void Position::do_move(Move m, StateInfo& newSt) {
CheckInfo ci(*this);
- do_move(m, newSt, ci, gives_check(m, ci));
+ do_move(m, newSt, gives_check(m, ci));
}
-void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveIsCheck) {
+void Position::do_move(Move m, StateInfo& newSt, bool moveIsCheck) {
assert(is_ok(m));
assert(&newSt != st);
// Update the key with the final value
st->key = k;
- // Update checkers bitboard: piece must be already moved due to attacks_from()
- st->checkersBB = 0;
-
- if (moveIsCheck)
- {
- if (type_of(m) != NORMAL)
- st->checkersBB = attackers_to(king_square(them)) & pieces(us);
- else
- {
- // Direct checks
- if (ci.checkSq[pt] & to)
- st->checkersBB |= to;
-
- // Discovered checks
- if (ci.dcCandidates && (ci.dcCandidates & from))
- {
- if (pt != ROOK)
- st->checkersBB |= attacks_from<ROOK>(king_square(them)) & pieces(us, QUEEN, ROOK);
-
- if (pt != BISHOP)
- st->checkersBB |= attacks_from<BISHOP>(king_square(them)) & pieces(us, QUEEN, BISHOP);
- }
- }
- }
+ // Calculate checkers bitboard (if move is check)
+ st->checkersBB = moveIsCheck ? attackers_to(king_square(them)) & pieces(us) : 0;
sideToMove = ~sideToMove;
// Locate and remove the next least valuable attacker
captured = min_attacker<PAWN>(byTypeBB, to, stmAttackers, occupied, attackers);
+
+ // Stop before processing a king capture
+ if (captured == KING)
+ {
+ if (stmAttackers == attackers)
+ ++slIndex;
+
+ break;
+ }
+
stm = ~stm;
stmAttackers = attackers & pieces(stm);
++slIndex;
- } while (stmAttackers && (captured != KING || (--slIndex, false))); // Stop before a king capture
+ } while (stmAttackers);
// Having built the swap list, we negamax through it to find the best
// achievable score from the point of view of the side to move.
/// Position::flip() flips position with the white and black sides reversed. This
/// is only useful for debugging e.g. for finding evaluation symmetry bugs.
+static char toggle_case(char c) {
+ return char(islower(c) ? toupper(c) : tolower(c));
+}
+
void Position::flip() {
string f, token;
ss >> token; // Castling availability
f += token + " ";
- std::transform(f.begin(), f.end(), f.begin(),
- [](char c) { return char(islower(c) ? toupper(c) : tolower(c)); });
+ std::transform(f.begin(), f.end(), f.begin(), toggle_case);
ss >> token; // En passant square
f += (token == "-" ? token : token.replace(1, 1, token[1] == '3' ? "6" : "3"));
/// Position::pos_is_ok() performs some consistency checks for the position object.
/// This is meant to be helpful when debugging.
-bool Position::pos_is_ok(bool fast, int* failedStep) const {
+bool Position::pos_is_ok(int* step) const {
- enum { Default, King, Bitboards, State, Lists, Castling };
+ // Which parts of the position should be verified?
+ const bool all = false;
- for (int step = Default; step <= (fast ? Default : Castling); step++)
+ const bool testBitboards = all || false;
+ const bool testState = all || false;
+ const bool testKingCount = all || false;
+ const bool testKingCapture = all || false;
+ const bool testPieceCounts = all || false;
+ const bool testPieceList = all || false;
+ const bool testCastlingSquares = all || false;
+
+ if (step)
+ *step = 1;
+
+ if ( (sideToMove != WHITE && sideToMove != BLACK)
+ || piece_on(king_square(WHITE)) != W_KING
+ || piece_on(king_square(BLACK)) != B_KING
+ || ( ep_square() != SQ_NONE
+ && relative_rank(sideToMove, ep_square()) != RANK_6))
+ return false;
+
+ if (step && ++*step, testBitboards)
{
- if (failedStep)
- *failedStep = step;
-
- if (step == Default)
- if ( (sideToMove != WHITE && sideToMove != BLACK)
- || piece_on(king_square(WHITE)) != W_KING
- || piece_on(king_square(BLACK)) != B_KING
- || ( ep_square() != SQ_NONE
- && relative_rank(sideToMove, ep_square()) != RANK_6))
