/// Position::pl_move_is_legal() tests whether a pseudo-legal move is legal
-bool Position::pl_move_is_legal(Move m) const {
-
- // If we're in check, all pseudo-legal moves are legal, because our
- // check evasion generator only generates true legal moves.
- return is_check() || pl_move_is_legal(m, pinned_pieces(side_to_move()));
-}
-
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()));
- assert(!is_check());
// Castling moves are checked for legality during move generation.
if (move_is_castle(m))
assert(color_of_piece_on(from) == us);
assert(piece_on(king_square(us)) == piece_of_color_and_type(us, KING));
- // En passant captures are a tricky special case. Because they are
+ // En passant captures are a tricky special case. Because they are
// rather uncommon, we do it simply by testing whether the king is attacked
// after the move is made
if (move_is_ep(m))
}
+/// Position::pl_move_is_evasion() tests whether a pseudo-legal move is a legal evasion
+
+bool Position::pl_move_is_evasion(Move m, Bitboard pinned) const
+{
+ assert(pos.is_check());
+
+ Color us = side_to_move();
+ Square from = move_from(m);
+ Square to = move_to(m);
+
+ // King moves and en-passant captures are verified in pl_move_is_legal()
+ if (type_of_piece_on(from) == KING || move_is_ep(m))
+ return pl_move_is_legal(m, pinned);
+
+ Bitboard target = checkers();
+ Square checksq = pop_1st_bit(&target);
+
+ if (target) // double check ?
+ return false;
+
+ // Our move must be a blocking evasion or a capture of the checking piece
+ target = squares_between(checksq, king_square(us)) | checkers();
+ return bit_is_set(target, to) && pl_move_is_legal(m, pinned);
+}
+
+
/// Position::move_is_check() tests whether a pseudo-legal move is a check
bool Position::move_is_check(Move m) const {
// pointer to point to the new, ready to be updated, state.
struct ReducedStateInfo {
Key key, pawnKey, materialKey;
- int castleRights, rule50;
- Square kingSquare[2], epSquare;
+ int castleRights, rule50, pliesFromNull;
+ Square epSquare;
Value mgValue, egValue;
Value npMaterial[2];
};
// Increment the 50 moves rule draw counter. Resetting it to zero in the
// case of non-reversible moves is taken care of later.
st->rule50++;
+ st->pliesFromNull++;
if (move_is_castle(m))
{
board[to] = board[from];
board[from] = EMPTY;
- // If the moving piece was a king, update the king square
- if (pt == KING)
- 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
// by known occupied squares.
Square lastPawnSquare = pieceList[us][PAWN][pieceCount[us][PAWN]];
index[lastPawnSquare] = index[to];
pieceList[us][PAWN][index[lastPawnSquare]] = lastPawnSquare;
+ pieceList[us][PAWN][pieceCount[us][PAWN]] = SQ_NONE;
index[to] = pieceCount[us][promotion] - 1;
pieceList[us][promotion][index[to]] = to;
Square lastPieceSquare = pieceList[them][capture][pieceCount[them][capture]];
index[lastPieceSquare] = index[capsq];
pieceList[them][capture][index[lastPieceSquare]] = lastPieceSquare;
+ pieceList[them][capture][pieceCount[them][capture]] = SQ_NONE;
// Reset rule 50 counter
st->rule50 = 0;
rto = relative_square(us, SQ_D1);
}
- // Move the pieces
- Bitboard kmove_bb = make_move_bb(kfrom, kto);
- do_move_bb(&(byColorBB[us]), kmove_bb);
- do_move_bb(&(byTypeBB[KING]), kmove_bb);
- do_move_bb(&(byTypeBB[0]), kmove_bb); // HACK: byTypeBB[0] == occupied squares
-
- Bitboard rmove_bb = make_move_bb(rfrom, rto);
- do_move_bb(&(byColorBB[us]), rmove_bb);
- do_move_bb(&(byTypeBB[ROOK]), rmove_bb);
- do_move_bb(&(byTypeBB[0]), rmove_bb); // HACK: byTypeBB[0] == occupied squares
-
+ // Remove pieces from source squares:
+ clear_bit(&(byColorBB[us]), kfrom);
+ clear_bit(&(byTypeBB[KING]), kfrom);
+ clear_bit(&(byTypeBB[0]), kfrom); // HACK: byTypeBB[0] == occupied squares
+ clear_bit(&(byColorBB[us]), rfrom);
+ clear_bit(&(byTypeBB[ROOK]), rfrom);
+ clear_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares
+
+ // Put pieces on destination squares:
+ set_bit(&(byColorBB[us]), kto);
+ set_bit(&(byTypeBB[KING]), kto);
+ set_bit(&(byTypeBB[0]), kto); // HACK: byTypeBB[0] == occupied squares
+ set_bit(&(byColorBB[us]), rto);
+ set_bit(&(byTypeBB[ROOK]), rto);
+ set_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares
+
// Update board array
Piece king = piece_of_color_and_type(us, KING);
Piece rook = piece_of_color_and_type(us, ROOK);
board[kto] = king;
board[rto] = rook;
- // Update king square
- st->kingSquare[us] = kto;
-
// Update piece lists
pieceList[us][KING][index[kfrom]] = kto;
pieceList[us][ROOK][index[rfrom]] = rto;
