X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=cc0f42e9c9ac1b004938a29968b554001e75c9f6;hp=76ebbde42e6d962b831e18dec60d02f43817d444;hb=243fa483d7b329ad8512c86eb152cca7a0982674;hpb=2f6c5f00e61baa69dd1d241dc88d17bc4296b2bc diff --git a/src/position.cpp b/src/position.cpp index 76ebbde4..cc0f42e9 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -23,8 +23,9 @@ //// #include -#include +#include #include +#include #include "mersenne.h" #include "movegen.h" @@ -192,7 +193,7 @@ void Position::from_fen(const std::string& fen) { if ( i < fen.length() - 2 && (fen[i] >= 'a' && fen[i] <= 'h') && (fen[i+1] == '3' || fen[i+1] == '6')) - st.epSquare = square_from_string(fen.substr(i, 2)); + st->epSquare = square_from_string(fen.substr(i, 2)); // Various initialisation for (Square sq = SQ_A1; sq <= SQ_H8; sq++) @@ -206,12 +207,13 @@ void Position::from_fen(const std::string& fen) { castleRightsMask[make_square(initialQRFile, RANK_8)] ^= BLACK_OOO; find_checkers(); + find_pinned(); - st.key = compute_key(); - st.pawnKey = compute_pawn_key(); - st.materialKey = compute_material_key(); - st.mgValue = compute_value(); - st.egValue = compute_value(); + st->key = compute_key(); + st->pawnKey = compute_pawn_key(); + st->materialKey = compute_material_key(); + st->mgValue = compute_value(); + st->egValue = compute_value(); npMaterial[WHITE] = compute_non_pawn_material(WHITE); npMaterial[BLACK] = compute_non_pawn_material(BLACK); } @@ -249,7 +251,7 @@ const std::string Position::to_fen() const { fen += (rank > RANK_1 ? '/' : ' '); } fen += (sideToMove == WHITE ? "w " : "b "); - if (st.castleRights != NO_CASTLES) + if (st->castleRights != NO_CASTLES) { if (can_castle_kingside(WHITE)) fen += 'K'; if (can_castle_queenside(WHITE)) fen += 'Q'; @@ -305,7 +307,7 @@ void Position::print(Move m) const { } std::cout << "+---+---+---+---+---+---+---+---+" << std::endl << "Fen is: " << to_fen() << std::endl - << "Key is: " << st.key << std::endl; + << "Key is: " << st->key << std::endl; RequestPending = false; } @@ -319,44 +321,11 @@ void Position::copy(const Position &pos) { } -/// Position:pinned_pieces() returns a bitboard of all pinned (against the -/// king) pieces for the given color. -Bitboard Position::pinned_pieces(Color c) const { - - if (st.pinned[c] != ~EmptyBoardBB) - return st.pinned[c]; - - Bitboard p1, p2; - Square ksq = king_square(c); - st.pinned[c] = hidden_checks(c, ksq, p1) | hidden_checks(c, ksq, p2); - st.pinners[c] = p1 | p2; - return st.pinned[c]; -} - -Bitboard Position::pinned_pieces(Color c, Bitboard& p) const { - - if (st.pinned[c] == ~EmptyBoardBB) - pinned_pieces(c); - - p = st.pinners[c]; - return st.pinned[c]; -} - -Bitboard Position::discovered_check_candidates(Color c) const { - - if (st.dcCandidates[c] != ~EmptyBoardBB) - return st.dcCandidates[c]; - - Bitboard dummy; - Square ksq = king_square(opposite_color(c)); - st.dcCandidates[c] = hidden_checks(c, ksq, dummy) | hidden_checks(c, ksq, dummy); - return st.dcCandidates[c]; -} - /// Position:hidden_checks<>() returns a bitboard of all pinned (against the /// king) pieces for the given color and for the given pinner type. Or, when /// template parameter FindPinned is false, the pinned pieces of opposite color /// that are, indeed, the pieces candidate for a discovery check. +/// Note that checkersBB bitboard must be already updated. template Bitboard Position::hidden_checks(Color c, Square ksq, Bitboard& pinners) const { @@ -368,14 +337,14 @@ Bitboard Position::hidden_checks(Color c, Square ksq, Bitboard& pinners) const { else sliders = bishops_and_queens(FindPinned ? opposite_color(c) : c) & BishopPseudoAttacks[ksq]; - if (sliders && (!FindPinned || (sliders & ~st.checkersBB))) + if (sliders && (!FindPinned || (sliders & ~st->checkersBB))) { // King blockers are candidate pinned pieces Bitboard