lib/Target/RISCV/RISCVExpandPseudoInsts.cpp - llvm-project/llvm - Git at Google

 //===-- RISCVExpandPseudoInsts.cpp - Expand pseudo instructions -----------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // This file contains a pass that expands pseudo instructions into target
 // instructions. This pass should be run after register allocation but before
 // the post-regalloc scheduling pass.
 //
 //===----------------------------------------------------------------------===//

 #include "RISCV.h"
 #include "RISCVInstrInfo.h"
 #include "RISCVTargetMachine.h"

 #include "llvm/CodeGen/LivePhysRegs.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MachineInstrBuilder.h"

 using namespace llvm;

 #define RISCV_EXPAND_PSEUDO_NAME "RISCV pseudo instruction expansion pass"

 namespace {

 class RISCVExpandPseudo : public MachineFunctionPass {
 public:
   const RISCVInstrInfo *TII;
   static char ID;

   RISCVExpandPseudo() : MachineFunctionPass(ID) {
     initializeRISCVExpandPseudoPass(*PassRegistry::getPassRegistry());
   }

   bool runOnMachineFunction(MachineFunction &MF) override;

   StringRef getPassName() const override { return RISCV_EXPAND_PSEUDO_NAME; }

 private:
   bool expandMBB(MachineBasicBlock &MBB);
   bool expandMI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
                 MachineBasicBlock::iterator &NextMBBI);
   bool expandAuipcInstPair(MachineBasicBlock &MBB,
                            MachineBasicBlock::iterator MBBI,
                            MachineBasicBlock::iterator &NextMBBI,
                            unsigned FlagsHi, unsigned SecondOpcode);
   bool expandLoadLocalAddress(MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator MBBI,
                               MachineBasicBlock::iterator &NextMBBI);
   bool expandLoadAddress(MachineBasicBlock &MBB,
                          MachineBasicBlock::iterator MBBI,
                          MachineBasicBlock::iterator &NextMBBI);
   bool expandLoadTLSIEAddress(MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator MBBI,
                               MachineBasicBlock::iterator &NextMBBI);
   bool expandLoadTLSGDAddress(MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator MBBI,
                               MachineBasicBlock::iterator &NextMBBI);
   bool expandVSetVL(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI);
   bool expandVMSET_VMCLR(MachineBasicBlock &MBB,
                          MachineBasicBlock::iterator MBBI, unsigned Opcode);
   bool expandVSPILL(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI);
   bool expandVRELOAD(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI);
 };

 char RISCVExpandPseudo::ID = 0;

 bool RISCVExpandPseudo::runOnMachineFunction(MachineFunction &MF) {
   TII = static_cast<const RISCVInstrInfo *>(MF.getSubtarget().getInstrInfo());
   bool Modified = false;
   for (auto &MBB : MF)
     Modified |= expandMBB(MBB);
   return Modified;
 }

 bool RISCVExpandPseudo::expandMBB(MachineBasicBlock &MBB) {
   bool Modified = false;

   MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end();
   while (MBBI != E) {
     MachineBasicBlock::iterator NMBBI = std::next(MBBI);
     Modified |= expandMI(MBB, MBBI, NMBBI);
     MBBI = NMBBI;
   }

