diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 4885163..295b450 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -647,6 +647,7 @@
     }
   }
 
+#ifndef NDEBUG
   bool isMetaDataOp = Op.getType() == MachineOperand::MO_Metadata;
   // OpNo now points as the desired insertion point.  Unless this is a variadic
   // instruction, only implicit regs are allowed beyond MCID->getNumOperands().
@@ -654,6 +655,7 @@
   assert((isImpReg || Op.isRegMask() || MCID->isVariadic() ||
           OpNo < MCID->getNumOperands() || isMetaDataOp) &&
          "Trying to add an operand to a machine instr that is already done!");
+#endif
 
   MachineRegisterInfo *MRI = getRegInfo();