1//===-- RISCVFrameLowering.h - Define frame lowering for RISC-V -*- 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// This class implements RISC-V specific bits of TargetFrameLowering class.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_LIB_TARGET_RISCV_RISCVFRAMELOWERING_H
14#define LLVM_LIB_TARGET_RISCV_RISCVFRAMELOWERING_H
15
16#include "llvm/CodeGen/TargetFrameLowering.h"
17#include "llvm/Support/TypeSize.h"
18
19namespace llvm {
20class RISCVSubtarget;
21
22class RISCVFrameLowering : public TargetFrameLowering {
23public:
24 explicit RISCVFrameLowering(const RISCVSubtarget &STI);
25
26 void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
27 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
28
29 uint64_t getStackSizeWithRVVPadding(const MachineFunction &MF) const;
30
31 StackOffset getFrameIndexReference(const MachineFunction &MF, int FI,
32 Register &FrameReg) const override;
33
34 void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
35 RegScavenger *RS) const override;
36
37 void processFunctionBeforeFrameFinalized(MachineFunction &MF,
38 RegScavenger *RS) const override;
39
40 bool hasBP(const MachineFunction &MF) const;
41
42 bool hasReservedCallFrame(const MachineFunction &MF) const override;
43 MachineBasicBlock::iterator
44 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
45 MachineBasicBlock::iterator MI) const override;
46
47 bool assignCalleeSavedSpillSlots(MachineFunction &MF,
48 const TargetRegisterInfo *TRI,
49 std::vector<CalleeSavedInfo> &CSI,
50 unsigned &MinCSFrameIndex,
51 unsigned &MaxCSFrameIndex) const override;
52 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
53 MachineBasicBlock::iterator MI,
54 ArrayRef<CalleeSavedInfo> CSI,
55 const TargetRegisterInfo *TRI) const override;
56 bool
57 restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
58 MachineBasicBlock::iterator MI,
59 MutableArrayRef<CalleeSavedInfo> CSI,
60 const TargetRegisterInfo *TRI) const override;
61
62 // Get the first stack adjustment amount for SplitSPAdjust.
63 // Return 0 if we don't want to split the SP adjustment in prologue and
64 // epilogue.
65 uint64_t getFirstSPAdjustAmount(const MachineFunction &MF) const;
66
67 bool canUseAsPrologue(const MachineBasicBlock &MBB) const override;
68 bool canUseAsEpilogue(const MachineBasicBlock &MBB) const override;
69
70 bool enableShrinkWrapping(const MachineFunction &MF) const override;
71
72 bool isSupportedStackID(TargetStackID::Value ID) const override;
73 TargetStackID::Value getStackIDForScalableVectors() const override;
74
75 bool isStackIdSafeForLocalArea(unsigned StackId) const override {
76 // We don't support putting RISC-V Vector objects into the pre-allocated
77 // local frame block at the moment.
78 return StackId != TargetStackID::ScalableVector;
79 }
80
81 void allocateStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
82 MachineFunction &MF, uint64_t Offset,
83 uint64_t RealStackSize, bool EmitCFI, bool NeedProbe,
84 uint64_t ProbeSize, bool DynAllocation) const;
85
86protected:
87 const RISCVSubtarget &STI;
88
89 bool hasFPImpl(const MachineFunction &MF) const override;
90
91private:
92 void determineFrameLayout(MachineFunction &MF) const;
93 void emitCalleeSavedRVVPrologCFI(MachineBasicBlock &MBB,
94 MachineBasicBlock::iterator MI,
95 bool HasFP) const;
96 void emitCalleeSavedRVVEpilogCFI(MachineBasicBlock &MBB,
97 MachineBasicBlock::iterator MI) const;
98 template <typename Emitter>
99 void emitCFIForCSI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
100 const SmallVector<CalleeSavedInfo, 8> &CSI) const;
101 void deallocateStack(MachineFunction &MF, MachineBasicBlock &MBB,
102 MachineBasicBlock::iterator MBBI, const DebugLoc &DL,
103 uint64_t &StackSize, int64_t CFAOffset) const;
104
105 std::pair<int64_t, Align>
106 assignRVVStackObjectOffsets(MachineFunction &MF) const;
107 // Replace a StackProbe stub (if any) with the actual probe code inline
108 void inlineStackProbe(MachineFunction &MF,
109 MachineBasicBlock &PrologueMBB) const override;
110 void allocateAndProbeStackForRVV(MachineFunction &MF, MachineBasicBlock &MBB,
111 MachineBasicBlock::iterator MBBI,
112 const DebugLoc &DL, int64_t Amount,
113 MachineInstr::MIFlag Flag, bool EmitCFI,
114 bool DynAllocation) const;
115};
116} // namespace llvm
117#endif
118