   return Modified;
 }

 bool RISCVExpandPseudo::expandMI(MachineBasicBlock &MBB,
                                  MachineBasicBlock::iterator MBBI,
                                  MachineBasicBlock::iterator &NextMBBI) {
   // RISCVInstrInfo::getInstSizeInBytes hard-codes the number of expanded
   // instructions for each pseudo, and must be updated when adding new pseudos
   // or changing existing ones.
   switch (MBBI->getOpcode()) {
   case RISCV::PseudoLLA:
     return expandLoadLocalAddress(MBB, MBBI, NextMBBI);
   case RISCV::PseudoLA:
     return expandLoadAddress(MBB, MBBI, NextMBBI);
   case RISCV::PseudoLA_TLS_IE:
     return expandLoadTLSIEAddress(MBB, MBBI, NextMBBI);
   case RISCV::PseudoLA_TLS_GD:
     return expandLoadTLSGDAddress(MBB, MBBI, NextMBBI);
   case RISCV::PseudoVSETVLI:
   case RISCV::PseudoVSETIVLI:
     return expandVSetVL(MBB, MBBI);
   case RISCV::PseudoVMCLR_M_B1:
   case RISCV::PseudoVMCLR_M_B2:
   case RISCV::PseudoVMCLR_M_B4:
   case RISCV::PseudoVMCLR_M_B8:
   case RISCV::PseudoVMCLR_M_B16:
   case RISCV::PseudoVMCLR_M_B32:
   case RISCV::PseudoVMCLR_M_B64:
     // vmclr.m vd => vmxor.mm vd, vd, vd
     return expandVMSET_VMCLR(MBB, MBBI, RISCV::VMXOR_MM);
   case RISCV::PseudoVMSET_M_B1:
   case RISCV::PseudoVMSET_M_B2:
   case RISCV::PseudoVMSET_M_B4:
   case RISCV::PseudoVMSET_M_B8:
   case RISCV::PseudoVMSET_M_B16:
   case RISCV::PseudoVMSET_M_B32:
   case RISCV::PseudoVMSET_M_B64:
     // vmset.m vd => vmxnor.mm vd, vd, vd
     return expandVMSET_VMCLR(MBB, MBBI, RISCV::VMXNOR_MM);
   case RISCV::PseudoVSPILL2_M1:
   case RISCV::PseudoVSPILL2_M2:
   case RISCV::PseudoVSPILL2_M4:
   case RISCV::PseudoVSPILL3_M1:
   case RISCV::PseudoVSPILL3_M2:
   case RISCV::PseudoVSPILL4_M1:
   case RISCV::PseudoVSPILL4_M2:
   case RISCV::PseudoVSPILL5_M1:
   case RISCV::PseudoVSPILL6_M1:
   case RISCV::PseudoVSPILL7_M1:
   case RISCV::PseudoVSPILL8_M1:
     return expandVSPILL(MBB, MBBI);
   case RISCV::PseudoVRELOAD2_M1:
   case RISCV::PseudoVRELOAD2_M2:
   case RISCV::PseudoVRELOAD2_M4:
   case RISCV::PseudoVRELOAD3_M1:
   case RISCV::PseudoVRELOAD3_M2:
   case RISCV::PseudoVRELOAD4_M1:
   case RISCV::PseudoVRELOAD4_M2:
   case RISCV::PseudoVRELOAD5_M1:
   case RISCV::PseudoVRELOAD6_M1:
   case RISCV::PseudoVRELOAD7_M1:
   case RISCV::PseudoVRELOAD8_M1:
     return expandVRELOAD(MBB, MBBI);
   }

   return false;
 }

 bool RISCVExpandPseudo::expandAuipcInstPair(
     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
     MachineBasicBlock::iterator &NextMBBI, unsigned FlagsHi,
     unsigned SecondOpcode) {
   MachineFunction *MF = MBB.getParent();
   MachineInstr &MI = *MBBI;
   DebugLoc DL = MI.getDebugLoc();

   Register DestReg = MI.getOperand(0).getReg();
   const MachineOperand &Symbol = MI.getOperand(1);

   MachineBasicBlock *NewMBB = MF->CreateMachineBasicBlock(MBB.getBasicBlock());

   // Tell AsmPrinter that we unconditionally want the symbol of this label to be
   // emitted.
   NewMBB->setLabelMustBeEmitted();

   MF->insert(++MBB.getIterator(), NewMBB);

   BuildMI(NewMBB, DL, TII->get(RISCV::AUIPC), DestReg)
       .addDisp(Symbol, 0, FlagsHi);
   BuildMI(NewMBB, DL, TII->get(SecondOpcode), DestReg)
       .addReg(DestReg)
       .addMBB(NewMBB, RISCVII::MO_PCREL_LO);

   // Move all the rest of the instructions to NewMBB.
   NewMBB->splice(NewMBB->end(), &MBB, std::next(MBBI), MBB.end());
   // Update machine-CFG edges.
   NewMBB->transferSuccessorsAndUpdatePHIs(&MBB);
   // Make the original basic block fall-through to the new.
   MBB.addSuccessor(NewMBB);

   // Make sure live-ins are correctly attached to this new basic block.
   LivePhysRegs LiveRegs;
   computeAndAddLiveIns(LiveRegs, *NewMBB);

