diff --git a/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp b/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
index 6c7c1a1..31552f8 100644
--- a/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -451,11 +451,11 @@
                                      const TargetInstrInfo *TII,
                                      bool &IsCopy,
                                      unsigned &DstReg, bool &IsDstPhys) {
-  MachineRegisterInfo::use_iterator UI = MRI->use_begin(Reg);
-  if (UI == MRI->use_end())
+  MachineRegisterInfo::use_nodbg_iterator UI = MRI->use_nodbg_begin(Reg);
+  if (UI == MRI->use_nodbg_end())
     return 0;
   MachineInstr &UseMI = *UI;
-  if (++UI != MRI->use_end())
+  if (++UI != MRI->use_nodbg_end())
     // More than one use.
     return 0;
   if (UseMI.getParent() != MBB)
@@ -923,6 +923,10 @@
     for (MachineBasicBlock::iterator mi = mbbi->begin(), me = mbbi->end();
          mi != me; ) {
       MachineBasicBlock::iterator nmi = llvm::next(mi);
+      if (mi->isDebugValue()) {
+        mi = nmi;
+        continue;
+      }
       const TargetInstrDesc &TID = mi->getDesc();
       bool FirstTied = true;