AMDGPUInstructionSelector.cpp

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//===- AMDGPUInstructionSelector.cpp ----------------------------*- C++ -*-==//
//
// 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
//
//===----------------------------------------------------------------------===//
/// \file
/// This file implements the targeting of the InstructionSelector class for
/// AMDGPU.
/// \todo This should be generated by TableGen.
//===----------------------------------------------------------------------===//
 
#include "AMDGPUInstructionSelector.h"
#include "AMDGPU.h"
#include "AMDGPUGlobalISelUtils.h"
#include "AMDGPUInstrInfo.h"
#include "AMDGPURegisterBankInfo.h"
#include "AMDGPUTargetMachine.h"
#include "SIMachineFunctionInfo.h"
#include "Utils/AMDGPUBaseInfo.h"
#include "llvm/CodeGen/GlobalISel/GIMatchTableExecutorImpl.h"
#include "llvm/CodeGen/GlobalISel/GISelKnownBits.h"
#include "llvm/CodeGen/GlobalISel/GenericMachineInstrs.h"
#include "llvm/CodeGen/GlobalISel/MIPatternMatch.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/IR/DiagnosticInfo.h"
#include "llvm/IR/IntrinsicsAMDGPU.h"
#include <optional>
 
#define DEBUG_TYPE "amdgpu-isel"
 
using namespace llvm;
using namespace MIPatternMatch;
 
#define GET_GLOBALISEL_IMPL
#define AMDGPUSubtarget GCNSubtarget
#include "AMDGPUGenGlobalISel.inc"
#undef GET_GLOBALISEL_IMPL
#undef AMDGPUSubtarget
 
AMDGPUInstructionSelector::AMDGPUInstructionSelector(
    const GCNSubtarget &STI, const AMDGPURegisterBankInfo &RBI,
    const AMDGPUTargetMachine &TM)
    : TII(*STI.getInstrInfo()), TRI(*STI.getRegisterInfo()), RBI(RBI), TM(TM),
      STI(STI),
      EnableLateStructurizeCFG(AMDGPUTargetMachine::EnableLateStructurizeCFG),
#define GET_GLOBALISEL_PREDICATES_INIT
#include "AMDGPUGenGlobalISel.inc"
#undef GET_GLOBALISEL_PREDICATES_INIT
#define GET_GLOBALISEL_TEMPORARIES_INIT
#include "AMDGPUGenGlobalISel.inc"
#undef GET_GLOBALISEL_TEMPORARIES_INIT
{
}
 
const char *AMDGPUInstructionSelector::getName() { return DEBUG_TYPE; }
 
void AMDGPUInstructionSelector::setupMF(MachineFunction &MF, GISelKnownBits *KB,
                                        CodeGenCoverage *CoverageInfo,
                                        ProfileSummaryInfo *PSI,
                                        BlockFrequencyInfo *BFI) {
  MRI = &MF.getRegInfo();
  Subtarget = &MF.getSubtarget<GCNSubtarget>();
  Subtarget->checkSubtargetFeatures(MF.getFunction());
  InstructionSelector::setupMF(MF, KB, CoverageInfo, PSI, BFI);
}
 
// Return the wave level SGPR base address if this is a wave address.
static Register getWaveAddress(const MachineInstr *Def) {
  return Def->getOpcode() == AMDGPU::G_AMDGPU_WAVE_ADDRESS
             ? Def->getOperand(1).getReg()
             : Register();
}
 
bool AMDGPUInstructionSelector::isVCC(Register Reg,
                                      const MachineRegisterInfo &MRI) const {
  // The verifier is oblivious to s1 being a valid value for wavesize registers.
  if (Reg.isPhysical())
    return false;
 
  auto &RegClassOrBank = MRI.getRegClassOrRegBank(Reg);
  const TargetRegisterClass *RC =
      RegClassOrBank.dyn_cast<const TargetRegisterClass*>();
  if (RC) {
    const LLT Ty = MRI.getType(Reg);
    if (!Ty.isValid() || Ty.getSizeInBits() != 1)
      return false;
    // G_TRUNC s1 result is never vcc.
    return MRI.getVRegDef(Reg)->getOpcode() != AMDGPU::G_TRUNC &&
           RC->hasSuperClassEq(TRI.getBoolRC());
  }
 
  const RegisterBank *RB = RegClassOrBank.get<const RegisterBank *>();
  return RB->getID() == AMDGPU::VCCRegBankID;
}
 
bool AMDGPUInstructionSelector::constrainCopyLikeIntrin(MachineInstr &MI,
                                                        unsigned NewOpc) const {
  MI.setDesc(TII.get(NewOpc));
  MI.removeOperand(1); // Remove intrinsic ID.
  MI.addOperand(*MF, MachineOperand::CreateReg(AMDGPU::EXEC, false, true));
 
  MachineOperand &Dst = MI.getOperand(0);
  MachineOperand &Src = MI.getOperand(1);
 
  // TODO: This should be legalized to s32 if needed
  if (MRI->getType(Dst.getReg()) == LLT::scalar(1))
    return false;
 
  const TargetRegisterClass *DstRC
    = TRI.getConstrainedRegClassForOperand(Dst, *MRI);
  const TargetRegisterClass *SrcRC
    = TRI.getConstrainedRegClassForOperand(Src, *MRI);
  if (!DstRC || DstRC != SrcRC)
    return false;
 
  return RBI.constrainGenericRegister(Dst.getReg(), *DstRC, *MRI) &&
         RBI.constrainGenericRegister(Src.getReg(), *SrcRC, *MRI);
}
 
bool AMDGPUInstructionSelector::selectCOPY(MachineInstr &I) const {
  const DebugLoc &DL = I.getDebugLoc();
  MachineBasicBlock *BB = I.getParent();
  I.setDesc(TII.get(TargetOpcode::COPY));
 
  const MachineOperand &Src = I.getOperand(1);
  MachineOperand &Dst = I.getOperand(0);
  Register DstReg = Dst.getReg();
  Register SrcReg = Src.getReg();
 
  if (isVCC(DstReg, *MRI)) {
    if (SrcReg == AMDGPU::SCC) {
      const TargetRegisterClass *RC
        = TRI.getConstrainedRegClassForOperand(Dst, *MRI);
      if (!RC)
        return true;
      return RBI.constrainGenericRegister(DstReg, *RC, *MRI);
    }
 
    if (!isVCC(SrcReg, *MRI)) {
      // TODO: Should probably leave the copy and let copyPhysReg expand it.
      if (!RBI.constrainGenericRegister(DstReg, *TRI.getBoolRC(), *MRI))
        return false;
 
      const TargetRegisterClass *SrcRC
        = TRI.getConstrainedRegClassForOperand(Src, *MRI);
 
      std::optional<ValueAndVReg> ConstVal =
          getIConstantVRegValWithLookThrough(SrcReg, *MRI, true);
      if (ConstVal) {
        unsigned MovOpc =
            STI.isWave64() ? AMDGPU::S_MOV_B64 : AMDGPU::S_MOV_B32;
        BuildMI(*BB, &I, DL, TII.get(MovOpc), DstReg)
            .addImm(ConstVal->Value.getBoolValue() ? -1 : 0);
      } else {
        Register MaskedReg = MRI->createVirtualRegister(SrcRC);
 
        // We can't trust the high bits at this point, so clear them.
 
        // TODO: Skip masking high bits if def is known boolean.
 
        bool IsSGPR = TRI.isSGPRClass(SrcRC);
        unsigned AndOpc =
            IsSGPR ? AMDGPU::S_AND_B32 : AMDGPU::V_AND_B32_e32;
        auto And = BuildMI(*BB, &I, DL, TII.get(AndOpc), MaskedReg)
            .addImm(1)
            .addReg(SrcReg);
        if (IsSGPR)
          And.setOperandDead(3); // Dead scc
 
        BuildMI(*BB, &I, DL, TII.get(AMDGPU::V_CMP_NE_U32_e64), DstReg)
            .addImm(0)
            .addReg(MaskedReg);
      }
 
      if (!MRI->getRegClassOrNull(SrcReg))
        MRI->setRegClass(SrcReg, SrcRC);
      I.eraseFromParent();
      return true;
    }
 
    const TargetRegisterClass *RC =
      TRI.getConstrainedRegClassForOperand(Dst, *MRI);
    if (RC && !RBI.constrainGenericRegister(DstReg, *RC, *MRI))
      return false;
 
    return true;
  }
 
  for (const MachineOperand &MO : I.operands()) {
    if (MO.getReg().isPhysical())
      continue;
 
    const TargetRegisterClass *RC =
            TRI.getConstrainedRegClassForOperand(MO, *MRI);
    if (!RC)
      continue;
    RBI.constrainGenericRegister(MO.getReg(), *RC, *MRI);
  }
  return true;
}
 
bool AMDGPUInstructionSelector::selectPHI(MachineInstr &I) const {
  const Register DefReg = I.getOperand(0).getReg();
  const LLT DefTy = MRI->getType(DefReg);
 
  // S1 G_PHIs should not be selected in instruction-select, instead:
  // - divergent S1 G_PHI should go through lane mask merging algorithm
  //   and be fully inst-selected in AMDGPUGlobalISelDivergenceLowering
  // - uniform S1 G_PHI should be lowered into S32 G_PHI in AMDGPURegBankSelect
  if (DefTy == LLT::scalar(1))
    return false;
 
  // TODO: Verify this doesn't have insane operands (i.e. VGPR to SGPR copy)
 
  const RegClassOrRegBank &RegClassOrBank =
    MRI->getRegClassOrRegBank(DefReg);
 
  const TargetRegisterClass *DefRC
    = RegClassOrBank.dyn_cast<const TargetRegisterClass *>();
  if (!DefRC) {
    if (!DefTy.isValid()) {
      LLVM_DEBUG(dbgs() << "PHI operand has no type, not a gvreg?\n");
      return false;
    }
 
    const RegisterBank &RB = *RegClassOrBank.get<const RegisterBank *>();
    DefRC = TRI.getRegClassForTypeOnBank(DefTy, RB);
    if (!DefRC) {
      LLVM_DEBUG(dbgs() << "PHI operand has unexpected size/bank\n");
      return false;
    }
  }
 
  // TODO: Verify that all registers have the same bank
  I.setDesc(TII.get(TargetOpcode::PHI));
  return RBI.constrainGenericRegister(DefReg, *DefRC, *MRI);
}
 
MachineOperand
AMDGPUInstructionSelector::getSubOperand64(MachineOperand &MO,
                                           const TargetRegisterClass &SubRC,
                                           unsigned SubIdx) const {
 
  MachineInstr *MI = MO.getParent();
  MachineBasicBlock *BB = MO.getParent()->getParent();
  Register DstReg = MRI->createVirtualRegister(&SubRC);
 
  if (MO.isReg()) {
    unsigned ComposedSubIdx = TRI.composeSubRegIndices(MO.getSubReg(), SubIdx);
    Register Reg = MO.getReg();
    BuildMI(*BB, MI, MI->getDebugLoc(), TII.get(AMDGPU::COPY), DstReg)
            .addReg(Reg, 0, ComposedSubIdx);
 
    return MachineOperand::CreateReg(DstReg, MO.isDef(), MO.isImplicit(),
                                     MO.isKill(), MO.isDead(), MO.isUndef(),
                                     MO.isEarlyClobber(), 0, MO.isDebug(),
                                     MO.isInternalRead());
  }
 
  assert(MO.isImm());
 
  APInt Imm(64, MO.getImm());
 
  switch (SubIdx) {
  default:
    llvm_unreachable("do not know to split immediate with this sub index.");
  case AMDGPU::sub0:
    return MachineOperand::CreateImm(Imm.getLoBits(32).getSExtValue());
  case AMDGPU::sub1:
    return MachineOperand::CreateImm(Imm.getHiBits(32).getSExtValue());
  }
}
 
static unsigned getLogicalBitOpcode(unsigned Opc, bool Is64) {
  switch (Opc) {
  case AMDGPU::G_AND:
    return Is64 ? AMDGPU::S_AND_B64 : AMDGPU::S_AND_B32;
  case AMDGPU::G_OR:
    return Is64 ? AMDGPU::S_OR_B64 : AMDGPU::S_OR_B32;
  case AMDGPU::G_XOR:
    return Is64 ? AMDGPU::S_XOR_B64 : AMDGPU::S_XOR_B32;
  default:
    llvm_unreachable("not a bit op");
  }
}
 
bool AMDGPUInstructionSelector::selectG_AND_OR_XOR(MachineInstr &I) const {
  Register DstReg = I.getOperand(0).getReg();
  unsigned Size = RBI.getSizeInBits(DstReg, *MRI, TRI);
 
  const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
  if (DstRB->getID() != AMDGPU::SGPRRegBankID &&
      DstRB->getID() != AMDGPU::VCCRegBankID)
    return false;
 
  bool Is64 = Size > 32 || (DstRB->getID() == AMDGPU::VCCRegBankID &&
                            STI.isWave64());
  I.setDesc(TII.get(getLogicalBitOpcode(I.getOpcode(), Is64)));
 
  // Dead implicit-def of scc
  I.addOperand(MachineOperand::CreateReg(AMDGPU::SCC, true, // isDef
                                         true, // isImp
                                         false, // isKill
                                         true)); // isDead
  return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
}
 
bool AMDGPUInstructionSelector::selectG_ADD_SUB(MachineInstr &I) const {
  MachineBasicBlock *BB = I.getParent();
  MachineFunction *MF = BB->getParent();
  Register DstReg = I.getOperand(0).getReg();
  const DebugLoc &DL = I.getDebugLoc();
  LLT Ty = MRI->getType(DstReg);
  if (Ty.isVector())
    return false;
 
  unsigned Size = Ty.getSizeInBits();
  const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
  const bool IsSALU = DstRB->getID() == AMDGPU::SGPRRegBankID;
  const bool Sub = I.getOpcode() == TargetOpcode::G_SUB;
 
  if (Size == 32) {
    if (IsSALU) {
      const unsigned Opc = Sub ? AMDGPU::S_SUB_U32 : AMDGPU::S_ADD_U32;
      MachineInstr *Add =
        BuildMI(*BB, &I, DL, TII.get(Opc), DstReg)
        .add(I.getOperand(1))
        .add(I.getOperand(2))
        .setOperandDead(3); // Dead scc
      I.eraseFromParent();
      return constrainSelectedInstRegOperands(*Add, TII, TRI, RBI);
    }
 
    if (STI.hasAddNoCarry()) {
      const unsigned Opc = Sub ? AMDGPU::V_SUB_U32_e64 : AMDGPU::V_ADD_U32_e64;
      I.setDesc(TII.get(Opc));
      I.addOperand(*MF, MachineOperand::CreateImm(0));
      I.addOperand(*MF, MachineOperand::CreateReg(AMDGPU::EXEC, false, true));
      return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
    }
 
    const unsigned Opc = Sub ? AMDGPU::V_SUB_CO_U32_e64 : AMDGPU::V_ADD_CO_U32_e64;
 
    Register UnusedCarry = MRI->createVirtualRegister(TRI.getWaveMaskRegClass());
    MachineInstr *Add
      = BuildMI(*BB, &I, DL, TII.get(Opc), DstReg)
      .addDef(UnusedCarry, RegState::Dead)
      .add(I.getOperand(1))
      .add(I.getOperand(2))
      .addImm(0);
    I.eraseFromParent();
    return constrainSelectedInstRegOperands(*Add, TII, TRI, RBI);
  }
 
  assert(!Sub && "illegal sub should not reach here");
 
  const TargetRegisterClass &RC
    = IsSALU ? AMDGPU::SReg_64_XEXECRegClass : AMDGPU::VReg_64RegClass;
  const TargetRegisterClass &HalfRC
    = IsSALU ? AMDGPU::SReg_32RegClass : AMDGPU::VGPR_32RegClass;
 
  MachineOperand Lo1(getSubOperand64(I.getOperand(1), HalfRC, AMDGPU::sub0));
  MachineOperand Lo2(getSubOperand64(I.getOperand(2), HalfRC, AMDGPU::sub0));
  MachineOperand Hi1(getSubOperand64(I.getOperand(1), HalfRC, AMDGPU::sub1));
  MachineOperand Hi2(getSubOperand64(I.getOperand(2), HalfRC, AMDGPU::sub1));
 
  Register DstLo = MRI->createVirtualRegister(&HalfRC);
  Register DstHi = MRI->createVirtualRegister(&HalfRC);
 
  if (IsSALU) {
    BuildMI(*BB, &I, DL, TII.get(AMDGPU::S_ADD_U32), DstLo)
      .add(Lo1)
      .add(Lo2);
    BuildMI(*BB, &I, DL, TII.get(AMDGPU::S_ADDC_U32), DstHi)
      .add(Hi1)
      .add(Hi2)
      .setOperandDead(3); // Dead scc
  } else {
    const TargetRegisterClass *CarryRC = TRI.getWaveMaskRegClass();
    Register CarryReg = MRI->createVirtualRegister(CarryRC);
    BuildMI(*BB, &I, DL, TII.get(AMDGPU::V_ADD_CO_U32_e64), DstLo)
      .addDef(CarryReg)
      .add(Lo1)
      .add(Lo2)
      .addImm(0);
    MachineInstr *Addc = BuildMI(*BB, &I, DL, TII.get(AMDGPU::V_ADDC_U32_e64), DstHi)
      .addDef(MRI->createVirtualRegister(CarryRC), RegState::Dead)
      .add(Hi1)
      .add(Hi2)
      .addReg(CarryReg, RegState::Kill)
      .addImm(0);
 
    if (!constrainSelectedInstRegOperands(*Addc, TII, TRI, RBI))
      return false;
  }
 
  BuildMI(*BB, &I, DL, TII.get(AMDGPU::REG_SEQUENCE), DstReg)
    .addReg(DstLo)
    .addImm(AMDGPU::sub0)
    .addReg(DstHi)
    .addImm(AMDGPU::sub1);
 
 
  if (!RBI.constrainGenericRegister(DstReg, RC, *MRI))
    return false;
 
  I.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectG_UADDO_USUBO_UADDE_USUBE(
  MachineInstr &I) const {
  MachineBasicBlock *BB = I.getParent();
  MachineFunction *MF = BB->getParent();
  const DebugLoc &DL = I.getDebugLoc();
  Register Dst0Reg = I.getOperand(0).getReg();
  Register Dst1Reg = I.getOperand(1).getReg();
  const bool IsAdd = I.getOpcode() == AMDGPU::G_UADDO ||
                     I.getOpcode() == AMDGPU::G_UADDE;
  const bool HasCarryIn = I.getOpcode() == AMDGPU::G_UADDE ||
                          I.getOpcode() == AMDGPU::G_USUBE;
 
  if (isVCC(Dst1Reg, *MRI)) {
    unsigned NoCarryOpc =
        IsAdd ? AMDGPU::V_ADD_CO_U32_e64 : AMDGPU::V_SUB_CO_U32_e64;
    unsigned CarryOpc = IsAdd ? AMDGPU::V_ADDC_U32_e64 : AMDGPU::V_SUBB_U32_e64;
    I.setDesc(TII.get(HasCarryIn ? CarryOpc : NoCarryOpc));
    I.addOperand(*MF, MachineOperand::CreateReg(AMDGPU::EXEC, false, true));
    I.addOperand(*MF, MachineOperand::CreateImm(0));
    return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
  }
 
  Register Src0Reg = I.getOperand(2).getReg();
  Register Src1Reg = I.getOperand(3).getReg();
 
  if (HasCarryIn) {
    BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), AMDGPU::SCC)
      .addReg(I.getOperand(4).getReg());
  }
 
  unsigned NoCarryOpc = IsAdd ? AMDGPU::S_ADD_U32 : AMDGPU::S_SUB_U32;
  unsigned CarryOpc = IsAdd ? AMDGPU::S_ADDC_U32 : AMDGPU::S_SUBB_U32;
 
  auto CarryInst = BuildMI(*BB, &I, DL, TII.get(HasCarryIn ? CarryOpc : NoCarryOpc), Dst0Reg)
    .add(I.getOperand(2))
    .add(I.getOperand(3));
 
  if (MRI->use_nodbg_empty(Dst1Reg)) {
    CarryInst.setOperandDead(3); // Dead scc
  } else {
    BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), Dst1Reg)
      .addReg(AMDGPU::SCC);
    if (!MRI->getRegClassOrNull(Dst1Reg))
      MRI->setRegClass(Dst1Reg, &AMDGPU::SReg_32RegClass);
  }
 
  if (!RBI.constrainGenericRegister(Dst0Reg, AMDGPU::SReg_32RegClass, *MRI) ||
      !RBI.constrainGenericRegister(Src0Reg, AMDGPU::SReg_32RegClass, *MRI) ||
      !RBI.constrainGenericRegister(Src1Reg, AMDGPU::SReg_32RegClass, *MRI))
    return false;
 
  if (HasCarryIn &&
      !RBI.constrainGenericRegister(I.getOperand(4).getReg(),
                                    AMDGPU::SReg_32RegClass, *MRI))
    return false;
 
