diff --git a/lib/CodeGen/RegisterScavenging.cpp b/lib/CodeGen/RegisterScavenging.cpp
index 0938e3a04e6..9135edcfb9e 100644
--- a/lib/CodeGen/RegisterScavenging.cpp
+++ b/lib/CodeGen/RegisterScavenging.cpp
@@ -76,10 +76,12 @@ void RegScavenger::forward() {
     const MachineOperand &MO = MI->getOperand(i);
     if (!MO.isReg() || !MO.isDef())
       continue;
-    // Skip two-address destination operand.
-    if (TID->findTiedToSrcOperand(i) != -1)
-      continue;
     unsigned Reg = MO.getReg();
+    // Skip two-address destination operand.
+    if (TID->findTiedToSrcOperand(i) != -1) {
+      assert(isUsed(Reg));
+      continue;
+    }
     assert(isUnused(Reg) || isReserved(Reg));
     if (!MO.isDead())
       setUsed(Reg);