diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 5fe1003..2f02601 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -187,7 +187,11 @@
       else
         OS << "%mreg" << getReg();
     }
-      
+
+    if (getSubReg() != 0) {
+      OS << ":" << getSubReg();
+    }
+
     if (isDef() || isKill() || isDead() || isImplicit() || isEarlyClobber()) {
       OS << "<";
       bool NeedComma = false;