  I.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectG_AMDGPU_MAD_64_32(
    MachineInstr &I) const {
  MachineBasicBlock *BB = I.getParent();
  MachineFunction *MF = BB->getParent();
  const bool IsUnsigned = I.getOpcode() == AMDGPU::G_AMDGPU_MAD_U64_U32;
 
  unsigned Opc;
  if (Subtarget->hasMADIntraFwdBug())
    Opc = IsUnsigned ? AMDGPU::V_MAD_U64_U32_gfx11_e64
                     : AMDGPU::V_MAD_I64_I32_gfx11_e64;
  else
    Opc = IsUnsigned ? AMDGPU::V_MAD_U64_U32_e64 : AMDGPU::V_MAD_I64_I32_e64;
  I.setDesc(TII.get(Opc));
  I.addOperand(*MF, MachineOperand::CreateImm(0));
  I.addImplicitDefUseOperands(*MF);
  return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
}
 
// TODO: We should probably legalize these to only using 32-bit results.
bool AMDGPUInstructionSelector::selectG_EXTRACT(MachineInstr &I) const {
  MachineBasicBlock *BB = I.getParent();
  Register DstReg = I.getOperand(0).getReg();
  Register SrcReg = I.getOperand(1).getReg();
  LLT DstTy = MRI->getType(DstReg);
  LLT SrcTy = MRI->getType(SrcReg);
  const unsigned SrcSize = SrcTy.getSizeInBits();
  unsigned DstSize = DstTy.getSizeInBits();
 
  // TODO: Should handle any multiple of 32 offset.
  unsigned Offset = I.getOperand(2).getImm();
  if (Offset % 32 != 0 || DstSize > 128)
    return false;
 
  // 16-bit operations really use 32-bit registers.
  // FIXME: Probably should not allow 16-bit G_EXTRACT results.
  if (DstSize == 16)
    DstSize = 32;
 
  const TargetRegisterClass *DstRC =
    TRI.getConstrainedRegClassForOperand(I.getOperand(0), *MRI);
  if (!DstRC || !RBI.constrainGenericRegister(DstReg, *DstRC, *MRI))
    return false;
 
  const RegisterBank *SrcBank = RBI.getRegBank(SrcReg, *MRI, TRI);
  const TargetRegisterClass *SrcRC =
      TRI.getRegClassForSizeOnBank(SrcSize, *SrcBank);
  if (!SrcRC)
    return false;
  unsigned SubReg = SIRegisterInfo::getSubRegFromChannel(Offset / 32,
                                                         DstSize / 32);
  SrcRC = TRI.getSubClassWithSubReg(SrcRC, SubReg);
  if (!SrcRC)
    return false;
 
  SrcReg = constrainOperandRegClass(*MF, TRI, *MRI, TII, RBI, I,
                                    *SrcRC, I.getOperand(1));
  const DebugLoc &DL = I.getDebugLoc();
  BuildMI(*BB, &I, DL, TII.get(TargetOpcode::COPY), DstReg)
    .addReg(SrcReg, 0, SubReg);
 
  I.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectG_MERGE_VALUES(MachineInstr &MI) const {
  MachineBasicBlock *BB = MI.getParent();
  Register DstReg = MI.getOperand(0).getReg();
  LLT DstTy = MRI->getType(DstReg);
  LLT SrcTy = MRI->getType(MI.getOperand(1).getReg());
 
  const unsigned SrcSize = SrcTy.getSizeInBits();
  if (SrcSize < 32)
    return selectImpl(MI, *CoverageInfo);
 
  const DebugLoc &DL = MI.getDebugLoc();
  const RegisterBank *DstBank = RBI.getRegBank(DstReg, *MRI, TRI);
  const unsigned DstSize = DstTy.getSizeInBits();
  const TargetRegisterClass *DstRC =
      TRI.getRegClassForSizeOnBank(DstSize, *DstBank);
  if (!DstRC)
    return false;
 
  ArrayRef<int16_t> SubRegs = TRI.getRegSplitParts(DstRC, SrcSize / 8);
  MachineInstrBuilder MIB =
    BuildMI(*BB, &MI, DL, TII.get(TargetOpcode::REG_SEQUENCE), DstReg);
  for (int I = 0, E = MI.getNumOperands() - 1; I != E; ++I) {
    MachineOperand &Src = MI.getOperand(I + 1);
    MIB.addReg(Src.getReg(), getUndefRegState(Src.isUndef()));
    MIB.addImm(SubRegs[I]);
 
    const TargetRegisterClass *SrcRC
      = TRI.getConstrainedRegClassForOperand(Src, *MRI);
    if (SrcRC && !RBI.constrainGenericRegister(Src.getReg(), *SrcRC, *MRI))
      return false;
  }
 
  if (!RBI.constrainGenericRegister(DstReg, *DstRC, *MRI))
    return false;
 
  MI.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectG_UNMERGE_VALUES(MachineInstr &MI) const {
  MachineBasicBlock *BB = MI.getParent();
  const int NumDst = MI.getNumOperands() - 1;
 
  MachineOperand &Src = MI.getOperand(NumDst);
 
  Register SrcReg = Src.getReg();
  Register DstReg0 = MI.getOperand(0).getReg();
  LLT DstTy = MRI->getType(DstReg0);
  LLT SrcTy = MRI->getType(SrcReg);
 
  const unsigned DstSize = DstTy.getSizeInBits();
  const unsigned SrcSize = SrcTy.getSizeInBits();
  const DebugLoc &DL = MI.getDebugLoc();
  const RegisterBank *SrcBank = RBI.getRegBank(SrcReg, *MRI, TRI);
 
  const TargetRegisterClass *SrcRC =
      TRI.getRegClassForSizeOnBank(SrcSize, *SrcBank);
  if (!SrcRC || !RBI.constrainGenericRegister(SrcReg, *SrcRC, *MRI))
    return false;
 
  // Note we could have mixed SGPR and VGPR destination banks for an SGPR
  // source, and this relies on the fact that the same subregister indices are
  // used for both.
  ArrayRef<int16_t> SubRegs = TRI.getRegSplitParts(SrcRC, DstSize / 8);
  for (int I = 0, E = NumDst; I != E; ++I) {
    MachineOperand &Dst = MI.getOperand(I);
    BuildMI(*BB, &MI, DL, TII.get(TargetOpcode::COPY), Dst.getReg())
      .addReg(SrcReg, 0, SubRegs[I]);
 
    // Make sure the subregister index is valid for the source register.
    SrcRC = TRI.getSubClassWithSubReg(SrcRC, SubRegs[I]);
    if (!SrcRC || !RBI.constrainGenericRegister(SrcReg, *SrcRC, *MRI))
      return false;
 
    const TargetRegisterClass *DstRC =
      TRI.getConstrainedRegClassForOperand(Dst, *MRI);
    if (DstRC && !RBI.constrainGenericRegister(Dst.getReg(), *DstRC, *MRI))
      return false;
  }
 
  MI.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectG_BUILD_VECTOR(MachineInstr &MI) const {
  assert(MI.getOpcode() == AMDGPU::G_BUILD_VECTOR_TRUNC ||
         MI.getOpcode() == AMDGPU::G_BUILD_VECTOR);
 
  Register Src0 = MI.getOperand(1).getReg();
  Register Src1 = MI.getOperand(2).getReg();
  LLT SrcTy = MRI->getType(Src0);
  const unsigned SrcSize = SrcTy.getSizeInBits();
 
  // BUILD_VECTOR with >=32 bits source is handled by MERGE_VALUE.
  if (MI.getOpcode() == AMDGPU::G_BUILD_VECTOR && SrcSize >= 32) {
    return selectG_MERGE_VALUES(MI);
  }
 
  // Selection logic below is for V2S16 only.
  // For G_BUILD_VECTOR_TRUNC, additionally check that the operands are s32.
  Register Dst = MI.getOperand(0).getReg();
  if (MRI->getType(Dst) != LLT::fixed_vector(2, 16) ||
      (MI.getOpcode() == AMDGPU::G_BUILD_VECTOR_TRUNC &&
       SrcTy != LLT::scalar(32)))
    return selectImpl(MI, *CoverageInfo);
 
  const RegisterBank *DstBank = RBI.getRegBank(Dst, *MRI, TRI);
  if (DstBank->getID() == AMDGPU::AGPRRegBankID)
    return false;
 
  assert(DstBank->getID() == AMDGPU::SGPRRegBankID ||
         DstBank->getID() == AMDGPU::VGPRRegBankID);
  const bool IsVector = DstBank->getID() == AMDGPU::VGPRRegBankID;
 
  const DebugLoc &DL = MI.getDebugLoc();
  MachineBasicBlock *BB = MI.getParent();
 
  // First, before trying TableGen patterns, check if both sources are
  // constants. In those cases, we can trivially compute the final constant
  // and emit a simple move.
  auto ConstSrc1 = getAnyConstantVRegValWithLookThrough(Src1, *MRI, true, true);
  if (ConstSrc1) {
    auto ConstSrc0 =
        getAnyConstantVRegValWithLookThrough(Src0, *MRI, true, true);
    if (ConstSrc0) {
      const int64_t K0 = ConstSrc0->Value.getSExtValue();
      const int64_t K1 = ConstSrc1->Value.getSExtValue();
      uint32_t Lo16 = static_cast<uint32_t>(K0) & 0xffff;
      uint32_t Hi16 = static_cast<uint32_t>(K1) & 0xffff;
      uint32_t Imm = Lo16 | (Hi16 << 16);
 
      // VALU
      if (IsVector) {
        BuildMI(*BB, &MI, DL, TII.get(AMDGPU::V_MOV_B32_e32), Dst).addImm(Imm);
        MI.eraseFromParent();
        return RBI.constrainGenericRegister(Dst, AMDGPU::VGPR_32RegClass, *MRI);
      }
 
      // SALU
      BuildMI(*BB, &MI, DL, TII.get(AMDGPU::S_MOV_B32), Dst).addImm(Imm);
      MI.eraseFromParent();
      return RBI.constrainGenericRegister(Dst, AMDGPU::SReg_32RegClass, *MRI);
    }
  }
 
  // Now try TableGen patterns.
  if (selectImpl(MI, *CoverageInfo))
    return true;
 
  // TODO: This should probably be a combine somewhere
  // (build_vector $src0, undef)  -> copy $src0
  MachineInstr *Src1Def = getDefIgnoringCopies(Src1, *MRI);
  if (Src1Def->getOpcode() == AMDGPU::G_IMPLICIT_DEF) {
    MI.setDesc(TII.get(AMDGPU::COPY));
    MI.removeOperand(2);
    const auto &RC =
        IsVector ? AMDGPU::VGPR_32RegClass : AMDGPU::SReg_32RegClass;
    return RBI.constrainGenericRegister(Dst, RC, *MRI) &&
           RBI.constrainGenericRegister(Src0, RC, *MRI);
  }
 
  // TODO: Can be improved?
  if (IsVector) {
    Register TmpReg = MRI->createVirtualRegister(&AMDGPU::VGPR_32RegClass);
    auto MIB = BuildMI(*BB, MI, DL, TII.get(AMDGPU::V_AND_B32_e32), TmpReg)
                   .addImm(0xFFFF)
                   .addReg(Src0);
    if (!constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI))
      return false;
 
    MIB = BuildMI(*BB, MI, DL, TII.get(AMDGPU::V_LSHL_OR_B32_e64), Dst)
              .addReg(Src1)
              .addImm(16)
              .addReg(TmpReg);
    if (!constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI))
      return false;
 
    MI.eraseFromParent();
    return true;
  }
 
  Register ShiftSrc0;
  Register ShiftSrc1;
 
  // With multiple uses of the shift, this will duplicate the shift and
  // increase register pressure.
  //
  // (build_vector (lshr_oneuse $src0, 16), (lshr_oneuse $src1, 16)
  //  => (S_PACK_HH_B32_B16 $src0, $src1)
  // (build_vector (lshr_oneuse SReg_32:$src0, 16), $src1)
  //  => (S_PACK_HL_B32_B16 $src0, $src1)
  // (build_vector $src0, (lshr_oneuse SReg_32:$src1, 16))
  //  => (S_PACK_LH_B32_B16 $src0, $src1)
  // (build_vector $src0, $src1)
  //  => (S_PACK_LL_B32_B16 $src0, $src1)
 
  bool Shift0 = mi_match(
      Src0, *MRI, m_OneUse(m_GLShr(m_Reg(ShiftSrc0), m_SpecificICst(16))));
 
  bool Shift1 = mi_match(
      Src1, *MRI, m_OneUse(m_GLShr(m_Reg(ShiftSrc1), m_SpecificICst(16))));
 
  unsigned Opc = AMDGPU::S_PACK_LL_B32_B16;
  if (Shift0 && Shift1) {
    Opc = AMDGPU::S_PACK_HH_B32_B16;
    MI.getOperand(1).setReg(ShiftSrc0);
    MI.getOperand(2).setReg(ShiftSrc1);
  } else if (Shift1) {
    Opc = AMDGPU::S_PACK_LH_B32_B16;
    MI.getOperand(2).setReg(ShiftSrc1);
  } else if (Shift0) {
    auto ConstSrc1 =
        getAnyConstantVRegValWithLookThrough(Src1, *MRI, true, true);
    if (ConstSrc1 && ConstSrc1->Value == 0) {
      // build_vector_trunc (lshr $src0, 16), 0 -> s_lshr_b32 $src0, 16
      auto MIB = BuildMI(*BB, &MI, DL, TII.get(AMDGPU::S_LSHR_B32), Dst)
                     .addReg(ShiftSrc0)
                     .addImm(16)
                     .setOperandDead(3); // Dead scc
 
      MI.eraseFromParent();
      return constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
    }
    if (STI.hasSPackHL()) {
      Opc = AMDGPU::S_PACK_HL_B32_B16;
      MI.getOperand(1).setReg(ShiftSrc0);
    }
  }
 
  MI.setDesc(TII.get(Opc));
  return constrainSelectedInstRegOperands(MI, TII, TRI, RBI);
}
 
bool AMDGPUInstructionSelector::selectG_IMPLICIT_DEF(MachineInstr &I) const {
  const MachineOperand &MO = I.getOperand(0);
 
  // FIXME: Interface for getConstrainedRegClassForOperand needs work. The
  // regbank check here is to know why getConstrainedRegClassForOperand failed.
  const TargetRegisterClass *RC = TRI.getConstrainedRegClassForOperand(MO, *MRI);
  if ((!RC && !MRI->getRegBankOrNull(MO.getReg())) ||
      (RC && RBI.constrainGenericRegister(MO.getReg(), *RC, *MRI))) {
    I.setDesc(TII.get(TargetOpcode::IMPLICIT_DEF));
    return true;
  }
 
  return false;
}
 
bool AMDGPUInstructionSelector::selectG_INSERT(MachineInstr &I) const {
  MachineBasicBlock *BB = I.getParent();
 
  Register DstReg = I.getOperand(0).getReg();
  Register Src0Reg = I.getOperand(1).getReg();
  Register Src1Reg = I.getOperand(2).getReg();
  LLT Src1Ty = MRI->getType(Src1Reg);
 
  unsigned DstSize = MRI->getType(DstReg).getSizeInBits();
  unsigned InsSize = Src1Ty.getSizeInBits();
 
  int64_t Offset = I.getOperand(3).getImm();
 
  // FIXME: These cases should have been illegal and unnecessary to check here.
  if (Offset % 32 != 0 || InsSize % 32 != 0)
    return false;
 
  // Currently not handled by getSubRegFromChannel.
  if (InsSize > 128)
    return false;
 
  unsigned SubReg = TRI.getSubRegFromChannel(Offset / 32, InsSize / 32);
  if (SubReg == AMDGPU::NoSubRegister)
    return false;
 
  const RegisterBank *DstBank = RBI.getRegBank(DstReg, *MRI, TRI);
  const TargetRegisterClass *DstRC =
      TRI.getRegClassForSizeOnBank(DstSize, *DstBank);
  if (!DstRC)
    return false;
 
  const RegisterBank *Src0Bank = RBI.getRegBank(Src0Reg, *MRI, TRI);
  const RegisterBank *Src1Bank = RBI.getRegBank(Src1Reg, *MRI, TRI);
  const TargetRegisterClass *Src0RC =
      TRI.getRegClassForSizeOnBank(DstSize, *Src0Bank);
  const TargetRegisterClass *Src1RC =
      TRI.getRegClassForSizeOnBank(InsSize, *Src1Bank);
 
  // Deal with weird cases where the class only partially supports the subreg
  // index.
  Src0RC = TRI.getSubClassWithSubReg(Src0RC, SubReg);
  if (!Src0RC || !Src1RC)
    return false;
 
  if (!RBI.constrainGenericRegister(DstReg, *DstRC, *MRI) ||
      !RBI.constrainGenericRegister(Src0Reg, *Src0RC, *MRI) ||
      !RBI.constrainGenericRegister(Src1Reg, *Src1RC, *MRI))
    return false;
 
  const DebugLoc &DL = I.getDebugLoc();
  BuildMI(*BB, &I, DL, TII.get(TargetOpcode::INSERT_SUBREG), DstReg)
    .addReg(Src0Reg)
    .addReg(Src1Reg)
    .addImm(SubReg);
 
  I.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectG_SBFX_UBFX(MachineInstr &MI) const {
  Register DstReg = MI.getOperand(0).getReg();
  Register SrcReg = MI.getOperand(1).getReg();
  Register OffsetReg = MI.getOperand(2).getReg();
  Register WidthReg = MI.getOperand(3).getReg();
 
  assert(RBI.getRegBank(DstReg, *MRI, TRI)->getID() == AMDGPU::VGPRRegBankID &&
         "scalar BFX instructions are expanded in regbankselect");
  assert(MRI->getType(MI.getOperand(0).getReg()).getSizeInBits() == 32 &&
         "64-bit vector BFX instructions are expanded in regbankselect");
 
  const DebugLoc &DL = MI.getDebugLoc();
  MachineBasicBlock *MBB = MI.getParent();
 
  bool IsSigned = MI.getOpcode() == TargetOpcode::G_SBFX;
  unsigned Opc = IsSigned ? AMDGPU::V_BFE_I32_e64 : AMDGPU::V_BFE_U32_e64;
  auto MIB = BuildMI(*MBB, &MI, DL, TII.get(Opc), DstReg)
                 .addReg(SrcReg)
                 .addReg(OffsetReg)
                 .addReg(WidthReg);
  MI.eraseFromParent();
  return constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
}
 
bool AMDGPUInstructionSelector::selectInterpP1F16(MachineInstr &MI) const {
  if (STI.getLDSBankCount() != 16)
    return selectImpl(MI, *CoverageInfo);
 
  Register Dst = MI.getOperand(0).getReg();
  Register Src0 = MI.getOperand(2).getReg();
  Register M0Val = MI.getOperand(6).getReg();
  if (!RBI.constrainGenericRegister(M0Val, AMDGPU::SReg_32RegClass, *MRI) ||
      !RBI.constrainGenericRegister(Dst, AMDGPU::VGPR_32RegClass, *MRI) ||
      !RBI.constrainGenericRegister(Src0, AMDGPU::VGPR_32RegClass, *MRI))
    return false;
 
  // This requires 2 instructions. It is possible to write a pattern to support
  // this, but the generated isel emitter doesn't correctly deal with multiple
  // output instructions using the same physical register input. The copy to m0
  // is incorrectly placed before the second instruction.
  //
  // TODO: Match source modifiers.
 