candidate_pinned = piece_attacks(ksq) & pieces_of_color(c); // Pinners are sliders, not checkers, that give check when // candidate pinned are removed. - pinners = (FindPinned ? sliders & ~st.checkersBB : sliders); + pinners = (FindPinned ? sliders & ~st->checkersBB : sliders); if (Piece == ROOK) pinners &= rook_attacks_bb(ksq, occupied_squares() ^ candidate_pinned); @@ -466,7 +435,7 @@ bool Position::move_attacks_square(Move m, Square s) const { /// Position::find_checkers() computes the checkersBB bitboard, which -/// contains a nonzero bit for each checking piece (0, 1 or 2). It +/// contains a nonzero bit for each checking piece (0, 1 or 2). It /// currently works by calling Position::attacks_to, which is probably /// inefficient. Consider rewriting this function to use the last move /// played, like in non-bitboard versions of Glaurung. @@ -474,7 +443,26 @@ bool Position::move_attacks_square(Move m, Square s) const { void Position::find_checkers() { Color us = side_to_move(); - st.checkersBB = attacks_to(king_square(us), opposite_color(us)); + st->checkersBB = attacks_to(king_square(us), opposite_color(us)); +} + + +/// Position:find_pinned() computes the pinned, pinners and dcCandidates +/// bitboards for both colors. Bitboard checkersBB must be already updated. + +void Position::find_pinned() { + + Bitboard p1, p2; + Square ksq; + + for (Color c = WHITE; c <= BLACK; c++) + { + ksq = king_square(c); + st->pinned[c] = hidden_checks(c, ksq, p1) | hidden_checks(c, ksq, p2); + st->pinners[c] = p1 | p2; + ksq = king_square(opposite_color(c)); + st->dcCandidates[c] = hidden_checks(c, ksq, p1) | hidden_checks(c, ksq, p2); + } } @@ -689,36 +677,51 @@ inline void Position::update_checkers(Bitboard* pCheckersBB, Square ksq, Square } -/// Position::do_move() makes a move, and backs up all information necessary -/// to undo the move to an UndoInfo object. The move is assumed to be legal. +/// Position::init_new_state() copies from the current state the fields +/// that will be updated incrementally, skips the fields, like bitboards +/// that will be recalculated form scratch anyway. + +void Position::init_new_state(StateInfo& newSt) { + + newSt.key = st->key; + newSt.pawnKey = st->pawnKey; + newSt.materialKey = st->materialKey; + newSt.castleRights = st->castleRights; + newSt.rule50 = st->rule50; + newSt.epSquare = st->epSquare; + newSt.mgValue = st->mgValue; + newSt.egValue = st->egValue; + newSt.capture = NO_PIECE_TYPE; + newSt.previous = st; +} + + +/// Position::do_move() makes a move, and saves all information necessary +/// to a StateInfo object. The move is assumed to be legal. /// Pseudo-legal moves should be filtered out before this function is called. -void Position::do_move(Move m, UndoInfo& u) { +void Position::do_move(Move m, StateInfo& newSt) { assert(is_ok()); assert(move_is_ok(m)); - // Get now the current (pre-move) dc candidates that we will use + // Get now the current (before to move) dc candidates that we will use // in update_checkers(). Bitboard oldDcCandidates = discovered_check_candidates(side_to_move()); - // Back up the necessary information to our UndoInfo object (except the - // captured piece, which is taken care of later. - u = undoInfoUnion; - u.capture = NO_PIECE_TYPE; - st.previous = &u; + // Copy some fields of old state to our new StateInfo object (except the + // captured piece, which is taken care of later) and switch state pointer + // to point to the new, ready to be updated, state. + init_new_state(newSt); + st = &newSt; // Save the current key to the history[] array, in order to be able to // detect repetition draws. - history[gamePly] = st.key; + history[gamePly] = st->key; // 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++; - - // Reset pinned bitboard and its friends - for (Color c = WHITE; c <= BLACK; c++) - st.pinners[c] = st.pinned[c] = st.dcCandidates[c] = ~EmptyBoardBB; + st->rule50++; if (move_is_castle(m)) do_castle_move(m); @@ -738,13 +741,10 @@ void Position::do_move(Move m, UndoInfo& u) { PieceType piece = type_of_piece_on(from); - st.capture = type_of_piece_on(to); + st->capture = type_of_piece_on(to); - if (st.capture) - { - u.capture = st.capture; - do_capture_move(m, st.capture, them, to); - } + if (st->capture) + do_capture_move(m, st->capture, them, to); // Move the piece clear_bit(&(byColorBB[us]), from); @@ -757,33 +757,33 @@ void Position::do_move(Move m, UndoInfo& u) { board[from] = EMPTY; // Update hash key - st.key ^= zobrist[us][piece][from] ^ zobrist[us][piece][to]; + st->key ^= zobrist[us][piece][from] ^ zobrist[us][piece][to]; // Update incremental scores - st.mgValue -= pst(us, piece, from); - st.mgValue += pst(us, piece, to); - st.egValue -= pst(us, piece, from); - st.egValue += pst(us, piece, to); + st->mgValue -= pst(us, piece, from); + st->mgValue += pst(us, piece, to); + st->egValue -= pst(us, piece, from); + st->egValue += pst(us, piece, to); // If the moving piece was a king, update the king square if (piece == KING) kingSquare[us] = to; // Reset en passant square - if (st.epSquare != SQ_NONE) + if (st->epSquare != SQ_NONE) { - st.key ^= zobEp[st.epSquare]; - st.epSquare = SQ_NONE; + st->key ^= zobEp[st->epSquare]; + st->epSquare = SQ_NONE; } // If the moving piece was a pawn do some special extra work if (piece == PAWN) { // Reset rule 50 draw counter - st.rule50 = 0; + st->rule50 = 0; // Update pawn hash key - st.pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; + st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; // Set en passant square, only if moved pawn can be captured if (abs(int(to) - int(from)) == 16) @@ -791,8 +791,8 @@ void Position::do_move(Move m, UndoInfo& u) { if ( (us == WHITE && (pawn_attacks(WHITE, from + DELTA_N) & pawns(BLACK))) || (us == BLACK && (pawn_attacks(BLACK, from + DELTA_S) & pawns(WHITE)))) { - st.epSquare = Square((int(from) + int(to)) / 2); - st.key ^= zobEp[st.epSquare]; + st->epSquare = Square((int(from) + int(to)) / 2); + st->key ^= zobEp[st->epSquare]; } } } @@ -802,33 +802,34 @@ void Position::do_move(Move m, UndoInfo& u) { index[to] = index[from]; // Update castle rights - st.key ^= zobCastle[st.castleRights]; - st.castleRights &= castleRightsMask[from]; - st.castleRights &= castleRightsMask[to]; - st.key ^= zobCastle[st.castleRights]; + st->key ^= zobCastle[st->castleRights]; + st->castleRights &= castleRightsMask[from]; + st->castleRights &= castleRightsMask[to]; + st->key ^= zobCastle[st->castleRights]; // Update checkers bitboard, piece must be already moved - st.checkersBB = EmptyBoardBB; + st->checkersBB = EmptyBoardBB; Square ksq = king_square(them); switch (piece) { - case PAWN: update_checkers(&st.checkersBB, ksq, from, to, oldDcCandidates); break; - case KNIGHT: update_checkers(&st.checkersBB, ksq, from, to, oldDcCandidates); break; - case BISHOP: update_checkers(&st.checkersBB, ksq, from, to, oldDcCandidates); break; - case ROOK: update_checkers(&st.checkersBB, ksq, from, to, oldDcCandidates); break; - case QUEEN: update_checkers(&st.checkersBB, ksq, from, to, oldDcCandidates); break; - case KING: update_checkers(&st.checkersBB, ksq, from, to, oldDcCandidates); break; + case PAWN: update_checkers(&st->checkersBB, ksq, from, to, oldDcCandidates); break; + case KNIGHT: update_checkers(&st->checkersBB, ksq, from, to, oldDcCandidates); break; + case BISHOP: update_checkers(&st->checkersBB, ksq, from, to, oldDcCandidates); break; + case ROOK: update_checkers(&st->checkersBB, ksq, from, to, oldDcCandidates); break; + case QUEEN: update_checkers(&st->checkersBB, ksq, from, to, oldDcCandidates); break; + case KING: update_checkers(&st->checkersBB, ksq, from, to, oldDcCandidates); break; default: