X86FrameLowering.h

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//===-- X86TargetFrameLowering.h - Define frame lowering for X86 -*- C++ -*-==//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This class implements X86-specific bits of TargetFrameLowering class.
//
//===----------------------------------------------------------------------===//

#ifndef X86_FRAMELOWERING_H
#define X86_FRAMELOWERING_H

#include "X86Subtarget.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/Target/TargetFrameLowering.h"

namespace llvm {

class MCSymbol;
class X86TargetMachine;

class X86FrameLowering : public TargetFrameLowering {
  const X86TargetMachine &TM;
  const X86Subtarget &STI;
public:
  explicit X86FrameLowering(const X86TargetMachine &tm, const X86Subtarget &sti)
    : TargetFrameLowering(StackGrowsDown,
                          sti.getStackAlignment(),
                          (sti.is64Bit() ? -8 : -4)),
      TM(tm), STI(sti) {
  }

  void emitCalleeSavedFrameMoves(MachineFunction &MF, MCSymbol *Label,
                                 unsigned FramePtr) const;

  /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
  /// the function.
  void emitPrologue(MachineFunction &MF) const;
  void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const;

  void adjustForSegmentedStacks(MachineFunction &MF) const;

  void adjustForHiPEPrologue(MachineFunction &MF) const;

  void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
                                            RegScavenger *RS = NULL) const;

  bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
                                 MachineBasicBlock::iterator MI,
                                 const std::vector<CalleeSavedInfo> &CSI,
                                 const TargetRegisterInfo *TRI) const;

  bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
                                   MachineBasicBlock::iterator MI,
                                   const std::vector<CalleeSavedInfo> &CSI,
                                   const TargetRegisterInfo *TRI) const;

  bool hasFP(const MachineFunction &MF) const;
  bool hasReservedCallFrame(const MachineFunction &MF) const;

  int getFrameIndexOffset(const MachineFunction &MF, int FI) const;
  int getFrameIndexReference(const MachineFunction &MF, int FI,
                             unsigned &FrameReg) const;

  void eliminateCallFramePseudoInstr(MachineFunction &MF,
                                     MachineBasicBlock &MBB,
                                     MachineBasicBlock::iterator MI) const;
};

} // End llvm namespace

#endif