  Register InterpMov = MRI->createVirtualRegister(&AMDGPU::VGPR_32RegClass);
  const DebugLoc &DL = MI.getDebugLoc();
  MachineBasicBlock *MBB = MI.getParent();
 
  BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
    .addReg(M0Val);
  BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::V_INTERP_MOV_F32), InterpMov)
    .addImm(2)
    .addImm(MI.getOperand(4).getImm())  // $attr
    .addImm(MI.getOperand(3).getImm()); // $attrchan
 
  BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::V_INTERP_P1LV_F16), Dst)
    .addImm(0)                          // $src0_modifiers
    .addReg(Src0)                       // $src0
    .addImm(MI.getOperand(4).getImm())  // $attr
    .addImm(MI.getOperand(3).getImm())  // $attrchan
    .addImm(0)                          // $src2_modifiers
    .addReg(InterpMov)                  // $src2 - 2 f16 values selected by high
    .addImm(MI.getOperand(5).getImm())  // $high
    .addImm(0)                          // $clamp
    .addImm(0);                         // $omod
 
  MI.eraseFromParent();
  return true;
}
 
// Writelane is special in that it can use SGPR and M0 (which would normally
// count as using the constant bus twice - but in this case it is allowed since
// the lane selector doesn't count as a use of the constant bus). However, it is
// still required to abide by the 1 SGPR rule. Fix this up if we might have
// multiple SGPRs.
bool AMDGPUInstructionSelector::selectWritelane(MachineInstr &MI) const {
  // With a constant bus limit of at least 2, there's no issue.
  if (STI.getConstantBusLimit(AMDGPU::V_WRITELANE_B32) > 1)
    return selectImpl(MI, *CoverageInfo);
 
  MachineBasicBlock *MBB = MI.getParent();
  const DebugLoc &DL = MI.getDebugLoc();
  Register VDst = MI.getOperand(0).getReg();
  Register Val = MI.getOperand(2).getReg();
  Register LaneSelect = MI.getOperand(3).getReg();
  Register VDstIn = MI.getOperand(4).getReg();
 
  auto MIB = BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::V_WRITELANE_B32), VDst);
 
  std::optional<ValueAndVReg> ConstSelect =
      getIConstantVRegValWithLookThrough(LaneSelect, *MRI);
  if (ConstSelect) {
    // The selector has to be an inline immediate, so we can use whatever for
    // the other operands.
    MIB.addReg(Val);
    MIB.addImm(ConstSelect->Value.getSExtValue() &
               maskTrailingOnes<uint64_t>(STI.getWavefrontSizeLog2()));
  } else {
    std::optional<ValueAndVReg> ConstVal =
        getIConstantVRegValWithLookThrough(Val, *MRI);
 
    // If the value written is an inline immediate, we can get away without a
    // copy to m0.
    if (ConstVal && AMDGPU::isInlinableLiteral32(ConstVal->Value.getSExtValue(),
                                                 STI.hasInv2PiInlineImm())) {
      MIB.addImm(ConstVal->Value.getSExtValue());
      MIB.addReg(LaneSelect);
    } else {
      MIB.addReg(Val);
 
      // If the lane selector was originally in a VGPR and copied with
      // readfirstlane, there's a hazard to read the same SGPR from the
      // VALU. Constrain to a different SGPR to help avoid needing a nop later.
      RBI.constrainGenericRegister(LaneSelect, AMDGPU::SReg_32_XM0RegClass, *MRI);
 
      BuildMI(*MBB, *MIB, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
        .addReg(LaneSelect);
      MIB.addReg(AMDGPU::M0);
    }
  }
 
  MIB.addReg(VDstIn);
 
  MI.eraseFromParent();
  return constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
}
 
// We need to handle this here because tablegen doesn't support matching
// instructions with multiple outputs.
bool AMDGPUInstructionSelector::selectDivScale(MachineInstr &MI) const {
  Register Dst0 = MI.getOperand(0).getReg();
  Register Dst1 = MI.getOperand(1).getReg();
 
  LLT Ty = MRI->getType(Dst0);
  unsigned Opc;
  if (Ty == LLT::scalar(32))
    Opc = AMDGPU::V_DIV_SCALE_F32_e64;
  else if (Ty == LLT::scalar(64))
    Opc = AMDGPU::V_DIV_SCALE_F64_e64;
  else
    return false;
 
  // TODO: Match source modifiers.
 
  const DebugLoc &DL = MI.getDebugLoc();
  MachineBasicBlock *MBB = MI.getParent();
 
  Register Numer = MI.getOperand(3).getReg();
  Register Denom = MI.getOperand(4).getReg();
  unsigned ChooseDenom = MI.getOperand(5).getImm();
 
  Register Src0 = ChooseDenom != 0 ? Numer : Denom;
 
  auto MIB = BuildMI(*MBB, &MI, DL, TII.get(Opc), Dst0)
    .addDef(Dst1)
    .addImm(0)     // $src0_modifiers
    .addUse(Src0)  // $src0
    .addImm(0)     // $src1_modifiers
    .addUse(Denom) // $src1
    .addImm(0)     // $src2_modifiers
    .addUse(Numer) // $src2
    .addImm(0)     // $clamp
    .addImm(0);    // $omod
 
  MI.eraseFromParent();
  return constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
}
 
bool AMDGPUInstructionSelector::selectG_INTRINSIC(MachineInstr &I) const {
  Intrinsic::ID IntrinsicID = cast<GIntrinsic>(I).getIntrinsicID();
  switch (IntrinsicID) {
  case Intrinsic::amdgcn_if_break: {
    MachineBasicBlock *BB = I.getParent();
 
    // FIXME: Manually selecting to avoid dealing with the SReg_1 trick
    // SelectionDAG uses for wave32 vs wave64.
    BuildMI(*BB, &I, I.getDebugLoc(), TII.get(AMDGPU::SI_IF_BREAK))
      .add(I.getOperand(0))
      .add(I.getOperand(2))
      .add(I.getOperand(3));
 
    Register DstReg = I.getOperand(0).getReg();
    Register Src0Reg = I.getOperand(2).getReg();
    Register Src1Reg = I.getOperand(3).getReg();
 
    I.eraseFromParent();
 
    for (Register Reg : { DstReg, Src0Reg, Src1Reg })
      MRI->setRegClass(Reg, TRI.getWaveMaskRegClass());
 
    return true;
  }
  case Intrinsic::amdgcn_interp_p1_f16:
    return selectInterpP1F16(I);
  case Intrinsic::amdgcn_wqm:
    return constrainCopyLikeIntrin(I, AMDGPU::WQM);
  case Intrinsic::amdgcn_softwqm:
    return constrainCopyLikeIntrin(I, AMDGPU::SOFT_WQM);
  case Intrinsic::amdgcn_strict_wwm:
  case Intrinsic::amdgcn_wwm:
    return constrainCopyLikeIntrin(I, AMDGPU::STRICT_WWM);
  case Intrinsic::amdgcn_strict_wqm:
    return constrainCopyLikeIntrin(I, AMDGPU::STRICT_WQM);
  case Intrinsic::amdgcn_writelane:
    return selectWritelane(I);
  case Intrinsic::amdgcn_div_scale:
    return selectDivScale(I);
  case Intrinsic::amdgcn_icmp:
  case Intrinsic::amdgcn_fcmp:
    if (selectImpl(I, *CoverageInfo))
      return true;
    return selectIntrinsicCmp(I);
  case Intrinsic::amdgcn_ballot:
    return selectBallot(I);
  case Intrinsic::amdgcn_reloc_constant:
    return selectRelocConstant(I);
  case Intrinsic::amdgcn_groupstaticsize:
    return selectGroupStaticSize(I);
  case Intrinsic::returnaddress:
    return selectReturnAddress(I);
  case Intrinsic::amdgcn_smfmac_f32_16x16x32_f16:
  case Intrinsic::amdgcn_smfmac_f32_32x32x16_f16:
  case Intrinsic::amdgcn_smfmac_f32_16x16x32_bf16:
  case Intrinsic::amdgcn_smfmac_f32_32x32x16_bf16:
  case Intrinsic::amdgcn_smfmac_i32_16x16x64_i8:
  case Intrinsic::amdgcn_smfmac_i32_32x32x32_i8:
  case Intrinsic::amdgcn_smfmac_f32_16x16x64_bf8_bf8:
  case Intrinsic::amdgcn_smfmac_f32_16x16x64_bf8_fp8:
  case Intrinsic::amdgcn_smfmac_f32_16x16x64_fp8_bf8:
  case Intrinsic::amdgcn_smfmac_f32_16x16x64_fp8_fp8:
  case Intrinsic::amdgcn_smfmac_f32_32x32x32_bf8_bf8:
  case Intrinsic::amdgcn_smfmac_f32_32x32x32_bf8_fp8:
  case Intrinsic::amdgcn_smfmac_f32_32x32x32_fp8_bf8:
  case Intrinsic::amdgcn_smfmac_f32_32x32x32_fp8_fp8:
    return selectSMFMACIntrin(I);
  default:
    return selectImpl(I, *CoverageInfo);
  }
}
 
static int getV_CMPOpcode(CmpInst::Predicate P, unsigned Size,
                          const GCNSubtarget &ST) {
  if (Size != 16 && Size != 32 && Size != 64)
    return -1;
 
  if (Size == 16 && !ST.has16BitInsts())
    return -1;
 
  const auto Select = [&](unsigned S16Opc, unsigned TrueS16Opc, unsigned S32Opc,
                          unsigned S64Opc) {
    if (Size == 16)
      return ST.hasTrue16BitInsts() ? TrueS16Opc : S16Opc;
    if (Size == 32)
      return S32Opc;
    return S64Opc;
  };
 
  switch (P) {
  default:
    llvm_unreachable("Unknown condition code!");
  case CmpInst::ICMP_NE:
    return Select(AMDGPU::V_CMP_NE_U16_e64, AMDGPU::V_CMP_NE_U16_t16_e64,
                  AMDGPU::V_CMP_NE_U32_e64, AMDGPU::V_CMP_NE_U64_e64);
  case CmpInst::ICMP_EQ:
    return Select(AMDGPU::V_CMP_EQ_U16_e64, AMDGPU::V_CMP_EQ_U16_t16_e64,
                  AMDGPU::V_CMP_EQ_U32_e64, AMDGPU::V_CMP_EQ_U64_e64);
  case CmpInst::ICMP_SGT:
    return Select(AMDGPU::V_CMP_GT_I16_e64, AMDGPU::V_CMP_GT_I16_t16_e64,
                  AMDGPU::V_CMP_GT_I32_e64, AMDGPU::V_CMP_GT_I64_e64);
  case CmpInst::ICMP_SGE:
    return Select(AMDGPU::V_CMP_GE_I16_e64, AMDGPU::V_CMP_GE_I16_t16_e64,
                  AMDGPU::V_CMP_GE_I32_e64, AMDGPU::V_CMP_GE_I64_e64);
  case CmpInst::ICMP_SLT:
    return Select(AMDGPU::V_CMP_LT_I16_e64, AMDGPU::V_CMP_LT_I16_t16_e64,
                  AMDGPU::V_CMP_LT_I32_e64, AMDGPU::V_CMP_LT_I64_e64);
  case CmpInst::ICMP_SLE:
    return Select(AMDGPU::V_CMP_LE_I16_e64, AMDGPU::V_CMP_LE_I16_t16_e64,
                  AMDGPU::V_CMP_LE_I32_e64, AMDGPU::V_CMP_LE_I64_e64);
  case CmpInst::ICMP_UGT:
    return Select(AMDGPU::V_CMP_GT_U16_e64, AMDGPU::V_CMP_GT_U16_t16_e64,
                  AMDGPU::V_CMP_GT_U32_e64, AMDGPU::V_CMP_GT_U64_e64);
  case CmpInst::ICMP_UGE:
    return Select(AMDGPU::V_CMP_GE_U16_e64, AMDGPU::V_CMP_GE_U16_t16_e64,
                  AMDGPU::V_CMP_GE_U32_e64, AMDGPU::V_CMP_GE_U64_e64);
  case CmpInst::ICMP_ULT:
    return Select(AMDGPU::V_CMP_LT_U16_e64, AMDGPU::V_CMP_LT_U16_t16_e64,
                  AMDGPU::V_CMP_LT_U32_e64, AMDGPU::V_CMP_LT_U64_e64);
  case CmpInst::ICMP_ULE:
    return Select(AMDGPU::V_CMP_LE_U16_e64, AMDGPU::V_CMP_LE_U16_t16_e64,
                  AMDGPU::V_CMP_LE_U32_e64, AMDGPU::V_CMP_LE_U64_e64);
 
  case CmpInst::FCMP_OEQ:
    return Select(AMDGPU::V_CMP_EQ_F16_e64, AMDGPU::V_CMP_EQ_F16_t16_e64,
                  AMDGPU::V_CMP_EQ_F32_e64, AMDGPU::V_CMP_EQ_F64_e64);
  case CmpInst::FCMP_OGT:
    return Select(AMDGPU::V_CMP_GT_F16_e64, AMDGPU::V_CMP_GT_F16_t16_e64,
                  AMDGPU::V_CMP_GT_F32_e64, AMDGPU::V_CMP_GT_F64_e64);
  case CmpInst::FCMP_OGE:
    return Select(AMDGPU::V_CMP_GE_F16_e64, AMDGPU::V_CMP_GE_F16_t16_e64,
                  AMDGPU::V_CMP_GE_F32_e64, AMDGPU::V_CMP_GE_F64_e64);
  case CmpInst::FCMP_OLT:
    return Select(AMDGPU::V_CMP_LT_F16_e64, AMDGPU::V_CMP_LT_F16_t16_e64,
                  AMDGPU::V_CMP_LT_F32_e64, AMDGPU::V_CMP_LT_F64_e64);
  case CmpInst::FCMP_OLE:
    return Select(AMDGPU::V_CMP_LE_F16_e64, AMDGPU::V_CMP_LE_F16_t16_e64,
                  AMDGPU::V_CMP_LE_F32_e64, AMDGPU::V_CMP_LE_F64_e64);
  case CmpInst::FCMP_ONE:
    return Select(AMDGPU::V_CMP_NEQ_F16_e64, AMDGPU::V_CMP_NEQ_F16_t16_e64,
                  AMDGPU::V_CMP_NEQ_F32_e64, AMDGPU::V_CMP_NEQ_F64_e64);
  case CmpInst::FCMP_ORD:
    return Select(AMDGPU::V_CMP_O_F16_e64, AMDGPU::V_CMP_O_F16_t16_e64,
                  AMDGPU::V_CMP_O_F32_e64, AMDGPU::V_CMP_O_F64_e64);
  case CmpInst::FCMP_UNO:
    return Select(AMDGPU::V_CMP_U_F16_e64, AMDGPU::V_CMP_U_F16_t16_e64,
                  AMDGPU::V_CMP_U_F32_e64, AMDGPU::V_CMP_U_F64_e64);
  case CmpInst::FCMP_UEQ:
    return Select(AMDGPU::V_CMP_NLG_F16_e64, AMDGPU::V_CMP_NLG_F16_t16_e64,
                  AMDGPU::V_CMP_NLG_F32_e64, AMDGPU::V_CMP_NLG_F64_e64);
  case CmpInst::FCMP_UGT:
    return Select(AMDGPU::V_CMP_NLE_F16_e64, AMDGPU::V_CMP_NLE_F16_t16_e64,
                  AMDGPU::V_CMP_NLE_F32_e64, AMDGPU::V_CMP_NLE_F64_e64);
  case CmpInst::FCMP_UGE:
    return Select(AMDGPU::V_CMP_NLT_F16_e64, AMDGPU::V_CMP_NLT_F16_t16_e64,
                  AMDGPU::V_CMP_NLT_F32_e64, AMDGPU::V_CMP_NLT_F64_e64);
  case CmpInst::FCMP_ULT:
    return Select(AMDGPU::V_CMP_NGE_F16_e64, AMDGPU::V_CMP_NGE_F16_t16_e64,
                  AMDGPU::V_CMP_NGE_F32_e64, AMDGPU::V_CMP_NGE_F64_e64);
  case CmpInst::FCMP_ULE:
    return Select(AMDGPU::V_CMP_NGT_F16_e64, AMDGPU::V_CMP_NGT_F16_t16_e64,
                  AMDGPU::V_CMP_NGT_F32_e64, AMDGPU::V_CMP_NGT_F64_e64);
  case CmpInst::FCMP_UNE:
    return Select(AMDGPU::V_CMP_NEQ_F16_e64, AMDGPU::V_CMP_NEQ_F16_t16_e64,
                  AMDGPU::V_CMP_NEQ_F32_e64, AMDGPU::V_CMP_NEQ_F64_e64);
  case CmpInst::FCMP_TRUE:
    return Select(AMDGPU::V_CMP_TRU_F16_e64, AMDGPU::V_CMP_TRU_F16_t16_e64,
                  AMDGPU::V_CMP_TRU_F32_e64, AMDGPU::V_CMP_TRU_F64_e64);
  case CmpInst::FCMP_FALSE:
    return Select(AMDGPU::V_CMP_F_F16_e64, AMDGPU::V_CMP_F_F16_t16_e64,
                  AMDGPU::V_CMP_F_F32_e64, AMDGPU::V_CMP_F_F64_e64);
  }
}
 
int AMDGPUInstructionSelector::getS_CMPOpcode(CmpInst::Predicate P,
                                              unsigned Size) const {
  if (Size == 64) {
    if (!STI.hasScalarCompareEq64())
      return -1;
 
    switch (P) {
    case CmpInst::ICMP_NE:
      return AMDGPU::S_CMP_LG_U64;
    case CmpInst::ICMP_EQ:
      return AMDGPU::S_CMP_EQ_U64;
    default:
      return -1;
    }
  }
 
  if (Size == 32) {
    switch (P) {
    case CmpInst::ICMP_NE:
      return AMDGPU::S_CMP_LG_U32;
    case CmpInst::ICMP_EQ:
      return AMDGPU::S_CMP_EQ_U32;
    case CmpInst::ICMP_SGT:
      return AMDGPU::S_CMP_GT_I32;
    case CmpInst::ICMP_SGE:
      return AMDGPU::S_CMP_GE_I32;
    case CmpInst::ICMP_SLT:
      return AMDGPU::S_CMP_LT_I32;
    case CmpInst::ICMP_SLE:
      return AMDGPU::S_CMP_LE_I32;
    case CmpInst::ICMP_UGT:
      return AMDGPU::S_CMP_GT_U32;
    case CmpInst::ICMP_UGE:
      return AMDGPU::S_CMP_GE_U32;
    case CmpInst::ICMP_ULT:
      return AMDGPU::S_CMP_LT_U32;
    case CmpInst::ICMP_ULE:
      return AMDGPU::S_CMP_LE_U32;
    case CmpInst::FCMP_OEQ:
      return AMDGPU::S_CMP_EQ_F32;
    case CmpInst::FCMP_OGT:
      return AMDGPU::S_CMP_GT_F32;
    case CmpInst::FCMP_OGE:
      return AMDGPU::S_CMP_GE_F32;
    case CmpInst::FCMP_OLT:
      return AMDGPU::S_CMP_LT_F32;
    case CmpInst::FCMP_OLE:
      return AMDGPU::S_CMP_LE_F32;
    case CmpInst::FCMP_ONE:
      return AMDGPU::S_CMP_LG_F32;
    case CmpInst::FCMP_ORD:
      return AMDGPU::S_CMP_O_F32;
    case CmpInst::FCMP_UNO:
      return AMDGPU::S_CMP_U_F32;
    case CmpInst::FCMP_UEQ:
      return AMDGPU::S_CMP_NLG_F32;
    case CmpInst::FCMP_UGT:
      return AMDGPU::S_CMP_NLE_F32;
    case CmpInst::FCMP_UGE:
      return AMDGPU::S_CMP_NLT_F32;
    case CmpInst::FCMP_ULT:
      return AMDGPU::S_CMP_NGE_F32;
    case CmpInst::FCMP_ULE:
      return AMDGPU::S_CMP_NGT_F32;
    case CmpInst::FCMP_UNE:
      return AMDGPU::S_CMP_NEQ_F32;
    default:
      llvm_unreachable("Unknown condition code!");
    }
  }
 
  if (Size == 16) {
    if (!STI.hasSALUFloatInsts())
      return -1;
 
    switch (P) {
    case CmpInst::FCMP_OEQ:
      return AMDGPU::S_CMP_EQ_F16;
    case CmpInst::FCMP_OGT:
      return AMDGPU::S_CMP_GT_F16;
    case CmpInst::FCMP_OGE:
      return AMDGPU::S_CMP_GE_F16;
    case CmpInst::FCMP_OLT:
      return AMDGPU::S_CMP_LT_F16;
    case CmpInst::FCMP_OLE:
      return AMDGPU::S_CMP_LE_F16;
    case CmpInst::FCMP_ONE:
      return AMDGPU::S_CMP_LG_F16;
    case CmpInst::FCMP_ORD:
      return AMDGPU::S_CMP_O_F16;
    case CmpInst::FCMP_UNO:
      return AMDGPU::S_CMP_U_F16;
    case CmpInst::FCMP_UEQ:
      return AMDGPU::S_CMP_NLG_F16;
    case CmpInst::FCMP_UGT:
      return AMDGPU::S_CMP_NLE_F16;
    case CmpInst::FCMP_UGE:
      return AMDGPU::S_CMP_NLT_F16;
    case CmpInst::FCMP_ULT:
      return AMDGPU::S_CMP_NGE_F16;
    case CmpInst::FCMP_ULE:
      return AMDGPU::S_CMP_NGT_F16;
    case CmpInst::FCMP_UNE:
      return AMDGPU::S_CMP_NEQ_F16;
    default:
      llvm_unreachable("Unknown condition code!");
    }
  }
 
  return -1;
}
 
bool AMDGPUInstructionSelector::selectG_ICMP_or_FCMP(MachineInstr &I) const {
 
  MachineBasicBlock *BB = I.getParent();
  const DebugLoc &DL = I.getDebugLoc();
 
  Register SrcReg = I.getOperand(2).getReg();
  unsigned Size = RBI.getSizeInBits(SrcReg, *MRI, TRI);
 
  auto Pred = (CmpInst::Predicate)I.getOperand(1).getPredicate();
 
