Index: llvm/lib/CodeGen/RegAllocGreedy.h
===================================================================
--- llvm/lib/CodeGen/RegAllocGreedy.h
+++ llvm/lib/CodeGen/RegAllocGreedy.h
@@ -150,7 +150,7 @@
 private:
   // Convenient shortcuts.
   using PQueue = std::priority_queue<std::pair<unsigned, unsigned>>;
-  using SmallLISet = SmallPtrSet<const LiveInterval *, 4>;
+  using SmallLISet = SmallSetVector<const LiveInterval *, 4>;
 
   // We need to track all tentative recolorings so we can roll back any
   // successful and unsuccessful recoloring attempts.