SRetReturnReg was set in LowerFormalArguments(). So only assert it here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104691 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index c0813f3..b02c33d 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1259,10 +1259,8 @@
     MachineFunction &MF = DAG.getMachineFunction();
     X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();
     unsigned Reg = FuncInfo->getSRetReturnReg();
-    if (!Reg) {
-      Reg = MRI.createVirtualRegister(getRegClassFor(MVT::i64));
-      FuncInfo->setSRetReturnReg(Reg);
-    }
+    assert(Reg && 
+           "SRetReturnReg should have been set in LowerFormalArguments().");
     SDValue Val = DAG.getCopyFromReg(Chain, dl, Reg, getPointerTy());
 
     Chain = DAG.getCopyToReg(Chain, dl, X86::RAX, Val, Flag);