1//===- ARMTargetFrameLowering.h - Define frame lowering for ARM -*- 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#ifndef LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H
10#define LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H
11
12#include "llvm/CodeGen/TargetFrameLowering.h"
13#include "llvm/Support/TypeSize.h"
14
15namespace llvm {
16
17class ARMSubtarget;
18class CalleeSavedInfo;
19class MachineFunction;
20
21class ARMFrameLowering : public TargetFrameLowering {
22protected:
23 const ARMSubtarget &STI;
24
25public:
26 explicit ARMFrameLowering(const ARMSubtarget &sti);
27
28 /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
29 /// the function.
30 void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
31 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
32
33 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
34 MachineBasicBlock::iterator MI,
35 ArrayRef<CalleeSavedInfo> CSI,
36 const TargetRegisterInfo *TRI) const override;
37
38 bool
39 restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
40 MachineBasicBlock::iterator MI,
41 MutableArrayRef<CalleeSavedInfo> CSI,
42 const TargetRegisterInfo *TRI) const override;
43
44 bool keepFramePointer(const MachineFunction &MF) const override;
45
46 bool enableCalleeSaveSkip(const MachineFunction &MF) const override;
47
48 bool hasFP(const MachineFunction &MF) const override;
49 bool isFPReserved(const MachineFunction &MF) const;
50 bool requiresAAPCSFrameRecord(const MachineFunction &MF) const;
51 bool hasReservedCallFrame(const MachineFunction &MF) const override;
52 bool canSimplifyCallFramePseudos(const MachineFunction &MF) const override;
53 StackOffset getFrameIndexReference(const MachineFunction &MF, int FI,
54 Register &FrameReg) const override;
55 int ResolveFrameIndexReference(const MachineFunction &MF, int FI,
56 Register &FrameReg, int SPAdj) const;
57
58 void getCalleeSaves(const MachineFunction &MF,
59 BitVector &SavedRegs) const override;
60 void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
61 RegScavenger *RS) const override;
62
63 /// Update the IsRestored flag on LR if it is spilled, based on the return
64 /// instructions.
65 static void updateLRRestored(MachineFunction &MF);
66
67 void processFunctionBeforeFrameFinalized(
68 MachineFunction &MF, RegScavenger *RS = nullptr) const override;
69
70 void adjustForSegmentedStacks(MachineFunction &MF,
71 MachineBasicBlock &MBB) const override;
72
73 /// Returns true if the target will correctly handle shrink wrapping.
74 bool enableShrinkWrapping(const MachineFunction &MF) const override;
75
76 bool isProfitableForNoCSROpt(const Function &F) const override {
77 // The no-CSR optimisation is bad for code size on ARM, because we can save
78 // many registers with a single PUSH/POP pair.
79 return false;
80 }
81
82 bool
83 assignCalleeSavedSpillSlots(MachineFunction &MF,
84 const TargetRegisterInfo *TRI,
85 std::vector<CalleeSavedInfo> &CSI) const override;
86
87 const SpillSlot *
88 getCalleeSavedSpillSlots(unsigned &NumEntries) const override;
89
90private:
91 void emitPushInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
92 ArrayRef<CalleeSavedInfo> CSI, unsigned StmOpc,
93 unsigned StrOpc, bool NoGap, bool (*Func)(unsigned, bool),
94 unsigned NumAlignedDPRCS2Regs, unsigned MIFlags = 0) const;
95 void emitPopInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
96 MutableArrayRef<CalleeSavedInfo> CSI, unsigned LdmOpc,
97 unsigned LdrOpc, bool isVarArg, bool NoGap,
98 bool (*Func)(unsigned, bool),
99 unsigned NumAlignedDPRCS2Regs) const;
100
101 MachineBasicBlock::iterator
102 eliminateCallFramePseudoInstr(MachineFunction &MF,
103 MachineBasicBlock &MBB,
104 MachineBasicBlock::iterator MI) const override;
105};
106
107} // end namespace llvm
108
109#endif // LLVM_LIB_TARGET_ARM_ARMFRAMELOWERING_H
110