1 files changed, 4 insertions, 35 deletions

diff --git a/llvm/lib/Target/X86/X86FrameLowering.cpp b/llvm/lib/Target/X86/X86FrameLowering.cpp
index 244f9bbfafe..c2b1cf7be2f 100644
--- a/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -650,7 +650,6 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
   unsigned SlotSize = RegInfo->getSlotSize();
   unsigned FramePtr = RegInfo->getFrameRegister(MF);
   unsigned StackPtr = RegInfo->getStackRegister();
-  unsigned BasePtr = RegInfo->getBaseRegister();
   DebugLoc DL;
 
   // If we're forcing a stack realignment we can't rely on just the frame
@@ -914,18 +913,6 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
     emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit,
                  UseLEA, TII, *RegInfo);
 
-  // If we need a base pointer, set it up here. It's whatever the value
-  // of the stack pointer is at this point. Any variable size objects
-  // will be allocated after this, so we can still use the base pointer
-  // to reference locals.
-  if (RegInfo->hasBasePointer(MF)) {
-    // Update the frame pointer with the current stack pointer.
-    unsigned Opc = Is64Bit ? X86::MOV64rr : X86::MOV32rr;
-    BuildMI(MBB, MBBI, DL, TII.get(Opc), BasePtr)
-      .addReg(StackPtr)
-      .setMIFlag(MachineInstr::FrameSetup);
-  }
-
   if (( (!HasFP && NumBytes) || PushedRegs) && needsFrameMoves) {
     // Mark end of stack pointer adjustment.
     MCSymbol *Label = MMI.getContext().CreateTempSymbol();
@@ -1161,16 +1148,7 @@ int X86FrameLowering::getFrameIndexOffset(const MachineFunction &MF, int FI) con
   int Offset = MFI->getObjectOffset(FI) - getOffsetOfLocalArea();
   uint64_t StackSize = MFI->getStackSize();
 
-  if (RegInfo->hasBasePointer(MF)) {
-    assert (hasFP(MF) && "VLAs and dynamic stack realign, but no FP?!");
-    if (FI < 0) {
-      // Skip the saved EBP.
-      return Offset + RegInfo->getSlotSize();
-    } else {
-      assert((-(Offset + StackSize)) % MFI->getObjectAlignment(FI) == 0);
-      return Offset + StackSize;
-    }
-  } else if (RegInfo->needsStackRealignment(MF)) {
+  if (RegInfo->needsStackRealignment(MF)) {
     if (FI < 0) {
       // Skip the saved EBP.
       return Offset + RegInfo->getSlotSize();
@@ -1201,14 +1179,9 @@ int X86FrameLowering::getFrameIndexReference(const MachineFunction &MF, int FI,
   const X86RegisterInfo *RegInfo =
       static_cast<const X86RegisterInfo*>(MF.getTarget().getRegisterInfo());
   // We can't calculate offset from frame pointer if the stack is realigned,
-  // so enforce usage of stack/base pointer.  The base pointer is used when we
-  // have dynamic allocas in addition to dynamic realignment.
-  if (RegInfo->hasBasePointer(MF))
-    FrameReg = RegInfo->getBaseRegister();
-  else if (RegInfo->needsStackRealignment(MF))
-    FrameReg = RegInfo->getStackRegister();
-  else
-    FrameReg = RegInfo->getFrameRegister(MF);
+  // so enforce usage of stack pointer.
+  FrameReg = (RegInfo->needsStackRealignment(MF)) ? 
+    RegInfo->getStackRegister() : RegInfo->getFrameRegister(MF);
   return getFrameIndexOffset(MF, FI);
 }
 
@@ -1345,10 +1318,6 @@ X86FrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
            "Slot for EBP register must be last in order to be found!");
     (void)FrameIdx;
   }
-
-  // Spill the BasePtr if it's used.
-  if (RegInfo->hasBasePointer(MF))
-    MF.getRegInfo().setPhysRegUsed(RegInfo->getBaseRegister());
 }
 
 static bool