1 //==-- AArch64FrameLowering.h - TargetFrameLowering for AArch64 --*- C++ -*-==//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 //
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_AARCH64_AARCH64FRAMELOWERING_H
14 #define LLVM_LIB_TARGET_AARCH64_AARCH64FRAMELOWERING_H
15 
16 #include "llvm/CodeGen/TargetFrameLowering.h"
17 
18 namespace llvm {
19 
20 class AArch64FrameLowering : public TargetFrameLowering {
21 public:
22   explicit AArch64FrameLowering()
23       : TargetFrameLowering(StackGrowsDown, 16, 0, 16,
24                             true /*StackRealignable*/) {}
25 
26   void emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
27                                  MachineBasicBlock::iterator MBBI) const;
28 
29   MachineBasicBlock::iterator
30   eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
31                                 MachineBasicBlock::iterator I) const override;
32 
33   /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
34   /// the function.
35   void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
36   void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
37 
38   bool canUseAsPrologue(const MachineBasicBlock &MBB) const override;
39 
40   int getFrameIndexReference(const MachineFunction &MF, int FI,
41                              unsigned &FrameReg) const override;
42   int resolveFrameIndexReference(const MachineFunction &MF, int FI,
43                                  unsigned &FrameReg, bool PreferFP,
44                                  bool ForSimm) const;
45   int resolveFrameOffsetReference(const MachineFunction &MF, int ObjectOffset,
46                                   bool isFixed, unsigned &FrameReg,
47                                   bool PreferFP, bool ForSimm) const;
48   bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
49                                  MachineBasicBlock::iterator MI,
50                                  const std::vector<CalleeSavedInfo> &CSI,
51                                  const TargetRegisterInfo *TRI) const override;
52 
53   bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
54                                   MachineBasicBlock::iterator MI,
55                                   std::vector<CalleeSavedInfo> &CSI,
56                                   const TargetRegisterInfo *TRI) const override;
57 
58   /// Can this function use the red zone for local allocations.
59   bool canUseRedZone(const MachineFunction &MF) const;
60 
61   bool hasFP(const MachineFunction &MF) const override;
62   bool hasReservedCallFrame(const MachineFunction &MF) const override;
63 
64   void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
65                             RegScavenger *RS) const override;
66 
67   /// Returns true if the target will correctly handle shrink wrapping.
68   bool enableShrinkWrapping(const MachineFunction &MF) const override {
69     return true;
70   }
71 
72   bool enableStackSlotScavenging(const MachineFunction &MF) const override;
73 
74   void processFunctionBeforeFrameFinalized(MachineFunction &MF,
75                                              RegScavenger *RS) const override;
76 
77   unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const override;
78 
79   unsigned getWinEHFuncletFrameSize(const MachineFunction &MF) const;
80 
81   int getFrameIndexReferencePreferSP(const MachineFunction &MF, int FI,
82                                      unsigned &FrameReg,
83                                      bool IgnoreSPUpdates) const override;
84   int getNonLocalFrameIndexReference(const MachineFunction &MF,
85                                int FI) const override;
86   int getSEHFrameIndexOffset(const MachineFunction &MF, int FI) const;
87 
88 private:
89   bool shouldCombineCSRLocalStackBump(MachineFunction &MF,
90                                       unsigned StackBumpBytes) const;
91 };
92 
93 } // End llvm namespace
94 
95 #endif
96