};
memcpy(&newSt, st, sizeof(ReducedStateInfo));
- newSt.capture = NO_PIECE_TYPE;
newSt.previous = st;
st = &newSt;
}
// Update castle rights, try to shortcut a common case
- if ((castleRightsMask[from] & castleRightsMask[to]) != ALL_CASTLES)
+ int cm = castleRightsMask[from] & castleRightsMask[to];
+ if (cm != ALL_CASTLES && ((cm & st->castleRights) != st->castleRights))
{
key ^= zobCastle[st->castleRights];
st->castleRights &= castleRightsMask[from];
if (pt == KING)
kingSquare[us] = to;
- // Update piece lists
- pieceList[us][pt][index[from]] = 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.
index[to] = index[from];
+ pieceList[us][pt][index[to]] = to;
// If the moving piece was a pawn do some special extra work
if (pt == PAWN)
// Set en passant square, only if moved pawn can be captured
if (abs(int(to) - int(from)) == 16)
{
- if ( (us == WHITE && (pawn_attacks(WHITE, from + DELTA_N) & pawns(BLACK)))
- || (us == BLACK && (pawn_attacks(BLACK, from + DELTA_S) & pawns(WHITE))))
- {
+ if (pawn_attacks(us, from + (us == WHITE ? DELTA_N : DELTA_S)) & pawns(them))
+ {
st->epSquare = Square((int(from) + int(to)) / 2);
key ^= zobEp[st->epSquare];
}
st->mgValue += pst_delta<MidGame>(piece, from, to);
st->egValue += pst_delta<EndGame>(piece, from, to);
- if (pm)
+ if (pm) // promotion ?
{
PieceType promotion = move_promotion_piece(m);
set_bit(&(byTypeBB[promotion]), to);
board[to] = piece_of_color_and_type(us, promotion);
+ // 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;
+ // Update piece lists, move the last pawn at index[to] position
+ // and shrink the list. Add a new promotion piece to the list.
+ Square lastPawnSquare = pieceList[us][PAWN][pieceCount[us][PAWN]];
+ index[lastPawnSquare] = index[to];
+ pieceList[us][PAWN][index[lastPawnSquare]] = lastPawnSquare;
index[to] = pieceCount[us][promotion] - 1;
+ pieceList[us][promotion][index[to]] = to;
// Partially revert hash keys update
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];
-
// Partially revert and update incremental scores
st->mgValue -= pst<MidGame>(us, PAWN, to);
st->mgValue += pst<MidGame>(us, promotion, to);
st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame;
st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame;
+
+ assert(is_ok());
}
Square capsq = to;
- if (ep)
+ if (ep) // en passant ?
{
capsq = (them == BLACK)? (to - DELTA_N) : (to - DELTA_S);
assert(to == st->epSquare);
assert(relative_rank(opposite_color(them), to) == RANK_6);
assert(piece_on(to) == EMPTY);
- assert(piece_on(from) == piece_of_color_and_type(opposite_color(them), PAWN));
assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN));
board[capsq] = EMPTY;
// Update piece count
pieceCount[them][capture]--;
- // Update piece list
- pieceList[them][capture][index[capsq]] = pieceList[them][capture][pieceCount[them][capture]];
- index[pieceList[them][capture][index[capsq]]] = index[capsq];
+ // Update piece list, move the last piece at index[capsq] position
+ //
+ // WARNING: this is a not perfectly revresible operation. When we
+ // will reinsert the captured piece in undo_move() we will put it
+ // at the end of the list and not in its original place, it means
+ // index[] and pieceList[] are not guaranteed to be invariant to a
+ // do_move() + undo_move() sequence.
+ Square lastPieceSquare = pieceList[them][capture][pieceCount[them][capture]];
+ index[lastPieceSquare] = index[capsq];
+ pieceList[them][capture][index[lastPieceSquare]] = lastPieceSquare;
// Reset rule 50 counter
st->rule50 = 0;
void Position::do_castle_move(Move m) {
- assert(is_ok());
assert(move_is_ok(m));
assert(move_is_castle(m));
Color us = side_to_move();
Color them = opposite_color(us);
+ // Reset capture field
+ st->capture = NO_PIECE_TYPE;
+
// Find source squares for king and rook
Square kfrom = move_from(m);
Square rfrom = move_to(m); // HACK: See comment at beginning of function
// Update piece lists
pieceList[us][KING][index[kfrom]] = kto;
pieceList[us][ROOK][index[rfrom]] = rto;
- int tmp = index[rfrom];
+ int tmp = index[rfrom]; // In Chess960 could be rto == kfrom
index[kto] = index[kfrom];
index[rto] = tmp;
st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame;
st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame;
+
+ assert(is_ok());
}
assert(!ep || relative_rank(us, to) == RANK_6);
assert(!ep || piece_on(to) == piece_of_color_and_type(us, PAWN));
- if (pm)
+ if (pm) // promotion ?