  Register CCReg = I.getOperand(0).getReg();
  if (!isVCC(CCReg, *MRI)) {
    int Opcode = getS_CMPOpcode(Pred, Size);
    if (Opcode == -1)
      return false;
    MachineInstr *ICmp = BuildMI(*BB, &I, DL, TII.get(Opcode))
            .add(I.getOperand(2))
            .add(I.getOperand(3));
    BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), CCReg)
      .addReg(AMDGPU::SCC);
    bool Ret =
        constrainSelectedInstRegOperands(*ICmp, TII, TRI, RBI) &&
        RBI.constrainGenericRegister(CCReg, AMDGPU::SReg_32RegClass, *MRI);
    I.eraseFromParent();
    return Ret;
  }
 
  if (I.getOpcode() == AMDGPU::G_FCMP)
    return false;
 
  int Opcode = getV_CMPOpcode(Pred, Size, *Subtarget);
  if (Opcode == -1)
    return false;
 
  MachineInstr *ICmp = BuildMI(*BB, &I, DL, TII.get(Opcode),
            I.getOperand(0).getReg())
            .add(I.getOperand(2))
            .add(I.getOperand(3));
  RBI.constrainGenericRegister(ICmp->getOperand(0).getReg(),
                               *TRI.getBoolRC(), *MRI);
  bool Ret = constrainSelectedInstRegOperands(*ICmp, TII, TRI, RBI);
  I.eraseFromParent();
  return Ret;
}
 
bool AMDGPUInstructionSelector::selectIntrinsicCmp(MachineInstr &I) const {
  Register Dst = I.getOperand(0).getReg();
  if (isVCC(Dst, *MRI))
    return false;
 
  LLT DstTy = MRI->getType(Dst);
  if (DstTy.getSizeInBits() != STI.getWavefrontSize())
    return false;
 
  MachineBasicBlock *BB = I.getParent();
  const DebugLoc &DL = I.getDebugLoc();
  Register SrcReg = I.getOperand(2).getReg();
  unsigned Size = RBI.getSizeInBits(SrcReg, *MRI, TRI);
 
  // i1 inputs are not supported in GlobalISel.
  if (Size == 1)
    return false;
 
  auto Pred = static_cast<CmpInst::Predicate>(I.getOperand(4).getImm());
  if (!CmpInst::isIntPredicate(Pred) && !CmpInst::isFPPredicate(Pred)) {
    BuildMI(*BB, &I, DL, TII.get(AMDGPU::IMPLICIT_DEF), Dst);
    I.eraseFromParent();
    return RBI.constrainGenericRegister(Dst, *TRI.getBoolRC(), *MRI);
  }
 
  const int Opcode = getV_CMPOpcode(Pred, Size, *Subtarget);
  if (Opcode == -1)
    return false;
 
  MachineInstrBuilder SelectedMI;
  MachineOperand &LHS = I.getOperand(2);
  MachineOperand &RHS = I.getOperand(3);
  auto [Src0, Src0Mods] = selectVOP3ModsImpl(LHS);
  auto [Src1, Src1Mods] = selectVOP3ModsImpl(RHS);
  Register Src0Reg =
      copyToVGPRIfSrcFolded(Src0, Src0Mods, LHS, &I, /*ForceVGPR*/ true);
  Register Src1Reg =
      copyToVGPRIfSrcFolded(Src1, Src1Mods, RHS, &I, /*ForceVGPR*/ true);
  SelectedMI = BuildMI(*BB, &I, DL, TII.get(Opcode), Dst);
  if (AMDGPU::hasNamedOperand(Opcode, AMDGPU::OpName::src0_modifiers))
    SelectedMI.addImm(Src0Mods);
  SelectedMI.addReg(Src0Reg);
  if (AMDGPU::hasNamedOperand(Opcode, AMDGPU::OpName::src1_modifiers))
    SelectedMI.addImm(Src1Mods);
  SelectedMI.addReg(Src1Reg);
  if (AMDGPU::hasNamedOperand(Opcode, AMDGPU::OpName::clamp))
    SelectedMI.addImm(0); // clamp
  if (AMDGPU::hasNamedOperand(Opcode, AMDGPU::OpName::op_sel))
    SelectedMI.addImm(0); // op_sel
 
  RBI.constrainGenericRegister(Dst, *TRI.getBoolRC(), *MRI);
  if (!constrainSelectedInstRegOperands(*SelectedMI, TII, TRI, RBI))
    return false;
 
  I.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectBallot(MachineInstr &I) const {
  MachineBasicBlock *BB = I.getParent();
  const DebugLoc &DL = I.getDebugLoc();
  Register DstReg = I.getOperand(0).getReg();
  const unsigned Size = MRI->getType(DstReg).getSizeInBits();
  const bool Is64 = Size == 64;
  const bool IsWave32 = (STI.getWavefrontSize() == 32);
 
  // In the common case, the return type matches the wave size.
  // However we also support emitting i64 ballots in wave32 mode.
  if (Size != STI.getWavefrontSize() && (!Is64 || !IsWave32))
    return false;
 
  std::optional<ValueAndVReg> Arg =
      getIConstantVRegValWithLookThrough(I.getOperand(2).getReg(), *MRI);
 
  const auto BuildCopy = [&](Register SrcReg) {
    if (Size == STI.getWavefrontSize()) {
      BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), DstReg)
          .addReg(SrcReg);
      return;
    }
 
    // If emitting a i64 ballot in wave32, fill the upper bits with zeroes.
    Register HiReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
    BuildMI(*BB, &I, DL, TII.get(AMDGPU::S_MOV_B32), HiReg).addImm(0);
    BuildMI(*BB, &I, DL, TII.get(AMDGPU::REG_SEQUENCE), DstReg)
        .addReg(SrcReg)
        .addImm(AMDGPU::sub0)
        .addReg(HiReg)
        .addImm(AMDGPU::sub1);
  };
 
  if (Arg) {
    const int64_t Value = Arg->Value.getSExtValue();
    if (Value == 0) {
      unsigned Opcode = Is64 ? AMDGPU::S_MOV_B64 : AMDGPU::S_MOV_B32;
      BuildMI(*BB, &I, DL, TII.get(Opcode), DstReg).addImm(0);
    } else if (Value == -1) // all ones
      BuildCopy(IsWave32 ? AMDGPU::EXEC_LO : AMDGPU::EXEC);
    else
      return false;
  } else
    BuildCopy(I.getOperand(2).getReg());
 
  I.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectRelocConstant(MachineInstr &I) const {
  Register DstReg = I.getOperand(0).getReg();
  const RegisterBank *DstBank = RBI.getRegBank(DstReg, *MRI, TRI);
  const TargetRegisterClass *DstRC = TRI.getRegClassForSizeOnBank(32, *DstBank);
  if (!DstRC || !RBI.constrainGenericRegister(DstReg, *DstRC, *MRI))
    return false;
 
  const bool IsVALU = DstBank->getID() == AMDGPU::VGPRRegBankID;
 
  Module *M = MF->getFunction().getParent();
  const MDNode *Metadata = I.getOperand(2).getMetadata();
  auto SymbolName = cast<MDString>(Metadata->getOperand(0))->getString();
  auto RelocSymbol = cast<GlobalVariable>(
    M->getOrInsertGlobal(SymbolName, Type::getInt32Ty(M->getContext())));
 
  MachineBasicBlock *BB = I.getParent();
  BuildMI(*BB, &I, I.getDebugLoc(),
          TII.get(IsVALU ? AMDGPU::V_MOV_B32_e32 : AMDGPU::S_MOV_B32), DstReg)
    .addGlobalAddress(RelocSymbol, 0, SIInstrInfo::MO_ABS32_LO);
 
  I.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectGroupStaticSize(MachineInstr &I) const {
  Triple::OSType OS = MF->getTarget().getTargetTriple().getOS();
 
  Register DstReg = I.getOperand(0).getReg();
  const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
  unsigned Mov = DstRB->getID() == AMDGPU::SGPRRegBankID ?
    AMDGPU::S_MOV_B32 : AMDGPU::V_MOV_B32_e32;
 
  MachineBasicBlock *MBB = I.getParent();
  const DebugLoc &DL = I.getDebugLoc();
 
  auto MIB = BuildMI(*MBB, &I, DL, TII.get(Mov), DstReg);
 
  if (OS == Triple::AMDHSA || OS == Triple::AMDPAL) {
    const SIMachineFunctionInfo *MFI = MF->getInfo<SIMachineFunctionInfo>();
    MIB.addImm(MFI->getLDSSize());
  } else {
    Module *M = MF->getFunction().getParent();
    const GlobalValue *GV
      = Intrinsic::getDeclaration(M, Intrinsic::amdgcn_groupstaticsize);
    MIB.addGlobalAddress(GV, 0, SIInstrInfo::MO_ABS32_LO);
  }
 
  I.eraseFromParent();
  return constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
}
 
bool AMDGPUInstructionSelector::selectReturnAddress(MachineInstr &I) const {
  MachineBasicBlock *MBB = I.getParent();
  MachineFunction &MF = *MBB->getParent();
  const DebugLoc &DL = I.getDebugLoc();
 
  MachineOperand &Dst = I.getOperand(0);
  Register DstReg = Dst.getReg();
  unsigned Depth = I.getOperand(2).getImm();
 
  const TargetRegisterClass *RC
    = TRI.getConstrainedRegClassForOperand(Dst, *MRI);
  if (!RC->hasSubClassEq(&AMDGPU::SGPR_64RegClass) ||
      !RBI.constrainGenericRegister(DstReg, *RC, *MRI))
    return false;
 
  // Check for kernel and shader functions
  if (Depth != 0 ||
      MF.getInfo<SIMachineFunctionInfo>()->isEntryFunction()) {
    BuildMI(*MBB, &I, DL, TII.get(AMDGPU::S_MOV_B64), DstReg)
      .addImm(0);
    I.eraseFromParent();
    return true;
  }
 
  MachineFrameInfo &MFI = MF.getFrameInfo();
  // There is a call to @llvm.returnaddress in this function
  MFI.setReturnAddressIsTaken(true);
 
  // Get the return address reg and mark it as an implicit live-in
  Register ReturnAddrReg = TRI.getReturnAddressReg(MF);
  Register LiveIn = getFunctionLiveInPhysReg(MF, TII, ReturnAddrReg,
                                             AMDGPU::SReg_64RegClass, DL);
  BuildMI(*MBB, &I, DL, TII.get(AMDGPU::COPY), DstReg)
    .addReg(LiveIn);
  I.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectEndCfIntrinsic(MachineInstr &MI) const {
  // FIXME: Manually selecting to avoid dealing with the SReg_1 trick
  // SelectionDAG uses for wave32 vs wave64.
  MachineBasicBlock *BB = MI.getParent();
  BuildMI(*BB, &MI, MI.getDebugLoc(), TII.get(AMDGPU::SI_END_CF))
      .add(MI.getOperand(1));
 
  Register Reg = MI.getOperand(1).getReg();
  MI.eraseFromParent();
 
  if (!MRI->getRegClassOrNull(Reg))
    MRI->setRegClass(Reg, TRI.getWaveMaskRegClass());
  return true;
}
 
bool AMDGPUInstructionSelector::selectDSOrderedIntrinsic(
  MachineInstr &MI, Intrinsic::ID IntrID) const {
  MachineBasicBlock *MBB = MI.getParent();
  MachineFunction *MF = MBB->getParent();
  const DebugLoc &DL = MI.getDebugLoc();
 
  unsigned IndexOperand = MI.getOperand(7).getImm();
  bool WaveRelease = MI.getOperand(8).getImm() != 0;
  bool WaveDone = MI.getOperand(9).getImm() != 0;
 
  if (WaveDone && !WaveRelease)
    report_fatal_error("ds_ordered_count: wave_done requires wave_release");
 
  unsigned OrderedCountIndex = IndexOperand & 0x3f;
  IndexOperand &= ~0x3f;
  unsigned CountDw = 0;
 
  if (STI.getGeneration() >= AMDGPUSubtarget::GFX10) {
    CountDw = (IndexOperand >> 24) & 0xf;
    IndexOperand &= ~(0xf << 24);
 
    if (CountDw < 1 || CountDw > 4) {
      report_fatal_error(
        "ds_ordered_count: dword count must be between 1 and 4");
    }
  }
 
  if (IndexOperand)
    report_fatal_error("ds_ordered_count: bad index operand");
 
  unsigned Instruction = IntrID == Intrinsic::amdgcn_ds_ordered_add ? 0 : 1;
  unsigned ShaderType = SIInstrInfo::getDSShaderTypeValue(*MF);
 
  unsigned Offset0 = OrderedCountIndex << 2;
  unsigned Offset1 = WaveRelease | (WaveDone << 1) | (Instruction << 4);
 
  if (STI.getGeneration() >= AMDGPUSubtarget::GFX10)
    Offset1 |= (CountDw - 1) << 6;
 
  if (STI.getGeneration() < AMDGPUSubtarget::GFX11)
    Offset1 |= ShaderType << 2;
 
  unsigned Offset = Offset0 | (Offset1 << 8);
 
  Register M0Val = MI.getOperand(2).getReg();
  BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
    .addReg(M0Val);
 
  Register DstReg = MI.getOperand(0).getReg();
  Register ValReg = MI.getOperand(3).getReg();
  MachineInstrBuilder DS =
    BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::DS_ORDERED_COUNT), DstReg)
      .addReg(ValReg)
      .addImm(Offset)
      .cloneMemRefs(MI);
 
  if (!RBI.constrainGenericRegister(M0Val, AMDGPU::SReg_32RegClass, *MRI))
    return false;
 
  bool Ret = constrainSelectedInstRegOperands(*DS, TII, TRI, RBI);
  MI.eraseFromParent();
  return Ret;
}
 
static unsigned gwsIntrinToOpcode(unsigned IntrID) {
  switch (IntrID) {
  case Intrinsic::amdgcn_ds_gws_init:
    return AMDGPU::DS_GWS_INIT;
  case Intrinsic::amdgcn_ds_gws_barrier:
    return AMDGPU::DS_GWS_BARRIER;
  case Intrinsic::amdgcn_ds_gws_sema_v:
    return AMDGPU::DS_GWS_SEMA_V;
  case Intrinsic::amdgcn_ds_gws_sema_br:
    return AMDGPU::DS_GWS_SEMA_BR;
  case Intrinsic::amdgcn_ds_gws_sema_p:
    return AMDGPU::DS_GWS_SEMA_P;
  case Intrinsic::amdgcn_ds_gws_sema_release_all:
    return AMDGPU::DS_GWS_SEMA_RELEASE_ALL;
  default:
    llvm_unreachable("not a gws intrinsic");
  }
}
 
bool AMDGPUInstructionSelector::selectDSGWSIntrinsic(MachineInstr &MI,
                                                     Intrinsic::ID IID) const {
  if (!STI.hasGWS() || (IID == Intrinsic::amdgcn_ds_gws_sema_release_all &&
                        !STI.hasGWSSemaReleaseAll()))
    return false;
 
  // intrinsic ID, vsrc, offset
  const bool HasVSrc = MI.getNumOperands() == 3;
  assert(HasVSrc || MI.getNumOperands() == 2);
 
  Register BaseOffset = MI.getOperand(HasVSrc ? 2 : 1).getReg();
  const RegisterBank *OffsetRB = RBI.getRegBank(BaseOffset, *MRI, TRI);
  if (OffsetRB->getID() != AMDGPU::SGPRRegBankID)
    return false;
 
  MachineInstr *OffsetDef = getDefIgnoringCopies(BaseOffset, *MRI);
  unsigned ImmOffset;
 
  MachineBasicBlock *MBB = MI.getParent();
  const DebugLoc &DL = MI.getDebugLoc();
 
  MachineInstr *Readfirstlane = nullptr;
 
  // If we legalized the VGPR input, strip out the readfirstlane to analyze the
  // incoming offset, in case there's an add of a constant. We'll have to put it
  // back later.
  if (OffsetDef->getOpcode() == AMDGPU::V_READFIRSTLANE_B32) {
    Readfirstlane = OffsetDef;
    BaseOffset = OffsetDef->getOperand(1).getReg();
    OffsetDef = getDefIgnoringCopies(BaseOffset, *MRI);
  }
 
  if (OffsetDef->getOpcode() == AMDGPU::G_CONSTANT) {
    // If we have a constant offset, try to use the 0 in m0 as the base.
    // TODO: Look into changing the default m0 initialization value. If the
    // default -1 only set the low 16-bits, we could leave it as-is and add 1 to
    // the immediate offset.
 
    ImmOffset = OffsetDef->getOperand(1).getCImm()->getZExtValue();
    BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::S_MOV_B32), AMDGPU::M0)
      .addImm(0);
  } else {
    std::tie(BaseOffset, ImmOffset) =
        AMDGPU::getBaseWithConstantOffset(*MRI, BaseOffset, KB);
 
    if (Readfirstlane) {
      // We have the constant offset now, so put the readfirstlane back on the
      // variable component.
      if (!RBI.constrainGenericRegister(BaseOffset, AMDGPU::VGPR_32RegClass, *MRI))
        return false;
 
      Readfirstlane->getOperand(1).setReg(BaseOffset);
      BaseOffset = Readfirstlane->getOperand(0).getReg();
    } else {
      if (!RBI.constrainGenericRegister(BaseOffset,
                                        AMDGPU::SReg_32RegClass, *MRI))
        return false;
    }
 
    Register M0Base = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
    BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::S_LSHL_B32), M0Base)
      .addReg(BaseOffset)
      .addImm(16)
      .setOperandDead(3); // Dead scc
 
    BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
      .addReg(M0Base);
  }
 
  // The resource id offset is computed as (<isa opaque base> + M0[21:16] +
  // offset field) % 64. Some versions of the programming guide omit the m0
  // part, or claim it's from offset 0.
  auto MIB = BuildMI(*MBB, &MI, DL, TII.get(gwsIntrinToOpcode(IID)));
 
  if (HasVSrc) {
    Register VSrc = MI.getOperand(1).getReg();
    MIB.addReg(VSrc);
 
    if (!RBI.constrainGenericRegister(VSrc, AMDGPU::VGPR_32RegClass, *MRI))
      return false;
  }
 
  MIB.addImm(ImmOffset)
     .cloneMemRefs(MI);
 
  TII.enforceOperandRCAlignment(*MIB, AMDGPU::OpName::data0);
 
  MI.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectDSAppendConsume(MachineInstr &MI,
                                                      bool IsAppend) const {
  Register PtrBase = MI.getOperand(2).getReg();
  LLT PtrTy = MRI->getType(PtrBase);
  bool IsGDS = PtrTy.getAddressSpace() == AMDGPUAS::REGION_ADDRESS;
 
  unsigned Offset;
  std::tie(PtrBase, Offset) = selectDS1Addr1OffsetImpl(MI.getOperand(2));
 
  // TODO: Should this try to look through readfirstlane like GWS?
  if (!isDSOffsetLegal(PtrBase, Offset)) {
    PtrBase = MI.getOperand(2).getReg();
    Offset = 0;
  }
 
  MachineBasicBlock *MBB = MI.getParent();
  const DebugLoc &DL = MI.getDebugLoc();
  const unsigned Opc = IsAppend ? AMDGPU::DS_APPEND : AMDGPU::DS_CONSUME;
 
  BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
    .addReg(PtrBase);
  if (!RBI.constrainGenericRegister(PtrBase, AMDGPU::SReg_32RegClass, *MRI))
    return false;
 
  auto MIB = BuildMI(*MBB, &MI, DL, TII.get(Opc), MI.getOperand(0).getReg())
    .addImm(Offset)
    .addImm(IsGDS ? -1 : 0)
    .cloneMemRefs(MI);
  MI.eraseFromParent();
  return constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
}
 
bool AMDGPUInstructionSelector::selectSBarrier(MachineInstr &MI) const {
  if (TM.getOptLevel() > CodeGenOptLevel::None) {
    unsigned WGSize = STI.getFlatWorkGroupSizes(MF->getFunction()).second;
    if (WGSize <= STI.getWavefrontSize()) {
      MachineBasicBlock *MBB = MI.getParent();
      const DebugLoc &DL = MI.getDebugLoc();
      BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::WAVE_BARRIER));
      MI.eraseFromParent();
      return true;
    }
  }
 
  // On GFX12 lower s_barrier into s_barrier_signal_imm and s_barrier_wait
  if (STI.hasSplitBarriers()) {
    MachineBasicBlock *MBB = MI.getParent();
    const DebugLoc &DL = MI.getDebugLoc();
    BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::S_BARRIER_SIGNAL_IMM))
        .addImm(AMDGPU::Barrier::WORKGROUP);
    BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::S_BARRIER_WAIT))
        .addImm(AMDGPU::Barrier::WORKGROUP);
    MI.eraseFromParent();
    return true;
  }
 
  return selectImpl(MI, *CoverageInfo);
}
 
static bool parseTexFail(uint64_t TexFailCtrl, bool &TFE, bool &LWE,
                         bool &IsTexFail) {
  if (TexFailCtrl)
    IsTexFail = true;
 
