moving
- occ = occupied_squares();
- do_move_bb(&occ, make_move_bb(from, to));
+ occ = occupied_squares() ^ from ^ to;
// The piece moved in 'to' attacks the square 's' ?
- if (bit_is_set(attacks_from(piece, to, occ), s))
+ if (attacks_from(piece, to, occ) & s)
return true;
// Scan for possible X-ray attackers behind the moved piece
- xray = (rook_attacks_bb(s, occ) & pieces(ROOK, QUEEN, color_of(piece)))
- |(bishop_attacks_bb(s, occ) & pieces(BISHOP, QUEEN, color_of(piece)));
+ xray = (attacks_bb<ROOK>(s, occ) & pieces(ROOK, QUEEN, color_of(piece)))
+ |(attacks_bb<BISHOP>(s, occ) & pieces(BISHOP, QUEEN, color_of(piece)));
// Verify attackers are triggered by our move and not already existing
return xray && (xray ^ (xray & attacks_from<QUEEN>(s)));
Color us = sideToMove;
Square from = from_sq(m);
- assert(color_of(piece_on(from)) == us);
+ assert(color_of(piece_moved(m)) == us);
assert(piece_on(king_square(us)) == make_piece(us, KING));
// En passant captures are a tricky special case. Because they are rather
Square to = to_sq(m);
Square capsq = to + pawn_push(them);
Square ksq = king_square(us);
- Bitboard b = occupied_squares();
+ Bitboard b = (occupied_squares() ^ from ^ capsq) | to;
assert(to == ep_square());
- assert(piece_on(from) == make_piece(us, PAWN));
+ assert(piece_moved(m) == make_piece(us, PAWN));
assert(piece_on(capsq) == make_piece(them, PAWN));
assert(piece_on(to) == NO_PIECE);
- clear_bit(&b, from);
- clear_bit(&b, capsq);
- set_bit(&b, to);
-
- return !(rook_attacks_bb(ksq, b) & pieces(ROOK, QUEEN, them))
- && !(bishop_attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, them));
+ return !(attacks_bb<ROOK>(ksq, b) & pieces(ROOK, QUEEN, them))
+ && !(attacks_bb<BISHOP>(ksq, b) & pieces(BISHOP, QUEEN, them));
}
// If the moving piece is a king, check whether the destination
// 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 !pinned
- || !bit_is_set(pinned, from)
+ || !(pinned & from)
|| squares_aligned(from, to_sq(m), king_square(us));
}
Color them = ~sideToMove;
Square from = from_sq(m);
Square to = to_sq(m);
- Piece pc = piece_on(from);
+ Piece pc = piece_moved(m);
// Use a slower but simpler function for uncommon cases
if (is_special(m))
return move_is_legal(m);
// Is not a promotion, so promotion piece must be empty
- if (promotion_piece_type(m) - 2 != NO_PIECE_TYPE)
+ if (promotion_type(m) - 2 != NO_PIECE_TYPE)
return false;
// If the from square is not occupied by a piece belonging to the side to
return false;
}
}
- else if (!bit_is_set(attacks_from(pc, from), to))
+ else if (!(attacks_from(pc, from) & to))
return false;
// Evasions generator already takes care to avoid some kind of illegal moves
// same kind of moves are filtered out here.
if (in_check())
{
- // In case of king moves under check we have to remove king so to catch
- // as invalid moves like b1a1 when opposite queen is on c1.