Square lastPromotionSquare = pieceList[us][promotion][pieceCount[us][promotion]];
index[lastPromotionSquare] = index[to];
pieceList[us][promotion][index[lastPromotionSquare]] = lastPromotionSquare;
+ pieceList[us][promotion][pieceCount[us][promotion]] = SQ_NONE;
index[to] = pieceCount[us][PAWN] - 1;
pieceList[us][PAWN][index[to]] = to;
}
+
// Put the piece back at the source square
Bitboard move_bb = make_move_bb(to, from);
do_move_bb(&(byColorBB[us]), move_bb);
assert(piece_on(kto) == piece_of_color_and_type(us, KING));
assert(piece_on(rto) == piece_of_color_and_type(us, ROOK));
-
- // Put the pieces back at the source square
- Bitboard kmove_bb = make_move_bb(kto, kfrom);
- do_move_bb(&(byColorBB[us]), kmove_bb);
- do_move_bb(&(byTypeBB[KING]), kmove_bb);
- do_move_bb(&(byTypeBB[0]), kmove_bb); // HACK: byTypeBB[0] == occupied squares
-
- Bitboard rmove_bb = make_move_bb(rto, rfrom);
- do_move_bb(&(byColorBB[us]), rmove_bb);
- do_move_bb(&(byTypeBB[ROOK]), rmove_bb);
- do_move_bb(&(byTypeBB[0]), rmove_bb); // HACK: byTypeBB[0] == occupied squares
+
+ // Remove pieces from destination squares:
+ clear_bit(&(byColorBB[us]), kto);
+ clear_bit(&(byTypeBB[KING]), kto);
+ clear_bit(&(byTypeBB[0]), kto); // HACK: byTypeBB[0] == occupied squares
+ clear_bit(&(byColorBB[us]), rto);
+ clear_bit(&(byTypeBB[ROOK]), rto);
+ clear_bit(&(byTypeBB[0]), rto); // HACK: byTypeBB[0] == occupied squares
+
+ // Put pieces on source squares:
+ set_bit(&(byColorBB[us]), kfrom);
+ set_bit(&(byTypeBB[KING]), kfrom);
+ set_bit(&(byTypeBB[0]), kfrom); // HACK: byTypeBB[0] == occupied squares
+ set_bit(&(byColorBB[us]), rfrom);
+ set_bit(&(byTypeBB[ROOK]), rfrom);
+ set_bit(&(byTypeBB[0]), rfrom); // HACK: byTypeBB[0] == occupied squares
// Update board
board[rto] = board[kto] = EMPTY;
backupSt.mgValue = st->mgValue;
backupSt.egValue = st->egValue;
backupSt.previous = st->previous;
+ backupSt.pliesFromNull = st->pliesFromNull;
st->previous = &backupSt;
// Save the current key to the history[] array, in order to be able to
sideToMove = opposite_color(sideToMove);
st->epSquare = SQ_NONE;
st->rule50++;
+ st->pliesFromNull = 0;
gamePly++;
st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame;
st->mgValue = backupSt->mgValue;
st->egValue = backupSt->egValue;
st->previous = backupSt->previous;
+ st->pliesFromNull = backupSt->pliesFromNull;
// Update the necessary information
sideToMove = opposite_color(sideToMove);
0, 0
};
- Bitboard attackers, stmAttackers, occ, b;
+ Bitboard attackers, stmAttackers, b;
assert(square_is_ok(from) || from == SQ_NONE);
assert(square_is_ok(to));
// Initialize pieces
Piece piece = piece_on(from);
Piece capture = piece_on(to);
+ Bitboard occ = occupied_squares();
- // Find all attackers to the destination square, with the moving piece
- // removed, but possibly an X-ray attacker added behind it.
- occ = occupied_squares();
+ // King cannot be recaptured
+ if (type_of_piece(piece) == KING)
+ return seeValues[capture];
// Handle en passant moves
if (st->epSquare == to && type_of_piece_on(from) == PAWN)
while (true)
{
+ // 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);
attackers = (rook_attacks_bb(to, occ) & pieces(ROOK, QUEEN))
| (bishop_attacks_bb(to, occ) & pieces(BISHOP, QUEEN))
for (int i = 0; i < 64; i++)
board[i] = EMPTY;
- for (int i = 0; i < 7; i++)
- for (int j = 0; j < 8; j++)
+ for (int i = 0; i < 8; i++)
+ for (int j = 0; j < 16; j++)
pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE;
sideToMove = WHITE;
set_bit(&byTypeBB[0], s); // HACK: byTypeBB[0] contains all occupied squares.
pieceCount[c][pt]++;
-
- if (pt == KING)
- st->kingSquare[c] = s;
}
return true;
// Draw by repetition?
- for (int i = 2; i < Min(gamePly, st->rule50); i += 2)
+ for (int i = 2; i < Min(Min(gamePly, st->rule50), st->pliesFromNull); i += 2)
if (history[gamePly - i] == st->key)
return true;
bool Position::is_mate() const {
MoveStack moves[256];
-
- return is_check() && (generate_evasions(*this, moves, pinned_pieces(sideToMove)) == moves);
+ return is_check() && (generate_moves(*this, moves, false) == moves);
}
MoveStack mlist[120];
bool result = false;
- Bitboard dc = discovered_check_candidates(sideToMove);
Bitboard pinned = pinned_pieces(sideToMove);
// Generate pseudo-legal non-capture and capture check moves
- MoveStack* last = generate_non_capture_checks(*this, mlist, dc);
+ MoveStack* last = generate_non_capture_checks(*this, mlist);
last = generate_captures(*this, last);
// Loop through the moves, and see if one of them is mate
projects / stockfish / blobdiff