   NextMBBI = MBB.end();
   MI.eraseFromParent();
   return true;
 }

 bool RISCVExpandPseudo::expandLoadLocalAddress(
     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
     MachineBasicBlock::iterator &NextMBBI) {
   return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_PCREL_HI,
                              RISCV::ADDI);
 }

 bool RISCVExpandPseudo::expandLoadAddress(
     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
     MachineBasicBlock::iterator &NextMBBI) {
   MachineFunction *MF = MBB.getParent();

   unsigned SecondOpcode;
   unsigned FlagsHi;
   if (MF->getTarget().isPositionIndependent()) {
     const auto &STI = MF->getSubtarget<RISCVSubtarget>();
     SecondOpcode = STI.is64Bit() ? RISCV::LD : RISCV::LW;
     FlagsHi = RISCVII::MO_GOT_HI;
   } else {
     SecondOpcode = RISCV::ADDI;
     FlagsHi = RISCVII::MO_PCREL_HI;
   }
   return expandAuipcInstPair(MBB, MBBI, NextMBBI, FlagsHi, SecondOpcode);
 }

 bool RISCVExpandPseudo::expandLoadTLSIEAddress(
     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
     MachineBasicBlock::iterator &NextMBBI) {
   MachineFunction *MF = MBB.getParent();

   const auto &STI = MF->getSubtarget<RISCVSubtarget>();
   unsigned SecondOpcode = STI.is64Bit() ? RISCV::LD : RISCV::LW;
   return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_TLS_GOT_HI,
                              SecondOpcode);
 }

 bool RISCVExpandPseudo::expandLoadTLSGDAddress(
     MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
     MachineBasicBlock::iterator &NextMBBI) {
   return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_TLS_GD_HI,
                              RISCV::ADDI);
 }

 bool RISCVExpandPseudo::expandVSetVL(MachineBasicBlock &MBB,
                                      MachineBasicBlock::iterator MBBI) {
   assert(MBBI->getNumOperands() == 5 && "Unexpected instruction format");

   DebugLoc DL = MBBI->getDebugLoc();

   assert((MBBI->getOpcode() == RISCV::PseudoVSETVLI ||
           MBBI->getOpcode() == RISCV::PseudoVSETIVLI) &&
          "Unexpected pseudo instruction");
   unsigned Opcode;
   if (MBBI->getOpcode() == RISCV::PseudoVSETVLI)
     Opcode = RISCV::VSETVLI;
   else
     Opcode = RISCV::VSETIVLI;
   const MCInstrDesc &Desc = TII->get(Opcode);
   assert(Desc.getNumOperands() == 3 && "Unexpected instruction format");

   Register DstReg = MBBI->getOperand(0).getReg();
   bool DstIsDead = MBBI->getOperand(0).isDead();
   BuildMI(MBB, MBBI, DL, Desc)
       .addReg(DstReg, RegState::Define | getDeadRegState(DstIsDead))
       .add(MBBI->getOperand(1))  // VL
       .add(MBBI->getOperand(2)); // VType

   MBBI->eraseFromParent(); // The pseudo instruction is gone now.
   return true;
 }

 bool RISCVExpandPseudo::expandVMSET_VMCLR(MachineBasicBlock &MBB,
                                           MachineBasicBlock::iterator MBBI,
                                           unsigned Opcode) {
   DebugLoc DL = MBBI->getDebugLoc();
   Register DstReg = MBBI->getOperand(0).getReg();
   const MCInstrDesc &Desc = TII->get(Opcode);
   BuildMI(MBB, MBBI, DL, Desc, DstReg)
       .addReg(DstReg, RegState::Undef)
       .addReg(DstReg, RegState::Undef);
   MBBI->eraseFromParent(); // The pseudo instruction is gone now.
   return true;
 }

