// pointer to point to the new, ready to be updated, state.
struct ReducedStateInfo {
Key pawnKey, materialKey;
- int castleRights, rule50, pliesFromNull;
+ int castleRights, rule50, ply, pliesFromNull;
Square epSquare;
Score value;
Value npMaterial[2];
// Save the current key to the history[] array, in order to be able to
// detect repetition draws.
- history[gamePly] = key;
- gamePly++;
+ history[st->ply++] = key;
// Update side to move
key ^= zobSideToMove;
key ^= zobEp[st->epSquare];
}
}
+
+ if (pm) // promotion ?
+ {
+ 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);
+
+ // Update piece counts
+ pieceCount[us][promotion]++;
+ pieceCount[us][PAWN]--;
+
+ // Update material key
+ st->materialKey ^= zobrist[us][PAWN][pieceCount[us][PAWN]];
+ st->materialKey ^= zobrist[us][promotion][pieceCount[us][promotion]-1];
+
+ // 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;
+ pieceList[us][PAWN][pieceCount[us][PAWN]] = SQ_NONE;
+ 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];
+
+ // Partially revert and update incremental scores
+ st->value -= pst(us, PAWN, to);
+ st->value += pst(us, promotion, to);
+
+ // Update material
+ st->npMaterial[us] += piece_value_midgame(promotion);
+ }
}
// Update incremental scores
// Set capture piece
st->capture = capture;
- if (pm) // promotion ?
- {
- 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);
-
- // Update piece counts
- pieceCount[us][promotion]++;
- pieceCount[us][PAWN]--;
-
- // Update material key
- st->materialKey ^= zobrist[us][PAWN][pieceCount[us][PAWN]];
- st->materialKey ^= zobrist[us][promotion][pieceCount[us][promotion]-1];
-
- // 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;
- pieceList[us][PAWN][pieceCount[us][PAWN]] = SQ_NONE;
- 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];
-
- // Partially revert and update incremental scores
- st->value -= pst(us, PAWN, to);
- st->value += pst(us, promotion, to);
-
- // Update material
- st->npMaterial[us] += piece_value_midgame(promotion);
- }
-
// Update the key with the final value
st->key = key;
Square capsq = to;
- if (ep) // en passant ?
+ // If the captured piece was a pawn, update pawn hash key,
+ // otherwise update non-pawn material.
+ if (capture == PAWN)
{
- capsq = (them == BLACK)? (to - DELTA_N) : (to - DELTA_S);
+ 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(capsq) == piece_of_color_and_type(them, PAWN));
+ assert(to == st->epSquare);
+ assert(relative_rank(opposite_color(them), to) == RANK_6);
+ assert(piece_on(to) == EMPTY);
+ assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN));
- board[capsq] = EMPTY;
+ board[capsq] = EMPTY;
+ }
+ st->pawnKey ^= zobrist[them][PAWN][capsq];
}
+ else
+ st->npMaterial[them] -= piece_value_midgame(capture);
// Remove captured piece
clear_bit(&(byColorBB[them]), capsq);
// Update incremental scores
st->value -= pst(them, capture, capsq);
- // 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 piece count
pieceCount[them][capture]--;
assert(is_ok());
assert(move_is_ok(m));
- gamePly--;
sideToMove = opposite_color(sideToMove);
if (move_is_castle(m))
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);
// Save the current key to the history[] array, in order to be able to
// detect repetition draws.
- history[gamePly] = st->key;
+ history[st->ply++] = st->key;
// Update the necessary information
if (st->epSquare != SQ_NONE)
st->rule50++;
st->pliesFromNull = 0;
st->value += (sideToMove == WHITE) ? TempoValue : -TempoValue;
- gamePly++;
}
// Update the necessary information
sideToMove = opposite_color(sideToMove);
st->rule50--;
- gamePly--;
+ st->ply--;
}
pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE;
sideToMove = WHITE;
- gamePly = 0;
initialKFile = FILE_E;
initialKRFile = FILE_H;
initialQRFile = FILE_A;
}
-/// Position::reset_game_ply() simply sets gamePly to 0. It is used from the
+/// Position::reset_ply() simply sets ply to 0. It is used from the
/// UCI interface code, whenever a non-reversible move is made in a
/// 'position fen <fen> moves m1 m2 ...' command. This makes it possible
/// for the program to handle games of arbitrary length, as long as the GUI
/// handles draws by the 50 move rule correctly.
-void Position::reset_game_ply() {
+void Position::reset_ply() {
- gamePly = 0;
+ st->ply = 0;
}
if (st->rule50 > 100 || (st->rule50 == 100 && !is_check()))
return true;
+ assert(st->ply >= st->rule50);
+
// Draw by repetition?
- for (int i = 4; i <= Min(Min(gamePly, st->rule50), st->pliesFromNull); i += 2)
- if (history[gamePly - i] == st->key)
+ for (int i = 4, e = Min(st->rule50, st->pliesFromNull); i <= e; i += 2)
+ if (history[st->ply - i] == st->key)
return true;
return false;