- if (type_of(piece_on(from)) == KING)
- {
- Bitboard b = occupied_squares();
- clear_bit(&b, from);
- if (attackers_to(to_sq(m), b) & pieces(~us))
- return false;
- }
- else
+ if (type_of(pc) != KING)
{
- Bitboard target = checkers();
- Square checksq = pop_1st_bit(&target);
+ Bitboard b = checkers();
+ Square checksq = pop_1st_bit(&b);
- if (target) // double check ? In this case a king move is required
+ if (b) // double check ? In this case a king move is required
return false;
// Our move must be a blocking evasion or a capture of the checking piece
- target = squares_between(checksq, king_square(us)) | checkers();
- if (!bit_is_set(target, to_sq(m)))
+ if (!((squares_between(checksq, king_square(us)) | checkers()) & to))
return false;
}
+ // In case of king moves under check we have to remove king so to catch
+ // as invalid moves like b1a1 when opposite queen is on c1.
+ else if (attackers_to(to, occupied_squares() ^ from) & pieces(~us))
+ return false;
}
return true;
PieceType pt = type_of(piece_on(from));
// Direct check ?
- if (bit_is_set(ci.checkSq[pt], to))
+ if (ci.checkSq[pt] & to)
return true;
// Discovery check ?
- if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from))
+ if (ci.dcCandidates && (ci.dcCandidates & from))
{
// For pawn and king moves we need to verify also direction
if ( (pt != PAWN && pt != KING)
return false;
Color us = sideToMove;
- Bitboard b = occupied_squares();
Square ksq = king_square(~us);
// Promotion with check ?
if (is_promotion(m))
- {
- clear_bit(&b, from);
- return bit_is_set(attacks_from(Piece(promotion_piece_type(m)), to, b), ksq);
- }
+ return attacks_from(Piece(promotion_type(m)), to, occupied_squares() ^ from) & ksq;
// En passant capture with check ? We have already handled the case
// of direct checks and ordinary discovered check, the only case we
if (is_enpassant(m))
{
Square capsq = make_square(file_of(to), rank_of(from));
- clear_bit(&b, from);
- clear_bit(&b, capsq);
- set_bit(&b, to);
- return (rook_attacks_bb(ksq, b) & pieces(ROOK, QUEEN, us))
- ||(bishop_attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, us));
+ Bitboard b = (occupied_squares() ^ from ^ capsq) | to;
+
+ return (attacks_bb< ROOK>(ksq, b) & pieces( ROOK, QUEEN, us))
+ | (attacks_bb<BISHOP>(ksq, b) & pieces(BISHOP, QUEEN, us));
}
// Castling with check ?
if (is_castle(m))
{
- Square kfrom, kto, rfrom, rto;
- kfrom = from;
- rfrom = to;
+ Square kfrom = from;
+ Square rfrom = to; // 'King captures the rook' notation
+ Square kto = relative_square(us, rfrom > kfrom ? SQ_G1 : SQ_C1);
+ Square rto = relative_square(us, rfrom > kfrom ? SQ_F1 : SQ_D1);
+ Bitboard b = (occupied_squares() ^ kfrom ^ rfrom) | rto | kto;
- if (rfrom > kfrom)
- {
- kto = relative_square(us, SQ_G1);
- rto = relative_square(us, SQ_F1);
- } else {
- kto = relative_square(us, SQ_C1);
- rto = relative_square(us, SQ_D1);
- }
- clear_bit(&b, kfrom);
- clear_bit(&b, rfrom);
- set_bit(&b, rto);
- set_bit(&b, kto);
- return bit_is_set(rook_attacks_bb(rto, b), ksq);
+ return attacks_bb<ROOK>(rto, b) & ksq;
}
return false;
k ^= zobSideToMove;
// Increment the 50 moves rule draw counter. Resetting it to zero in the
- // case of non-reversible moves is taken care of later.
+ // case of a capture or a pawn move is taken care of later.
st->rule50++;
st->pliesFromNull++;
st->npMaterial[them] -= PieceValueMidgame[capture];
// Remove the captured piece
- clear_bit(&byColorBB[them], capsq);
- clear_bit(&byTypeBB[capture], capsq);
- clear_bit(&occupied, capsq);
+ byColorBB[them] ^= capsq;
+ byTypeBB[capture] ^= capsq;
+ occupied ^= capsq;
// Update piece list, move the last piece at index[capsq] position and
// shrink the list.
