if (move_is_castle(m))
do_castle_move(m);
- else if (move_is_promotion(m))
- do_promotion_move(m);
else
{
Color us = side_to_move();
Square from = move_from(m);
Square to = move_to(m);
bool ep = move_is_ep(m);
-
- assert(color_of_piece_on(from) == us);
- assert(color_of_piece_on(to) == them || piece_on(to) == EMPTY);
- assert(!ep || piece_on(from) == piece_of_color_and_type(us, PAWN));
+ bool pm = move_is_promotion(m);
Piece piece = piece_on(from);
PieceType pt = type_of_piece(piece);
- st->capture = type_of_piece_on(to);
+ assert(color_of_piece_on(from) == us);
+ assert(color_of_piece_on(to) == them || square_is_empty(to));
+ assert(!(ep || pm) || piece == piece_of_color_and_type(us, PAWN));
+ assert(!pm || relative_rank(us, to) == RANK_8);
+
+ st->capture = ep ? PAWN : type_of_piece_on(to);
- if (st->capture || ep)
+ if (st->capture)
do_capture_move(st->capture, them, to, ep);
// Update hash key
pieceList[us][pt][index[from]] = to;
index[to] = index[from];
+ if (pm)
+ {
+ PieceType promotion = move_promotion_piece(m);
+
+ assert(promotion >= KNIGHT && promotion <= QUEEN);
+
+ // Insert promoted piece instead of pawn
+ clear_bit(&(byTypeBB[PAWN]), to);
+ set_bit(&(byTypeBB[promotion]), to);
+ board[to] = piece_of_color_and_type(us, promotion);
+
+ // Partially revert hash keys update
+ st->key ^= zobrist[us][PAWN][to] ^ zobrist[us][promotion][to];
+ st->pawnKey ^= zobrist[us][PAWN][to];
+
+ // Update material key
+ st->materialKey ^= zobMaterial[us][PAWN][pieceCount[us][PAWN]];
+ st->materialKey ^= zobMaterial[us][promotion][pieceCount[us][promotion]+1];
+
+ // Update piece counts
+ pieceCount[us][PAWN]--;
+ pieceCount[us][promotion]++;
+
+ // Update piece lists
+ pieceList[us][PAWN][index[from]] = pieceList[us][PAWN][pieceCount[us][PAWN]];
+ index[pieceList[us][PAWN][index[from]]] = index[from];
+ pieceList[us][promotion][pieceCount[us][promotion] - 1] = to;
+ index[to] = pieceCount[us][promotion] - 1;
+
+ // Partially revert and update incremental scores
+ st->mgValue -= pst<MidGame>(us, PAWN, to);
+ st->mgValue += pst<MidGame>(us, promotion, to);
+ st->egValue -= pst<EndGame>(us, PAWN, to);
+ st->egValue += pst<EndGame>(us, promotion, to);
+
+ // Update material
+ st->npMaterial[us] += piece_value_midgame(promotion);
+ }
+
// Update checkers bitboard, piece must be already moved
- if (ep)
+ if (ep || pm)
st->checkersBB = attacks_to(king_square(them), us);
else
{
if (ep)
{
- capture = PAWN;
capsq = (them == BLACK)? (to - DELTA_N) : (to - DELTA_S);
assert(to == st->epSquare);
- assert(relative_rank(us, to) == RANK_6);
+ assert(relative_rank(opposite_color(them), to) == RANK_6);
assert(piece_on(to) == EMPTY);
//assert(piece_on(from) == piece_of_color_and_type(us, PAWN));
assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN));
}
-/// Position::do_promotion_move() is a private method used to make a promotion
-/// move. It is called from the main Position::do_move function.