  TFE = (TexFailCtrl & 0x1) ? true : false;
  TexFailCtrl &= ~(uint64_t)0x1;
  LWE = (TexFailCtrl & 0x2) ? true : false;
  TexFailCtrl &= ~(uint64_t)0x2;
 
  return TexFailCtrl == 0;
}
 
bool AMDGPUInstructionSelector::selectImageIntrinsic(
  MachineInstr &MI, const AMDGPU::ImageDimIntrinsicInfo *Intr) const {
  MachineBasicBlock *MBB = MI.getParent();
  const DebugLoc &DL = MI.getDebugLoc();
 
  const AMDGPU::MIMGBaseOpcodeInfo *BaseOpcode =
    AMDGPU::getMIMGBaseOpcodeInfo(Intr->BaseOpcode);
 
  const AMDGPU::MIMGDimInfo *DimInfo = AMDGPU::getMIMGDimInfo(Intr->Dim);
  unsigned IntrOpcode = Intr->BaseOpcode;
  const bool IsGFX10Plus = AMDGPU::isGFX10Plus(STI);
  const bool IsGFX11Plus = AMDGPU::isGFX11Plus(STI);
  const bool IsGFX12Plus = AMDGPU::isGFX12Plus(STI);
 
  const unsigned ArgOffset = MI.getNumExplicitDefs() + 1;
 
  Register VDataIn, VDataOut;
  LLT VDataTy;
  int NumVDataDwords = -1;
  bool IsD16 = MI.getOpcode() == AMDGPU::G_AMDGPU_INTRIN_IMAGE_LOAD_D16 ||
               MI.getOpcode() == AMDGPU::G_AMDGPU_INTRIN_IMAGE_STORE_D16;
 
  bool Unorm;
  if (!BaseOpcode->Sampler)
    Unorm = true;
  else
    Unorm = MI.getOperand(ArgOffset + Intr->UnormIndex).getImm() != 0;
 
  bool TFE;
  bool LWE;
  bool IsTexFail = false;
  if (!parseTexFail(MI.getOperand(ArgOffset + Intr->TexFailCtrlIndex).getImm(),
                    TFE, LWE, IsTexFail))
    return false;
 
  const int Flags = MI.getOperand(ArgOffset + Intr->NumArgs).getImm();
  const bool IsA16 = (Flags & 1) != 0;
  const bool IsG16 = (Flags & 2) != 0;
 
  // A16 implies 16 bit gradients if subtarget doesn't support G16
  if (IsA16 && !STI.hasG16() && !IsG16)
    return false;
 
  unsigned DMask = 0;
  unsigned DMaskLanes = 0;
 
  if (BaseOpcode->Atomic) {
    VDataOut = MI.getOperand(0).getReg();
    VDataIn = MI.getOperand(2).getReg();
    LLT Ty = MRI->getType(VDataIn);
 
    // Be careful to allow atomic swap on 16-bit element vectors.
    const bool Is64Bit = BaseOpcode->AtomicX2 ?
      Ty.getSizeInBits() == 128 :
      Ty.getSizeInBits() == 64;
 
    if (BaseOpcode->AtomicX2) {
      assert(MI.getOperand(3).getReg() == AMDGPU::NoRegister);
 
      DMask = Is64Bit ? 0xf : 0x3;
      NumVDataDwords = Is64Bit ? 4 : 2;
    } else {
      DMask = Is64Bit ? 0x3 : 0x1;
      NumVDataDwords = Is64Bit ? 2 : 1;
    }
  } else {
    DMask = MI.getOperand(ArgOffset + Intr->DMaskIndex).getImm();
    DMaskLanes = BaseOpcode->Gather4 ? 4 : llvm::popcount(DMask);
 
    if (BaseOpcode->Store) {
      VDataIn = MI.getOperand(1).getReg();
      VDataTy = MRI->getType(VDataIn);
      NumVDataDwords = (VDataTy.getSizeInBits() + 31) / 32;
    } else if (BaseOpcode->NoReturn) {
      NumVDataDwords = 0;
    } else {
      VDataOut = MI.getOperand(0).getReg();
      VDataTy = MRI->getType(VDataOut);
      NumVDataDwords = DMaskLanes;
 
      if (IsD16 && !STI.hasUnpackedD16VMem())
        NumVDataDwords = (DMaskLanes + 1) / 2;
    }
  }
 
  // Set G16 opcode
  if (Subtarget->hasG16() && IsG16) {
    const AMDGPU::MIMGG16MappingInfo *G16MappingInfo =
        AMDGPU::getMIMGG16MappingInfo(Intr->BaseOpcode);
    assert(G16MappingInfo);
    IntrOpcode = G16MappingInfo->G16; // set opcode to variant with _g16
  }
 
  // TODO: Check this in verifier.
  assert((!IsTexFail || DMaskLanes >= 1) && "should have legalized this");
 
  unsigned CPol = MI.getOperand(ArgOffset + Intr->CachePolicyIndex).getImm();
  if (BaseOpcode->Atomic)
    CPol |= AMDGPU::CPol::GLC; // TODO no-return optimization
  if (CPol & ~((IsGFX12Plus ? AMDGPU::CPol::ALL : AMDGPU::CPol::ALL_pregfx12) |
               AMDGPU::CPol::VOLATILE))
    return false;
 
  int NumVAddrRegs = 0;
  int NumVAddrDwords = 0;
  for (unsigned I = Intr->VAddrStart; I < Intr->VAddrEnd; I++) {
    // Skip the $noregs and 0s inserted during legalization.
    MachineOperand &AddrOp = MI.getOperand(ArgOffset + I);
    if (!AddrOp.isReg())
      continue; // XXX - Break?
 
    Register Addr = AddrOp.getReg();
    if (!Addr)
      break;
 
    ++NumVAddrRegs;
    NumVAddrDwords += (MRI->getType(Addr).getSizeInBits() + 31) / 32;
  }
 
  // The legalizer preprocessed the intrinsic arguments. If we aren't using
  // NSA, these should have been packed into a single value in the first
  // address register
  const bool UseNSA =
      NumVAddrRegs != 1 &&
      (STI.hasPartialNSAEncoding() ? NumVAddrDwords >= NumVAddrRegs
                                   : NumVAddrDwords == NumVAddrRegs);
  if (UseNSA && !STI.hasFeature(AMDGPU::FeatureNSAEncoding)) {
    LLVM_DEBUG(dbgs() << "Trying to use NSA on non-NSA target\n");
    return false;
  }
 
  if (IsTexFail)
    ++NumVDataDwords;
 
  int Opcode = -1;
  if (IsGFX12Plus) {
    Opcode = AMDGPU::getMIMGOpcode(IntrOpcode, AMDGPU::MIMGEncGfx12,
                                   NumVDataDwords, NumVAddrDwords);
  } else if (IsGFX11Plus) {
    Opcode = AMDGPU::getMIMGOpcode(IntrOpcode,
                                   UseNSA ? AMDGPU::MIMGEncGfx11NSA
                                          : AMDGPU::MIMGEncGfx11Default,
                                   NumVDataDwords, NumVAddrDwords);
  } else if (IsGFX10Plus) {
    Opcode = AMDGPU::getMIMGOpcode(IntrOpcode,
                                   UseNSA ? AMDGPU::MIMGEncGfx10NSA
                                          : AMDGPU::MIMGEncGfx10Default,
                                   NumVDataDwords, NumVAddrDwords);
  } else {
    if (Subtarget->hasGFX90AInsts()) {
      Opcode = AMDGPU::getMIMGOpcode(IntrOpcode, AMDGPU::MIMGEncGfx90a,
                                     NumVDataDwords, NumVAddrDwords);
      if (Opcode == -1) {
        LLVM_DEBUG(
            dbgs()
            << "requested image instruction is not supported on this GPU\n");
        return false;
      }
    }
    if (Opcode == -1 &&
        STI.getGeneration() >= AMDGPUSubtarget::VOLCANIC_ISLANDS)
      Opcode = AMDGPU::getMIMGOpcode(IntrOpcode, AMDGPU::MIMGEncGfx8,
                                     NumVDataDwords, NumVAddrDwords);
    if (Opcode == -1)
      Opcode = AMDGPU::getMIMGOpcode(IntrOpcode, AMDGPU::MIMGEncGfx6,
                                     NumVDataDwords, NumVAddrDwords);
  }
  if (Opcode == -1)
    return false;
 
  auto MIB = BuildMI(*MBB, &MI, DL, TII.get(Opcode))
    .cloneMemRefs(MI);
 
  if (VDataOut) {
    if (BaseOpcode->AtomicX2) {
      const bool Is64 = MRI->getType(VDataOut).getSizeInBits() == 64;
 
      Register TmpReg = MRI->createVirtualRegister(
        Is64 ? &AMDGPU::VReg_128RegClass : &AMDGPU::VReg_64RegClass);
      unsigned SubReg = Is64 ? AMDGPU::sub0_sub1 : AMDGPU::sub0;
 
      MIB.addDef(TmpReg);
      if (!MRI->use_empty(VDataOut)) {
        BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::COPY), VDataOut)
            .addReg(TmpReg, RegState::Kill, SubReg);
      }
 
    } else {
      MIB.addDef(VDataOut); // vdata output
    }
  }
 
  if (VDataIn)
    MIB.addReg(VDataIn); // vdata input
 
  for (int I = 0; I != NumVAddrRegs; ++I) {
    MachineOperand &SrcOp = MI.getOperand(ArgOffset + Intr->VAddrStart + I);
    if (SrcOp.isReg()) {
      assert(SrcOp.getReg() != 0);
      MIB.addReg(SrcOp.getReg());
    }
  }
 
  MIB.addReg(MI.getOperand(ArgOffset + Intr->RsrcIndex).getReg());
  if (BaseOpcode->Sampler)
    MIB.addReg(MI.getOperand(ArgOffset + Intr->SampIndex).getReg());
 
  MIB.addImm(DMask); // dmask
 
  if (IsGFX10Plus)
    MIB.addImm(DimInfo->Encoding);
  if (AMDGPU::hasNamedOperand(Opcode, AMDGPU::OpName::unorm))
    MIB.addImm(Unorm);
 
  MIB.addImm(CPol);
  MIB.addImm(IsA16 &&  // a16 or r128
             STI.hasFeature(AMDGPU::FeatureR128A16) ? -1 : 0);
  if (IsGFX10Plus)
    MIB.addImm(IsA16 ? -1 : 0);
 
  if (!Subtarget->hasGFX90AInsts()) {
    MIB.addImm(TFE); // tfe
  } else if (TFE) {
    LLVM_DEBUG(dbgs() << "TFE is not supported on this GPU\n");
    return false;
  }
 
  if (AMDGPU::hasNamedOperand(Opcode, AMDGPU::OpName::lwe))
    MIB.addImm(LWE); // lwe
  if (!IsGFX10Plus)
    MIB.addImm(DimInfo->DA ? -1 : 0);
  if (BaseOpcode->HasD16)
    MIB.addImm(IsD16 ? -1 : 0);
 
  MI.eraseFromParent();
  constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
  TII.enforceOperandRCAlignment(*MIB, AMDGPU::OpName::vaddr);
  return true;
}
 
// We need to handle this here because tablegen doesn't support matching
// instructions with multiple outputs.
bool AMDGPUInstructionSelector::selectDSBvhStackIntrinsic(
    MachineInstr &MI) const {
  Register Dst0 = MI.getOperand(0).getReg();
  Register Dst1 = MI.getOperand(1).getReg();
 
  const DebugLoc &DL = MI.getDebugLoc();
  MachineBasicBlock *MBB = MI.getParent();
 
  Register Addr = MI.getOperand(3).getReg();
  Register Data0 = MI.getOperand(4).getReg();
  Register Data1 = MI.getOperand(5).getReg();
  unsigned Offset = MI.getOperand(6).getImm();
 
  auto MIB = BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::DS_BVH_STACK_RTN_B32), Dst0)
                 .addDef(Dst1)
                 .addUse(Addr)
                 .addUse(Data0)
                 .addUse(Data1)
                 .addImm(Offset)
                 .cloneMemRefs(MI);
 
  MI.eraseFromParent();
  return constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
}
 
bool AMDGPUInstructionSelector::selectG_INTRINSIC_W_SIDE_EFFECTS(
    MachineInstr &I) const {
  Intrinsic::ID IntrinsicID = cast<GIntrinsic>(I).getIntrinsicID();
  switch (IntrinsicID) {
  case Intrinsic::amdgcn_end_cf:
    return selectEndCfIntrinsic(I);
  case Intrinsic::amdgcn_ds_ordered_add:
  case Intrinsic::amdgcn_ds_ordered_swap:
    return selectDSOrderedIntrinsic(I, IntrinsicID);
  case Intrinsic::amdgcn_ds_gws_init:
  case Intrinsic::amdgcn_ds_gws_barrier:
  case Intrinsic::amdgcn_ds_gws_sema_v:
  case Intrinsic::amdgcn_ds_gws_sema_br:
  case Intrinsic::amdgcn_ds_gws_sema_p:
  case Intrinsic::amdgcn_ds_gws_sema_release_all:
    return selectDSGWSIntrinsic(I, IntrinsicID);
  case Intrinsic::amdgcn_ds_append:
    return selectDSAppendConsume(I, true);
  case Intrinsic::amdgcn_ds_consume:
    return selectDSAppendConsume(I, false);
  case Intrinsic::amdgcn_s_barrier:
    return selectSBarrier(I);
  case Intrinsic::amdgcn_raw_buffer_load_lds:
  case Intrinsic::amdgcn_raw_ptr_buffer_load_lds:
  case Intrinsic::amdgcn_struct_buffer_load_lds:
  case Intrinsic::amdgcn_struct_ptr_buffer_load_lds:
    return selectBufferLoadLds(I);
  case Intrinsic::amdgcn_global_load_lds:
    return selectGlobalLoadLds(I);
  case Intrinsic::amdgcn_exp_compr:
    if (!STI.hasCompressedExport()) {
      Function &F = I.getMF()->getFunction();
      DiagnosticInfoUnsupported NoFpRet(
          F, "intrinsic not supported on subtarget", I.getDebugLoc(), DS_Error);
      F.getContext().diagnose(NoFpRet);
      return false;
    }
    break;
  case Intrinsic::amdgcn_ds_bvh_stack_rtn:
    return selectDSBvhStackIntrinsic(I);
  case Intrinsic::amdgcn_s_barrier_init:
  case Intrinsic::amdgcn_s_barrier_join:
  case Intrinsic::amdgcn_s_wakeup_barrier:
  case Intrinsic::amdgcn_s_get_barrier_state:
    return selectNamedBarrierInst(I, IntrinsicID);
  case Intrinsic::amdgcn_s_barrier_signal_isfirst:
  case Intrinsic::amdgcn_s_barrier_signal_isfirst_var:
    return selectSBarrierSignalIsfirst(I, IntrinsicID);
  case Intrinsic::amdgcn_s_barrier_leave:
    return selectSBarrierLeave(I);
  }
  return selectImpl(I, *CoverageInfo);
}
 
bool AMDGPUInstructionSelector::selectG_SELECT(MachineInstr &I) const {
  if (selectImpl(I, *CoverageInfo))
    return true;
 
  MachineBasicBlock *BB = I.getParent();
  const DebugLoc &DL = I.getDebugLoc();
 
  Register DstReg = I.getOperand(0).getReg();
  unsigned Size = RBI.getSizeInBits(DstReg, *MRI, TRI);
  assert(Size <= 32 || Size == 64);
  const MachineOperand &CCOp = I.getOperand(1);
  Register CCReg = CCOp.getReg();
  if (!isVCC(CCReg, *MRI)) {
    unsigned SelectOpcode = Size == 64 ? AMDGPU::S_CSELECT_B64 :
                                         AMDGPU::S_CSELECT_B32;
    MachineInstr *CopySCC = BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), AMDGPU::SCC)
            .addReg(CCReg);
 
    // The generic constrainSelectedInstRegOperands doesn't work for the scc register
    // bank, because it does not cover the register class that we used to represent
    // for it.  So we need to manually set the register class here.
    if (!MRI->getRegClassOrNull(CCReg))
        MRI->setRegClass(CCReg, TRI.getConstrainedRegClassForOperand(CCOp, *MRI));
    MachineInstr *Select = BuildMI(*BB, &I, DL, TII.get(SelectOpcode), DstReg)
            .add(I.getOperand(2))
            .add(I.getOperand(3));
 
    bool Ret = false;
    Ret |= constrainSelectedInstRegOperands(*Select, TII, TRI, RBI);
    Ret |= constrainSelectedInstRegOperands(*CopySCC, TII, TRI, RBI);
    I.eraseFromParent();
    return Ret;
  }
 
  // Wide VGPR select should have been split in RegBankSelect.
  if (Size > 32)
    return false;
 
  MachineInstr *Select =
      BuildMI(*BB, &I, DL, TII.get(AMDGPU::V_CNDMASK_B32_e64), DstReg)
              .addImm(0)
              .add(I.getOperand(3))
              .addImm(0)
              .add(I.getOperand(2))
              .add(I.getOperand(1));
 
  bool Ret = constrainSelectedInstRegOperands(*Select, TII, TRI, RBI);
  I.eraseFromParent();
  return Ret;
}
 
static int sizeToSubRegIndex(unsigned Size) {
  switch (Size) {
  case 32:
    return AMDGPU::sub0;
  case 64:
    return AMDGPU::sub0_sub1;
  case 96:
    return AMDGPU::sub0_sub1_sub2;
  case 128:
    return AMDGPU::sub0_sub1_sub2_sub3;
  case 256:
    return AMDGPU::sub0_sub1_sub2_sub3_sub4_sub5_sub6_sub7;
  default:
    if (Size < 32)
      return AMDGPU::sub0;
    if (Size > 256)
      return -1;
    return sizeToSubRegIndex(llvm::bit_ceil(Size));
  }
}
 
bool AMDGPUInstructionSelector::selectG_TRUNC(MachineInstr &I) const {
  Register DstReg = I.getOperand(0).getReg();
  Register SrcReg = I.getOperand(1).getReg();
  const LLT DstTy = MRI->getType(DstReg);
  const LLT SrcTy = MRI->getType(SrcReg);
  const LLT S1 = LLT::scalar(1);
 
  const RegisterBank *SrcRB = RBI.getRegBank(SrcReg, *MRI, TRI);
  const RegisterBank *DstRB;
  if (DstTy == S1) {
    // This is a special case. We don't treat s1 for legalization artifacts as
    // vcc booleans.
    DstRB = SrcRB;
  } else {
    DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
    if (SrcRB != DstRB)
      return false;
  }
 
  const bool IsVALU = DstRB->getID() == AMDGPU::VGPRRegBankID;
 
  unsigned DstSize = DstTy.getSizeInBits();
  unsigned SrcSize = SrcTy.getSizeInBits();
 
  const TargetRegisterClass *SrcRC =
      TRI.getRegClassForSizeOnBank(SrcSize, *SrcRB);
  const TargetRegisterClass *DstRC =
      TRI.getRegClassForSizeOnBank(DstSize, *DstRB);
  if (!SrcRC || !DstRC)
    return false;
 
  if (!RBI.constrainGenericRegister(SrcReg, *SrcRC, *MRI) ||
      !RBI.constrainGenericRegister(DstReg, *DstRC, *MRI)) {
    LLVM_DEBUG(dbgs() << "Failed to constrain G_TRUNC\n");
    return false;
  }
 
  if (DstTy == LLT::fixed_vector(2, 16) && SrcTy == LLT::fixed_vector(2, 32)) {
    MachineBasicBlock *MBB = I.getParent();
    const DebugLoc &DL = I.getDebugLoc();
 
    Register LoReg = MRI->createVirtualRegister(DstRC);
    Register HiReg = MRI->createVirtualRegister(DstRC);
    BuildMI(*MBB, I, DL, TII.get(AMDGPU::COPY), LoReg)
      .addReg(SrcReg, 0, AMDGPU::sub0);
    BuildMI(*MBB, I, DL, TII.get(AMDGPU::COPY), HiReg)
      .addReg(SrcReg, 0, AMDGPU::sub1);
 
    if (IsVALU && STI.hasSDWA()) {
      // Write the low 16-bits of the high element into the high 16-bits of the
      // low element.
      MachineInstr *MovSDWA =
        BuildMI(*MBB, I, DL, TII.get(AMDGPU::V_MOV_B32_sdwa), DstReg)
        .addImm(0)                             // $src0_modifiers
        .addReg(HiReg)                         // $src0
        .addImm(0)                             // $clamp
        .addImm(AMDGPU::SDWA::WORD_1)          // $dst_sel
        .addImm(AMDGPU::SDWA::UNUSED_PRESERVE) // $dst_unused
        .addImm(AMDGPU::SDWA::WORD_0)          // $src0_sel
        .addReg(LoReg, RegState::Implicit);
      MovSDWA->tieOperands(0, MovSDWA->getNumOperands() - 1);
    } else {
      Register TmpReg0 = MRI->createVirtualRegister(DstRC);
      Register TmpReg1 = MRI->createVirtualRegister(DstRC);
      Register ImmReg = MRI->createVirtualRegister(DstRC);
      if (IsVALU) {
        BuildMI(*MBB, I, DL, TII.get(AMDGPU::V_LSHLREV_B32_e64), TmpReg0)
          .addImm(16)
          .addReg(HiReg);
      } else {
        BuildMI(*MBB, I, DL, TII.get(AMDGPU::S_LSHL_B32), TmpReg0)
          .addReg(HiReg)
          .addImm(16)
          .setOperandDead(3); // Dead scc
      }
 
      unsigned MovOpc = IsVALU ? AMDGPU::V_MOV_B32_e32 : AMDGPU::S_MOV_B32;
      unsigned AndOpc = IsVALU ? AMDGPU::V_AND_B32_e64 : AMDGPU::S_AND_B32;
      unsigned OrOpc = IsVALU ? AMDGPU::V_OR_B32_e64 : AMDGPU::S_OR_B32;
 
