diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index bd598e2..a7cf6cf 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1332,7 +1332,7 @@
     } else {
       assert(VA.isMemLoc());
       if (StackPtr.Val == 0)
-        StackPtr = DAG.getRegister(getStackPtrReg(), getPointerTy());
+        StackPtr = DAG.getCopyFromReg(Chain, X86StackPtr, getPointerTy());
 
       MemOpChains.push_back(LowerMemOpCallTo(Op, DAG, StackPtr, VA, Chain,
                                              Arg));