assert(false); break; } } // Finish - st.key ^= zobSideToMove; + find_pinned(); + st->key ^= zobSideToMove; sideToMove = opposite_color(sideToMove); gamePly++; - st.mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; - st.egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; + st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; + st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; assert(is_ok()); } @@ -846,15 +847,15 @@ void Position::do_capture_move(Move m, PieceType capture, Color them, Square to) clear_bit(&(byTypeBB[capture]), to); // Update hash key - st.key ^= zobrist[them][capture][to]; + st->key ^= zobrist[them][capture][to]; // If the captured piece was a pawn, update pawn hash key if (capture == PAWN) - st.pawnKey ^= zobrist[them][PAWN][to]; + st->pawnKey ^= zobrist[them][PAWN][to]; // Update incremental scores - st.mgValue -= pst(them, capture, to); - st.egValue -= pst(them, capture, to); + st->mgValue -= pst(them, capture, to); + st->egValue -= pst(them, capture, to); assert(!move_promotion(m) || capture != PAWN); @@ -863,7 +864,7 @@ void Position::do_capture_move(Move m, PieceType capture, Color them, Square to) npMaterial[them] -= piece_value_midgame(capture); // Update material hash key - st.materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]]; + st->materialKey ^= zobMaterial[them][capture][pieceCount[them][capture]]; // Update piece count pieceCount[them][capture]--; @@ -873,7 +874,7 @@ void Position::do_capture_move(Move m, PieceType capture, Color them, Square to) index[pieceList[them][capture][index[to]]] = index[to]; // Reset rule 50 counter - st.rule50 = 0; + st->rule50 = 0; } @@ -941,43 +942,41 @@ void Position::do_castle_move(Move m) { index[rto] = tmp; // Update incremental scores - st.mgValue -= pst(us, KING, kfrom); - st.mgValue += pst(us, KING, kto); - st.egValue -= pst(us, KING, kfrom); - st.egValue += pst(us, KING, kto); - st.mgValue -= pst(us, ROOK, rfrom); - st.mgValue += pst(us, ROOK, rto); - st.egValue -= pst(us, ROOK, rfrom); - st.egValue += pst(us, ROOK, rto); + st->mgValue -= pst(us, KING, kfrom); + st->mgValue += pst(us, KING, kto); + st->egValue -= pst(us, KING, kfrom); + st->egValue += pst(us, KING, kto); + st->mgValue -= pst(us, ROOK, rfrom); + st->mgValue += pst(us, ROOK, rto); + st->egValue -= pst(us, ROOK, rfrom); + st->egValue += pst(us, ROOK, rto); // Update hash key - st.key ^= zobrist[us][KING][kfrom] ^ zobrist[us][KING][kto]; - st.key ^= zobrist[us][ROOK][rfrom] ^ zobrist[us][ROOK][rto]; + st->key ^= zobrist[us][KING][kfrom] ^ zobrist[us][KING][kto]; + st->key ^= zobrist[us][ROOK][rfrom] ^ zobrist[us][ROOK][rto]; // Clear en passant square - if (st.epSquare != SQ_NONE) + if (st->epSquare != SQ_NONE) { - st.key ^= zobEp[st.epSquare]; - st.epSquare = SQ_NONE; + st->key ^= zobEp[st->epSquare]; + st->epSquare = SQ_NONE; } // Update castling rights - st.key ^= zobCastle[st.castleRights]; - st.castleRights &= castleRightsMask[kfrom]; - st.key ^= zobCastle[st.castleRights]; + st->key ^= zobCastle[st->castleRights]; + st->castleRights &= castleRightsMask[kfrom]; + st->key ^= zobCastle[st->castleRights]; // Reset rule 50 counter - st.rule50 = 0; + st->rule50 = 0; // Update checkers BB - st.checkersBB = attacks_to(king_square(them), us); + st->checkersBB = attacks_to(king_square(them), us); } /// Position::do_promotion_move() is a private method used to make a promotion -/// move. It is called from the main Position::do_move function. The -/// UndoInfo object, which has been initialized in Position::do_move, is -/// used to store the captured piece (if any). +/// move. It is called from the main Position::do_move function. void Position::do_promotion_move(Move m) { @@ -998,13 +997,10 @@ void Position::do_promotion_move(Move m) { 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); + st->capture = type_of_piece_on(to); - if (st.capture) - { - st.previous->capture = st.capture; - do_capture_move(m, st.capture, them, to); - } + if (st->capture) + do_capture_move(m, st->capture, them, to); // Remove pawn clear_bit(&(byColorBB[us]), from); @@ -1021,14 +1017,14 @@ void Position::do_promotion_move(Move m) { board[to] = piece_of_color_and_type(us, promotion); // Update hash key - st.key ^= zobrist[us][PAWN][from] ^ zobrist[us][promotion][to]; + st->key ^= zobrist[us][PAWN][from] ^ zobrist[us][promotion][to]; // Update pawn hash key - st.pawnKey ^= zobrist[us][PAWN][from]; + 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]; + st->materialKey ^= zobMaterial[us][PAWN][pieceCount[us][PAWN]]; + st->materialKey ^= zobMaterial[us][promotion][pieceCount[us][promotion]+1]; // Update piece counts pieceCount[us][PAWN]--; @@ -1041,38 +1037,36 @@ void Position::do_promotion_move(Move m) { index[to] = pieceCount[us][promotion] - 1; // Update incremental scores - st.mgValue -= pst(us, PAWN, from); - st.mgValue += pst(us, promotion, to); - st.egValue -= pst(us, PAWN, from); - st.egValue += pst(us, promotion, to); + st->mgValue -= pst(us, PAWN, from); + st->mgValue += pst(us, promotion, to); + st->egValue -= pst(us, PAWN, from); + st->egValue += pst(us, promotion, to); // Update material npMaterial[us] += piece_value_midgame(promotion); // Clear the en passant square - if (st.epSquare != SQ_NONE) + if (st->epSquare != SQ_NONE) { - st.key ^= zobEp[st.epSquare]; - 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]; + st->key ^= zobCastle[st->castleRights]; + st->castleRights &= castleRightsMask[to]; + st->key ^= zobCastle[st->castleRights]; // Reset rule 50 counter - st.rule50 = 0; + st->rule50 = 0; // Update checkers BB - st.checkersBB = attacks_to(king_square(them), us); + st->checkersBB = attacks_to(king_square(them), us); } /// Position::do_ep_move() is a private method used to make an en passant -/// capture. It is called from the main Position::do_move function. Because -/// the captured piece is always a pawn, we don't need to pass an UndoInfo -/// object in which to store the captured piece. +/// capture. It is called from the main Position::do_move function. void Position::do_ep_move(Move m) { @@ -1089,7 +1083,7 @@ void Position::do_ep_move(Move m) { to = move_to(m); capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S); - assert(to == st.epSquare); + assert(to == st->epSquare); assert(relative_rank(us, to) == RANK_6); assert(piece_on(to) == EMPTY); assert(piece_on(from) == piece_of_color_and_type(us, PAWN)); @@ -1114,7 +1108,7 @@ void Position::do_ep_move(Move m) { board[from] = EMPTY; // Update material hash key - st.materialKey ^= zobMaterial[them][PAWN][pieceCount[them][PAWN]]; + st->materialKey ^= zobMaterial[them][PAWN][pieceCount[them][PAWN]]; // Update piece count pieceCount[them][PAWN]--; @@ -1126,37 +1120,35 @@ void Position::do_ep_move(Move m) { index[pieceList[them][PAWN][index[capsq]]] = index[capsq]; // Update hash key - st.key ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; - st.key ^= zobrist[them][PAWN][capsq]; - st.key ^= zobEp[st.epSquare]; + st->key ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; + st->key ^= zobrist[them][PAWN][capsq]; + st->key ^= zobEp[st->epSquare]; // Update pawn hash key - st.pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; - st.pawnKey ^= zobrist[them][PAWN][capsq]; + st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; + st->pawnKey ^= zobrist[them][PAWN][capsq]; // Update incremental scores - st.mgValue -= pst(them, PAWN, capsq); - st.mgValue -= pst(us, PAWN, from); - st.mgValue += pst(us, PAWN, to); - st.egValue -= pst(them, PAWN, capsq); - st.egValue -= pst(us, PAWN, from); - st.egValue += pst(us, PAWN, to); + st->mgValue -= pst(them, PAWN, capsq); + st->mgValue -= pst(us, PAWN, from); + st->mgValue += pst(us, PAWN, to); + st->egValue -= pst(them, PAWN, capsq); + st->egValue -= pst(us, PAWN, from); + st->egValue += pst(us, PAWN, to); // Reset en passant square - st.epSquare = SQ_NONE; + st->epSquare = SQ_NONE; // Reset rule 50 counter - st.rule50 = 0; + st->rule50 = 0; // Update checkers BB - st.checkersBB = attacks_to(king_square(them), us); + 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. It is -/// important that Position::undo_move is called with the same move and UndoInfo -/// object as the earlier call to Position::do_move. +/// be restored to exactly the same state as before the move was made. void Position::undo_move(Move m) { @@ -1166,10 +1158,6 @@ void Position::undo_move(Move m) { gamePly--; sideToMove = opposite_color(sideToMove); - // Restore information from our UndoInfo object (except the captured piece, - // which is taken care of later) - undoInfoUnion = *(st.previous); - if (move_is_castle(m)) undo_castle_move(m); else if (move_promotion(m)) @@ -1210,30 +1198,33 @@ void Position::undo_move(Move m) { pieceList[us][piece][index[to]] = from; index[from] = index[to]; - if (st.capture) + if (st->capture) { - assert(capture != KING); + assert(st->capture != KING); // Replace the captured piece set_bit(&(byColorBB[them]), to); - set_bit(&(byTypeBB[st.capture]), to); + set_bit(&(byTypeBB[st->capture]), to); set_bit(&(byTypeBB[0]), to); - board[to] = piece_of_color_and_type(them, st.capture); + board[to] = piece_of_color_and_type(them, st->capture); // Update material - if (st.capture != PAWN) - npMaterial[them] += piece_value_midgame(st.capture); + if (st->capture != PAWN) + npMaterial[them] += piece_value_midgame(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]] = to; + index[to] = pieceCount[them][st->capture]; // Update piece count - pieceCount[them][st.capture]++; + pieceCount[them][st->capture]++; } else board[to] = EMPTY; } + // Finally point out state pointer back to the previous state + st = st->previous; + assert(is_ok()); } @@ -1306,8 +1297,7 @@ void Position::undo_castle_move(Move m) { /// Position::undo_promotion_move() is a private method used to unmake a /// promotion move. It is called from the main Position::do_move -/// function. The UndoInfo object, which has been initialized in -/// Position::do_move, is used to put back the captured piece (if any). +/// function. void Position::undo_promotion_move(Move m) { @@ -1357,36 +1347,34 @@ void Position::undo_promotion_move(Move m) { pieceCount[us][promotion]--; pieceCount[us][PAWN]++; - if (st.capture) + if (st->capture) { - assert(capture != KING); + assert(st->capture != KING); // Insert captured piece: set_bit(&(byColorBB[them]), to); - set_bit(&(byTypeBB[st.capture]), 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); + board[to] = piece_of_color_and_type(them, st->capture); // Update material. Because the move is a promotion move, we know // that the captured piece cannot be a pawn. - assert(capture != PAWN); - npMaterial[them] += piece_value_midgame(st.capture); + assert(st->capture != PAWN); + npMaterial[them] += piece_value_midgame(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]] = to; + index[to] = pieceCount[them][st->capture]; // Update piece count - pieceCount[them][st.capture]++; + 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. Because -/// the captured piece is always a pawn, we don't need to pass an UndoInfo -/// object from which to retrieve the captured piece. +/// capture. It is called from the main Position::undo_move function. void Position::undo_ep_move(Move m) { @@ -1402,7 +1390,7 @@ void Position::undo_ep_move(Move m) { Square to = move_to(m); Square capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S); - assert(to == ep_square()); + 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); @@ -1440,35 +1428,35 @@ void Position::undo_ep_move(Move m) { /// 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. -void Position::do_null_move(UndoInfo& u) { +void Position::do_null_move(StateInfo& newSt) { assert(is_ok()); assert(!is_check()); // Back up the information necessary to undo the null move to the supplied - // UndoInfo object. In the case of a null move, the only thing we need to + // StateInfo object. In the case of a null move, the only thing we need to // remember is the last move made and the en passant square. - u.lastMove = st.lastMove; - u.epSquare = st.epSquare; - u.previous = st.previous; - st.previous = &u; + newSt.lastMove = st->lastMove; + newSt.epSquare = st->epSquare; + newSt.previous = st->previous; + st->previous = &newSt; // Save the current key to the history[] array, in order to be able to // detect repetition draws. - history[gamePly] = st.key; + history[gamePly] = st->key; // Update the necessary information sideToMove = opposite_color(sideToMove); - if (st.epSquare != SQ_NONE) - st.key ^= zobEp[st.epSquare]; + if (st->epSquare != SQ_NONE) + st->key ^= zobEp[st->epSquare]; - st.epSquare = SQ_NONE; - st.rule50++; + st->epSquare = SQ_NONE; + st->rule50++; gamePly++; - st.key ^= zobSideToMove; + st->key ^= zobSideToMove; - st.mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; - st.egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; + st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; + st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; assert(is_ok()); } @@ -1481,22 +1469,22 @@ void Position::undo_null_move() { assert(is_ok()); assert(!is_check()); - // Restore information from the our UndoInfo object - st.lastMove = st.previous->lastMove; - st.epSquare = st.previous->epSquare; - st.previous = st.previous->previous; + // Restore information from the our StateInfo object + st->lastMove = st->previous->lastMove; + st->epSquare = st->previous->epSquare; + st->previous = st->previous->previous; - if (st.epSquare != SQ_NONE) - st.key ^= zobEp[st.epSquare]; + if (st->epSquare != SQ_NONE) + st->key ^= zobEp[st->epSquare]; // Update the necessary information sideToMove = opposite_color(sideToMove); - st.rule50--; + st->rule50--; gamePly--; - st.key ^= zobSideToMove; + st->key ^= zobSideToMove; - st.mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; - st.egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; + st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; + st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; assert(is_ok()); } @@ -1549,7 +1537,7 @@ int Position::see(Square from, Square to) const { occ = occupied_squares(); // Handle en passant moves - if (st.epSquare == to && type_of_piece_on(from) == PAWN) + if (st->epSquare == to && type_of_piece_on(from) == PAWN) { assert(capture == EMPTY); @@ -1657,14 +1645,15 @@ int Position::see(Square from, Square to) const { void Position::clear() { + st = &startState; + memset(st, 0, sizeof(StateInfo)); + st->epSquare = SQ_NONE; + + memset(index, 0, sizeof(int) * 64); + memset(byColorBB, 0, sizeof(Bitboard) * 2); + for (int i = 0; i < 64; i++) - { board[i] = EMPTY; - index[i] = 0; - } - - for (int i = 0; i < 2; i++) - byColorBB[i] = EmptyBoardBB; for (int i = 0; i < 7; i++) { @@ -1674,21 +1663,11 @@ void Position::clear() { pieceList[0][i][j] = pieceList[1][i][j] = SQ_NONE; } - st.checkersBB = EmptyBoardBB; - for (Color c = WHITE; c <= BLACK; c++) - st.pinners[c] = st.pinned[c] = st.dcCandidates[c] = ~EmptyBoardBB; - - st.lastMove = MOVE_NONE; - sideToMove = WHITE; - st.castleRights = NO_CASTLES; + gamePly = 0; initialKFile = FILE_E; initialKRFile = FILE_H; initialQRFile = FILE_A; - st.epSquare = SQ_NONE; - st.rule50 = 0; - st.previous = NULL; - gamePly = 0; } @@ -1732,7 +1711,7 @@ void Position::put_piece(Piece p, Square s) { void