      BuildMI(*MBB, I, DL, TII.get(MovOpc), ImmReg)
        .addImm(0xffff);
      auto And = BuildMI(*MBB, I, DL, TII.get(AndOpc), TmpReg1)
        .addReg(LoReg)
        .addReg(ImmReg);
      auto Or = BuildMI(*MBB, I, DL, TII.get(OrOpc), DstReg)
        .addReg(TmpReg0)
        .addReg(TmpReg1);
 
      if (!IsVALU) {
        And.setOperandDead(3); // Dead scc
        Or.setOperandDead(3); // Dead scc
      }
    }
 
    I.eraseFromParent();
    return true;
  }
 
  if (!DstTy.isScalar())
    return false;
 
  if (SrcSize > 32) {
    int SubRegIdx = sizeToSubRegIndex(DstSize);
    if (SubRegIdx == -1)
      return false;
 
    // Deal with weird cases where the class only partially supports the subreg
    // index.
    const TargetRegisterClass *SrcWithSubRC
      = TRI.getSubClassWithSubReg(SrcRC, SubRegIdx);
    if (!SrcWithSubRC)
      return false;
 
    if (SrcWithSubRC != SrcRC) {
      if (!RBI.constrainGenericRegister(SrcReg, *SrcWithSubRC, *MRI))
        return false;
    }
 
    I.getOperand(1).setSubReg(SubRegIdx);
  }
 
  I.setDesc(TII.get(TargetOpcode::COPY));
  return true;
}
 
/// \returns true if a bitmask for \p Size bits will be an inline immediate.
static bool shouldUseAndMask(unsigned Size, unsigned &Mask) {
  Mask = maskTrailingOnes<unsigned>(Size);
  int SignedMask = static_cast<int>(Mask);
  return SignedMask >= -16 && SignedMask <= 64;
}
 
// Like RegisterBankInfo::getRegBank, but don't assume vcc for s1.
const RegisterBank *AMDGPUInstructionSelector::getArtifactRegBank(
  Register Reg, const MachineRegisterInfo &MRI,
  const TargetRegisterInfo &TRI) const {
  const RegClassOrRegBank &RegClassOrBank = MRI.getRegClassOrRegBank(Reg);
  if (auto *RB = RegClassOrBank.dyn_cast<const RegisterBank *>())
    return RB;
 
  // Ignore the type, since we don't use vcc in artifacts.
  if (auto *RC = RegClassOrBank.dyn_cast<const TargetRegisterClass *>())
    return &RBI.getRegBankFromRegClass(*RC, LLT());
  return nullptr;
}
 
bool AMDGPUInstructionSelector::selectG_SZA_EXT(MachineInstr &I) const {
  bool InReg = I.getOpcode() == AMDGPU::G_SEXT_INREG;
  bool Signed = I.getOpcode() == AMDGPU::G_SEXT || InReg;
  const DebugLoc &DL = I.getDebugLoc();
  MachineBasicBlock &MBB = *I.getParent();
  const Register DstReg = I.getOperand(0).getReg();
  const Register SrcReg = I.getOperand(1).getReg();
 
  const LLT DstTy = MRI->getType(DstReg);
  const LLT SrcTy = MRI->getType(SrcReg);
  const unsigned SrcSize = I.getOpcode() == AMDGPU::G_SEXT_INREG ?
    I.getOperand(2).getImm() : SrcTy.getSizeInBits();
  const unsigned DstSize = DstTy.getSizeInBits();
  if (!DstTy.isScalar())
    return false;
 
  // Artifact casts should never use vcc.
  const RegisterBank *SrcBank = getArtifactRegBank(SrcReg, *MRI, TRI);
 
  // FIXME: This should probably be illegal and split earlier.
  if (I.getOpcode() == AMDGPU::G_ANYEXT) {
    if (DstSize <= 32)
      return selectCOPY(I);
 
    const TargetRegisterClass *SrcRC =
        TRI.getRegClassForTypeOnBank(SrcTy, *SrcBank);
    const RegisterBank *DstBank = RBI.getRegBank(DstReg, *MRI, TRI);
    const TargetRegisterClass *DstRC =
        TRI.getRegClassForSizeOnBank(DstSize, *DstBank);
 
    Register UndefReg = MRI->createVirtualRegister(SrcRC);
    BuildMI(MBB, I, DL, TII.get(AMDGPU::IMPLICIT_DEF), UndefReg);
    BuildMI(MBB, I, DL, TII.get(AMDGPU::REG_SEQUENCE), DstReg)
      .addReg(SrcReg)
      .addImm(AMDGPU::sub0)
      .addReg(UndefReg)
      .addImm(AMDGPU::sub1);
    I.eraseFromParent();
 
    return RBI.constrainGenericRegister(DstReg, *DstRC, *MRI) &&
           RBI.constrainGenericRegister(SrcReg, *SrcRC, *MRI);
  }
 
  if (SrcBank->getID() == AMDGPU::VGPRRegBankID && DstSize <= 32) {
    // 64-bit should have been split up in RegBankSelect
 
    // Try to use an and with a mask if it will save code size.
    unsigned Mask;
    if (!Signed && shouldUseAndMask(SrcSize, Mask)) {
      MachineInstr *ExtI =
      BuildMI(MBB, I, DL, TII.get(AMDGPU::V_AND_B32_e32), DstReg)
        .addImm(Mask)
        .addReg(SrcReg);
      I.eraseFromParent();
      return constrainSelectedInstRegOperands(*ExtI, TII, TRI, RBI);
    }
 
    const unsigned BFE = Signed ? AMDGPU::V_BFE_I32_e64 : AMDGPU::V_BFE_U32_e64;
    MachineInstr *ExtI =
      BuildMI(MBB, I, DL, TII.get(BFE), DstReg)
      .addReg(SrcReg)
      .addImm(0) // Offset
      .addImm(SrcSize); // Width
    I.eraseFromParent();
    return constrainSelectedInstRegOperands(*ExtI, TII, TRI, RBI);
  }
 
  if (SrcBank->getID() == AMDGPU::SGPRRegBankID && DstSize <= 64) {
    const TargetRegisterClass &SrcRC = InReg && DstSize > 32 ?
      AMDGPU::SReg_64RegClass : AMDGPU::SReg_32RegClass;
    if (!RBI.constrainGenericRegister(SrcReg, SrcRC, *MRI))
      return false;
 
    if (Signed && DstSize == 32 && (SrcSize == 8 || SrcSize == 16)) {
      const unsigned SextOpc = SrcSize == 8 ?
        AMDGPU::S_SEXT_I32_I8 : AMDGPU::S_SEXT_I32_I16;
      BuildMI(MBB, I, DL, TII.get(SextOpc), DstReg)
        .addReg(SrcReg);
      I.eraseFromParent();
      return RBI.constrainGenericRegister(DstReg, AMDGPU::SReg_32RegClass, *MRI);
    }
 
    // Using a single 32-bit SALU to calculate the high half is smaller than
    // S_BFE with a literal constant operand.
    if (DstSize > 32 && SrcSize == 32) {
      Register HiReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
      unsigned SubReg = InReg ? AMDGPU::sub0 : AMDGPU::NoSubRegister;
      if (Signed) {
        BuildMI(MBB, I, DL, TII.get(AMDGPU::S_ASHR_I32), HiReg)
          .addReg(SrcReg, 0, SubReg)
          .addImm(31)
          .setOperandDead(3); // Dead scc
      } else {
        BuildMI(MBB, I, DL, TII.get(AMDGPU::S_MOV_B32), HiReg)
          .addImm(0);
      }
      BuildMI(MBB, I, DL, TII.get(AMDGPU::REG_SEQUENCE), DstReg)
        .addReg(SrcReg, 0, SubReg)
        .addImm(AMDGPU::sub0)
        .addReg(HiReg)
        .addImm(AMDGPU::sub1);
      I.eraseFromParent();
      return RBI.constrainGenericRegister(DstReg, AMDGPU::SReg_64RegClass,
                                          *MRI);
    }
 
    const unsigned BFE64 = Signed ? AMDGPU::S_BFE_I64 : AMDGPU::S_BFE_U64;
    const unsigned BFE32 = Signed ? AMDGPU::S_BFE_I32 : AMDGPU::S_BFE_U32;
 
    // Scalar BFE is encoded as S1[5:0] = offset, S1[22:16]= width.
    if (DstSize > 32 && (SrcSize <= 32 || InReg)) {
      // We need a 64-bit register source, but the high bits don't matter.
      Register ExtReg = MRI->createVirtualRegister(&AMDGPU::SReg_64RegClass);
      Register UndefReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
      unsigned SubReg = InReg ? AMDGPU::sub0 : AMDGPU::NoSubRegister;
 
      BuildMI(MBB, I, DL, TII.get(AMDGPU::IMPLICIT_DEF), UndefReg);
      BuildMI(MBB, I, DL, TII.get(AMDGPU::REG_SEQUENCE), ExtReg)
        .addReg(SrcReg, 0, SubReg)
        .addImm(AMDGPU::sub0)
        .addReg(UndefReg)
        .addImm(AMDGPU::sub1);
 
      BuildMI(MBB, I, DL, TII.get(BFE64), DstReg)
        .addReg(ExtReg)
        .addImm(SrcSize << 16);
 
      I.eraseFromParent();
      return RBI.constrainGenericRegister(DstReg, AMDGPU::SReg_64RegClass, *MRI);
    }
 
    unsigned Mask;
    if (!Signed && shouldUseAndMask(SrcSize, Mask)) {
      BuildMI(MBB, I, DL, TII.get(AMDGPU::S_AND_B32), DstReg)
        .addReg(SrcReg)
        .addImm(Mask)
        .setOperandDead(3); // Dead scc
    } else {
      BuildMI(MBB, I, DL, TII.get(BFE32), DstReg)
        .addReg(SrcReg)
        .addImm(SrcSize << 16);
    }
 
    I.eraseFromParent();
    return RBI.constrainGenericRegister(DstReg, AMDGPU::SReg_32RegClass, *MRI);
  }
 
  return false;
}
 
static bool isExtractHiElt(MachineRegisterInfo &MRI, Register In,
                           Register &Out) {
  Register LShlSrc;
  if (mi_match(In, MRI,
               m_GTrunc(m_GLShr(m_Reg(LShlSrc), m_SpecificICst(16))))) {
    Out = LShlSrc;
    return true;
  }
  return false;
}
 
bool AMDGPUInstructionSelector::selectG_FPEXT(MachineInstr &I) const {
  if (!Subtarget->hasSALUFloatInsts())
    return false;
 
  Register Dst = I.getOperand(0).getReg();
  const RegisterBank *DstRB = RBI.getRegBank(Dst, *MRI, TRI);
  if (DstRB->getID() != AMDGPU::SGPRRegBankID)
    return false;
 
  Register Src = I.getOperand(1).getReg();
 
  if (MRI->getType(Dst) == LLT::scalar(32) &&
      MRI->getType(Src) == LLT::scalar(16)) {
    if (isExtractHiElt(*MRI, Src, Src)) {
      MachineBasicBlock *BB = I.getParent();
      BuildMI(*BB, &I, I.getDebugLoc(), TII.get(AMDGPU::S_CVT_HI_F32_F16), Dst)
          .addUse(Src);
      I.eraseFromParent();
      return RBI.constrainGenericRegister(Dst, AMDGPU::SReg_32RegClass, *MRI);
    }
  }
 
  return false;
}
 
bool AMDGPUInstructionSelector::selectG_CONSTANT(MachineInstr &I) const {
  MachineBasicBlock *BB = I.getParent();
  MachineOperand &ImmOp = I.getOperand(1);
  Register DstReg = I.getOperand(0).getReg();
  unsigned Size = MRI->getType(DstReg).getSizeInBits();
  bool IsFP = false;
 
  // The AMDGPU backend only supports Imm operands and not CImm or FPImm.
  if (ImmOp.isFPImm()) {
    const APInt &Imm = ImmOp.getFPImm()->getValueAPF().bitcastToAPInt();
    ImmOp.ChangeToImmediate(Imm.getZExtValue());
    IsFP = true;
  } else if (ImmOp.isCImm()) {
    ImmOp.ChangeToImmediate(ImmOp.getCImm()->getSExtValue());
  } else {
    llvm_unreachable("Not supported by g_constants");
  }
 
  const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
  const bool IsSgpr = DstRB->getID() == AMDGPU::SGPRRegBankID;
 
  unsigned Opcode;
  if (DstRB->getID() == AMDGPU::VCCRegBankID) {
    Opcode = STI.isWave32() ? AMDGPU::S_MOV_B32 : AMDGPU::S_MOV_B64;
  } else if (Size == 64 &&
             AMDGPU::isValid32BitLiteral(I.getOperand(1).getImm(), IsFP)) {
    Opcode = IsSgpr ? AMDGPU::S_MOV_B64_IMM_PSEUDO : AMDGPU::V_MOV_B64_PSEUDO;
    I.setDesc(TII.get(Opcode));
    I.addImplicitDefUseOperands(*MF);
    return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
  } else {
    Opcode = IsSgpr ? AMDGPU::S_MOV_B32 : AMDGPU::V_MOV_B32_e32;
 
    // We should never produce s1 values on banks other than VCC. If the user of
    // this already constrained the register, we may incorrectly think it's VCC
    // if it wasn't originally.
    if (Size == 1)
      return false;
  }
 
  if (Size != 64) {
    I.setDesc(TII.get(Opcode));
    I.addImplicitDefUseOperands(*MF);
    return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
  }
 
  const DebugLoc &DL = I.getDebugLoc();
 
  APInt Imm(Size, I.getOperand(1).getImm());
 
  MachineInstr *ResInst;
  if (IsSgpr && TII.isInlineConstant(Imm)) {
    ResInst = BuildMI(*BB, &I, DL, TII.get(AMDGPU::S_MOV_B64), DstReg)
      .addImm(I.getOperand(1).getImm());
  } else {
    const TargetRegisterClass *RC = IsSgpr ?
      &AMDGPU::SReg_32RegClass : &AMDGPU::VGPR_32RegClass;
    Register LoReg = MRI->createVirtualRegister(RC);
    Register HiReg = MRI->createVirtualRegister(RC);
 
    BuildMI(*BB, &I, DL, TII.get(Opcode), LoReg)
      .addImm(Imm.trunc(32).getZExtValue());
 
    BuildMI(*BB, &I, DL, TII.get(Opcode), HiReg)
      .addImm(Imm.ashr(32).getZExtValue());
 
    ResInst = BuildMI(*BB, &I, DL, TII.get(AMDGPU::REG_SEQUENCE), DstReg)
      .addReg(LoReg)
      .addImm(AMDGPU::sub0)
      .addReg(HiReg)
      .addImm(AMDGPU::sub1);
  }
 
  // We can't call constrainSelectedInstRegOperands here, because it doesn't
  // work for target independent opcodes
  I.eraseFromParent();
  const TargetRegisterClass *DstRC =
    TRI.getConstrainedRegClassForOperand(ResInst->getOperand(0), *MRI);
  if (!DstRC)
    return true;
  return RBI.constrainGenericRegister(DstReg, *DstRC, *MRI);
}
 
bool AMDGPUInstructionSelector::selectG_FNEG(MachineInstr &MI) const {
  // Only manually handle the f64 SGPR case.
  //
  // FIXME: This is a workaround for 2.5 different tablegen problems. Because
  // the bit ops theoretically have a second result due to the implicit def of
  // SCC, the GlobalISelEmitter is overly conservative and rejects it. Fixing
  // that is easy by disabling the check. The result works, but uses a
  // nonsensical sreg32orlds_and_sreg_1 regclass.
  //
  // The DAG emitter is more problematic, and incorrectly adds both S_XOR_B32 to
  // the variadic REG_SEQUENCE operands.
 
  Register Dst = MI.getOperand(0).getReg();
  const RegisterBank *DstRB = RBI.getRegBank(Dst, *MRI, TRI);
  if (DstRB->getID() != AMDGPU::SGPRRegBankID ||
      MRI->getType(Dst) != LLT::scalar(64))
    return false;
 
  Register Src = MI.getOperand(1).getReg();
  MachineInstr *Fabs = getOpcodeDef(TargetOpcode::G_FABS, Src, *MRI);
  if (Fabs)
    Src = Fabs->getOperand(1).getReg();
 
  if (!RBI.constrainGenericRegister(Src, AMDGPU::SReg_64RegClass, *MRI) ||
      !RBI.constrainGenericRegister(Dst, AMDGPU::SReg_64RegClass, *MRI))
    return false;
 
  MachineBasicBlock *BB = MI.getParent();
  const DebugLoc &DL = MI.getDebugLoc();
  Register LoReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
  Register HiReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
  Register ConstReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
  Register OpReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
 
  BuildMI(*BB, &MI, DL, TII.get(AMDGPU::COPY), LoReg)
    .addReg(Src, 0, AMDGPU::sub0);
  BuildMI(*BB, &MI, DL, TII.get(AMDGPU::COPY), HiReg)
    .addReg(Src, 0, AMDGPU::sub1);
  BuildMI(*BB, &MI, DL, TII.get(AMDGPU::S_MOV_B32), ConstReg)
    .addImm(0x80000000);
 
  // Set or toggle sign bit.
  unsigned Opc = Fabs ? AMDGPU::S_OR_B32 : AMDGPU::S_XOR_B32;
  BuildMI(*BB, &MI, DL, TII.get(Opc), OpReg)
    .addReg(HiReg)
    .addReg(ConstReg)
    .setOperandDead(3); // Dead scc
  BuildMI(*BB, &MI, DL, TII.get(AMDGPU::REG_SEQUENCE), Dst)
    .addReg(LoReg)
    .addImm(AMDGPU::sub0)
    .addReg(OpReg)
    .addImm(AMDGPU::sub1);
  MI.eraseFromParent();
  return true;
}
 
// FIXME: This is a workaround for the same tablegen problems as G_FNEG
bool AMDGPUInstructionSelector::selectG_FABS(MachineInstr &MI) const {
  Register Dst = MI.getOperand(0).getReg();
  const RegisterBank *DstRB = RBI.getRegBank(Dst, *MRI, TRI);
  if (DstRB->getID() != AMDGPU::SGPRRegBankID ||
      MRI->getType(Dst) != LLT::scalar(64))
    return false;
 
  Register Src = MI.getOperand(1).getReg();
  MachineBasicBlock *BB = MI.getParent();
  const DebugLoc &DL = MI.getDebugLoc();
  Register LoReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
  Register HiReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
  Register ConstReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
  Register OpReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
 
  if (!RBI.constrainGenericRegister(Src, AMDGPU::SReg_64RegClass, *MRI) ||
      !RBI.constrainGenericRegister(Dst, AMDGPU::SReg_64RegClass, *MRI))
    return false;
 
  BuildMI(*BB, &MI, DL, TII.get(AMDGPU::COPY), LoReg)
    .addReg(Src, 0, AMDGPU::sub0);
  BuildMI(*BB, &MI, DL, TII.get(AMDGPU::COPY), HiReg)
    .addReg(Src, 0, AMDGPU::sub1);
  BuildMI(*BB, &MI, DL, TII.get(AMDGPU::S_MOV_B32), ConstReg)
    .addImm(0x7fffffff);
 
  // Clear sign bit.
  // TODO: Should this used S_BITSET0_*?
  BuildMI(*BB, &MI, DL, TII.get(AMDGPU::S_AND_B32), OpReg)
    .addReg(HiReg)
    .addReg(ConstReg)
    .setOperandDead(3); // Dead scc
  BuildMI(*BB, &MI, DL, TII.get(AMDGPU::REG_SEQUENCE), Dst)
    .addReg(LoReg)
    .addImm(AMDGPU::sub0)
    .addReg(OpReg)
    .addImm(AMDGPU::sub1);
 
  MI.eraseFromParent();
  return true;
}
 
static bool isConstant(const MachineInstr &MI) {
  return MI.getOpcode() == TargetOpcode::G_CONSTANT;
}
 
void AMDGPUInstructionSelector::getAddrModeInfo(const MachineInstr &Load,
    const MachineRegisterInfo &MRI, SmallVectorImpl<GEPInfo> &AddrInfo) const {
 
  unsigned OpNo = Load.getOpcode() == AMDGPU::G_PREFETCH ? 0 : 1;
  const MachineInstr *PtrMI =
      MRI.getUniqueVRegDef(Load.getOperand(OpNo).getReg());
 
  assert(PtrMI);
 
  if (PtrMI->getOpcode() != TargetOpcode::G_PTR_ADD)
    return;
 
