SystemZFrameLowering.h revision 52c28b07f039da61a20f21275793c8d3b9b97fe9 
1//===-- SystemZFrameLowering.h - Frame lowering for SystemZ -----*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef SYSTEMZFRAMELOWERING_H
11#define SYSTEMZFRAMELOWERING_H
12
13#include "SystemZSubtarget.h"
14#include "llvm/ADT/IndexedMap.h"
15#include "llvm/Target/TargetFrameLowering.h"
16
17namespace llvm {
18class SystemZTargetMachine;
19class SystemZSubtarget;
20
21class SystemZFrameLowering : public TargetFrameLowering {
22  IndexedMap<unsigned> RegSpillOffsets;
23
24protected:
25  const SystemZTargetMachine &TM;
26  const SystemZSubtarget &STI;
27
28public:
29  SystemZFrameLowering(const SystemZTargetMachine &tm,
30                       const SystemZSubtarget &sti);
31
32  // Override TargetFrameLowering.
33  virtual const SpillSlot *getCalleeSavedSpillSlots(unsigned &NumEntries) const
34    LLVM_OVERRIDE;
35  virtual void
36    processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
37                                         RegScavenger *RS) const LLVM_OVERRIDE;
38  virtual bool
39    spillCalleeSavedRegisters(MachineBasicBlock &MBB,
40                              MachineBasicBlock::iterator MBBI,
41                              const std::vector<CalleeSavedInfo> &CSI,
42                              const TargetRegisterInfo *TRI) const
43    LLVM_OVERRIDE;
44  virtual bool
45    restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
46                                MachineBasicBlock::iterator MBBII,
47                                const std::vector<CalleeSavedInfo> &CSI,
48                                const TargetRegisterInfo *TRI) const
49    LLVM_OVERRIDE;
50  virtual void emitPrologue(MachineFunction &MF) const LLVM_OVERRIDE;
51  virtual void emitEpilogue(MachineFunction &MF,
52                            MachineBasicBlock &MBB) const LLVM_OVERRIDE;
53  virtual bool hasFP(const MachineFunction &MF) const LLVM_OVERRIDE;
54  virtual int getFrameIndexOffset(const MachineFunction &MF,
55                                  int FI) const LLVM_OVERRIDE;
56  virtual bool hasReservedCallFrame(const MachineFunction &MF) const
57    LLVM_OVERRIDE;
58  virtual void
59  eliminateCallFramePseudoInstr(MachineFunction &MF,
60                                MachineBasicBlock &MBB,
61                                MachineBasicBlock::iterator MI) const
62    LLVM_OVERRIDE;
63
64  // Return the number of bytes in the callee-allocated part of the frame.
65  uint64_t getAllocatedStackSize(const MachineFunction &MF) const;
66
67  // Return the number of frame bytes that should be reserved for
68  // an emergency spill slot, for use by the register scaveneger.
69  // Return 0 if register scaveging won't be needed.
70  unsigned getEmergencySpillSlotSize(const MachineFunction &MF) const;
71
72  // Return the offset from the frame pointer of the emergency spill slot,
73  // which always fits within a 12-bit unsigned displacement field.
74  // Only valid if getEmergencySpillSlotSize(MF) returns nonzero.
75  unsigned getEmergencySpillSlotOffset(const MachineFunction &MF) const;
76
77  // Return the byte offset from the incoming stack pointer of Reg's
78  // ABI-defined save slot.  Return 0 if no slot is defined for Reg.
79  unsigned getRegSpillOffset(unsigned Reg) const {
80    return RegSpillOffsets[Reg];
81  }
82};
83} // end namespace llvm
84
85#endif
86