diff --git a/jadx-core/src/main/java/jadx/core/dex/nodes/BlockNode.java b/jadx-core/src/main/java/jadx/core/dex/nodes/BlockNode.java
index b7feecff5..1ec50ae15 100644
--- a/jadx-core/src/main/java/jadx/core/dex/nodes/BlockNode.java
+++ b/jadx-core/src/main/java/jadx/core/dex/nodes/BlockNode.java
@@ -25,10 +25,9 @@ public final class BlockNode extends AttrNode implements IBlock, Comparable<Bloc
 	private final int cid;
 
 	/**
-	 * ID linked to position in blocks list (easier to use BitSet)
-	 * TODO: rename to avoid confusion
+	 * Position in blocks list (easier to use BitSet)
 	 */
-	private int id;
+	private int pos;
 
 	/**
 	 * Offset in methods bytecode
@@ -71,9 +70,9 @@ public final class BlockNode extends AttrNode implements IBlock, Comparable<Bloc
 	 */
 	private List<BlockNode> dominatesOn = new ArrayList<>(3);
 
-	public BlockNode(int cid, int id, int offset) {
+	public BlockNode(int cid, int pos, int offset) {
 		this.cid = cid;
-		this.id = id;
+		this.pos = pos;
 		this.startOffset = offset;
 	}
 
@@ -81,12 +80,20 @@ public final class BlockNode extends AttrNode implements IBlock, Comparable<Bloc
 		return cid;
 	}
 
-	void setId(int id) {
-		this.id = id;
+	void setPos(int id) {
+		this.pos = id;
 	}
 
+	/**
+	 * Deprecated. Use {@link #getPos()}.
+	 */
+	@Deprecated
 	public int getId() {
-		return id;
+		return pos;
+	}
+
+	public int getPos() {
+		return pos;
 	}
 
 	public List<BlockNode> getPredecessors() {
@@ -105,6 +112,13 @@ public final class BlockNode extends AttrNode implements IBlock, Comparable<Bloc
 		cleanSuccessors = cleanSuccessors(this);
 	}
 
+	public static void updateBlockPositions(List<BlockNode> blocks) {
+		int count = blocks.size();
+		for (int i = 0; i < count; i++) {
+			blocks.get(i).setPos(i);
+		}
+	}
+
 	public void lock() {
 		try {
 			List<BlockNode> successorsList = successors;
@@ -161,7 +175,7 @@ public final class BlockNode extends AttrNode implements IBlock, Comparable<Bloc
 	 * Check if 'block' dominated on this node
 	 */
 	public boolean isDominator(BlockNode block) {
-		return doms.get(block.getId());
+		return doms.get(block.getPos());
 	}
 
 	/**
@@ -236,7 +250,7 @@ public final class BlockNode extends AttrNode implements IBlock, Comparable<Bloc
 
 	@Override
 	public int hashCode() {
-		return startOffset;
+		return cid;
 	}
 
 	@Override
@@ -248,7 +262,7 @@ public final class BlockNode extends AttrNode implements IBlock, Comparable<Bloc
 			return false;
 		}
 		BlockNode other = (BlockNode) obj;
-		return cid == other.cid && startOffset == other.startOffset;
+		return cid == other.cid;
 	}
 
 	@Override
@@ -258,11 +272,11 @@ public final class BlockNode extends AttrNode implements IBlock, Comparable<Bloc
 
 	@Override
 	public String baseString() {
-		return Integer.toString(id);
+		return Integer.toString(cid);
 	}
 
 	@Override
 	public String toString() {
-		return "B:" + id + ':' + InsnUtils.formatOffset(startOffset);
+		return "B:" + cid + ':' + InsnUtils.formatOffset(startOffset);
 	}
 }
diff --git a/jadx-core/src/main/java/jadx/core/dex/nodes/MethodNode.java b/jadx-core/src/main/java/jadx/core/dex/nodes/MethodNode.java
index c2a12e648..3da876296 100644
--- a/jadx-core/src/main/java/jadx/core/dex/nodes/MethodNode.java
+++ b/jadx-core/src/main/java/jadx/core/dex/nodes/MethodNode.java
@@ -366,14 +366,11 @@ public class MethodNode extends NotificationAttrNode implements IMethodDetails,
 
 	public void setBasicBlocks(List<BlockNode> blocks) {
 		this.blocks = blocks;
-		updateBlockIds(blocks);
+		updateBlockPositions();
 	}
 