  GEPInfo GEPInfo;
 
  for (unsigned i = 1; i != 3; ++i) {
    const MachineOperand &GEPOp = PtrMI->getOperand(i);
    const MachineInstr *OpDef = MRI.getUniqueVRegDef(GEPOp.getReg());
    assert(OpDef);
    if (i == 2 && isConstant(*OpDef)) {
      // TODO: Could handle constant base + variable offset, but a combine
      // probably should have commuted it.
      assert(GEPInfo.Imm == 0);
      GEPInfo.Imm = OpDef->getOperand(1).getCImm()->getSExtValue();
      continue;
    }
    const RegisterBank *OpBank = RBI.getRegBank(GEPOp.getReg(), MRI, TRI);
    if (OpBank->getID() == AMDGPU::SGPRRegBankID)
      GEPInfo.SgprParts.push_back(GEPOp.getReg());
    else
      GEPInfo.VgprParts.push_back(GEPOp.getReg());
  }
 
  AddrInfo.push_back(GEPInfo);
  getAddrModeInfo(*PtrMI, MRI, AddrInfo);
}
 
bool AMDGPUInstructionSelector::isSGPR(Register Reg) const {
  return RBI.getRegBank(Reg, *MRI, TRI)->getID() == AMDGPU::SGPRRegBankID;
}
 
bool AMDGPUInstructionSelector::isInstrUniform(const MachineInstr &MI) const {
  if (!MI.hasOneMemOperand())
    return false;
 
  const MachineMemOperand *MMO = *MI.memoperands_begin();
  const Value *Ptr = MMO->getValue();
 
  // UndefValue means this is a load of a kernel input.  These are uniform.
  // Sometimes LDS instructions have constant pointers.
  // If Ptr is null, then that means this mem operand contains a
  // PseudoSourceValue like GOT.
  if (!Ptr || isa<UndefValue>(Ptr) || isa<Argument>(Ptr) ||
      isa<Constant>(Ptr) || isa<GlobalValue>(Ptr))
    return true;
 
  if (MMO->getAddrSpace() == AMDGPUAS::CONSTANT_ADDRESS_32BIT)
    return true;
 
  if (MI.getOpcode() == AMDGPU::G_PREFETCH)
    return RBI.getRegBank(MI.getOperand(0).getReg(), *MRI, TRI)->getID() ==
           AMDGPU::SGPRRegBankID;
 
  const Instruction *I = dyn_cast<Instruction>(Ptr);
  return I && I->getMetadata("amdgpu.uniform");
}
 
bool AMDGPUInstructionSelector::hasVgprParts(ArrayRef<GEPInfo> AddrInfo) const {
  for (const GEPInfo &GEPInfo : AddrInfo) {
    if (!GEPInfo.VgprParts.empty())
      return true;
  }
  return false;
}
 
void AMDGPUInstructionSelector::initM0(MachineInstr &I) const {
  const LLT PtrTy = MRI->getType(I.getOperand(1).getReg());
  unsigned AS = PtrTy.getAddressSpace();
  if ((AS == AMDGPUAS::LOCAL_ADDRESS || AS == AMDGPUAS::REGION_ADDRESS) &&
      STI.ldsRequiresM0Init()) {
    MachineBasicBlock *BB = I.getParent();
 
    // If DS instructions require M0 initialization, insert it before selecting.
    BuildMI(*BB, &I, I.getDebugLoc(), TII.get(AMDGPU::S_MOV_B32), AMDGPU::M0)
      .addImm(-1);
  }
}
 
bool AMDGPUInstructionSelector::selectG_LOAD_STORE_ATOMICRMW(
  MachineInstr &I) const {
  initM0(I);
  return selectImpl(I, *CoverageInfo);
}
 
static bool isVCmpResult(Register Reg, MachineRegisterInfo &MRI) {
  if (Reg.isPhysical())
    return false;
 
  MachineInstr &MI = *MRI.getUniqueVRegDef(Reg);
  const unsigned Opcode = MI.getOpcode();
 
  if (Opcode == AMDGPU::COPY)
    return isVCmpResult(MI.getOperand(1).getReg(), MRI);
 
  if (Opcode == AMDGPU::G_AND || Opcode == AMDGPU::G_OR ||
      Opcode == AMDGPU::G_XOR)
    return isVCmpResult(MI.getOperand(1).getReg(), MRI) &&
           isVCmpResult(MI.getOperand(2).getReg(), MRI);
 
  if (auto *GI = dyn_cast<GIntrinsic>(&MI))
    return GI->is(Intrinsic::amdgcn_class);
 
  return Opcode == AMDGPU::G_ICMP || Opcode == AMDGPU::G_FCMP;
}
 
bool AMDGPUInstructionSelector::selectG_BRCOND(MachineInstr &I) const {
  MachineBasicBlock *BB = I.getParent();
  MachineOperand &CondOp = I.getOperand(0);
  Register CondReg = CondOp.getReg();
  const DebugLoc &DL = I.getDebugLoc();
 
  unsigned BrOpcode;
  Register CondPhysReg;
  const TargetRegisterClass *ConstrainRC;
 
  // In SelectionDAG, we inspect the IR block for uniformity metadata to decide
  // whether the branch is uniform when selecting the instruction. In
  // GlobalISel, we should push that decision into RegBankSelect. Assume for now
  // RegBankSelect knows what it's doing if the branch condition is scc, even
  // though it currently does not.
  if (!isVCC(CondReg, *MRI)) {
    if (MRI->getType(CondReg) != LLT::scalar(32))
      return false;
 
    CondPhysReg = AMDGPU::SCC;
    BrOpcode = AMDGPU::S_CBRANCH_SCC1;
    ConstrainRC = &AMDGPU::SReg_32RegClass;
  } else {
    // FIXME: Should scc->vcc copies and with exec?
 
    // Unless the value of CondReg is a result of a V_CMP* instruction then we
    // need to insert an and with exec.
    if (!isVCmpResult(CondReg, *MRI)) {
      const bool Is64 = STI.isWave64();
      const unsigned Opcode = Is64 ? AMDGPU::S_AND_B64 : AMDGPU::S_AND_B32;
      const Register Exec = Is64 ? AMDGPU::EXEC : AMDGPU::EXEC_LO;
 
      Register TmpReg = MRI->createVirtualRegister(TRI.getBoolRC());
      BuildMI(*BB, &I, DL, TII.get(Opcode), TmpReg)
          .addReg(CondReg)
          .addReg(Exec)
          .setOperandDead(3); // Dead scc
      CondReg = TmpReg;
    }
 
    CondPhysReg = TRI.getVCC();
    BrOpcode = AMDGPU::S_CBRANCH_VCCNZ;
    ConstrainRC = TRI.getBoolRC();
  }
 
  if (!MRI->getRegClassOrNull(CondReg))
    MRI->setRegClass(CondReg, ConstrainRC);
 
  BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), CondPhysReg)
    .addReg(CondReg);
  BuildMI(*BB, &I, DL, TII.get(BrOpcode))
    .addMBB(I.getOperand(1).getMBB());
 
  I.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectG_GLOBAL_VALUE(
  MachineInstr &I) const {
  Register DstReg = I.getOperand(0).getReg();
  const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
  const bool IsVGPR = DstRB->getID() == AMDGPU::VGPRRegBankID;
  I.setDesc(TII.get(IsVGPR ? AMDGPU::V_MOV_B32_e32 : AMDGPU::S_MOV_B32));
  if (IsVGPR)
    I.addOperand(*MF, MachineOperand::CreateReg(AMDGPU::EXEC, false, true));
 
  return RBI.constrainGenericRegister(
    DstReg, IsVGPR ? AMDGPU::VGPR_32RegClass : AMDGPU::SReg_32RegClass, *MRI);
}
 
bool AMDGPUInstructionSelector::selectG_PTRMASK(MachineInstr &I) const {
  Register DstReg = I.getOperand(0).getReg();
  Register SrcReg = I.getOperand(1).getReg();
  Register MaskReg = I.getOperand(2).getReg();
  LLT Ty = MRI->getType(DstReg);
  LLT MaskTy = MRI->getType(MaskReg);
  MachineBasicBlock *BB = I.getParent();
  const DebugLoc &DL = I.getDebugLoc();
 
  const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
  const RegisterBank *SrcRB = RBI.getRegBank(SrcReg, *MRI, TRI);
  const RegisterBank *MaskRB = RBI.getRegBank(MaskReg, *MRI, TRI);
  const bool IsVGPR = DstRB->getID() == AMDGPU::VGPRRegBankID;
  if (DstRB != SrcRB) // Should only happen for hand written MIR.
    return false;
 
  // Try to avoid emitting a bit operation when we only need to touch half of
  // the 64-bit pointer.
  APInt MaskOnes = KB->getKnownOnes(MaskReg).zext(64);
  const APInt MaskHi32 = APInt::getHighBitsSet(64, 32);
  const APInt MaskLo32 = APInt::getLowBitsSet(64, 32);
 
  const bool CanCopyLow32 = (MaskOnes & MaskLo32) == MaskLo32;
  const bool CanCopyHi32 = (MaskOnes & MaskHi32) == MaskHi32;
 
  if (!IsVGPR && Ty.getSizeInBits() == 64 &&
      !CanCopyLow32 && !CanCopyHi32) {
    auto MIB = BuildMI(*BB, &I, DL, TII.get(AMDGPU::S_AND_B64), DstReg)
      .addReg(SrcReg)
      .addReg(MaskReg)
      .setOperandDead(3); // Dead scc
    I.eraseFromParent();
    return constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
  }
 
  unsigned NewOpc = IsVGPR ? AMDGPU::V_AND_B32_e64 : AMDGPU::S_AND_B32;
  const TargetRegisterClass &RegRC
    = IsVGPR ? AMDGPU::VGPR_32RegClass : AMDGPU::SReg_32RegClass;
 
  const TargetRegisterClass *DstRC = TRI.getRegClassForTypeOnBank(Ty, *DstRB);
  const TargetRegisterClass *SrcRC = TRI.getRegClassForTypeOnBank(Ty, *SrcRB);
  const TargetRegisterClass *MaskRC =
      TRI.getRegClassForTypeOnBank(MaskTy, *MaskRB);
 
  if (!RBI.constrainGenericRegister(DstReg, *DstRC, *MRI) ||
      !RBI.constrainGenericRegister(SrcReg, *SrcRC, *MRI) ||
      !RBI.constrainGenericRegister(MaskReg, *MaskRC, *MRI))
    return false;
 
  if (Ty.getSizeInBits() == 32) {
    assert(MaskTy.getSizeInBits() == 32 &&
           "ptrmask should have been narrowed during legalize");
 
    auto NewOp = BuildMI(*BB, &I, DL, TII.get(NewOpc), DstReg)
      .addReg(SrcReg)
      .addReg(MaskReg);
 
    if (!IsVGPR)
      NewOp.setOperandDead(3); // Dead scc
    I.eraseFromParent();
    return true;
  }
 
  Register HiReg = MRI->createVirtualRegister(&RegRC);
  Register LoReg = MRI->createVirtualRegister(&RegRC);
 
  // Extract the subregisters from the source pointer.
  BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), LoReg)
    .addReg(SrcReg, 0, AMDGPU::sub0);
  BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), HiReg)
    .addReg(SrcReg, 0, AMDGPU::sub1);
 
  Register MaskedLo, MaskedHi;
 
  if (CanCopyLow32) {
    // If all the bits in the low half are 1, we only need a copy for it.
    MaskedLo = LoReg;
  } else {
    // Extract the mask subregister and apply the and.
    Register MaskLo = MRI->createVirtualRegister(&RegRC);
    MaskedLo = MRI->createVirtualRegister(&RegRC);
 
    BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), MaskLo)
      .addReg(MaskReg, 0, AMDGPU::sub0);
    BuildMI(*BB, &I, DL, TII.get(NewOpc), MaskedLo)
      .addReg(LoReg)
      .addReg(MaskLo);
  }
 
  if (CanCopyHi32) {
    // If all the bits in the high half are 1, we only need a copy for it.
    MaskedHi = HiReg;
  } else {
    Register MaskHi = MRI->createVirtualRegister(&RegRC);
    MaskedHi = MRI->createVirtualRegister(&RegRC);
 
    BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), MaskHi)
      .addReg(MaskReg, 0, AMDGPU::sub1);
    BuildMI(*BB, &I, DL, TII.get(NewOpc), MaskedHi)
      .addReg(HiReg)
      .addReg(MaskHi);
  }
 
  BuildMI(*BB, &I, DL, TII.get(AMDGPU::REG_SEQUENCE), DstReg)
    .addReg(MaskedLo)
    .addImm(AMDGPU::sub0)
    .addReg(MaskedHi)
    .addImm(AMDGPU::sub1);
  I.eraseFromParent();
  return true;
}
 
/// Return the register to use for the index value, and the subregister to use
/// for the indirectly accessed register.
static std::pair<Register, unsigned>
computeIndirectRegIndex(MachineRegisterInfo &MRI, const SIRegisterInfo &TRI,
                        const TargetRegisterClass *SuperRC, Register IdxReg,
                        unsigned EltSize, GISelKnownBits &KnownBits) {
  Register IdxBaseReg;
  int Offset;
 
  std::tie(IdxBaseReg, Offset) =
      AMDGPU::getBaseWithConstantOffset(MRI, IdxReg, &KnownBits);
  if (IdxBaseReg == AMDGPU::NoRegister) {
    // This will happen if the index is a known constant. This should ordinarily
    // be legalized out, but handle it as a register just in case.
    assert(Offset == 0);
    IdxBaseReg = IdxReg;
  }
 
  ArrayRef<int16_t> SubRegs = TRI.getRegSplitParts(SuperRC, EltSize);
 
  // Skip out of bounds offsets, or else we would end up using an undefined
  // register.
  if (static_cast<unsigned>(Offset) >= SubRegs.size())
    return std::pair(IdxReg, SubRegs[0]);
  return std::pair(IdxBaseReg, SubRegs[Offset]);
}
 
bool AMDGPUInstructionSelector::selectG_EXTRACT_VECTOR_ELT(
  MachineInstr &MI) const {
  Register DstReg = MI.getOperand(0).getReg();
  Register SrcReg = MI.getOperand(1).getReg();
  Register IdxReg = MI.getOperand(2).getReg();
 
  LLT DstTy = MRI->getType(DstReg);
  LLT SrcTy = MRI->getType(SrcReg);
 
  const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
  const RegisterBank *SrcRB = RBI.getRegBank(SrcReg, *MRI, TRI);
  const RegisterBank *IdxRB = RBI.getRegBank(IdxReg, *MRI, TRI);
 
  // The index must be scalar. If it wasn't RegBankSelect should have moved this
  // into a waterfall loop.
  if (IdxRB->getID() != AMDGPU::SGPRRegBankID)
    return false;
 
  const TargetRegisterClass *SrcRC =
      TRI.getRegClassForTypeOnBank(SrcTy, *SrcRB);
  const TargetRegisterClass *DstRC =
      TRI.getRegClassForTypeOnBank(DstTy, *DstRB);
  if (!SrcRC || !DstRC)
    return false;
  if (!RBI.constrainGenericRegister(SrcReg, *SrcRC, *MRI) ||
      !RBI.constrainGenericRegister(DstReg, *DstRC, *MRI) ||
      !RBI.constrainGenericRegister(IdxReg, AMDGPU::SReg_32RegClass, *MRI))
    return false;
 
  MachineBasicBlock *BB = MI.getParent();
  const DebugLoc &DL = MI.getDebugLoc();
  const bool Is64 = DstTy.getSizeInBits() == 64;
 
  unsigned SubReg;
  std::tie(IdxReg, SubReg) = computeIndirectRegIndex(
      *MRI, TRI, SrcRC, IdxReg, DstTy.getSizeInBits() / 8, *KB);
 
  if (SrcRB->getID() == AMDGPU::SGPRRegBankID) {
    if (DstTy.getSizeInBits() != 32 && !Is64)
      return false;
 
    BuildMI(*BB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
      .addReg(IdxReg);
 
    unsigned Opc = Is64 ? AMDGPU::S_MOVRELS_B64 : AMDGPU::S_MOVRELS_B32;
    BuildMI(*BB, &MI, DL, TII.get(Opc), DstReg)
      .addReg(SrcReg, 0, SubReg)
      .addReg(SrcReg, RegState::Implicit);
    MI.eraseFromParent();
    return true;
  }
 
  if (SrcRB->getID() != AMDGPU::VGPRRegBankID || DstTy.getSizeInBits() != 32)
    return false;
 
  if (!STI.useVGPRIndexMode()) {
    BuildMI(*BB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
      .addReg(IdxReg);
    BuildMI(*BB, &MI, DL, TII.get(AMDGPU::V_MOVRELS_B32_e32), DstReg)
      .addReg(SrcReg, 0, SubReg)
      .addReg(SrcReg, RegState::Implicit);
    MI.eraseFromParent();
    return true;
  }
 
  const MCInstrDesc &GPRIDXDesc =
      TII.getIndirectGPRIDXPseudo(TRI.getRegSizeInBits(*SrcRC), true);
  BuildMI(*BB, MI, DL, GPRIDXDesc, DstReg)
      .addReg(SrcReg)
      .addReg(IdxReg)
      .addImm(SubReg);
 
  MI.eraseFromParent();
  return true;
}
 
// TODO: Fold insert_vector_elt (extract_vector_elt) into movrelsd
bool AMDGPUInstructionSelector::selectG_INSERT_VECTOR_ELT(
  MachineInstr &MI) const {
  Register DstReg = MI.getOperand(0).getReg();
  Register VecReg = MI.getOperand(1).getReg();
  Register ValReg = MI.getOperand(2).getReg();
  Register IdxReg = MI.getOperand(3).getReg();
 
  LLT VecTy = MRI->getType(DstReg);
  LLT ValTy = MRI->getType(ValReg);
  unsigned VecSize = VecTy.getSizeInBits();
  unsigned ValSize = ValTy.getSizeInBits();
 
  const RegisterBank *VecRB = RBI.getRegBank(VecReg, *MRI, TRI);
  const RegisterBank *ValRB = RBI.getRegBank(ValReg, *MRI, TRI);
  const RegisterBank *IdxRB = RBI.getRegBank(IdxReg, *MRI, TRI);
 
  assert(VecTy.getElementType() == ValTy);
 
  // The index must be scalar. If it wasn't RegBankSelect should have moved this
  // into a waterfall loop.
  if (IdxRB->getID() != AMDGPU::SGPRRegBankID)
    return false;
 
  const TargetRegisterClass *VecRC =
      TRI.getRegClassForTypeOnBank(VecTy, *VecRB);
  const TargetRegisterClass *ValRC =
      TRI.getRegClassForTypeOnBank(ValTy, *ValRB);
 
  if (!RBI.constrainGenericRegister(VecReg, *VecRC, *MRI) ||
      !RBI.constrainGenericRegister(DstReg, *VecRC, *MRI) ||
      !RBI.constrainGenericRegister(ValReg, *ValRC, *MRI) ||
      !RBI.constrainGenericRegister(IdxReg, AMDGPU::SReg_32RegClass, *MRI))
    return false;
 
  if (VecRB->getID() == AMDGPU::VGPRRegBankID && ValSize != 32)
    return false;
 
  unsigned SubReg;
  std::tie(IdxReg, SubReg) =
      computeIndirectRegIndex(*MRI, TRI, VecRC, IdxReg, ValSize / 8, *KB);
 
  const bool IndexMode = VecRB->getID() == AMDGPU::VGPRRegBankID &&
                         STI.useVGPRIndexMode();
 
  MachineBasicBlock *BB = MI.getParent();
  const DebugLoc &DL = MI.getDebugLoc();
 
  if (!IndexMode) {
    BuildMI(*BB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
      .addReg(IdxReg);
 
    const MCInstrDesc &RegWriteOp = TII.getIndirectRegWriteMovRelPseudo(
        VecSize, ValSize, VecRB->getID() == AMDGPU::SGPRRegBankID);
    BuildMI(*BB, MI, DL, RegWriteOp, DstReg)
        .addReg(VecReg)
        .addReg(ValReg)
        .addImm(SubReg);
    MI.eraseFromParent();
    return true;
  }
 
  const MCInstrDesc &GPRIDXDesc =
      TII.getIndirectGPRIDXPseudo(TRI.getRegSizeInBits(*VecRC), false);
  BuildMI(*BB, MI, DL, GPRIDXDesc, DstReg)
      .addReg(VecReg)
      .addReg(ValReg)
      .addReg(IdxReg)
      .addImm(SubReg);
 
  MI.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectBufferLoadLds(MachineInstr &MI) const {
  assert(!AMDGPU::isGFX12Plus(STI));
  unsigned Opc;
  unsigned Size = MI.getOperand(3).getImm();
 