-
-void Position::do_promotion_move(Move m) {
-
- Color us, them;
- Square from, to;
- PieceType promotion;
-
- assert(is_ok());
- assert(move_is_ok(m));
- assert(move_is_promotion(m));
-
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- to = move_to(m);
-
- assert(relative_rank(us, to) == RANK_8);
- assert(piece_on(from) == piece_of_color_and_type(us, PAWN));
- assert(color_of_piece_on(to) == them || square_is_empty(to));
-
- st->capture = type_of_piece_on(to);
-
- if (st->capture)
- do_capture_move(st->capture, them, to, false);
-
- // Remove pawn
- clear_bit(&(byColorBB[us]), from);
- clear_bit(&(byTypeBB[PAWN]), from);
- clear_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares
- board[from] = EMPTY;
-
- // Insert promoted piece
- promotion = move_promotion_piece(m);
- assert(promotion >= KNIGHT && promotion <= QUEEN);
- set_bit(&(byColorBB[us]), to);
- set_bit(&(byTypeBB[promotion]), to);
- set_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares
- board[to] = piece_of_color_and_type(us, promotion);
-
- // Update hash key
- st->key ^= zobrist[us][PAWN][from] ^ zobrist[us][promotion][to];
-
- // Update pawn hash key
- st->pawnKey ^= zobrist[us][PAWN][from];
-
- // Update material key
- st->materialKey ^= zobMaterial[us][PAWN][pieceCount[us][PAWN]];
- st->materialKey ^= zobMaterial[us][promotion][pieceCount[us][promotion]+1];
-
- // Update piece counts
- pieceCount[us][PAWN]--;
- pieceCount[us][promotion]++;
-
- // Update piece lists
- pieceList[us][PAWN][index[from]] = pieceList[us][PAWN][pieceCount[us][PAWN]];
- index[pieceList[us][PAWN][index[from]]] = index[from];
- pieceList[us][promotion][pieceCount[us][promotion] - 1] = to;
- index[to] = pieceCount[us][promotion] - 1;
-
- // Update incremental scores
- st->mgValue -= pst<MidGame>(us, PAWN, from);
- st->mgValue += pst<MidGame>(us, promotion, to);
- st->egValue -= pst<EndGame>(us, PAWN, from);
- st->egValue += pst<EndGame>(us, promotion, to);
-
- // Update material
- st->npMaterial[us] += piece_value_midgame(promotion);
-
- // Clear the en passant square
- if (st->epSquare != SQ_NONE)
- {
- st->key ^= zobEp[st->epSquare];
- st->epSquare = SQ_NONE;
- }
-
- // Update castle rights
- st->key ^= zobCastle[st->castleRights];
- st->castleRights &= castleRightsMask[to];
- st->key ^= zobCastle[st->castleRights];
-
- // Reset rule 50 counter
- st->rule50 = 0;
-
- // Update checkers BB
- st->checkersBB = attacks_to(king_square(them), us);
-}
-
-
/// Position::undo_move() unmakes a move. When it returns, the position should
/// be restored to exactly the same state as before the move was made.
if (move_is_castle(m))
undo_castle_move(m);
- else if (move_is_promotion(m))
- undo_promotion_move(m);
- else if (move_is_ep(m))
- undo_ep_move(m);
else
{
- Color us, them;
- Square from, to;
- PieceType piece;
+ Color us = side_to_move();
+ Color them = opposite_color(us);
+ Square from = move_from(m);
+ Square to = move_to(m);
+ bool ep = move_is_ep(m);
+ bool pm = move_is_promotion(m);
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- to = move_to(m);
+ PieceType piece = type_of_piece_on(to);
- assert(piece_on(from) == EMPTY);
+ assert(square_is_empty(from));
assert(color_of_piece_on(to) == us);
+ assert(!pm || relative_rank(us, to) == RANK_8);
+ assert(!ep || to == st->previous->epSquare);
+ assert(!ep || relative_rank(us, to) == RANK_6);
+ assert(!ep || piece_on(to) == piece_of_color_and_type(us, PAWN));
+
+ if (pm)
+ {
+ PieceType promotion = move_promotion_piece(m);
+
+ assert(piece_on(to) == piece_of_color_and_type(us, promotion));
+ assert(promotion >= KNIGHT && promotion <= QUEEN);
+
+ // Replace promoted piece with a pawn
+ clear_bit(&(byTypeBB[promotion]), to);
+ set_bit(&(byTypeBB[PAWN]), to);
+
+ // Update piece list replacing promotion piece with a pawn
+ pieceList[us][promotion][index[to]] = pieceList[us][promotion][pieceCount[us][promotion] - 1];
+ index[pieceList[us][promotion][index[to]]] = index[to];
+ pieceList[us][PAWN][pieceCount[us][PAWN]] = to;
+ index[to] = pieceCount[us][PAWN];
+
+ // Update piece counts
+ pieceCount[us][promotion]--;
+ pieceCount[us][PAWN]++;
+
+ piece = PAWN;
+ }
// Put the piece back at the source square
Bitboard move_bb = make_move_bb(to, from);
- piece = type_of_piece_on(to);
do_move_bb(&(byColorBB[us]), move_bb);
do_move_bb(&(byTypeBB[piece]), move_bb);
do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares
board[from] = piece_of_color_and_type(us, piece);
+ board[to] = EMPTY;
// If the moving piece was a king, update the king square
if (piece == KING)
if (st->capture)
{
+ Square capsq = to;
+
+ if (ep)
+ capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S);
+
assert(st->capture != KING);
+ assert(!ep || square_is_empty(capsq));
// Restore the captured piece
- set_bit(&(byColorBB[them]), to);
- set_bit(&(byTypeBB[st->capture]), to);
- set_bit(&(byTypeBB[0]), to);
- board[to] = piece_of_color_and_type(them, st->capture);
+ set_bit(&(byColorBB[them]), capsq);
+ set_bit(&(byTypeBB[st->capture]), capsq);
+ set_bit(&(byTypeBB[0]), capsq);
+ board[capsq] = piece_of_color_and_type(them, st->capture);
// Update piece list
- pieceList[them][st->capture][pieceCount[them][st->capture]] = to;
- index[to] = pieceCount[them][st->capture];
+ pieceList[them][st->capture][pieceCount[them][st->capture]] = capsq;
+ index[capsq] = pieceCount[them][st->capture];
// Update piece count
pieceCount[them][st->capture]++;
- } else
- board[to] = EMPTY;
+ }
}
// Finally point our state pointer back to the previous state
}
-/// Position::undo_promotion_move() is a private method used to unmake a
-/// promotion move. It is called from the main Position::do_move
-/// function.