 bool RISCVExpandPseudo::expandVSPILL(MachineBasicBlock &MBB,
                                      MachineBasicBlock::iterator MBBI) {
   const TargetRegisterInfo *TRI =
       MBB.getParent()->getSubtarget().getRegisterInfo();
   DebugLoc DL = MBBI->getDebugLoc();
   Register SrcReg = MBBI->getOperand(0).getReg();
   Register Base = MBBI->getOperand(1).getReg();
   Register VL = MBBI->getOperand(2).getReg();
   auto ZvlssegInfo = TII->isRVVSpillForZvlsseg(MBBI->getOpcode());
   if (!ZvlssegInfo)
     return false;
   unsigned NF = ZvlssegInfo->first;
   unsigned LMUL = ZvlssegInfo->second;
   assert(NF * LMUL <= 8 && "Invalid NF/LMUL combinations.");
   unsigned Opcode = RISCV::VS1R_V;
   unsigned SubRegIdx = RISCV::sub_vrm1_0;
   static_assert(RISCV::sub_vrm1_7 == RISCV::sub_vrm1_0 + 7,
                 "Unexpected subreg numbering");
   if (LMUL == 2) {
     Opcode = RISCV::VS2R_V;
     SubRegIdx = RISCV::sub_vrm2_0;
     static_assert(RISCV::sub_vrm2_3 == RISCV::sub_vrm2_0 + 3,
                   "Unexpected subreg numbering");
   } else if (LMUL == 4) {
     Opcode = RISCV::VS4R_V;
     SubRegIdx = RISCV::sub_vrm4_0;
     static_assert(RISCV::sub_vrm4_1 == RISCV::sub_vrm4_0 + 1,
                   "Unexpected subreg numbering");
   } else
     assert(LMUL == 1 && "LMUL must be 1, 2, or 4.");

   for (unsigned I = 0; I < NF; ++I) {
     BuildMI(MBB, MBBI, DL, TII->get(Opcode))
         .addReg(TRI->getSubReg(SrcReg, SubRegIdx + I))
         .addReg(Base)
         .addMemOperand(*(MBBI->memoperands_begin()));
     if (I != NF - 1)
       BuildMI(MBB, MBBI, DL, TII->get(RISCV::ADD), Base)
           .addReg(Base)
           .addReg(VL);
   }
   MBBI->eraseFromParent();
   return true;
 }

 bool RISCVExpandPseudo::expandVRELOAD(MachineBasicBlock &MBB,
                                       MachineBasicBlock::iterator MBBI) {
   const TargetRegisterInfo *TRI =
       MBB.getParent()->getSubtarget().getRegisterInfo();
   DebugLoc DL = MBBI->getDebugLoc();
   Register DestReg = MBBI->getOperand(0).getReg();
   Register Base = MBBI->getOperand(1).getReg();
   Register VL = MBBI->getOperand(2).getReg();
   auto ZvlssegInfo = TII->isRVVSpillForZvlsseg(MBBI->getOpcode());
   if (!ZvlssegInfo)
     return false;
   unsigned NF = ZvlssegInfo->first;
   unsigned LMUL = ZvlssegInfo->second;
   assert(NF * LMUL <= 8 && "Invalid NF/LMUL combinations.");
   unsigned Opcode = RISCV::VL1RE8_V;
   unsigned SubRegIdx = RISCV::sub_vrm1_0;
   static_assert(RISCV::sub_vrm1_7 == RISCV::sub_vrm1_0 + 7,
                 "Unexpected subreg numbering");
   if (LMUL == 2) {
     Opcode = RISCV::VL2RE8_V;
     SubRegIdx = RISCV::sub_vrm2_0;
     static_assert(RISCV::sub_vrm2_3 == RISCV::sub_vrm2_0 + 3,
                   "Unexpected subreg numbering");
   } else if (LMUL == 4) {
     Opcode = RISCV::VL4RE8_V;
     SubRegIdx = RISCV::sub_vrm4_0;
     static_assert(RISCV::sub_vrm4_1 == RISCV::sub_vrm4_0 + 1,
                   "Unexpected subreg numbering");
   } else
     assert(LMUL == 1 && "LMUL must be 1, 2, or 4.");

   for (unsigned I = 0; I < NF; ++I) {
     BuildMI(MBB, MBBI, DL, TII->get(Opcode),
             TRI->getSubReg(DestReg, SubRegIdx + I))
         .addReg(Base)
         .addMemOperand(*(MBBI->memoperands_begin()));
     if (I != NF - 1)
       BuildMI(MBB, MBBI, DL, TII->get(RISCV::ADD), Base)
           .addReg(Base)
           .addReg(VL);
   }
   MBBI->eraseFromParent();
   return true;
 }

 } // end of anonymous namespace

 INITIALIZE_PASS(RISCVExpandPseudo, "riscv-expand-pseudo",
                 RISCV_EXPAND_PSEUDO_NAME, false, false)
 namespace llvm {

 FunctionPass *createRISCVExpandPseudoPass() { return new RISCVExpandPseudo(); }

 } // end of namespace llvm
	//===-- RISCVExpandPseudoInsts.cpp - Expand pseudo instructions -----------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//
	//
	// This file contains a pass that expands pseudo instructions into target
	// instructions. This pass should be run after register allocation but before
	// the post-regalloc scheduling pass.
	//
	//===----------------------------------------------------------------------===//