-	public void updateBlockIds(List<BlockNode> blocks) {
-		int count = blocks.size();
-		for (int i = 0; i < count; i++) {
-			blocks.get(i).setId(i);
-		}
+	public void updateBlockPositions() {
+		BlockNode.updateBlockPositions(blocks);
 	}
 
 	public int getNextBlockCId() {
diff --git a/jadx-core/src/main/java/jadx/core/dex/regions/conditions/ConditionRegion.java b/jadx-core/src/main/java/jadx/core/dex/regions/conditions/ConditionRegion.java
index 2756f72b2..f7f86a054 100644
--- a/jadx-core/src/main/java/jadx/core/dex/regions/conditions/ConditionRegion.java
+++ b/jadx-core/src/main/java/jadx/core/dex/regions/conditions/ConditionRegion.java
@@ -68,11 +68,11 @@ public abstract class ConditionRegion extends AbstractRegion implements IConditi
 	}
 
 	/**
-	 * Prefer way for update condition info
+	 * Preferred way to update condition info
 	 */
 	public void updateCondition(IfInfo info) {
 		this.condition = info.getCondition();
-		this.conditionBlocks = info.getMergedBlocks();
+		this.conditionBlocks = info.getMergedBlocks().toList();
 	}
 
 	public void updateCondition(IfCondition condition, List<BlockNode> conditionBlocks) {
diff --git a/jadx-core/src/main/java/jadx/core/dex/regions/conditions/IfInfo.java b/jadx-core/src/main/java/jadx/core/dex/regions/conditions/IfInfo.java
index b7667e71f..bd85f069c 100644
--- a/jadx-core/src/main/java/jadx/core/dex/regions/conditions/IfInfo.java
+++ b/jadx-core/src/main/java/jadx/core/dex/regions/conditions/IfInfo.java
@@ -8,11 +8,12 @@ import java.util.Set;
 import jadx.core.dex.nodes.BlockNode;
 import jadx.core.dex.nodes.InsnNode;
 import jadx.core.dex.nodes.MethodNode;
+import jadx.core.utils.blocks.BlockSet;
 
 public final class IfInfo {
 	private final MethodNode mth;
 	private final IfCondition condition;
-	private final List<BlockNode> mergedBlocks;
+	private final BlockSet mergedBlocks;
 	private final BlockNode thenBlock;
 	private final BlockNode elseBlock;
 	private final Set<BlockNode> skipBlocks;
@@ -20,7 +21,7 @@ public final class IfInfo {
 	private BlockNode outBlock;
 
 	public IfInfo(MethodNode mth, IfCondition condition, BlockNode thenBlock, BlockNode elseBlock) {
-		this(mth, condition, thenBlock, elseBlock, new ArrayList<>(), new HashSet<>(), new ArrayList<>());
+		this(mth, condition, thenBlock, elseBlock, BlockSet.empty(mth), new HashSet<>(), new ArrayList<>());
 	}
 
 	public IfInfo(IfInfo info, BlockNode thenBlock, BlockNode elseBlock) {
@@ -29,7 +30,7 @@ public final class IfInfo {
 	}
 
 	private IfInfo(MethodNode mth, IfCondition condition, BlockNode thenBlock, BlockNode elseBlock,
-			List<BlockNode> mergedBlocks, Set<BlockNode> skipBlocks, List<InsnNode> forceInlineInsns) {
+			BlockSet mergedBlocks, Set<BlockNode> skipBlocks, List<InsnNode> forceInlineInsns) {
 		this.mth = mth;
 		this.condition = condition;
 		this.thenBlock = thenBlock;
@@ -56,7 +57,11 @@ public final class IfInfo {
 
 	@Deprecated
 	public BlockNode getFirstIfBlock() {
-		return mergedBlocks.get(0);
+		return mergedBlocks.getFirst();
+	}
+
+	public BlockSet getMergedBlocks() {
+		return mergedBlocks;
 	}
 
 	public MethodNode getMth() {
@@ -67,10 +72,6 @@ public final class IfInfo {
 		return condition;
 	}
 