- return false;
+ // The intersection of the white and black pieces must be empty
+ if (pieces(WHITE) & pieces(BLACK))
+ return false;
- if (step == King)
- if ( std::count(board, board + SQUARE_NB, W_KING) != 1
- || std::count(board, board + SQUARE_NB, B_KING) != 1
- || attackers_to(king_square(~sideToMove)) & pieces(sideToMove))
- return false;
+ // The union of the white and black pieces must be equal to all
+ // occupied squares
+ if ((pieces(WHITE) | pieces(BLACK)) != pieces())
+ return false;
- if (step == Bitboards)
- {
- if ( (pieces(WHITE) & pieces(BLACK))
- ||(pieces(WHITE) | pieces(BLACK)) != pieces())
- return false;
+ // Separate piece type bitboards must have empty intersections
+ for (PieceType p1 = PAWN; p1 <= KING; ++p1)
+ for (PieceType p2 = PAWN; p2 <= KING; ++p2)
+ if (p1 != p2 && (pieces(p1) & pieces(p2)))
+ return false;
+ }
- for (PieceType p1 = PAWN; p1 <= KING; ++p1)
- for (PieceType p2 = PAWN; p2 <= KING; ++p2)
- if (p1 != p2 && (pieces(p1) & pieces(p2)))
- return false;
- }
+ if (step && ++*step, testState)
+ {
+ StateInfo si;
+ set_state(&si);
+ if ( st->key != si.key
+ || st->pawnKey != si.pawnKey
+ || st->materialKey != si.materialKey
+ || st->nonPawnMaterial[WHITE] != si.nonPawnMaterial[WHITE]
+ || st->nonPawnMaterial[BLACK] != si.nonPawnMaterial[BLACK]
+ || st->psq != si.psq
+ || st->checkersBB != si.checkersBB)
+ return false;
+ }
- if (step == State)
- {
- StateInfo si;
- set_state(&si);
- if ( st->key != si.key
- || st->pawnKey != si.pawnKey
- || st->materialKey != si.materialKey
- || st->nonPawnMaterial[WHITE] != si.nonPawnMaterial[WHITE]
- || st->nonPawnMaterial[BLACK] != si.nonPawnMaterial[BLACK]
- || st->psq != si.psq
- || st->checkersBB != si.checkersBB)
- return false;
- }
+ if (step && ++*step, testKingCount)
+ if ( std::count(board, board + SQUARE_NB, W_KING) != 1
+ || std::count(board, board + SQUARE_NB, B_KING) != 1)
+ return false;
- if (step == Lists)
- for (Color c = WHITE; c <= BLACK; ++c)
- for (PieceType pt = PAWN; pt <= KING; ++pt)
- {
- if (pieceCount[c][pt] != popcount<Full>(pieces(c, pt)))
- return false;
+ if (step && ++*step, testKingCapture)
+ if (attackers_to(king_square(~sideToMove)) & pieces(sideToMove))
+ return false;
- for (int i = 0; i < pieceCount[c][pt]; ++i)
- if ( board[pieceList[c][pt][i]] != make_piece(c, pt)
- || index[pieceList[c][pt][i]] != i)
- return false;
- }
-
- if (step == Castling)
- for (Color c = WHITE; c <= BLACK; ++c)
- for (CastlingSide s = KING_SIDE; s <= QUEEN_SIDE; s = CastlingSide(s + 1))
- {
- if (!can_castle(c | s))
- continue;
-
- if ( piece_on(castlingRookSquare[c | s]) != make_piece(c, ROOK)
- || castlingRightsMask[castlingRookSquare[c | s]] != (c | s)
- ||(castlingRightsMask[king_square(c)] & (c | s)) != (c | s))
+ if (step && ++*step, testPieceCounts)
+ for (Color c = WHITE; c <= BLACK; ++c)
+ for (PieceType pt = PAWN; pt <= KING; ++pt)
+ if (pieceCount[c][pt] != popcount<Full>(pieces(c, pt)))
+ return false;
+
+ if (step && ++*step, testPieceList)
+ for (Color c = WHITE; c <= BLACK; ++c)
+ for (PieceType pt = PAWN; pt <= KING; ++pt)
+ for (int i = 0; i < pieceCount[c][pt]; ++i)
+ if ( board[pieceList[c][pt][i]] != make_piece(c, pt)
+ || index[pieceList[c][pt][i]] != i)
return false;
- }
- }
+
+ if (step && ++*step, testCastlingSquares)
+ for (Color c = WHITE; c <= BLACK; ++c)
+ for (CastlingSide s = KING_SIDE; s <= QUEEN_SIDE; s = CastlingSide(s + 1))
+ {
+ if (!can_castle(c | s))
+ continue;
+
+ if ( (castlingRightsMask[king_square(c)] & (c | s)) != (c | s)
+ || piece_on(castlingRookSquare[c | s]) != make_piece(c, ROOK)
+ || castlingRightsMask[castlingRookSquare[c | s]] != (c | s))
+ return false;
+ }
return true;
}
projects / stockfish / blobdiff