	#include "RISCV.h"
	#include "RISCVInstrInfo.h"
	#include "RISCVTargetMachine.h"

	#include "llvm/CodeGen/LivePhysRegs.h"
	#include "llvm/CodeGen/MachineFunctionPass.h"
	#include "llvm/CodeGen/MachineInstrBuilder.h"

	using namespace llvm;

	#define RISCV_EXPAND_PSEUDO_NAME "RISCV pseudo instruction expansion pass"

	namespace {

	class RISCVExpandPseudo : public MachineFunctionPass {
	public:
	const RISCVInstrInfo *TII;
	static char ID;

	RISCVExpandPseudo() : MachineFunctionPass(ID) {
	initializeRISCVExpandPseudoPass(*PassRegistry::getPassRegistry());
	}

	bool runOnMachineFunction(MachineFunction &MF) override;

	StringRef getPassName() const override { return RISCV_EXPAND_PSEUDO_NAME; }

	private:
	bool expandMBB(MachineBasicBlock &MBB);
	bool expandMI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
	MachineBasicBlock::iterator &NextMBBI);
	bool expandAuipcInstPair(MachineBasicBlock &MBB,
	MachineBasicBlock::iterator MBBI,
	MachineBasicBlock::iterator &NextMBBI,
	unsigned FlagsHi, unsigned SecondOpcode);
	bool expandLoadLocalAddress(MachineBasicBlock &MBB,
	MachineBasicBlock::iterator MBBI,
	MachineBasicBlock::iterator &NextMBBI);
	bool expandLoadAddress(MachineBasicBlock &MBB,
	MachineBasicBlock::iterator MBBI,
	MachineBasicBlock::iterator &NextMBBI);
	bool expandLoadTLSIEAddress(MachineBasicBlock &MBB,
	MachineBasicBlock::iterator MBBI,
	MachineBasicBlock::iterator &NextMBBI);
	bool expandLoadTLSGDAddress(MachineBasicBlock &MBB,
	MachineBasicBlock::iterator MBBI,
	MachineBasicBlock::iterator &NextMBBI);
	bool expandVSetVL(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI);
	bool expandVMSET_VMCLR(MachineBasicBlock &MBB,
	MachineBasicBlock::iterator MBBI, unsigned Opcode);
	bool expandVSPILL(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI);
	bool expandVRELOAD(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI);
	};

	char RISCVExpandPseudo::ID = 0;

	bool RISCVExpandPseudo::runOnMachineFunction(MachineFunction &MF) {
	TII = static_cast<const RISCVInstrInfo *>(MF.getSubtarget().getInstrInfo());
	bool Modified = false;
	for (auto &MBB : MF)
	Modified \|= expandMBB(MBB);
	return Modified;
	}

	bool RISCVExpandPseudo::expandMBB(MachineBasicBlock &MBB) {
	bool Modified = false;

	MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end();
	while (MBBI != E) {
	MachineBasicBlock::iterator NMBBI = std::next(MBBI);
	Modified \|= expandMI(MBB, MBBI, NMBBI);
	MBBI = NMBBI;
	}

