diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 7436c17..7433a79 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1852,7 +1852,10 @@
       return C_Other;
     }
   }
-  // TODO: Handle registers.
+  
+  if (Constraint.size() > 1 && Constraint[0] == '{' && 
+      Constraint[Constraint.size()-1] == '}')
+    return C_Register;
   return C_Unknown;
 }