-	public List<BlockNode> getMergedBlocks() {
-		return mergedBlocks;
-	}
-
 	public Set<BlockNode> getSkipBlocks() {
 		return skipBlocks;
 	}
diff --git a/jadx-core/src/main/java/jadx/core/dex/visitors/DotGraphVisitor.java b/jadx-core/src/main/java/jadx/core/dex/visitors/DotGraphVisitor.java
index 27d28a2a6..b521d1489 100644
--- a/jadx-core/src/main/java/jadx/core/dex/visitors/DotGraphVisitor.java
+++ b/jadx-core/src/main/java/jadx/core/dex/visitors/DotGraphVisitor.java
@@ -89,7 +89,7 @@ public class DotGraphVisitor extends AbstractVisitor {
 
 		public void process(MethodNode mth) {
 			dot.startLine("digraph \"CFG for");
-			dot.add(escape(mth.getParentClass() + "." + mth.getMethodInfo().getShortId()));
+			dot.add(escape(mth.getMethodInfo().getFullId()));
 			dot.add("\" {");
 
 			BlockNode enterBlock = mth.getEnterBlock();
@@ -204,7 +204,7 @@ public class DotGraphVisitor extends AbstractVisitor {
 				dot.add("color=red,");
 			}
 			dot.add("label=\"{");
-			dot.add(String.valueOf(block.getId())).add("\\:\\ ");
+			dot.add(String.valueOf(block.getCId())).add("\\:\\ ");
 			dot.add(InsnUtils.formatOffset(block.getStartOffset()));
 			if (!attrs.isEmpty()) {
 				dot.add('|').add(attrs);
@@ -237,10 +237,10 @@ public class DotGraphVisitor extends AbstractVisitor {
 
 			if (PRINT_DOMINATORS) {
 				for (BlockNode c : block.getDominatesOn()) {
-					conn.startLine(block.getId() + " -> " + c.getId() + "[color=green];");
+					conn.startLine(block.getCId() + " -> " + c.getCId() + "[color=green];");
 				}
 				for (BlockNode dom : BlockUtils.bitSetToBlocks(mth, block.getDomFrontier())) {
-					conn.startLine("f_" + block.getId() + " -> f_" + dom.getId() + "[color=blue];");
+					conn.startLine("f_" + block.getCId() + " -> f_" + dom.getCId() + "[color=blue];");
 				}
 			}
 		}
@@ -280,7 +280,7 @@ public class DotGraphVisitor extends AbstractVisitor {
 		private String makeName(IContainer c) {
 			String name;
 			if (c instanceof BlockNode) {
-				name = "Node_" + ((BlockNode) c).getId();
+				name = "Node_" + ((BlockNode) c).getCId();
 			} else if (c instanceof IBlock) {
 				name = "Node_" + c.getClass().getSimpleName() + '_' + c.hashCode();
 			} else {
diff --git a/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/BlockExceptionHandler.java b/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/BlockExceptionHandler.java
index c8408d0f2..75cc71c71 100644
--- a/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/BlockExceptionHandler.java
+++ b/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/BlockExceptionHandler.java
@@ -68,7 +68,7 @@ public class BlockExceptionHandler {
 		BlockProcessor.removeMarkedBlocks(mth);
 
 		BlockSet sorted = new BlockSet(mth);
-		BlockUtils.visitDFS(mth, sorted::set);
+		BlockUtils.visitDFS(mth, sorted::add);
 		removeUnusedExcHandlers(mth, tryBlocks, sorted);
 		return true;
 	}
@@ -623,7 +623,7 @@ public class BlockExceptionHandler {
 		for (ExceptionHandler eh : mth.getExceptionHandlers()) {
 			boolean notProcessed = true;
 			BlockNode handlerBlock = eh.getHandlerBlock();
-			if (handlerBlock == null || blocks.get(handlerBlock)) {
+			if (handlerBlock == null || blocks.contains(handlerBlock)) {
 				continue;
 			}
 			for (TryCatchBlockAttr tcb : tryBlocks) {
diff --git a/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/BlockProcessor.java b/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/BlockProcessor.java
index f60d4735e..3d3809d97 100644
--- a/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/BlockProcessor.java
+++ b/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/BlockProcessor.java
@@ -103,7 +103,7 @@ public class BlockProcessor extends AbstractVisitor {
 	 * - post dominators (only if {@link AFlag#COMPUTE_POST_DOM} added to method)
 	 * - loops and nested loop info
 	 * </pre>
-	 *
+	 * <p>
 	 * This method should be called after changing a block tree in custom passes added before
 	 * {@link BlockFinisher}.
 	 */
@@ -679,7 +679,7 @@ public class BlockProcessor extends AbstractVisitor {
 	}
 