	return Modified;
	}

	bool RISCVExpandPseudo::expandMI(MachineBasicBlock &MBB,
	MachineBasicBlock::iterator MBBI,
	MachineBasicBlock::iterator &NextMBBI) {
	// RISCVInstrInfo::getInstSizeInBytes hard-codes the number of expanded
	// instructions for each pseudo, and must be updated when adding new pseudos
	// or changing existing ones.
	switch (MBBI->getOpcode()) {
	case RISCV::PseudoLLA:
	return expandLoadLocalAddress(MBB, MBBI, NextMBBI);
	case RISCV::PseudoLA:
	return expandLoadAddress(MBB, MBBI, NextMBBI);
	case RISCV::PseudoLA_TLS_IE:
	return expandLoadTLSIEAddress(MBB, MBBI, NextMBBI);
	case RISCV::PseudoLA_TLS_GD:
	return expandLoadTLSGDAddress(MBB, MBBI, NextMBBI);
	case RISCV::PseudoVSETVLI:
	case RISCV::PseudoVSETIVLI:
	return expandVSetVL(MBB, MBBI);
	case RISCV::PseudoVMCLR_M_B1:
	case RISCV::PseudoVMCLR_M_B2:
	case RISCV::PseudoVMCLR_M_B4:
	case RISCV::PseudoVMCLR_M_B8:
	case RISCV::PseudoVMCLR_M_B16:
	case RISCV::PseudoVMCLR_M_B32:
	case RISCV::PseudoVMCLR_M_B64:
	// vmclr.m vd => vmxor.mm vd, vd, vd
	return expandVMSET_VMCLR(MBB, MBBI, RISCV::VMXOR_MM);
	case RISCV::PseudoVMSET_M_B1:
	case RISCV::PseudoVMSET_M_B2:
	case RISCV::PseudoVMSET_M_B4:
	case RISCV::PseudoVMSET_M_B8:
	case RISCV::PseudoVMSET_M_B16:
	case RISCV::PseudoVMSET_M_B32:
	case RISCV::PseudoVMSET_M_B64:
	// vmset.m vd => vmxnor.mm vd, vd, vd
	return expandVMSET_VMCLR(MBB, MBBI, RISCV::VMXNOR_MM);
	case RISCV::PseudoVSPILL2_M1:
	case RISCV::PseudoVSPILL2_M2:
	case RISCV::PseudoVSPILL2_M4:
	case RISCV::PseudoVSPILL3_M1:
	case RISCV::PseudoVSPILL3_M2:
	case RISCV::PseudoVSPILL4_M1:
	case RISCV::PseudoVSPILL4_M2:
	case RISCV::PseudoVSPILL5_M1:
	case RISCV::PseudoVSPILL6_M1:
	case RISCV::PseudoVSPILL7_M1:
	case RISCV::PseudoVSPILL8_M1:
	return expandVSPILL(MBB, MBBI);
	case RISCV::PseudoVRELOAD2_M1:
	case RISCV::PseudoVRELOAD2_M2:
	case RISCV::PseudoVRELOAD2_M4:
	case RISCV::PseudoVRELOAD3_M1:
	case RISCV::PseudoVRELOAD3_M2:
	case RISCV::PseudoVRELOAD4_M1:
	case RISCV::PseudoVRELOAD4_M2:
	case RISCV::PseudoVRELOAD5_M1:
	case RISCV::PseudoVRELOAD6_M1:
	case RISCV::PseudoVRELOAD7_M1:
	case RISCV::PseudoVRELOAD8_M1:
	return expandVRELOAD(MBB, MBBI);
	}

	return false;
	}

	bool RISCVExpandPseudo::expandAuipcInstPair(
	MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
	MachineBasicBlock::iterator &NextMBBI, unsigned FlagsHi,
	unsigned SecondOpcode) {
	MachineFunction *MF = MBB.getParent();
	MachineInstr &MI = *MBBI;
	DebugLoc DL = MI.getDebugLoc();

	Register DestReg = MI.getOperand(0).getReg();
	const MachineOperand &Symbol = MI.getOperand(1);

	MachineBasicBlock *NewMBB = MF->CreateMachineBasicBlock(MBB.getBasicBlock());

	// Tell AsmPrinter that we unconditionally want the symbol of this label to be
	// emitted.
	NewMBB->setLabelMustBeEmitted();

	MF->insert(++MBB.getIterator(), NewMBB);

	BuildMI(NewMBB, DL, TII->get(RISCV::AUIPC), DestReg)
	.addDisp(Symbol, 0, FlagsHi);
	BuildMI(NewMBB, DL, TII->get(SecondOpcode), DestReg)
	.addReg(DestReg)
	.addMBB(NewMBB, RISCVII::MO_PCREL_LO);

	// Move all the rest of the instructions to NewMBB.
	NewMBB->splice(NewMBB->end(), &MBB, std::next(MBBI), MBB.end());
	// Update machine-CFG edges.
	NewMBB->transferSuccessorsAndUpdatePHIs(&MBB);
	// Make the original basic block fall-through to the new.
	MBB.addSuccessor(NewMBB);

	// Make sure live-ins are correctly attached to this new basic block.
	LivePhysRegs LiveRegs;
	computeAndAddLiveIns(LiveRegs, *NewMBB);

