1 files changed, 12 insertions, 0 deletions
diff --git a/src/main/java/com/android/tools/r8/ir/code/IRCode.java b/src/main/java/com/android/tools/r8/ir/code/IRCode.java
index c96bf92fa..e1e9a99ba 100644
--- a/src/main/java/com/android/tools/r8/ir/code/IRCode.java
+++ b/src/main/java/com/android/tools/r8/ir/code/IRCode.java
@@ -17,6 +17,7 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.ListIterator;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 public class IRCode {
 
@@ -135,6 +136,7 @@ public class IRCode {
   }
 
   public boolean isConsistentGraph() {
+    assert consistentBlockNumbering();
     assert consistentPredecessorSuccessors();
     assert consistentCatchHandlers();
     assert consistentBlockInstructions();
@@ -263,6 +265,12 @@ public class IRCode {
     return true;
   }
 
+  public boolean consistentBlockNumbering() {
+    return blocks.stream()
+        .collect(Collectors.groupingBy(BasicBlock::getNumber, Collectors.counting()))
+        .entrySet().stream().noneMatch((bb2count) -> bb2count.getValue() > 1);
+  }
+
   private boolean consistentBlockInstructions() {
     for (BasicBlock block : blocks) {
       for (Instruction instruction : block.getInstructions()) {
@@ -378,4 +386,8 @@ public class IRCode {
   public ConstNumber createFalse() {
     return new ConstNumber(ConstType.INT, createValue(MoveType.SINGLE), 0);
   }
+
+  public final int getHighestBlockNumber() {
+    return blocks.stream().max(Comparator.comparingInt(BasicBlock::getNumber)).get().getNumber();
+  }
 }