//===-- BPFFrameLowering.cpp - BPF Frame Information ----------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains the BPF implementation of TargetFrameLowering class.
//
//===----------------------------------------------------------------------===//

#include "BPFFrameLowering.h"
#include "BPFSubtarget.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"

using namespace llvm;

bool BPFFrameLowering::hasFPImpl(const MachineFunction &MF) const {
  return true;
}

void BPFFrameLowering::emitPrologue(MachineFunction &MF,
                                    MachineBasicBlock &MBB) const {}

void BPFFrameLowering::emitEpilogue(MachineFunction &MF,
                                    MachineBasicBlock &MBB) const {}

void BPFFrameLowering::determineCalleeSaves(MachineFunction &MF,
                                            BitVector &SavedRegs,
                                            RegScavenger *RS) const {
  TargetFrameLowering::determineCalleeSaves(MF, SavedRegs, RS);
  SavedRegs.reset(BPF::R6);
  SavedRegs.reset(BPF::R7);
  SavedRegs.reset(BPF::R8);
  SavedRegs.reset(BPF::R9);
}

StackOffset BPFFrameLowering::getFrameIndexReference(const MachineFunction &MF,
                                                     int FI,
                                                     Register &FrameReg) const {
  const MachineFrameInfo &MFI = MF.getFrameInfo();
  const TargetRegisterInfo *RI = MF.getSubtarget().getRegisterInfo();

  FrameReg = RI->getFrameRegister(MF);

  return StackOffset::getFixed(MFI.getObjectOffset(FI));
}