	NextMBBI = MBB.end();
	MI.eraseFromParent();
	return true;
	}

	bool RISCVExpandPseudo::expandLoadLocalAddress(
	MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
	MachineBasicBlock::iterator &NextMBBI) {
	return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_PCREL_HI,
	RISCV::ADDI);
	}

	bool RISCVExpandPseudo::expandLoadAddress(
	MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
	MachineBasicBlock::iterator &NextMBBI) {
	MachineFunction *MF = MBB.getParent();

	unsigned SecondOpcode;
	unsigned FlagsHi;
	if (MF->getTarget().isPositionIndependent()) {
	const auto &STI = MF->getSubtarget<RISCVSubtarget>();
	SecondOpcode = STI.is64Bit() ? RISCV::LD : RISCV::LW;
	FlagsHi = RISCVII::MO_GOT_HI;
	} else {
	SecondOpcode = RISCV::ADDI;
	FlagsHi = RISCVII::MO_PCREL_HI;
	}
	return expandAuipcInstPair(MBB, MBBI, NextMBBI, FlagsHi, SecondOpcode);
	}

	bool RISCVExpandPseudo::expandLoadTLSIEAddress(
	MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
	MachineBasicBlock::iterator &NextMBBI) {
	MachineFunction *MF = MBB.getParent();

	const auto &STI = MF->getSubtarget<RISCVSubtarget>();
	unsigned SecondOpcode = STI.is64Bit() ? RISCV::LD : RISCV::LW;
	return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_TLS_GOT_HI,
	SecondOpcode);
	}

	bool RISCVExpandPseudo::expandLoadTLSGDAddress(
	MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
	MachineBasicBlock::iterator &NextMBBI) {
	return expandAuipcInstPair(MBB, MBBI, NextMBBI, RISCVII::MO_TLS_GD_HI,
	RISCV::ADDI);
	}

	bool RISCVExpandPseudo::expandVSetVL(MachineBasicBlock &MBB,
	MachineBasicBlock::iterator MBBI) {
	assert(MBBI->getNumOperands() == 5 && "Unexpected instruction format");

	DebugLoc DL = MBBI->getDebugLoc();

	assert((MBBI->getOpcode() == RISCV::PseudoVSETVLI \|\|
	MBBI->getOpcode() == RISCV::PseudoVSETIVLI) &&
	"Unexpected pseudo instruction");
	unsigned Opcode;
	if (MBBI->getOpcode() == RISCV::PseudoVSETVLI)
	Opcode = RISCV::VSETVLI;
	else
	Opcode = RISCV::VSETIVLI;
	const MCInstrDesc &Desc = TII->get(Opcode);
	assert(Desc.getNumOperands() == 3 && "Unexpected instruction format");

	Register DstReg = MBBI->getOperand(0).getReg();
	bool DstIsDead = MBBI->getOperand(0).isDead();
	BuildMI(MBB, MBBI, DL, Desc)
	.addReg(DstReg, RegState::Define \| getDeadRegState(DstIsDead))
	.add(MBBI->getOperand(1)) // VL
	.add(MBBI->getOperand(2)); // VType

	MBBI->eraseFromParent(); // The pseudo instruction is gone now.
	return true;
	}

	bool RISCVExpandPseudo::expandVMSET_VMCLR(MachineBasicBlock &MBB,
	MachineBasicBlock::iterator MBBI,
	unsigned Opcode) {
	DebugLoc DL = MBBI->getDebugLoc();
	Register DstReg = MBBI->getOperand(0).getReg();
	const MCInstrDesc &Desc = TII->get(Opcode);
	BuildMI(MBB, MBBI, DL, Desc, DstReg)
	.addReg(DstReg, RegState::Undef)
	.addReg(DstReg, RegState::Undef);
	MBBI->eraseFromParent(); // The pseudo instruction is gone now.
	return true;
	}