{
PieceType promotion = move_promotion_piece(m);
pt = PAWN;
pieceCount[us][PAWN]++;
// Update piece list replacing promotion piece with a pawn
- pieceList[us][promotion][index[to]] = pieceList[us][promotion][pieceCount[us][promotion]];
- index[pieceList[us][promotion][index[to]]] = index[to];
- pieceList[us][PAWN][pieceCount[us][PAWN] - 1] = to;
+ Square lastPromotionSquare = pieceList[us][promotion][pieceCount[us][promotion]];
+ index[lastPromotionSquare] = index[to];
+ pieceList[us][promotion][index[lastPromotionSquare]] = lastPromotionSquare;
index[to] = pieceCount[us][PAWN] - 1;
+ pieceList[us][PAWN][index[to]] = to;
}
// Put the piece back at the source square
kingSquare[us] = from;
// Update piece list
- pieceList[us][pt][index[to]] = from;
index[from] = index[to];
+ pieceList[us][pt][index[from]] = from;
if (st->capture)
{
board[capsq] = piece_of_color_and_type(them, st->capture);
- // Update piece list
- pieceList[them][st->capture][pieceCount[them][st->capture]] = capsq;
- index[capsq] = pieceCount[them][st->capture];
-
// Update piece count
pieceCount[them][st->capture]++;
+
+ // Update piece list, add a new captured piece in capsq square
+ index[capsq] = pieceCount[them][st->capture] - 1;
+ pieceList[them][st->capture][index[capsq]] = capsq;
}
// Finally point our state pointer back to the previous state
st = st->previous;
+
+ assert(is_ok());
}
// Update piece lists
pieceList[us][KING][index[kto]] = kfrom;
pieceList[us][ROOK][index[rto]] = rfrom;
- int tmp = index[rto]; // Necessary because we may have rto == kfrom in FRC.
+ int tmp = index[rto]; // In Chess960 could be rto == kfrom
index[kfrom] = index[kto];
index[rfrom] = tmp;
// Finally point our state pointer back to the previous state
st = st->previous;
+
+ assert(is_ok());
}
// StateInfo object.
// Note that differently from normal case here backupSt is actually used as
// a backup storage not as a new state to be used.
+ backupSt.key = st->key;
backupSt.epSquare = st->epSquare;
- backupSt.key = st->key;
- backupSt.mgValue = st->mgValue;
- backupSt.egValue = st->egValue;
+ backupSt.mgValue = st->mgValue;
+ backupSt.egValue = st->egValue;
backupSt.previous = st->previous;
st->previous = &backupSt;
st->key ^= zobSideToMove;
TT.prefetch(st->key);
+
sideToMove = opposite_color(sideToMove);
st->epSquare = SQ_NONE;
st->rule50++;
st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame;
st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame;
-
- assert(is_ok());
}
assert(!is_check());
// Restore information from the our backup StateInfo object
- st->epSquare = st->previous->epSquare;
- st->key = st->previous->key;
- st->mgValue = st->previous->mgValue;
- st->egValue = st->previous->egValue;
- st->previous = st->previous->previous;
+ StateInfo* backupSt = st->previous;
+ st->key = backupSt->key;
+ st->epSquare = backupSt->epSquare;
+ st->mgValue = backupSt->mgValue;
+ st->egValue = backupSt->egValue;
+ st->previous = backupSt->previous;
// Update the necessary information
sideToMove = opposite_color(sideToMove);
st->rule50--;
gamePly--;
-
- assert(is_ok());
}
memset(st, 0, sizeof(StateInfo));
st->epSquare = SQ_NONE;
- memset(index, 0, sizeof(int) * 64);
- memset(byColorBB, 0, sizeof(Bitboard) * 2);
+ 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 < 64; i++)
board[i] = EMPTY;
for (int i = 0; i < 7; i++)
- {
- byTypeBB[i] = EmptyBoardBB;
- pieceCount[0][i] = pieceCount[1][i] = 0;
for (int j = 0; j < 8; j++)
pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE;
- }
sideToMove = WHITE;
gamePly = 0;
MoveStack moves[256];
- return is_check() && !generate_evasions(*this, moves, pinned_pieces(sideToMove));
+ return is_check() && (generate_evasions(*this, moves, pinned_pieces(sideToMove)) == moves);
}
do_null_move(st1);
MoveStack mlist[120];
- int count;
bool result = false;
Bitboard dc = discovered_check_candidates(sideToMove);
Bitboard pinned = pinned_pieces(sideToMove);
// Generate pseudo-legal non-capture and capture check moves
- count = generate_non_capture_checks(*this, mlist, dc);
- count += generate_captures(*this, mlist + count);
+ MoveStack* last = generate_non_capture_checks(*this, mlist, dc);
+ last = generate_captures(*this, last);
// Loop through the moves, and see if one of them is mate
- for (int i = 0; i < count; i++)
+ for (MoveStack* cur = mlist; cur != last; cur++)
{
- Move move = mlist[i].move;
-
+ Move move = cur->move;
if (!pl_move_is_legal(move, pinned))
continue;
projects / stockfish / blobdiff