 	public static void removeMarkedBlocks(MethodNode mth) {
-		mth.getBasicBlocks().removeIf(block -> {
+		boolean removed = mth.getBasicBlocks().removeIf(block -> {
 			if (block.contains(AFlag.REMOVE)) {
 				if (!block.getPredecessors().isEmpty() || !block.getSuccessors().isEmpty()) {
 					LOG.warn("Block {} not deleted, method: {}", block, mth);
@@ -693,6 +693,9 @@ public class BlockProcessor extends AbstractVisitor {
 			}
 			return false;
 		});
+		if (removed) {
+			mth.updateBlockPositions();
+		}
 	}
 
 	private static void removeUnreachableBlocks(MethodNode mth) {
@@ -728,6 +731,7 @@ public class BlockProcessor extends AbstractVisitor {
 
 		toRemove.forEach(BlockSplitter::detachBlock);
 		mth.getBasicBlocks().removeAll(toRemove);
+		mth.updateBlockPositions();
 	}
 
 	private static void clearBlocksState(MethodNode mth) {
diff --git a/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/BlockSplitter.java b/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/BlockSplitter.java
index c10f28c18..3464fe716 100644
--- a/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/BlockSplitter.java
+++ b/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/BlockSplitter.java
@@ -79,6 +79,7 @@ public class BlockSplitter extends AbstractVisitor {
 		addTempConnectionsForExcHandlers(mth, blocksMap);
 		setupExitConnections(mth);
 
+		mth.updateBlockPositions();
 		mth.unloadInsnArr();
 	}
 
diff --git a/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/PostDominatorTree.java b/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/PostDominatorTree.java
index 59f31e056..e09decd9f 100644
--- a/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/PostDominatorTree.java
+++ b/jadx-core/src/main/java/jadx/core/dex/visitors/blocks/PostDominatorTree.java
@@ -20,14 +20,14 @@ public class PostDominatorTree {
 			int mthBlocksCount = mth.getBasicBlocks().size();
 			List<BlockNode> sorted = new ArrayList<>(mthBlocksCount);
 			BlockUtils.visitReverseDFS(mth, sorted::add);
-			// temporary set block ids to match reverse sorted order
-			// save old ids for later remapping
+			// temporary set block positions to match reverse sorted order
+			// save old positions for later remapping
 			int blocksCount = sorted.size();
-			int[] ids = new int[mthBlocksCount];
+			int[] posMapping = new int[mthBlocksCount];
 			for (int i = 0; i < blocksCount; i++) {
-				ids[i] = sorted.get(i).getId();
+				posMapping[i] = sorted.get(i).getPos();
 			}
-			mth.updateBlockIds(sorted);
+			BlockNode.updateBlockPositions(sorted);
 
 			BlockNode[] postDoms = DominatorTree.build(sorted, BlockNode::getSuccessors);
 			BlockNode firstBlock = sorted.get(0);
@@ -43,8 +43,8 @@ public class PostDominatorTree {
 			for (int i = 1; i < blocksCount; i++) {
 				BlockNode block = sorted.get(i);
 				BitSet bs = new BitSet(blocksCount);
-				block.getPostDoms().stream().forEach(n -> bs.set(ids[n]));
-				bs.clear(ids[i]);
+				block.getPostDoms().stream().forEach(n -> bs.set(posMapping[n]));
+				bs.clear(posMapping[i]);
 				block.setPostDoms(bs);
 			}
 			// check for missing blocks in 'sorted' list
@@ -65,8 +65,8 @@ public class PostDominatorTree {
 			// show error as a warning because this info not always used
 			mth.addWarnComment("Failed to build post-dominance tree", e);
 		} finally {
-			// revert block ids change
-			mth.updateBlockIds(mth.getBasicBlocks());
+			// revert block positions change
+			mth.updateBlockPositions();
 		}
 	}
 }
diff --git a/jadx-core/src/main/java/jadx/core/dex/visitors/regions/maker/IfRegionMaker.java b/jadx-core/src/main/java/jadx/core/dex/visitors/regions/maker/IfRegionMaker.java
index ce94e72ec..4497adbaa 100644
--- a/jadx-core/src/main/java/jadx/core/dex/visitors/regions/maker/IfRegionMaker.java
+++ b/jadx-core/src/main/java/jadx/core/dex/visitors/regions/maker/IfRegionMaker.java
@@ -29,6 +29,7 @@ import jadx.core.dex.regions.conditions.IfInfo;
 import jadx.core.dex.regions.conditions.IfRegion;
 import jadx.core.dex.regions.loops.LoopRegion;
 import jadx.core.utils.BlockUtils;
+import jadx.core.utils.blocks.BlockSet;
 import jadx.core.utils.exceptions.JadxRuntimeException;
 
