X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=2b50ff2ae258df7a49eb0d892b79511d41e31908;hp=7fcbe670711361d0ae0cd90e53059672a1f11079;hb=9e4befe3f1ea324bece88aee2e97b38659411c52;hpb=05e70d674019e27f2c9a58839f6a9c17e16f9fcc diff --git a/src/position.cpp b/src/position.cpp index 7fcbe670..2b50ff2a 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -696,6 +696,8 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { assert(is_ok()); assert(move_is_ok(m)); + Bitboard key = st->key; + // Copy some fields of old state to our new StateInfo object except the // ones which are recalculated from scratch anyway, then switch our state // pointer to point to the new, ready to be updated, state. @@ -708,171 +710,179 @@ 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; // Save the current key to the history[] array, in order to be able to // detect repetition draws. - history[gamePly] = st->key; + history[gamePly] = key; + gamePly++; + + // Update side to move + key ^= zobSideToMove; // 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++; - // Update side to move - st->key ^= zobSideToMove; - if (move_is_castle(m)) - do_castle_move(m); - else { - Color us = side_to_move(); - Color them = opposite_color(us); - Square from = move_from(m); - Square to = move_to(m); - bool ep = move_is_ep(m); - bool pm = move_is_promotion(m); - - Piece piece = piece_on(from); - PieceType pt = type_of_piece(piece); - - assert(color_of_piece_on(from) == us); - assert(color_of_piece_on(to) == them || square_is_empty(to)); - assert(!(ep || pm) || piece == piece_of_color_and_type(us, PAWN)); - assert(!pm || relative_rank(us, to) == RANK_8); - - st->capture = ep ? PAWN : type_of_piece_on(to); - - if (st->capture) - do_capture_move(st->capture, them, to, ep); + st->key = key; + do_castle_move(m); + return; + } - // Update hash key - st->key ^= zobrist[us][pt][from] ^ zobrist[us][pt][to]; + Color us = side_to_move(); + Color them = opposite_color(us); + Square from = move_from(m); + Square to = move_to(m); + bool ep = move_is_ep(m); + bool pm = move_is_promotion(m); - // Reset en passant square - if (st->epSquare != SQ_NONE) - { - st->key ^= zobEp[st->epSquare]; - st->epSquare = SQ_NONE; - } + Piece piece = piece_on(from); + PieceType pt = type_of_piece(piece); - // Update castle rights, try to shortcut a common case - if ((castleRightsMask[from] & castleRightsMask[to]) != ALL_CASTLES) - { - st->key ^= zobCastle[st->castleRights]; - st->castleRights &= castleRightsMask[from]; - st->castleRights &= castleRightsMask[to]; - st->key ^= zobCastle[st->castleRights]; - } + assert(color_of_piece_on(from) == us); + assert(color_of_piece_on(to) == them || square_is_empty(to)); + assert(!(ep || pm) || piece == piece_of_color_and_type(us, PAWN)); + assert(!pm || relative_rank(us, to) == RANK_8); - // Prefetch TT access as soon as we know key is updated - TT.prefetch(st->key); + st->capture = ep ? PAWN : type_of_piece_on(to); - // Move the piece - Bitboard move_bb = make_move_bb(from, to); - do_move_bb(&(byColorBB[us]), move_bb); - do_move_bb(&(byTypeBB[pt]), move_bb); - do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares + if (st->capture) + do_capture_move(key, st->capture, them, to, ep); - board[to] = board[from]; - board[from] = EMPTY; + // Update hash key + key ^= zobrist[us][pt][from] ^ zobrist[us][pt][to]; - // If the moving piece was a pawn do some special extra work - if (pt == PAWN) - { - // Reset rule 50 draw counter - st->rule50 = 0; - - // Update pawn hash key - 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) - { - 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]; - } - } - } + // Reset en passant square + if (st->epSquare != SQ_NONE) + { + key ^= zobEp[st->epSquare]; + st->epSquare = SQ_NONE; + } - // Update incremental scores - st->mgValue += pst_delta(piece, from, to); - st->egValue += pst_delta(piece, from, to); + // Update castle rights, try to shortcut a common case + int cm = castleRightsMask[from] & castleRightsMask[to]; + if (cm != ALL_CASTLES && ((cm & st->castleRights) != st->castleRights)) + { + key ^= zobCastle[st->castleRights]; + st->castleRights &= castleRightsMask[from]; + st->castleRights &= castleRightsMask[to]; + key ^= zobCastle[st->castleRights]; + } - // If the moving piece was a king, update the king square - if (pt == KING) - kingSquare[us] = to; + // Prefetch TT access as soon as we know key is updated + TT.prefetch(key); - // Update piece lists - pieceList[us][pt][index[from]] = to; - index[to] = index[from]; + // Move the piece + Bitboard move_bb = make_move_bb(from, to); + do_move_bb(&(byColorBB[us]), move_bb); + do_move_bb(&(byTypeBB[pt]), move_bb); + do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares - if (pm) - { - PieceType promotion = move_promotion_piece(m); + board[to] = board[from]; + board[from] = EMPTY; - assert(promotion >= KNIGHT && promotion <= QUEEN); + // If the moving piece was a king, update the king square + if (pt == KING) + kingSquare[us] = to; - // 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 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; - // Partially revert hash keys update - st->key ^= zobrist[us][PAWN][to] ^ zobrist[us][promotion][to]; - st->pawnKey ^= zobrist[us][PAWN][to]; + // If the moving piece was a pawn do some special extra work + if (pt == PAWN) + { + // Reset rule 50 draw counter + st->rule50 = 0; - // Update material key - st->materialKey ^= zobMaterial[us][PAWN][pieceCount[us][PAWN]]; - st->materialKey ^= zobMaterial[us][promotion][pieceCount[us][promotion]+1]; + // Update pawn hash key + st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; - // Update piece counts - pieceCount[us][PAWN]--; - pieceCount[us][promotion]++; + // Set en passant square, only if moved pawn can be captured + if (abs(int(to) - int(from)) == 16) + { + 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]; + } + } + } - // 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; - index[to] = pieceCount[us][promotion] - 1; + // Update incremental scores + st->mgValue += pst_delta(piece, from, to); + st->egValue += pst_delta(piece, from, to); - // Partially revert and update incremental scores - st->mgValue -= pst(us, PAWN, to); - st->mgValue += pst(us, promotion, to); - st->egValue -= pst(us, PAWN, to); - st->egValue += pst(us, promotion, to); + 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 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, 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]; + + // Partially revert and update incremental scores + st->mgValue -= pst(us, PAWN, to); + st->mgValue += pst(us, promotion, to); + st->egValue -= pst(us, PAWN, to); + st->egValue += pst(us, promotion, to); + + // Update material + st->npMaterial[us] += piece_value_midgame(promotion); + } - // Update material - st->npMaterial[us] += piece_value_midgame(promotion); - } + // Update the key with the final value + st->key = key; - // Update checkers bitboard, piece must be already moved - if (ep || pm) - st->checkersBB = attacks_to(king_square(them), us); - else - { - st->checkersBB = EmptyBoardBB; // FIXME EP ? - Square ksq = king_square(them); - switch (pt) - { - case PAWN: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case KNIGHT: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case BISHOP: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case ROOK: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case QUEEN: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - case KING: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; - default: assert(false); break; - } - } + // Update checkers bitboard, piece must be already moved + if (ep | pm) + st->checkersBB = attacks_to(king_square(them), us); + else + { + st->checkersBB = EmptyBoardBB; + Square ksq = king_square(them); + switch (pt) + { + case PAWN: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case KNIGHT: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case BISHOP: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case ROOK: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case QUEEN: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + case KING: update_checkers(&(st->checkersBB), ksq, from, to, dcCandidates); break; + default: assert(false); break; + } } // Finish sideToMove = opposite_color(sideToMove); - gamePly++; st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; @@ -884,20 +894,19 @@ void Position::do_move(Move m, StateInfo& newSt, Bitboard dcCandidates) { /// Position::do_capture_move() is a private method used to update captured /// piece info. It is called from the main Position::do_move function. -void Position::do_capture_move(PieceType capture, Color them, Square to, bool ep) { +void Position::do_capture_move(Bitboard& key, PieceType capture, Color them, Square to, bool ep) { assert(capture != KING); 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(us, PAWN)); assert(piece_on(capsq) == piece_of_color_and_type(them, PAWN)); board[capsq] = EMPTY; @@ -906,10 +915,10 @@ void Position::do_capture_move(PieceType capture, Color them, Square to, bool ep // Remove captured piece clear_bit(&(byColorBB[them]), capsq); clear_bit(&(byTypeBB[capture]), capsq); - clear_bit(&(byTypeBB[0]), capsq); // HACK: byTypeBB[0] == occupied squares + clear_bit(&(byTypeBB[0]), capsq); // Update hash key - st->key ^= zobrist[them][capture][capsq]; + key ^= zobrist[them][capture][capsq]; // If the captured piece was a pawn, update pawn hash key if (capture == PAWN) @@ -929,9 +938,10 @@ void Position::do_capture_move(PieceType capture, Color them, Square to, bool ep // 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 + 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; @@ -945,13 +955,15 @@ void Position::do_capture_move(PieceType capture, Color them, Square to, bool ep 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 @@ -994,7 +1006,7 @@ 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; @@ -1025,6 +1037,14 @@ void Position::do_castle_move(Move m) { // Update checkers BB st->checkersBB = attacks_to(king_square(them), us); + + // Finish + sideToMove = opposite_color(sideToMove); + + st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; + st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; + + assert(is_ok()); } @@ -1040,88 +1060,91 @@ void Position::undo_move(Move m) { sideToMove = opposite_color(sideToMove); if (move_is_castle(m)) - undo_castle_move(m); - else { - Color us = side_to_move(); - Color them = opposite_color(us); - Square from = move_from(m); - Square to = move_to(m); - bool ep = move_is_ep(m); - bool pm = move_is_promotion(m); - - PieceType piece = type_of_piece_on(to); - - assert(square_is_empty(from)); - assert(color_of_piece_on(to) == us); - assert(!pm || relative_rank(us, to) == RANK_8); - assert(!ep || to == st->previous->epSquare); - assert(!ep || relative_rank(us, to) == RANK_6); - assert(!ep || piece_on(to) == piece_of_color_and_type(us, PAWN)); + undo_castle_move(m); + return; + } - if (pm) - { - PieceType promotion = move_promotion_piece(m); + Color us = side_to_move(); + Color them = opposite_color(us); + Square from = move_from(m); + Square to = move_to(m); + bool ep = move_is_ep(m); + bool pm = move_is_promotion(m); - assert(piece_on(to) == piece_of_color_and_type(us, promotion)); - assert(promotion >= KNIGHT && promotion <= QUEEN); + PieceType pt = type_of_piece_on(to); - // Replace promoted piece with a pawn - clear_bit(&(byTypeBB[promotion]), to); - set_bit(&(byTypeBB[PAWN]), to); + assert(square_is_empty(from)); + assert(color_of_piece_on(to) == us); + assert(!pm || relative_rank(us, to) == RANK_8); + assert(!ep || to == st->previous->epSquare); + assert(!ep || relative_rank(us, to) == RANK_6); + assert(!ep || piece_on(to) == piece_of_color_and_type(us, PAWN)); - // Update piece list replacing promotion piece with a pawn - pieceList[us][promotion][index[to]] = pieceList[us][promotion][pieceCount[us][promotion] - 1]; - index[pieceList[us][promotion][index[to]]] = index[to]; - pieceList[us][PAWN][pieceCount[us][PAWN]] = to; - index[to] = pieceCount[us][PAWN]; + if (pm) // promotion ? + { + PieceType promotion = move_promotion_piece(m); + pt = PAWN; + + assert(promotion >= KNIGHT && promotion <= QUEEN); + assert(piece_on(to) == piece_of_color_and_type(us, promotion)); + + // Replace promoted piece with a pawn + clear_bit(&(byTypeBB[promotion]), to); + set_bit(&(byTypeBB[PAWN]), to); + + // Update piece counts + pieceCount[us][promotion]--; + pieceCount[us][PAWN]++; + + // Update piece list replacing promotion piece with a pawn + 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; + } - // Update piece counts - pieceCount[us][promotion]--; - pieceCount[us][PAWN]++; + // Put the piece back at the source square + Bitboard move_bb = make_move_bb(to, from); + do_move_bb(&(byColorBB[us]), move_bb); + do_move_bb(&(byTypeBB[pt]), move_bb); + do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares - piece = PAWN; - } + board[from] = piece_of_color_and_type(us, pt); + board[to] = EMPTY; - // Put the piece back at the source square - Bitboard move_bb = make_move_bb(to, from); - do_move_bb(&(byColorBB[us]), move_bb); - do_move_bb(&(byTypeBB[piece]), move_bb); - do_move_bb(&(byTypeBB[0]), move_bb); // HACK: byTypeBB[0] == occupied squares - board[from] = piece_of_color_and_type(us, piece); - board[to] = EMPTY; + // If the moving piece was a king, update the king square + if (pt == KING) + kingSquare[us] = from; - // If the moving piece was a king, update the king square - if (piece == KING) - kingSquare[us] = from; + // Update piece list + index[from] = index[to]; + pieceList[us][pt][index[from]] = from; - // Update piece list - pieceList[us][piece][index[to]] = from; - index[from] = index[to]; + if (st->capture) + { + Square capsq = to; - if (st->capture) - { - Square capsq = to; + if (ep) + capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S); - if (ep) - capsq = (us == WHITE)? (to - DELTA_N) : (to - DELTA_S); + assert(st->capture != KING); + assert(!ep || square_is_empty(capsq)); - assert(st->capture != KING); - assert(!ep || square_is_empty(capsq)); + // Restore the captured piece + set_bit(&(byColorBB[them]), capsq); + set_bit(&(byTypeBB[st->capture]), capsq); + set_bit(&(byTypeBB[0]), capsq); - // Restore the captured piece - set_bit(&(byColorBB[them]), capsq); - set_bit(&(byTypeBB[st->capture]), capsq); - set_bit(&(byTypeBB[0]), capsq); - board[capsq] = piece_of_color_and_type(them, 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 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 @@ -1186,9 +1209,14 @@ 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()); } @@ -1204,10 +1232,10 @@ 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; @@ -1221,6 +1249,7 @@ void Position::do_null_move(StateInfo& backupSt) { st->key ^= zobSideToMove; TT.prefetch(st->key); + sideToMove = opposite_color(sideToMove); st->epSquare = SQ_NONE; st->rule50++; @@ -1228,8 +1257,6 @@ void Position::do_null_move(StateInfo& backupSt) { st->mgValue += (sideToMove == WHITE)? TempoValueMidgame : -TempoValueMidgame; st->egValue += (sideToMove == WHITE)? TempoValueEndgame : -TempoValueEndgame; - - assert(is_ok()); } @@ -1241,18 +1268,17 @@ 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()); } @@ -1445,19 +1471,17 @@ 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; @@ -1672,7 +1696,7 @@ 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); } @@ -1692,20 +1716,18 @@ 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;