diff --git a/llvm/lib/CodeGen/SlotIndexes.cpp b/llvm/lib/CodeGen/SlotIndexes.cpp
index a55e74c..ce00fa9 100644
--- a/llvm/lib/CodeGen/SlotIndexes.cpp
+++ b/llvm/lib/CodeGen/SlotIndexes.cpp
@@ -94,7 +94,7 @@
   }
 
   // Sort the Idx2MBBMap
-  llvm::sort(idx2MBBMap, Idx2MBBCompare());
+  llvm::sort(idx2MBBMap, less_first());
 
   LLVM_DEBUG(mf->print(dbgs(), this));