Clean up redundant SP register maintained in X86 TLI



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167104 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index ce9b0a8..73e7dda 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -158,7 +158,6 @@
   Subtarget = &TM.getSubtarget<X86Subtarget>();
   X86ScalarSSEf64 = Subtarget->hasSSE2();
   X86ScalarSSEf32 = Subtarget->hasSSE1();
-  X86StackPtr = Subtarget->is64Bit() ? X86::RSP : X86::ESP;
 
   RegInfo = TM.getRegisterInfo();
   TD = getDataLayout();
@@ -180,7 +179,7 @@
     setSchedulingPreference(Sched::ILP);
   else
     setSchedulingPreference(Sched::RegPressure);
-  setStackPointerRegisterToSaveRestore(X86StackPtr);
+  setStackPointerRegisterToSaveRestore(RegInfo->getStackRegister());
 
   // Bypass i32 with i8 on Atom when compiling with O2
   if (Subtarget->hasSlowDivide() && TM.getOptLevel() >= CodeGenOpt::Default)
@@ -2351,7 +2350,8 @@
     } else if (!IsSibcall && (!isTailCall || isByVal)) {
       assert(VA.isMemLoc());
       if (StackPtr.getNode() == 0)
-        StackPtr = DAG.getCopyFromReg(Chain, dl, X86StackPtr, getPointerTy());
+        StackPtr = DAG.getCopyFromReg(Chain, dl, RegInfo->getStackRegister(),
+                                      getPointerTy());
       MemOpChains.push_back(LowerMemOpCallTo(Chain, StackPtr, Arg,
                                              dl, DAG, VA, Flags));
     }
@@ -2439,7 +2439,8 @@
           // Copy relative to framepointer.
           SDValue Source = DAG.getIntPtrConstant(VA.getLocMemOffset());
           if (StackPtr.getNode() == 0)
-            StackPtr = DAG.getCopyFromReg(Chain, dl, X86StackPtr,
+            StackPtr = DAG.getCopyFromReg(Chain, dl,
+                                          RegInfo->getStackRegister(),
                                           getPointerTy());
           Source = DAG.getNode(ISD::ADD, dl, getPointerTy(), StackPtr, Source);
 
@@ -9771,7 +9772,8 @@
     Chain = DAG.getNode(X86ISD::WIN_ALLOCA, dl, NodeTys, Chain, Flag);
     Flag = Chain.getValue(1);
 
-    Chain = DAG.getCopyFromReg(Chain, dl, X86StackPtr, SPTy).getValue(1);
+    Chain = DAG.getCopyFromReg(Chain, dl, RegInfo->getStackRegister(),
+                               SPTy).getValue(1);
 
     SDValue Ops1[2] = { Chain.getValue(0), Chain };
     return DAG.getMergeValues(Ops1, 2, dl);