text: //==-- ARMTargetFrameLowering.h - Define frame lowering for ARM --*- C++ -*-==//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  //
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H
  #define LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H
  
  #include "llvm/Target/TargetFrameLowering.h"
  
  namespace llvm {
    class ARMSubtarget;
  
  class ARMFrameLowering : public TargetFrameLowering {
  protected:
    const ARMSubtarget &STI;
  
  public:
    explicit ARMFrameLowering(const ARMSubtarget &sti);
  
    /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
    /// the function.
    void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
    void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
  
    bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
                                   MachineBasicBlock::iterator MI,
                                   const std::vector<CalleeSavedInfo> &CSI,
                                   const TargetRegisterInfo *TRI) const override;
  
    bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
                                    MachineBasicBlock::iterator MI,
                                    const std::vector<CalleeSavedInfo> &CSI,
                                    const TargetRegisterInfo *TRI) const override;
  
    bool noFramePointerElim(const MachineFunction &MF) const override;
  
    bool hasFP(const MachineFunction &MF) const override;
    bool hasReservedCallFrame(const MachineFunction &MF) const override;
    bool canSimplifyCallFramePseudos(const MachineFunction &MF) const override;
    int getFrameIndexReference(const MachineFunction &MF, int FI,
                               unsigned &FrameReg) const override;
    int ResolveFrameIndexReference(const MachineFunction &MF, int FI,
                                   unsigned &FrameReg, int SPAdj) const;
  
    void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
                              RegScavenger *RS) const override;
  
    void adjustForSegmentedStacks(MachineFunction &MF,
                                  MachineBasicBlock &MBB) const override;
  
    /// Returns true if the target will correctly handle shrink wrapping.
    bool enableShrinkWrapping(const MachineFunction &MF) const override {
      return true;
    }
  
   private:
    void emitPushInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
                      const std::vector<CalleeSavedInfo> &CSI, unsigned StmOpc,
                      unsigned StrOpc, bool NoGap,
                      bool(*Func)(unsigned, bool), unsigned NumAlignedDPRCS2Regs,
                      unsigned MIFlags = 0) const;
    void emitPopInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
                     const std::vector<CalleeSavedInfo> &CSI, unsigned LdmOpc,
                     unsigned LdrOpc, bool isVarArg, bool NoGap,
                     bool(*Func)(unsigned, bool),
                     unsigned NumAlignedDPRCS2Regs) const;
  
    void
    eliminateCallFramePseudoInstr(MachineFunction &MF,
                                  MachineBasicBlock &MBB,
                                  MachineBasicBlock::iterator MI) const override;
  };
  
  } // End llvm namespace
  
  #endif
  