diff --git a/llvm/include/llvm/CodeGen/LiveIntervalUnion.h b/llvm/include/llvm/CodeGen/LiveIntervalUnion.h
--- a/llvm/include/llvm/CodeGen/LiveIntervalUnion.h
+++ b/llvm/include/llvm/CodeGen/LiveIntervalUnion.h
@@ -75,6 +75,7 @@
 
   bool empty() const { return Segments.empty(); }
   SlotIndex startIndex() const { return Segments.start(); }
+  SlotIndex endIndex() const { return Segments.stop(); }
 
   // Provide public access to the underlying map to allow overlap iteration.
   using Map = LiveSegments;