diff --git a/lib/CodeGen/RegAllocSimple.cpp b/lib/CodeGen/RegAllocSimple.cpp
index 7dc9890..5e5290c 100644
--- a/lib/CodeGen/RegAllocSimple.cpp
+++ b/lib/CodeGen/RegAllocSimple.cpp
@@ -122,7 +122,9 @@
 unsigned RegAllocSimple::getFreeReg(unsigned virtualReg) {
   const TargetRegisterClass* RC = MF->getRegInfo().getRegClass(virtualReg);
   TargetRegisterClass::iterator RI = RC->allocation_order_begin(*MF);
+#ifndef NDEBUG
   TargetRegisterClass::iterator RE = RC->allocation_order_end(*MF);
+#endif
 
   while (1) {
     unsigned regIdx = RegClassIdx[RC]++;
diff --git a/lib/CodeGen/RegisterScavenging.cpp b/lib/CodeGen/RegisterScavenging.cpp
index add639a..ff593c1 100644
--- a/lib/CodeGen/RegisterScavenging.cpp
+++ b/lib/CodeGen/RegisterScavenging.cpp
@@ -139,6 +139,7 @@
   ScavengedRC = NULL;
 }
 
+#ifndef NDEBUG
 /// isLiveInButUnusedBefore - Return true if register is livein the MBB not
 /// not used before it reaches the MI that defines register.
 static bool isLiveInButUnusedBefore(unsigned Reg, MachineInstr *MI,
@@ -172,6 +173,7 @@
       return false;
   return true;
 }
+#endif
 
 void RegScavenger::forward() {
   // Move ptr forward.