diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h
index beba6923ee7..9d0d8d950e0 100644
--- a/include/llvm/CodeGen/MachineInstr.h
+++ b/include/llvm/CodeGen/MachineInstr.h
@@ -340,7 +340,7 @@ public:
   /// MachineInstr ctor - This constructor create a MachineInstr and add the
   /// implicit operands. It reserves space for number of operands specified by
   /// TargetInstrDescriptor.
-  explicit MachineInstr(const TargetInstrDescriptor &TID);
+  explicit MachineInstr(const TargetInstrDescriptor &TID, bool NoImp = false);
 
   /// MachineInstr ctor - Work exactly the same as the ctor above, except that
   /// the MachineInstr is created and added to the end of the specified basic
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index 1ac955a743c..a3485bc524c 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -58,16 +58,17 @@ void MachineInstr::addImplicitDefUseOperands() {
 /// implicit operands. It reserves space for number of operands specified by
 /// TargetInstrDescriptor or the numOperands if it is not zero. (for
 /// instructions with variable number of operands).
-MachineInstr::MachineInstr(const TargetInstrDescriptor &tid)
+MachineInstr::MachineInstr(const TargetInstrDescriptor &tid, bool NoImp)
   : TID(&tid), NumImplicitOps(0), parent(0) {
-  if (TID->ImplicitDefs)
+  if (!NoImp && TID->ImplicitDefs)
     for (const unsigned *ImpDefs = TID->ImplicitDefs; *ImpDefs; ++ImpDefs)
       NumImplicitOps++;
-  if (TID->ImplicitUses)
+  if (!NoImp && TID->ImplicitUses)
     for (const unsigned *ImpUses = TID->ImplicitUses; *ImpUses; ++ImpUses)
       NumImplicitOps++;
   Operands.reserve(NumImplicitOps + TID->numOperands);
-  addImplicitDefUseOperands();
+  if (!NoImp)
+    addImplicitDefUseOperands();
   // Make sure that we get added to a machine basicblock
   LeakDetector::addGarbageObject(this);
 }