// Reset en passant square
if (st->epSquare != SQ_NONE)
{
- k ^= zobEp[st->epSquare];
+ k ^= zobEp[file_of(st->epSquare)];
st->epSquare = SQ_NONE;
}
// Update castle rights if needed
- if ( st->castleRights != CASTLES_NONE
- && (castleRightsMask[from] & castleRightsMask[to]) != ALL_CASTLES)
+ if (st->castleRights && (castleRightsMask[from] | castleRightsMask[to]))
{
- k ^= zobCastle[st->castleRights];
- st->castleRights &= castleRightsMask[from] & castleRightsMask[to];
- k ^= zobCastle[st->castleRights];
+ int cr = castleRightsMask[from] | castleRightsMask[to];
+ k ^= zobCastle[st->castleRights & cr];
+ st->castleRights &= ~cr;
}
// Prefetch TT access as soon as we know key is updated
prefetch((char*)TT.first_entry(k));
// Move the piece
- Bitboard move_bb = make_move_bb(from, to);
- do_move_bb(&byColorBB[us], move_bb);
- do_move_bb(&byTypeBB[pt], move_bb);
- do_move_bb(&occupied, move_bb);
+ Bitboard from_to_bb = SquareBB[from] | SquareBB[to];
+ byColorBB[us] ^= from_to_bb;
+ byTypeBB[pt] ^= from_to_bb;
+ occupied ^= from_to_bb;
board[to] = board[from];
board[from] = NO_PIECE;
if (pt == PAWN)
{
// Set en-passant square, only if moved pawn can be captured
- if ( (to ^ from) == 16
+ if ( (int(to) ^ int(from)) == 16
&& (attacks_from<PAWN>(from + pawn_push(us), us) & pieces(PAWN, them)))
{
st->epSquare = Square((from + to) / 2);
- k ^= zobEp[st->epSquare];
+ k ^= zobEp[file_of(st->epSquare)];
}
if (is_promotion(m))
{
- PieceType promotion = promotion_piece_type(m);
+ PieceType promotion = promotion_type(m);
assert(relative_rank(us, to) == RANK_8);
assert(promotion >= KNIGHT && promotion <= QUEEN);
// Replace the pawn with the promoted piece
- clear_bit(&byTypeBB[PAWN], to);
- set_bit(&byTypeBB[promotion], to);
+ byTypeBB[PAWN] ^= to;
+ byTypeBB[promotion] |= to;
board[to] = make_piece(us, promotion);
// Update piece lists, move the last pawn at index[to] position
else
{
// Direct checks
- if (bit_is_set(ci.checkSq[pt], to))
- st->checkersBB = SetMaskBB[to];
+ if (ci.checkSq[pt] & to)
+ st->checkersBB |= to;
// Discovery checks
- if (ci.dcCandidates && bit_is_set(ci.dcCandidates, from))
+ if (ci.dcCandidates && (ci.dcCandidates & from))
{
if (pt != ROOK)
st->checkersBB |= attacks_from<ROOK>(king_square(them)) & pieces(ROOK, QUEEN, us);
if (is_promotion(m))
{
- PieceType promotion = promotion_piece_type(m);
+ PieceType promotion = promotion_type(m);
assert(promotion == pt);
assert(relative_rank(us, to) == RANK_8);
assert(promotion >= KNIGHT && promotion <= QUEEN);
// Replace the promoted piece with the pawn
- clear_bit(&byTypeBB[promotion], to);
- set_bit(&byTypeBB[PAWN], to);
+ byTypeBB[promotion] ^= to;
+ byTypeBB[PAWN] |= to;
board[to] = make_piece(us, PAWN);
// Update piece lists, move the last promoted piece at index[to] position
}
// Put the piece back at the source square
- Bitboard move_bb = make_move_bb(to, from);
