llvm/lib/Target/RISCV/RISCVFrameLowering.h

   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
  19 namespace llvm {
  20 class RISCVSubtarget;
  21
  22 class RISCVFrameLowering : public TargetFrameLowering {
  23 public:
  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
  86 protected:
  87   const RISCVSubtarget &STI;
  88
  89   bool hasFPImpl(const MachineFunction &MF) const override;
  90
  91 private:
  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