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 "AArch64StackOffset.h"
17#include "llvm/CodeGen/TargetFrameLowering.h"
18
19namespace llvm {
20
21class MCCFIInstruction;
22
23class AArch64FrameLowering : public TargetFrameLowering {
24public:
25  explicit AArch64FrameLowering()
26      : TargetFrameLowering(StackGrowsDown, Align(16), 0, Align(16),
27                            true /*StackRealignable*/) {}
28
29  void
30  emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
31                            MachineBasicBlock::iterator MBBI) const override;
32
33  MachineBasicBlock::iterator
34  eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
35                                MachineBasicBlock::iterator I) const override;
36
37  /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
38  /// the function.
39  void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
40  void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
41
42  bool canUseAsPrologue(const MachineBasicBlock &MBB) const override;
43
44  int getFrameIndexReference(const MachineFunction &MF, int FI,
45                             Register &FrameReg) const override;
46  StackOffset resolveFrameIndexReference(const MachineFunction &MF, int FI,
47                                         Register &FrameReg, bool PreferFP,
48                                         bool ForSimm) const;
49  StackOffset resolveFrameOffsetReference(const MachineFunction &MF,
50                                          int64_t ObjectOffset, bool isFixed,
51                                          bool isSVE, Register &FrameReg,
52                                          bool PreferFP, bool ForSimm) const;
53  bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
54                                 MachineBasicBlock::iterator MI,
55                                 ArrayRef<CalleeSavedInfo> CSI,
56                                 const TargetRegisterInfo *TRI) const override;
57
58  bool
59  restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
60                              MachineBasicBlock::iterator MI,
61                              MutableArrayRef<CalleeSavedInfo> CSI,
62                              const TargetRegisterInfo *TRI) const override;
63
64  /// Can this function use the red zone for local allocations.
65  bool canUseRedZone(const MachineFunction &MF) const;
66
67  bool hasFP(const MachineFunction &MF) const override;
68  bool hasReservedCallFrame(const MachineFunction &MF) const override;
69
70  void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
71                            RegScavenger *RS) const override;
72
73  /// Returns true if the target will correctly handle shrink wrapping.
74  bool enableShrinkWrapping(const MachineFunction &MF) const override {
75    return true;
76  }
77
78  bool enableStackSlotScavenging(const MachineFunction &MF) const override;
79  TargetStackID::Value getStackIDForScalableVectors() const override;
80
81  void processFunctionBeforeFrameFinalized(MachineFunction &MF,
82                                             RegScavenger *RS) const override;
83
84  void
85  processFunctionBeforeFrameIndicesReplaced(MachineFunction &MF,
86                                            RegScavenger *RS) const override;
87
88  unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const override;
89
90  unsigned getWinEHFuncletFrameSize(const MachineFunction &MF) const;
91
92  int getFrameIndexReferencePreferSP(const MachineFunction &MF, int FI,
93                                     Register &FrameReg,
94                                     bool IgnoreSPUpdates) const override;
95  int getNonLocalFrameIndexReference(const MachineFunction &MF,
96                               int FI) const override;
97  int getSEHFrameIndexOffset(const MachineFunction &MF, int FI) const;
98
99  bool isSupportedStackID(TargetStackID::Value ID) const override {
100    switch (ID) {
101    default:
102      return false;
103    case TargetStackID::Default:
104    case TargetStackID::SVEVector:
105    case TargetStackID::NoAlloc:
106      return true;
107    }
108  }
109
110  bool isStackIdSafeForLocalArea(unsigned StackId) const override {
111    // We don't support putting SVE objects into the pre-allocated local
112    // frame block at the moment.
113    return StackId != TargetStackID::SVEVector;
114  }
115
116private:
117  bool shouldCombineCSRLocalStackBump(MachineFunction &MF,
118                                      uint64_t StackBumpBytes) const;
119
120  int64_t estimateSVEStackObjectOffsets(MachineFrameInfo &MF) const;
121  int64_t assignSVEStackObjectOffsets(MachineFrameInfo &MF,
122                                      int &MinCSFrameIndex,
123                                      int &MaxCSFrameIndex) const;
124  MCCFIInstruction
125  createDefCFAExpressionFromSP(const TargetRegisterInfo &TRI,
126                               const StackOffset &OffsetFromSP) const;
127  MCCFIInstruction createCfaOffset(const TargetRegisterInfo &MRI, unsigned DwarfReg,
128                                   const StackOffset &OffsetFromDefCFA) const;
129  bool shouldCombineCSRLocalStackBumpInEpilogue(MachineBasicBlock &MBB,
130                                                unsigned StackBumpBytes) const;
131};
132
133} // End llvm namespace
134
135#endif
136