 import static jadx.core.utils.BlockUtils.isEqualPaths;
@@ -228,7 +229,7 @@ final class IfRegionMaker {
 
 	private static boolean allPathsFromIf(BlockNode block, IfInfo info) {
 		List<BlockNode> preds = block.getPredecessors();
-		List<BlockNode> ifBlocks = info.getMergedBlocks();
+		BlockSet ifBlocks = info.getMergedBlocks();
 		for (BlockNode pred : preds) {
 			if (pred.contains(AFlag.LOOP_END)) {
 				// ignore loop back edge
diff --git a/jadx-core/src/main/java/jadx/core/dex/visitors/regions/maker/LoopRegionMaker.java b/jadx-core/src/main/java/jadx/core/dex/visitors/regions/maker/LoopRegionMaker.java
index 5ce38ac86..d1d31061b 100644
--- a/jadx-core/src/main/java/jadx/core/dex/visitors/regions/maker/LoopRegionMaker.java
+++ b/jadx-core/src/main/java/jadx/core/dex/visitors/regions/maker/LoopRegionMaker.java
@@ -77,7 +77,7 @@ final class LoopRegionMaker {
 		loopRegion.updateCondition(condInfo);
 		// prevent if's merge with loop condition
 		condInfo.getMergedBlocks().forEach(b -> b.add(AFlag.ADDED_TO_REGION));
-		exitBlocks.removeAll(condInfo.getMergedBlocks());
+		exitBlocks.removeAll(condInfo.getMergedBlocks().toList());
 
 		if (!exitBlocks.isEmpty()) {
 			BlockNode loopExit = condInfo.getElseBlock();
diff --git a/jadx-core/src/main/java/jadx/core/dex/visitors/regions/maker/RegionMaker.java b/jadx-core/src/main/java/jadx/core/dex/visitors/regions/maker/RegionMaker.java
index aadd88add..3fda1bae5 100644
--- a/jadx-core/src/main/java/jadx/core/dex/visitors/regions/maker/RegionMaker.java
+++ b/jadx-core/src/main/java/jadx/core/dex/visitors/regions/maker/RegionMaker.java
@@ -1,7 +1,6 @@
 package jadx.core.dex.visitors.regions.maker;
 
 import java.util.ArrayList;
-import java.util.BitSet;
 import java.util.List;
 import java.util.Objects;
 
@@ -19,6 +18,7 @@ import jadx.core.dex.nodes.InsnNode;
 import jadx.core.dex.nodes.MethodNode;
 import jadx.core.dex.regions.Region;
 import jadx.core.utils.BlockUtils;
+import jadx.core.utils.blocks.BlockSet;
 import jadx.core.utils.exceptions.JadxOverflowException;
 
 import static jadx.core.utils.BlockUtils.getNextBlock;
@@ -30,7 +30,7 @@ public class RegionMaker {
 	private final IfRegionMaker ifMaker;
 	private final LoopRegionMaker loopMaker;
 
-	private final BitSet processedBlocks;
+	private final BlockSet processedBlocks;
 	private final int regionsLimit;
 
 	private int regionsCount;
@@ -40,9 +40,8 @@ public class RegionMaker {
 		this.stack = new RegionStack(mth);
 		this.ifMaker = new IfRegionMaker(mth, this);
 		this.loopMaker = new LoopRegionMaker(mth, this, ifMaker);
-		int blocksCount = mth.getBasicBlocks().size();
-		this.processedBlocks = new BitSet(blocksCount);
-		this.regionsLimit = blocksCount * 100;
+		this.processedBlocks = BlockSet.empty(mth);
+		this.regionsLimit = mth.getBasicBlocks().size() * 100;
 	}
 
 	public Region makeMthRegion() {
@@ -57,12 +56,10 @@ public class RegionMaker {
 			return region;
 		}
 
