CSKYFrameLowering.h

//===-- CSKYFrameLowering.h - Define frame lowering for CSKY -*- C++ -*--===//
//
// 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 class implements CSKY-specific bits of TargetFrameLowering class.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_TARGET_CSKY_CSKYFRAMELOWERING_H
#define LLVM_LIB_TARGET_CSKY_CSKYFRAMELOWERING_H

#include "llvm/CodeGen/TargetFrameLowering.h"

namespace llvm {
class CSKYSubtarget;

class CSKYFrameLowering : public TargetFrameLowering {
  const CSKYSubtarget &STI;

  void determineFrameLayout(MachineFunction &MF) const;
  void adjustReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
                 const DebugLoc &DL, Register DestReg, Register SrcReg,
                 int64_t Val, MachineInstr::MIFlag Flag) const;

public:
  explicit CSKYFrameLowering(const CSKYSubtarget &STI)
      : TargetFrameLowering(StackGrowsDown,
                            /*StackAlignment=*/Align(4),
                            /*LocalAreaOffset=*/0),
        STI(STI) {}

  void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
  void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;

  StackOffset getFrameIndexReference(const MachineFunction &MF, int FI,
                                     Register &FrameReg) const override;

  void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
                            RegScavenger *RS) const override;

  bool assignCalleeSavedSpillSlots(
      MachineFunction &MF, const TargetRegisterInfo *TRI,
      std::vector<CalleeSavedInfo> &CSI) const override {

    std::reverse(CSI.begin(), CSI.end());

    return false;
  }

  bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
                                 MachineBasicBlock::iterator MI,
                                 ArrayRef<CalleeSavedInfo> CSI,
                                 const TargetRegisterInfo *TRI) const override;
  bool
  restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
                              MachineBasicBlock::iterator MI,
                              MutableArrayRef<CalleeSavedInfo> CSI,
                              const TargetRegisterInfo *TRI) const override;

  bool hasFP(const MachineFunction &MF) const override;
  bool hasBP(const MachineFunction &MF) const;

  bool hasReservedCallFrame(const MachineFunction &MF) const override;

  MachineBasicBlock::iterator
  eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                                MachineBasicBlock::iterator MI) const override;
};
} // namespace llvm
#endif