Check if subreg index is zero.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88899 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/TargetInstrInfoImpl.cpp b/lib/CodeGen/TargetInstrInfoImpl.cpp
index 349d43c..102e2a3 100644
--- a/lib/CodeGen/TargetInstrInfoImpl.cpp
+++ b/lib/CodeGen/TargetInstrInfoImpl.cpp
@@ -142,8 +142,10 @@
   if (TargetRegisterInfo::isVirtualRegister(DestReg)) {
     MO.setReg(DestReg);
     MO.setSubReg(SubIdx);
-  } else {
+  } else if (SubIdx) {
     MO.setReg(TRI->getSubReg(DestReg, SubIdx));
+  } else {
+    MO.setReg(DestReg);
   }
   MBB.insert(I, MI);
 }