-		int startBlockId = startBlock.getId();
-		if (processedBlocks.get(startBlockId)) {
+		if (processedBlocks.addChecked(startBlock)) {
 			mth.addWarn("Removed duplicated region for block: " + startBlock + ' ' + startBlock.getAttributesString());
 			return region;
 		}
-		processedBlocks.set(startBlockId);
 
 		BlockNode next = startBlock;
 		while (next != null) {
@@ -159,10 +156,10 @@ public class RegionMaker {
 	}
 
 	boolean isProcessed(BlockNode block) {
-		return processedBlocks.get(block.getId());
+		return processedBlocks.contains(block);
 	}
 
 	void clearBlockProcessedState(BlockNode block) {
-		processedBlocks.clear(block.getId());
+		processedBlocks.remove(block);
 	}
 }
diff --git a/jadx-core/src/main/java/jadx/core/utils/BlockUtils.java b/jadx-core/src/main/java/jadx/core/utils/BlockUtils.java
index 0d040b8e2..ba28ca1c0 100644
--- a/jadx-core/src/main/java/jadx/core/utils/BlockUtils.java
+++ b/jadx-core/src/main/java/jadx/core/utils/BlockUtils.java
@@ -443,7 +443,7 @@ public class BlockUtils {
 	 */
 	public static @Nullable BlockNode getPrevBlockOnPath(MethodNode mth, BlockNode block, BlockNode pathStart) {
 		BlockSet preds = BlockSet.from(mth, block.getPredecessors());
-		if (preds.get(pathStart)) {
+		if (preds.contains(pathStart)) {
 			return pathStart;
 		}
 		DFSIteration dfs = new DFSIteration(mth, pathStart, BlockNode::getCleanSuccessors);
@@ -452,7 +452,7 @@ public class BlockUtils {
 			if (next == null) {
 				return null;
 			}
-			if (preds.get(next)) {
+			if (preds.contains(next)) {
 				return next;
 			}
 		}
diff --git a/jadx-core/src/main/java/jadx/core/utils/blocks/BlockSet.java b/jadx-core/src/main/java/jadx/core/utils/blocks/BlockSet.java
index 1c9073645..f8a6b5ca1 100644
--- a/jadx-core/src/main/java/jadx/core/utils/blocks/BlockSet.java
+++ b/jadx-core/src/main/java/jadx/core/utils/blocks/BlockSet.java
@@ -4,20 +4,32 @@ import java.util.ArrayList;
 import java.util.BitSet;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.Iterator;
 import java.util.List;
+import java.util.NoSuchElementException;
+import java.util.Spliterator;
+import java.util.Spliterators;
 import java.util.function.Consumer;
 
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import jadx.core.dex.nodes.BlockNode;
 import jadx.core.dex.nodes.MethodNode;
 import jadx.core.utils.EmptyBitSet;
 
-public class BlockSet {
+/**
+ * BlockNode set implementation based on BitSet.
+ */
+public class BlockSet implements Iterable<BlockNode> {
+
+	public static BlockSet empty(MethodNode mth) {
+		return new BlockSet(mth);
+	}
 
 	public static BlockSet from(MethodNode mth, Collection<BlockNode> blocks) {
 		BlockSet newBS = new BlockSet(mth);
-		newBS.set(blocks);
+		newBS.addAll(blocks);
 		return newBS;
 	}
 
@@ -29,28 +41,49 @@ public class BlockSet {
 		this.bs = new BitSet(mth.getBasicBlocks().size());
 	}
 
-	public boolean get(BlockNode block) {
-		return bs.get(block.getId());
+	public boolean contains(BlockNode block) {
+		return bs.get(block.getPos());
 	}
 
-	public void set(BlockNode block) {
-		bs.set(block.getId());
+	public void add(BlockNode block) {
+		bs.set(block.getPos());
 	}
 
-	public void set(Collection<BlockNode> blocks) {
-		blocks.forEach(this::set);
+	public void addAll(Collection<BlockNode> blocks) {
+		blocks.forEach(this::add);
 	}
 
