X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=c673225737b2906d428743b8a6f034d60d75d1c9;hp=5f1f843b2b075d683b7b1aa1d154335e6e4932b3;hb=97dd7568edf74f8797e152258ebe30ecdc8bac0d;hpb=fbec55e52ea35b5e47efa6c1f98816c7bb410568 diff --git a/src/position.cpp b/src/position.cpp index 5f1f843b..c6732257 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -710,7 +710,6 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { }; memcpy(&newSt, st, sizeof(ReducedStateInfo)); - newSt.capture = NO_PIECE_TYPE; newSt.previous = st; st = &newSt; @@ -764,7 +763,8 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { } // 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]; @@ -788,9 +788,11 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { 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) @@ -804,9 +806,8 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { // 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]; } @@ -817,7 +818,7 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { st->mgValue += pst_delta(piece, from, to); st->egValue += pst_delta(piece, from, to); - if (pm) + if (pm) // promotion ? { PieceType promotion = move_promotion_piece(m); @@ -828,24 +829,26 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { 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(us, PAWN, to); st->mgValue += pst(us, promotion, to); @@ -883,6 +886,8 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; + + assert(is_ok()); } @@ -895,14 +900,13 @@ void Position::do_capture_move(Bitboard& key, PieceType capture, Color them, Squ 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; @@ -934,9 +938,16 @@ void Position::do_capture_move(Bitboard& key, PieceType capture, Color them, Squ // 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; @@ -950,13 +961,15 @@ void Position::do_capture_move(Bitboard& key, PieceType capture, Color them, Squ 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 @@ -999,7 +1012,7 @@ void Position::do_castle_move(Move m) { // 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; @@ -1036,6 +1049,8 @@ void Position::do_castle_move(Move m) { st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; + + assert(is_ok()); } @@ -1072,7 +1087,7 @@ void Position::undo_move(Move m) { 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; @@ -1089,10 +1104,11 @@ void Position::undo_move(Move m) { 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 @@ -1109,8 +1125,8 @@ void Position::undo_move(Move m) { 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) { @@ -1129,16 +1145,18 @@ void Position::undo_move(Move m) { 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()); } @@ -1197,12 +1215,14 @@ void Position::undo_castle_move(Move m) { // 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()); } @@ -1218,10 +1238,10 @@ void Position::do_null_move(StateInfo& backupSt) { // 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; @@ -1235,6 +1255,7 @@ void Position::do_null_move(StateInfo& backupSt) { st->key ^= zobSideToMove; TT.prefetch(st->key); + sideToMove = opposite_color(sideToMove); st->epSquare = SQ_NONE; st->rule50++; @@ -1242,8 +1263,6 @@ void Position::do_null_move(StateInfo& backupSt) { st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; - - assert(is_ok()); } @@ -1255,18 +1274,17 @@ void Position::undo_null_move() { 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()); } @@ -1459,19 +1477,17 @@ void Position::clear() { 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; @@ -1686,7 +1702,7 @@ bool Position::is_mate() const { MoveStack moves[256]; - return is_check() && !generate_evasions(*this, moves, pinned_pieces(sideToMove)); + return is_check() && (generate_evasions(*this, moves, pinned_pieces(sideToMove)) == moves); } @@ -1706,20 +1722,18 @@ bool Position::has_mate_threat(Color c) { 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;