- do_move_bb(&byColorBB[us], move_bb);
- do_move_bb(&byTypeBB[pt], move_bb);
- do_move_bb(&occupied, move_bb);
+ Bitboard from_to_bb = SquareBB[from] | SquareBB[to];
+ byColorBB[us] ^= from_to_bb;
+ byTypeBB[pt] ^= from_to_bb;
+ occupied ^= from_to_bb;
board[from] = board[to];
board[to] = NO_PIECE;
}
// Restore the captured piece
- set_bit(&byColorBB[them], capsq);
- set_bit(&byTypeBB[capture], capsq);
- set_bit(&occupied, capsq);
+ byColorBB[them] |= capsq;
+ byTypeBB[capture] |= capsq;
+ occupied |= capsq;
board[capsq] = make_piece(them, capture);
assert(piece_on(rfrom) == make_piece(us, ROOK));
// Remove pieces from source squares
- clear_bit(&byColorBB[us], kfrom);
- clear_bit(&byTypeBB[KING], kfrom);
- clear_bit(&occupied, kfrom);
- clear_bit(&byColorBB[us], rfrom);
- clear_bit(&byTypeBB[ROOK], rfrom);
- clear_bit(&occupied, rfrom);
+ byColorBB[us] ^= kfrom;
+ byTypeBB[KING] ^= kfrom;
+ occupied ^= kfrom;
+ byColorBB[us] ^= rfrom;
+ byTypeBB[ROOK] ^= rfrom;
+ occupied ^= rfrom;
// Put pieces on destination squares
- set_bit(&byColorBB[us], kto);
- set_bit(&byTypeBB[KING], kto);
- set_bit(&occupied, kto);
- set_bit(&byColorBB[us], rto);
- set_bit(&byTypeBB[ROOK], rto);
- set_bit(&occupied, rto);
+ byColorBB[us] |= kto;
+ byTypeBB[KING] |= kto;
+ occupied |= kto;
+ byColorBB[us] |= rto;
+ byTypeBB[ROOK] |= rto;
+ occupied |= rto;
// Update board
Piece king = make_piece(us, KING);
// Clear en passant square
if (st->epSquare != SQ_NONE)
{
- st->key ^= zobEp[st->epSquare];
+ st->key ^= zobEp[file_of(st->epSquare)];
st->epSquare = SQ_NONE;
}
// Update castling rights
- st->key ^= zobCastle[st->castleRights];
- st->castleRights &= castleRightsMask[kfrom];
- st->key ^= zobCastle[st->castleRights];
-
- // Reset rule 50 counter
- st->rule50 = 0;
+ st->key ^= zobCastle[st->castleRights & castleRightsMask[kfrom]];
+ st->castleRights &= ~castleRightsMask[kfrom];
// Update checkers BB
st->checkersBB = attackers_to(king_square(~us)) & pieces(us);
if (Do)
{
if (st->epSquare != SQ_NONE)
- st->key ^= zobEp[st->epSquare];
+ st->key ^= zobEp[file_of(st->epSquare)];
st->key ^= zobSideToMove;
prefetch((char*)TT.first_entry(st->key));
assert(is_ok(m));
- Square from = from_sq(m);
- Square to = to_sq(m);
-
// Early return if SEE cannot be negative because captured piece value
// is not less then capturing one. Note that king moves always return
// here because king midgame value is set to 0.
- if (PieceValueMidgame[piece_on(to)] >= PieceValueMidgame[piece_on(from)])
+ if (PieceValueMidgame[piece_on(to_sq(m))] >= PieceValueMidgame[piece_moved(m)])
return 1;
return see(m);
assert(type_of(piece_on(capQq)) == PAWN);
// Remove the captured pawn
- clear_bit(&occ, capQq);
+ occ ^= capQq;
capturedType = PAWN;
}
// Find all attackers to the destination square, with the moving piece
// removed, but possibly an X-ray attacker added behind it.