	bool RISCVExpandPseudo::expandVSPILL(MachineBasicBlock &MBB,
	MachineBasicBlock::iterator MBBI) {
	const TargetRegisterInfo *TRI =
	MBB.getParent()->getSubtarget().getRegisterInfo();
	DebugLoc DL = MBBI->getDebugLoc();
	Register SrcReg = MBBI->getOperand(0).getReg();
	Register Base = MBBI->getOperand(1).getReg();
	Register VL = MBBI->getOperand(2).getReg();
	auto ZvlssegInfo = TII->isRVVSpillForZvlsseg(MBBI->getOpcode());
	if (!ZvlssegInfo)
	return false;
	unsigned NF = ZvlssegInfo->first;
	unsigned LMUL = ZvlssegInfo->second;
	assert(NF * LMUL <= 8 && "Invalid NF/LMUL combinations.");
	unsigned Opcode = RISCV::VS1R_V;
	unsigned SubRegIdx = RISCV::sub_vrm1_0;
	static_assert(RISCV::sub_vrm1_7 == RISCV::sub_vrm1_0 + 7,
	"Unexpected subreg numbering");
	if (LMUL == 2) {
	Opcode = RISCV::VS2R_V;
	SubRegIdx = RISCV::sub_vrm2_0;
	static_assert(RISCV::sub_vrm2_3 == RISCV::sub_vrm2_0 + 3,
	"Unexpected subreg numbering");
	} else if (LMUL == 4) {
	Opcode = RISCV::VS4R_V;
	SubRegIdx = RISCV::sub_vrm4_0;
	static_assert(RISCV::sub_vrm4_1 == RISCV::sub_vrm4_0 + 1,
	"Unexpected subreg numbering");
	} else
	assert(LMUL == 1 && "LMUL must be 1, 2, or 4.");

	for (unsigned I = 0; I < NF; ++I) {
	BuildMI(MBB, MBBI, DL, TII->get(Opcode))
	.addReg(TRI->getSubReg(SrcReg, SubRegIdx + I))
	.addReg(Base)
	.addMemOperand(*(MBBI->memoperands_begin()));
	if (I != NF - 1)
	BuildMI(MBB, MBBI, DL, TII->get(RISCV::ADD), Base)
	.addReg(Base)
	.addReg(VL);
	}
	MBBI->eraseFromParent();
	return true;
	}

	bool RISCVExpandPseudo::expandVRELOAD(MachineBasicBlock &MBB,
	MachineBasicBlock::iterator MBBI) {
	const TargetRegisterInfo *TRI =
	MBB.getParent()->getSubtarget().getRegisterInfo();
	DebugLoc DL = MBBI->getDebugLoc();
	Register DestReg = MBBI->getOperand(0).getReg();
	Register Base = MBBI->getOperand(1).getReg();
	Register VL = MBBI->getOperand(2).getReg();
	auto ZvlssegInfo = TII->isRVVSpillForZvlsseg(MBBI->getOpcode());
	if (!ZvlssegInfo)
	return false;
	unsigned NF = ZvlssegInfo->first;
	unsigned LMUL = ZvlssegInfo->second;
	assert(NF * LMUL <= 8 && "Invalid NF/LMUL combinations.");
	unsigned Opcode = RISCV::VL1RE8_V;
	unsigned SubRegIdx = RISCV::sub_vrm1_0;
	static_assert(RISCV::sub_vrm1_7 == RISCV::sub_vrm1_0 + 7,
	"Unexpected subreg numbering");
	if (LMUL == 2) {
	Opcode = RISCV::VL2RE8_V;
	SubRegIdx = RISCV::sub_vrm2_0;
	static_assert(RISCV::sub_vrm2_3 == RISCV::sub_vrm2_0 + 3,
	"Unexpected subreg numbering");
	} else if (LMUL == 4) {
	Opcode = RISCV::VL4RE8_V;
	SubRegIdx = RISCV::sub_vrm4_0;
	static_assert(RISCV::sub_vrm4_1 == RISCV::sub_vrm4_0 + 1,
	"Unexpected subreg numbering");
	} else
	assert(LMUL == 1 && "LMUL must be 1, 2, or 4.");

	for (unsigned I = 0; I < NF; ++I) {
	BuildMI(MBB, MBBI, DL, TII->get(Opcode),
	TRI->getSubReg(DestReg, SubRegIdx + I))
	.addReg(Base)
	.addMemOperand(*(MBBI->memoperands_begin()));
	if (I != NF - 1)
	BuildMI(MBB, MBBI, DL, TII->get(RISCV::ADD), Base)
	.addReg(Base)
	.addReg(VL);
	}
	MBBI->eraseFromParent();
	return true;
	}

	} // end of anonymous namespace

	INITIALIZE_PASS(RISCVExpandPseudo, "riscv-expand-pseudo",
	RISCV_EXPAND_PSEUDO_NAME, false, false)
	namespace llvm {

	FunctionPass *createRISCVExpandPseudoPass() { return new RISCVExpandPseudo(); }

	} // end of namespace llvm