Position::allow_oo(Color c) { - st.castleRights |= (1 + int(c)); + st->castleRights |= (1 + int(c)); } @@ -1741,7 +1720,7 @@ void Position::allow_oo(Color c) { void Position::allow_ooo(Color c) { - st.castleRights |= (4 + 4*int(c)); + st->castleRights |= (4 + 4*int(c)); } @@ -1761,7 +1740,7 @@ Key Position::compute_key() const { if (ep_square() != SQ_NONE) result ^= zobEp[ep_square()]; - result ^= zobCastle[st.castleRights]; + result ^= zobCastle[st->castleRights]; if (side_to_move() == BLACK) result ^= zobSideToMove; @@ -1894,12 +1873,12 @@ bool Position::is_draw() const { return true; // Draw by the 50 moves rule? - if (st.rule50 > 100 || (st.rule50 == 100 && !is_check())) + if (st->rule50 > 100 || (st->rule50 == 100 && !is_check())) return true; // Draw by repetition? - for (int i = 2; i < Min(gamePly, st.rule50); i += 2) - if (history[gamePly - i] == st.key) + for (int i = 2; i < Min(gamePly, st->rule50); i += 2) + if (history[gamePly - i] == st->key) return true; return false; @@ -1912,21 +1891,21 @@ bool Position::is_draw() const { bool Position::has_mate_threat(Color c) { - UndoInfo u1, u2; + StateInfo st1, st2; Color stm = side_to_move(); // The following lines are useless and silly, but prevents gcc from // emitting a stupid warning stating that u1.lastMove and u1.epSquare might // be used uninitialized. - u1.lastMove = st.lastMove; - u1.epSquare = st.epSquare; + st1.lastMove = st->lastMove; + st1.epSquare = st->epSquare; if (is_check()) return false; // If the input color is not equal to the side to move, do a null move if (c != stm) - do_null_move(u1); + do_null_move(st1); MoveStack mlist[120]; int count; @@ -1938,7 +1917,7 @@ bool Position::has_mate_threat(Color c) { // Loop through the moves, and see if one of them is mate for (int i = 0; i < count; i++) { - do_move(mlist[i].move, u2); + do_move(mlist[i].move, st2); if (is_mate()) result = true; @@ -2047,20 +2026,20 @@ void Position::flipped_copy(const Position &pos) { castleRightsMask[make_square(initialQRFile, RANK_8)] ^= BLACK_OOO; // En passant square - if (pos.st.epSquare != SQ_NONE) - st.epSquare = flip_square(pos.st.epSquare); + if (pos.st->epSquare != SQ_NONE) + st->epSquare = flip_square(pos.st->epSquare); // Checkers find_checkers(); // Hash keys - st.key = compute_key(); - st.pawnKey = compute_pawn_key(); - st.materialKey = compute_material_key(); + st->key = compute_key(); + st->pawnKey = compute_pawn_key(); + st->materialKey = compute_material_key(); // Incremental scores - st.mgValue = compute_value(); - st.egValue = compute_value(); + st->mgValue = compute_value(); + st->egValue = compute_value(); // Material npMaterial[WHITE] = compute_non_pawn_material(WHITE); @@ -2137,7 +2116,7 @@ bool Position::is_ok(int* failedStep) const { // Is there more than 2 checkers? if (failedStep) (*failedStep)++; - if (debugCheckerCount && count_1s(st.checkersBB) > 2) + if (debugCheckerCount && count_1s(st->checkersBB) > 2) return false; // Bitboards OK? @@ -2172,27 +2151,27 @@ bool Position::is_ok(int* failedStep) const { // Hash key OK? if (failedStep) (*failedStep)++; - if (debugKey && st.key != compute_key()) + if (debugKey && st->key != compute_key()) return false; // Pawn hash key OK? if (failedStep) (*failedStep)++; - if (debugPawnKey && st.pawnKey != compute_pawn_key()) + if (debugPawnKey && st->pawnKey != compute_pawn_key()) return false; // Material hash key OK? if (failedStep) (*failedStep)++; - if (debugMaterialKey && st.materialKey != compute_material_key()) + if (debugMaterialKey && st->materialKey != compute_material_key()) return false; // Incremental eval OK? if (failedStep) (*failedStep)++; if (debugIncrementalEval) { - if (st.mgValue != compute_value()) + if (st->mgValue != compute_value()) return false; - if (st.egValue != compute_value()) + if (st->egValue != compute_value()) return false; }