diff --git a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
index 9e0d5d2325fa038db69b78c29a437b04da0f00de..f1f608d27134f67a34e9e2e213804e92a1124e2b 100644
--- a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -820,8 +820,11 @@ void LiveIntervals::joinIntervals() {
 
   DEBUG(std::cerr << "*** Register mapping ***\n");
   DEBUG(for (int i = 0, e = r2rMap_.size(); i != e; ++i)
-          if (r2rMap_[i])
-             std::cerr << "  reg " << i << " -> reg " << r2rMap_[i] << "\n");
+          if (r2rMap_[i]) {
+            std::cerr << "  reg " << i << " -> ";
+            printRegName(r2rMap_[i]);
+            std::cerr << "\n";
+          });
 }
 
 /// Return true if the two specified registers belong to different register