- clear_bit(&occ, from);
+ occ ^= from;
attackers = attackers_to(to, occ);
// If the opponent has no attackers we are finished
// and scan for new X-ray attacks behind the attacker.
b = stmAttackers & pieces(pt);
occ ^= (b & (~b + 1));
- attackers |= (rook_attacks_bb(to, occ) & pieces(ROOK, QUEEN))
- | (bishop_attacks_bb(to, occ) & pieces(BISHOP, QUEEN));
+ attackers |= (attacks_bb<ROOK>(to, occ) & pieces(ROOK, QUEEN))
+ | (attacks_bb<BISHOP>(to, occ) & pieces(BISHOP, QUEEN));
attackers &= occ; // Cut out pieces we've already done
void Position::clear() {
+ memset(this, 0, sizeof(Position));
+ startState.epSquare = SQ_NONE;
st = &startState;
- memset(st, 0, sizeof(StateInfo));
- st->epSquare = SQ_NONE;
-
- memset(byColorBB, 0, sizeof(Bitboard) * 2);
- memset(byTypeBB, 0, sizeof(Bitboard) * 8);
- memset(pieceCount, 0, sizeof(int) * 2 * 8);
- memset(index, 0, sizeof(int) * 64);
for (int i = 0; i < 8; i++)
for (int j = 0; j < 16; j++)
pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE;
for (Square sq = SQ_A1; sq <= SQ_H8; sq++)
- {
board[sq] = NO_PIECE;
- castleRightsMask[sq] = ALL_CASTLES;
- }
- sideToMove = WHITE;
- nodes = 0;
- occupied = 0;
}
index[s] = pieceCount[c][pt]++;
pieceList[c][pt][index[s]] = s;
- set_bit(&byTypeBB[pt], s);
- set_bit(&byColorBB[c], s);
- set_bit(&occupied, s);
+ byTypeBB[pt] |= s;
+ byColorBB[c] |= s;
+ occupied |= s;
}
result ^= zobrist[color_of(piece_on(s))][type_of(piece_on(s))][s];
if (ep_square() != SQ_NONE)
- result ^= zobEp[ep_square()];
+ result ^= zobEp[file_of(ep_square())];
if (sideToMove == BLACK)
result ^= zobSideToMove;
for (Square s = SQ_A1; s <= SQ_H8; s++)
zobrist[c][pt][s] = rk.rand<Key>();
- for (Square s = SQ_A1; s <= SQ_H8; s++)
- zobEp[s] = rk.rand<Key>();
+ for (File f = FILE_A; f <= FILE_H; f++)
+ zobEp[f] = rk.rand<Key>();
- for (int i = 0; i < 16; i++)
- zobCastle[i] = rk.rand<Key>();
+ for (int cr = CASTLES_NONE; cr <= ALL_CASTLES; cr++)
+ {
+ Bitboard b = cr;
+ while (b)
+ {
+ Key k = zobCastle[1 << pop_1st_bit(&b)];
+ zobCastle[cr] ^= k ? k : rk.rand<Key>();
+ }
+ }
zobSideToMove = rk.rand<Key>();
zobExclusion = rk.rand<Key>();
if (debugBitboards)
{
// The intersection of the white and black pieces must be empty
- if (!(pieces(WHITE) & pieces(BLACK)))
+ if (pieces(WHITE) & pieces(BLACK))
return false;
// The union of the white and black pieces must be equal to all
Piece rook = (f & (WHITE_OO | WHITE_OOO) ? W_ROOK : B_ROOK);
- if ( castleRightsMask[castleRookSquare[f]] != (ALL_CASTLES ^ f)
- || piece_on(castleRookSquare[f]) != rook)
+ if ( piece_on(castleRookSquare[f]) != rook
+ || castleRightsMask[castleRookSquare[f]] != f)
return false;
}
projects / stockfish / blobdiff