-	public boolean checkAndSet(BlockNode block) {
-		int id = block.getId();
+	public void addAll(BlockSet otherBlockSet) {
+		bs.or(otherBlockSet.bs);
+	}
+
+	public void remove(BlockNode block) {
+		bs.clear(block.getPos());
+	}
+
+	public void remove(Collection<BlockNode> blocks) {
+		blocks.forEach(this::remove);
+	}
+
+	public boolean addChecked(BlockNode block) {
+		int id = block.getPos();
 		boolean state = bs.get(id);
 		bs.set(id);
 		return state;
 	}
 
+	public boolean containsAll(List<BlockNode> blocks) {
+		for (BlockNode block : blocks) {
+			if (!contains(block)) {
+				return false;
+			}
+		}
+		return true;
+	}
+
 	public boolean intersects(List<BlockNode> blocks) {
 		for (BlockNode block : blocks) {
-			if (get(block)) {
+			if (contains(block)) {
 				return true;
 			}
 		}
@@ -67,13 +100,17 @@ public class BlockSet {
 	}
 
 	public boolean isEmpty() {
-		return bs.cardinality() == 0;
+		return bs.isEmpty();
 	}
 
 	public int size() {
 		return bs.cardinality();
 	}
 
+	public void remove() {
+		bs.clear();
+	}
+
 	public @Nullable BlockNode getOne() {
 		if (bs.cardinality() == 1) {
 			return mth.getBasicBlocks().get(bs.nextSetBit(0));
@@ -81,6 +118,11 @@ public class BlockSet {
 		return null;
 	}
 
+	public BlockNode getFirst() {
+		return mth.getBasicBlocks().get(bs.nextSetBit(0));
+	}
+
+	@Override
 	public void forEach(Consumer<? super BlockNode> consumer) {
 		if (bs.isEmpty()) {
 			return;
@@ -91,6 +133,18 @@ public class BlockSet {
 		}
 	}
 
+	@Override
+	public @NotNull Iterator<BlockNode> iterator() {
+		return new BlockSetIterator(bs, size(), mth.getBasicBlocks());
+	}
+
+	@Override
+	public Spliterator<BlockNode> spliterator() {
+		int size = size();
+		BlockSetIterator iterator = new BlockSetIterator(bs, size, mth.getBasicBlocks());
+		return Spliterators.spliterator(iterator, size, Spliterator.ORDERED | Spliterator.DISTINCT);
+	}
+
 	public List<BlockNode> toList() {
 		if (bs == null || bs == EmptyBitSet.EMPTY) {
 			return Collections.emptyList();
@@ -111,4 +165,35 @@ public class BlockSet {
 	public String toString() {
 		return toList().toString();
 	}
+
+	private static final class BlockSetIterator implements Iterator<BlockNode> {
+		private final BitSet bs;
+		private final int size;
+		private final List<BlockNode> blocks;
+
+		private int cursor;
+		private int start;
+
+		public BlockSetIterator(BitSet bs, int size, List<BlockNode> blocks) {
+			this.bs = bs;
+			this.size = size;
+			this.blocks = blocks;
+		}
+
+		@Override
+		public boolean hasNext() {
+			return cursor != size;
+		}
+
+		@Override
+		public BlockNode next() {
+			int pos = bs.nextSetBit(start);
+			if (pos == -1) {
+				throw new NoSuchElementException();
+			}
+			start = pos + 1;
+			cursor++;
+			return blocks.get(pos);
+		}
+	}
 }
diff --git a/jadx-core/src/main/java/jadx/core/utils/blocks/DFSIteration.java b/jadx-core/src/main/java/jadx/core/utils/blocks/DFSIteration.java
index c8ce2b529..1212ac64c 100644
--- a/jadx-core/src/main/java/jadx/core/utils/blocks/DFSIteration.java
+++ b/jadx-core/src/main/java/jadx/core/utils/blocks/DFSIteration.java
@@ -20,7 +20,7 @@ public class DFSIteration {
 		queue = new ArrayDeque<>();
 		visited = new BlockSet(mth);
 		queue.addLast(startBlock);
-		visited.set(startBlock);
+		visited.add(startBlock);
 	}
 
 	public @Nullable BlockNode next() {
@@ -32,7 +32,7 @@ public class DFSIteration {
 		int count = nextBlocks.size();
 		for (int i = count - 1; i >= 0; i--) { // to preserve order in queue
 			BlockNode next = nextBlocks.get(i);
-			if (!visited.checkAndSet(next)) {
+			if (!visited.addChecked(next)) {
 				queue.addLast(next);
 			}
 		}