-
-void Position::undo_promotion_move(Move m) {
-
- Color us, them;
- Square from, to;
- PieceType promotion;
-
- assert(move_is_ok(m));
- assert(move_is_promotion(m));
-
- // When we have arrived here, some work has already been done by
- // Position::undo_move. In particular, the side to move has been switched,
- // so the code below is correct.
- us = side_to_move();
- them = opposite_color(us);
- from = move_from(m);
- to = move_to(m);
-
- assert(relative_rank(us, to) == RANK_8);
- assert(piece_on(from) == EMPTY);
-
- // Remove promoted piece
- promotion = move_promotion_piece(m);
- assert(piece_on(to)==piece_of_color_and_type(us, promotion));
- assert(promotion >= KNIGHT && promotion <= QUEEN);
- clear_bit(&(byColorBB[us]), to);
- clear_bit(&(byTypeBB[promotion]), to);
- clear_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares
-
- // Insert pawn at source square
- set_bit(&(byColorBB[us]), from);
- set_bit(&(byTypeBB[PAWN]), from);
- set_bit(&(byTypeBB[0]), from); // HACK: byTypeBB[0] == occupied squares
- board[from] = piece_of_color_and_type(us, PAWN);
-
- // Update piece list
- pieceList[us][PAWN][pieceCount[us][PAWN]] = from;
- index[from] = pieceCount[us][PAWN];
- pieceList[us][promotion][index[to]] =
- pieceList[us][promotion][pieceCount[us][promotion] - 1];
- index[pieceList[us][promotion][index[to]]] = index[to];
-
- // Update piece counts
- pieceCount[us][promotion]--;
- pieceCount[us][PAWN]++;
-
- if (st->capture)
- {
- assert(st->capture != KING);
-
- // Insert captured piece:
- set_bit(&(byColorBB[them]), to);
- set_bit(&(byTypeBB[st->capture]), to);
- set_bit(&(byTypeBB[0]), to); // HACK: byTypeBB[0] == occupied squares
- board[to] = piece_of_color_and_type(them, st->capture);
-
- // Update piece list
- pieceList[them][st->capture][pieceCount[them][st->capture]] = to;
- index[to] = pieceCount[them][st->capture];
-
- // Update piece count
- pieceCount[them][st->capture]++;
- } else
- board[to] = EMPTY;
-}
-
-
-/// Position::undo_ep_move() is a private method used to unmake an en passant
-/// capture. It is called from the main Position::undo_move function.
-
-void Position::undo_ep_move(Move m) {
-
- assert(move_is_ok(m));
- assert(move_is_ep(m));
-
- // When we have arrived here, some work has already been done by
- // Position::undo_move. In particular, the side to move has been switched,
- // so the code below is correct.
- Color us = side_to_move();
- Color them = opposite_color(us);
- Square from = move_from(m);
- Square to = move_to(m);
- Square capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S);
-
- assert(to == st->previous->epSquare);
- assert(relative_rank(us, to) == RANK_6);
- assert(piece_on(to) == piece_of_color_and_type(us, PAWN));
- assert(piece_on(from) == EMPTY);
- assert(piece_on(capsq) == EMPTY);
-
- // Restore captured pawn
- set_bit(&(byColorBB[them]), capsq);
- set_bit(&(byTypeBB[PAWN]), capsq);
- set_bit(&(byTypeBB[0]), capsq);
- board[capsq] = piece_of_color_and_type(them, PAWN);
-
- // Move capturing pawn back to source square
- Bitboard move_bb = make_move_bb(to, from);
- do_move_bb(&(byColorBB[us]), move_bb);
- do_move_bb(&(byTypeBB[PAWN]), move_bb);
- do_move_bb(&(byTypeBB[0]), move_bb);
- board[to] = EMPTY;
- board[from] = piece_of_color_and_type(us, PAWN);
-
- // Update piece list
- pieceList[us][PAWN][index[to]] = from;
- index[from] = index[to];
- pieceList[them][PAWN][pieceCount[them][PAWN]] = capsq;
- index[capsq] = pieceCount[them][PAWN];
-
- // Update piece count
- pieceCount[them][PAWN]++;
-}
-
-
/// Position::do_null_move makes() a "null move": It switches the side to move
/// and updates the hash key without executing any move on the board.