RISCVFrameLowering.h revision 360784 
1//===-- RISCVFrameLowering.h - Define frame lowering for RISCV -*- 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 RISCV-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
18namespace llvm {
19class RISCVSubtarget;
20
21class RISCVFrameLowering : public TargetFrameLowering {
22public:
23  explicit RISCVFrameLowering(const RISCVSubtarget &STI)
24      : TargetFrameLowering(StackGrowsDown,
25                            /*StackAlignment=*/Align(16),
26                            /*LocalAreaOffset=*/0),
27        STI(STI) {}
28
29  void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
30  void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
31
32  int getFrameIndexReference(const MachineFunction &MF, int FI,
33                             unsigned &FrameReg) const override;
34
35  void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
36                            RegScavenger *RS) const override;
37
38  void processFunctionBeforeFrameFinalized(MachineFunction &MF,
39                                           RegScavenger *RS) const override;
40
41  bool hasFP(const MachineFunction &MF) const override;
42
43  bool hasBP(const MachineFunction &MF) const;
44
45  bool hasReservedCallFrame(const MachineFunction &MF) const override;
46  MachineBasicBlock::iterator
47  eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
48                                MachineBasicBlock::iterator MI) const override;
49
50  // Get the first stack adjustment amount for SplitSPAdjust.
51  // Return 0 if we don't want to to split the SP adjustment in prologue and
52  // epilogue.
53  uint64_t getFirstSPAdjustAmount(const MachineFunction &MF) const;
54
55protected:
56  const RISCVSubtarget &STI;
57
58private:
59  void determineFrameLayout(MachineFunction &MF) const;
60  void adjustReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
61                 const DebugLoc &DL, Register DestReg, Register SrcReg,
62                 int64_t Val, MachineInstr::MIFlag Flag) const;
63};
64}
65#endif
66