lib/Target/RISCV/RISCVFrameLowering.h

   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
  18 namespace llvm {
  19 class RISCVSubtarget;
  20
  21 class RISCVFrameLowering : public TargetFrameLowering {
  22 public:
  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 hasReservedCallFrame(const MachineFunction &MF) const override;
  44   MachineBasicBlock::iterator
  45   eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
  46                                 MachineBasicBlock::iterator MI) const override;
  47
  48   // Get the first stack adjustment amount for SplitSPAdjust.
  49   // Return 0 if we don't want to to split the SP adjustment in prologue and
  50   // epilogue.
  51   uint64_t getFirstSPAdjustAmount(const MachineFunction &MF) const;
  52
  53 protected:
  54   const RISCVSubtarget &STI;
  55
  56 private:
  57   void determineFrameLayout(MachineFunction &MF) const;
  58   void adjustReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
  59                  const DebugLoc &DL, Register DestReg, Register SrcReg,
  60                  int64_t Val, MachineInstr::MIFlag Flag) const;
  61 };
  62 }
  63 #endif