  // The struct intrinsic variants add one additional operand over raw.
  const bool HasVIndex = MI.getNumOperands() == 9;
  Register VIndex;
  int OpOffset = 0;
  if (HasVIndex) {
    VIndex = MI.getOperand(4).getReg();
    OpOffset = 1;
  }
 
  Register VOffset = MI.getOperand(4 + OpOffset).getReg();
  std::optional<ValueAndVReg> MaybeVOffset =
      getIConstantVRegValWithLookThrough(VOffset, *MRI);
  const bool HasVOffset = !MaybeVOffset || MaybeVOffset->Value.getZExtValue();
 
  switch (Size) {
  default:
    return false;
  case 1:
    Opc = HasVIndex ? HasVOffset ? AMDGPU::BUFFER_LOAD_UBYTE_LDS_BOTHEN
                                 : AMDGPU::BUFFER_LOAD_UBYTE_LDS_IDXEN
                    : HasVOffset ? AMDGPU::BUFFER_LOAD_UBYTE_LDS_OFFEN
                                 : AMDGPU::BUFFER_LOAD_UBYTE_LDS_OFFSET;
    break;
  case 2:
    Opc = HasVIndex ? HasVOffset ? AMDGPU::BUFFER_LOAD_USHORT_LDS_BOTHEN
                                 : AMDGPU::BUFFER_LOAD_USHORT_LDS_IDXEN
                    : HasVOffset ? AMDGPU::BUFFER_LOAD_USHORT_LDS_OFFEN
                                 : AMDGPU::BUFFER_LOAD_USHORT_LDS_OFFSET;
    break;
  case 4:
    Opc = HasVIndex ? HasVOffset ? AMDGPU::BUFFER_LOAD_DWORD_LDS_BOTHEN
                                 : AMDGPU::BUFFER_LOAD_DWORD_LDS_IDXEN
                    : HasVOffset ? AMDGPU::BUFFER_LOAD_DWORD_LDS_OFFEN
                                 : AMDGPU::BUFFER_LOAD_DWORD_LDS_OFFSET;
    break;
  }
 
  MachineBasicBlock *MBB = MI.getParent();
  const DebugLoc &DL = MI.getDebugLoc();
  BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
    .add(MI.getOperand(2));
 
  auto MIB = BuildMI(*MBB, &MI, DL, TII.get(Opc));
 
  if (HasVIndex && HasVOffset) {
    Register IdxReg = MRI->createVirtualRegister(TRI.getVGPR64Class());
    BuildMI(*MBB, &*MIB, DL, TII.get(AMDGPU::REG_SEQUENCE), IdxReg)
      .addReg(VIndex)
      .addImm(AMDGPU::sub0)
      .addReg(VOffset)
      .addImm(AMDGPU::sub1);
 
    MIB.addReg(IdxReg);
  } else if (HasVIndex) {
    MIB.addReg(VIndex);
  } else if (HasVOffset) {
    MIB.addReg(VOffset);
  }
 
  MIB.add(MI.getOperand(1));            // rsrc
  MIB.add(MI.getOperand(5 + OpOffset)); // soffset
  MIB.add(MI.getOperand(6 + OpOffset)); // imm offset
  unsigned Aux = MI.getOperand(7 + OpOffset).getImm();
  MIB.addImm(Aux & AMDGPU::CPol::ALL);                  // cpol
  MIB.addImm(Aux & AMDGPU::CPol::SWZ_pregfx12 ? 1 : 0); // swz
 
  MachineMemOperand *LoadMMO = *MI.memoperands_begin();
  MachinePointerInfo LoadPtrI = LoadMMO->getPointerInfo();
  LoadPtrI.Offset = MI.getOperand(6 + OpOffset).getImm();
  MachinePointerInfo StorePtrI = LoadPtrI;
  StorePtrI.V = nullptr;
  StorePtrI.AddrSpace = AMDGPUAS::LOCAL_ADDRESS;
 
  auto F = LoadMMO->getFlags() &
           ~(MachineMemOperand::MOStore | MachineMemOperand::MOLoad);
  LoadMMO = MF->getMachineMemOperand(LoadPtrI, F | MachineMemOperand::MOLoad,
                                     Size, LoadMMO->getBaseAlign());
 
  MachineMemOperand *StoreMMO =
      MF->getMachineMemOperand(StorePtrI, F | MachineMemOperand::MOStore,
                               sizeof(int32_t), LoadMMO->getBaseAlign());
 
  MIB.setMemRefs({LoadMMO, StoreMMO});
 
  MI.eraseFromParent();
  return constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
}
 
/// Match a zero extend from a 32-bit value to 64-bits.
static Register matchZeroExtendFromS32(MachineRegisterInfo &MRI, Register Reg) {
  Register ZExtSrc;
  if (mi_match(Reg, MRI, m_GZExt(m_Reg(ZExtSrc))))
    return MRI.getType(ZExtSrc) == LLT::scalar(32) ? ZExtSrc : Register();
 
  // Match legalized form %zext = G_MERGE_VALUES (s32 %x), (s32 0)
  const MachineInstr *Def = getDefIgnoringCopies(Reg, MRI);
  if (Def->getOpcode() != AMDGPU::G_MERGE_VALUES)
    return Register();
 
  assert(Def->getNumOperands() == 3 &&
         MRI.getType(Def->getOperand(0).getReg()) == LLT::scalar(64));
  if (mi_match(Def->getOperand(2).getReg(), MRI, m_ZeroInt())) {
    return Def->getOperand(1).getReg();
  }
 
  return Register();
}
 
bool AMDGPUInstructionSelector::selectGlobalLoadLds(MachineInstr &MI) const{
  unsigned Opc;
  unsigned Size = MI.getOperand(3).getImm();
 
  switch (Size) {
  default:
    return false;
  case 1:
    Opc = AMDGPU::GLOBAL_LOAD_LDS_UBYTE;
    break;
  case 2:
    Opc = AMDGPU::GLOBAL_LOAD_LDS_USHORT;
    break;
  case 4:
    Opc = AMDGPU::GLOBAL_LOAD_LDS_DWORD;
    break;
  }
 
  MachineBasicBlock *MBB = MI.getParent();
  const DebugLoc &DL = MI.getDebugLoc();
  BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
    .add(MI.getOperand(2));
 
  Register Addr = MI.getOperand(1).getReg();
  Register VOffset;
  // Try to split SAddr and VOffset. Global and LDS pointers share the same
  // immediate offset, so we cannot use a regular SelectGlobalSAddr().
  if (!isSGPR(Addr)) {
    auto AddrDef = getDefSrcRegIgnoringCopies(Addr, *MRI);
    if (isSGPR(AddrDef->Reg)) {
      Addr = AddrDef->Reg;
    } else if (AddrDef->MI->getOpcode() == AMDGPU::G_PTR_ADD) {
      Register SAddr =
          getSrcRegIgnoringCopies(AddrDef->MI->getOperand(1).getReg(), *MRI);
      if (isSGPR(SAddr)) {
        Register PtrBaseOffset = AddrDef->MI->getOperand(2).getReg();
        if (Register Off = matchZeroExtendFromS32(*MRI, PtrBaseOffset)) {
          Addr = SAddr;
          VOffset = Off;
        }
      }
    }
  }
 
  if (isSGPR(Addr)) {
    Opc = AMDGPU::getGlobalSaddrOp(Opc);
    if (!VOffset) {
      VOffset = MRI->createVirtualRegister(&AMDGPU::VGPR_32RegClass);
      BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::V_MOV_B32_e32), VOffset)
        .addImm(0);
    }
  }
 
  auto MIB = BuildMI(*MBB, &MI, DL, TII.get(Opc))
    .addReg(Addr);
 
  if (isSGPR(Addr))
    MIB.addReg(VOffset);
 
  MIB.add(MI.getOperand(4))  // offset
     .add(MI.getOperand(5)); // cpol
 
  MachineMemOperand *LoadMMO = *MI.memoperands_begin();
  MachinePointerInfo LoadPtrI = LoadMMO->getPointerInfo();
  LoadPtrI.Offset = MI.getOperand(4).getImm();
  MachinePointerInfo StorePtrI = LoadPtrI;
  LoadPtrI.AddrSpace = AMDGPUAS::GLOBAL_ADDRESS;
  StorePtrI.AddrSpace = AMDGPUAS::LOCAL_ADDRESS;
  auto F = LoadMMO->getFlags() &
           ~(MachineMemOperand::MOStore | MachineMemOperand::MOLoad);
  LoadMMO = MF->getMachineMemOperand(LoadPtrI, F | MachineMemOperand::MOLoad,
                                     Size, LoadMMO->getBaseAlign());
  MachineMemOperand *StoreMMO =
      MF->getMachineMemOperand(StorePtrI, F | MachineMemOperand::MOStore,
                               sizeof(int32_t), Align(4));
 
  MIB.setMemRefs({LoadMMO, StoreMMO});
 
  MI.eraseFromParent();
  return constrainSelectedInstRegOperands(*MIB, TII, TRI, RBI);
}
 
bool AMDGPUInstructionSelector::selectBVHIntrinsic(MachineInstr &MI) const{
  MI.setDesc(TII.get(MI.getOperand(1).getImm()));
  MI.removeOperand(1);
  MI.addImplicitDefUseOperands(*MI.getParent()->getParent());
  return true;
}
 
bool AMDGPUInstructionSelector::selectSMFMACIntrin(MachineInstr &MI) const {
  unsigned Opc;
  switch (cast<GIntrinsic>(MI).getIntrinsicID()) {
  case Intrinsic::amdgcn_smfmac_f32_16x16x32_f16:
    Opc = AMDGPU::V_SMFMAC_F32_16X16X32_F16_e64;
    break;
  case Intrinsic::amdgcn_smfmac_f32_32x32x16_f16:
    Opc = AMDGPU::V_SMFMAC_F32_32X32X16_F16_e64;
    break;
  case Intrinsic::amdgcn_smfmac_f32_16x16x32_bf16:
    Opc = AMDGPU::V_SMFMAC_F32_16X16X32_BF16_e64;
    break;
  case Intrinsic::amdgcn_smfmac_f32_32x32x16_bf16:
    Opc = AMDGPU::V_SMFMAC_F32_32X32X16_BF16_e64;
    break;
  case Intrinsic::amdgcn_smfmac_i32_16x16x64_i8:
    Opc = AMDGPU::V_SMFMAC_I32_16X16X64_I8_e64;
    break;
  case Intrinsic::amdgcn_smfmac_i32_32x32x32_i8:
    Opc = AMDGPU::V_SMFMAC_I32_32X32X32_I8_e64;
    break;
  case Intrinsic::amdgcn_smfmac_f32_16x16x64_bf8_bf8:
    Opc = AMDGPU::V_SMFMAC_F32_16X16X64_BF8_BF8_e64;
    break;
  case Intrinsic::amdgcn_smfmac_f32_16x16x64_bf8_fp8:
    Opc = AMDGPU::V_SMFMAC_F32_16X16X64_BF8_FP8_e64;
    break;
  case Intrinsic::amdgcn_smfmac_f32_16x16x64_fp8_bf8:
    Opc = AMDGPU::V_SMFMAC_F32_16X16X64_FP8_BF8_e64;
    break;
  case Intrinsic::amdgcn_smfmac_f32_16x16x64_fp8_fp8:
    Opc = AMDGPU::V_SMFMAC_F32_16X16X64_FP8_FP8_e64;
    break;
  case Intrinsic::amdgcn_smfmac_f32_32x32x32_bf8_bf8:
    Opc = AMDGPU::V_SMFMAC_F32_32X32X32_BF8_BF8_e64;
    break;
  case Intrinsic::amdgcn_smfmac_f32_32x32x32_bf8_fp8:
    Opc = AMDGPU::V_SMFMAC_F32_32X32X32_BF8_FP8_e64;
    break;
  case Intrinsic::amdgcn_smfmac_f32_32x32x32_fp8_bf8:
    Opc = AMDGPU::V_SMFMAC_F32_32X32X32_FP8_BF8_e64;
    break;
  case Intrinsic::amdgcn_smfmac_f32_32x32x32_fp8_fp8:
    Opc = AMDGPU::V_SMFMAC_F32_32X32X32_FP8_FP8_e64;
    break;
  default:
    llvm_unreachable("unhandled smfmac intrinsic");
  }
 
  auto VDst_In = MI.getOperand(4);
 
  MI.setDesc(TII.get(Opc));
  MI.removeOperand(4); // VDst_In
  MI.removeOperand(1); // Intrinsic ID
  MI.addOperand(VDst_In); // Readd VDst_In to the end
  MI.addImplicitDefUseOperands(*MI.getParent()->getParent());
  return true;
}
 
bool AMDGPUInstructionSelector::selectWaveAddress(MachineInstr &MI) const {
  Register DstReg = MI.getOperand(0).getReg();
  Register SrcReg = MI.getOperand(1).getReg();
  const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
  const bool IsVALU = DstRB->getID() == AMDGPU::VGPRRegBankID;
  MachineBasicBlock *MBB = MI.getParent();
  const DebugLoc &DL = MI.getDebugLoc();
 
  if (IsVALU) {
    BuildMI(*MBB, MI, DL, TII.get(AMDGPU::V_LSHRREV_B32_e64), DstReg)
      .addImm(Subtarget->getWavefrontSizeLog2())
      .addReg(SrcReg);
  } else {
    BuildMI(*MBB, MI, DL, TII.get(AMDGPU::S_LSHR_B32), DstReg)
      .addReg(SrcReg)
      .addImm(Subtarget->getWavefrontSizeLog2())
      .setOperandDead(3); // Dead scc
  }
 
  const TargetRegisterClass &RC =
      IsVALU ? AMDGPU::VGPR_32RegClass : AMDGPU::SReg_32RegClass;
  if (!RBI.constrainGenericRegister(DstReg, RC, *MRI))
    return false;
 
  MI.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectStackRestore(MachineInstr &MI) const {
  Register SrcReg = MI.getOperand(0).getReg();
  if (!RBI.constrainGenericRegister(SrcReg, AMDGPU::SReg_32RegClass, *MRI))
    return false;
 
  MachineInstr *DefMI = MRI->getVRegDef(SrcReg);
  Register SP =
      Subtarget->getTargetLowering()->getStackPointerRegisterToSaveRestore();
  Register WaveAddr = getWaveAddress(DefMI);
  MachineBasicBlock *MBB = MI.getParent();
  const DebugLoc &DL = MI.getDebugLoc();
 
  if (!WaveAddr) {
    WaveAddr = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
    BuildMI(*MBB, MI, DL, TII.get(AMDGPU::S_LSHR_B32), WaveAddr)
      .addReg(SrcReg)
      .addImm(Subtarget->getWavefrontSizeLog2())
      .setOperandDead(3); // Dead scc
  }
 
  BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::COPY), SP)
    .addReg(WaveAddr);
 
  MI.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::select(MachineInstr &I) {
 
  if (!I.isPreISelOpcode()) {
    if (I.isCopy())
      return selectCOPY(I);
    return true;
  }
 
  switch (I.getOpcode()) {
  case TargetOpcode::G_AND:
  case TargetOpcode::G_OR:
  case TargetOpcode::G_XOR:
    if (selectImpl(I, *CoverageInfo))
      return true;
    return selectG_AND_OR_XOR(I);
  case TargetOpcode::G_ADD:
  case TargetOpcode::G_SUB:
  case TargetOpcode::G_PTR_ADD:
    if (selectImpl(I, *CoverageInfo))
      return true;
    return selectG_ADD_SUB(I);
  case TargetOpcode::G_UADDO:
  case TargetOpcode::G_USUBO:
  case TargetOpcode::G_UADDE:
  case TargetOpcode::G_USUBE:
    return selectG_UADDO_USUBO_UADDE_USUBE(I);
  case AMDGPU::G_AMDGPU_MAD_U64_U32:
  case AMDGPU::G_AMDGPU_MAD_I64_I32:
    return selectG_AMDGPU_MAD_64_32(I);
  case TargetOpcode::G_INTTOPTR:
  case TargetOpcode::G_BITCAST:
  case TargetOpcode::G_PTRTOINT:
  case TargetOpcode::G_FREEZE:
    return selectCOPY(I);
  case TargetOpcode::G_CONSTANT:
  case TargetOpcode::G_FCONSTANT:
    return selectG_CONSTANT(I);
  case TargetOpcode::G_FNEG:
    if (selectImpl(I, *CoverageInfo))
      return true;
    return selectG_FNEG(I);
  case TargetOpcode::G_FABS:
    if (selectImpl(I, *CoverageInfo))
      return true;
    return selectG_FABS(I);
  case TargetOpcode::G_EXTRACT:
    return selectG_EXTRACT(I);
  case TargetOpcode::G_MERGE_VALUES:
  case TargetOpcode::G_CONCAT_VECTORS:
    return selectG_MERGE_VALUES(I);
  case TargetOpcode::G_UNMERGE_VALUES:
    return selectG_UNMERGE_VALUES(I);
  case TargetOpcode::G_BUILD_VECTOR:
  case TargetOpcode::G_BUILD_VECTOR_TRUNC:
    return selectG_BUILD_VECTOR(I);
  case TargetOpcode::G_IMPLICIT_DEF:
    return selectG_IMPLICIT_DEF(I);
  case TargetOpcode::G_INSERT:
    return selectG_INSERT(I);
  case TargetOpcode::G_INTRINSIC:
  case TargetOpcode::G_INTRINSIC_CONVERGENT:
    return selectG_INTRINSIC(I);
  case TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS:
  case TargetOpcode::G_INTRINSIC_CONVERGENT_W_SIDE_EFFECTS:
    return selectG_INTRINSIC_W_SIDE_EFFECTS(I);
  case TargetOpcode::G_ICMP:
  case TargetOpcode::G_FCMP:
    if (selectG_ICMP_or_FCMP(I))
      return true;
    return selectImpl(I, *CoverageInfo);
  case TargetOpcode::G_LOAD:
  case TargetOpcode::G_STORE:
  case TargetOpcode::G_ATOMIC_CMPXCHG:
  case TargetOpcode::G_ATOMICRMW_XCHG:
  case TargetOpcode::G_ATOMICRMW_ADD:
  case TargetOpcode::G_ATOMICRMW_SUB:
  case TargetOpcode::G_ATOMICRMW_AND:
  case TargetOpcode::G_ATOMICRMW_OR:
  case TargetOpcode::G_ATOMICRMW_XOR:
  case TargetOpcode::G_ATOMICRMW_MIN:
  case TargetOpcode::G_ATOMICRMW_MAX:
  case TargetOpcode::G_ATOMICRMW_UMIN:
  case TargetOpcode::G_ATOMICRMW_UMAX:
  case TargetOpcode::G_ATOMICRMW_UINC_WRAP:
  case TargetOpcode::G_ATOMICRMW_UDEC_WRAP:
  case TargetOpcode::G_ATOMICRMW_FADD:
  case TargetOpcode::G_ATOMICRMW_FMIN:
  case TargetOpcode::G_ATOMICRMW_FMAX:
    return selectG_LOAD_STORE_ATOMICRMW(I);
  case TargetOpcode::G_SELECT:
    return selectG_SELECT(I);
  case TargetOpcode::G_TRUNC:
    return selectG_TRUNC(I);
  case TargetOpcode::G_SEXT:
  case TargetOpcode::G_ZEXT:
  case TargetOpcode::G_ANYEXT:
  case TargetOpcode::G_SEXT_INREG:
    // This is a workaround. For extension from type i1, `selectImpl()` uses
    // patterns from TD file and generates an illegal VGPR to SGPR COPY as type
    // i1 can only be hold in a SGPR class.
    if (MRI->getType(I.getOperand(1).getReg()) != LLT::scalar(1) &&
        selectImpl(I, *CoverageInfo))
      return true;
    return selectG_SZA_EXT(I);
  case TargetOpcode::G_FPEXT:
    if (selectG_FPEXT(I))
      return true;
    return selectImpl(I, *CoverageInfo);
  case TargetOpcode::G_BRCOND:
    return selectG_BRCOND(I);
  case TargetOpcode::G_GLOBAL_VALUE:
    return selectG_GLOBAL_VALUE(I);
  case TargetOpcode::G_PTRMASK:
    return selectG_PTRMASK(I);
  case TargetOpcode::G_EXTRACT_VECTOR_ELT:
    return selectG_EXTRACT_VECTOR_ELT(I);
  case TargetOpcode::G_INSERT_VECTOR_ELT:
    return selectG_INSERT_VECTOR_ELT(I);
  case AMDGPU::G_AMDGPU_INTRIN_IMAGE_LOAD:
  case AMDGPU::G_AMDGPU_INTRIN_IMAGE_LOAD_D16:
  case AMDGPU::G_AMDGPU_INTRIN_IMAGE_LOAD_NORET:
  case AMDGPU::G_AMDGPU_INTRIN_IMAGE_STORE:
  case AMDGPU::G_AMDGPU_INTRIN_IMAGE_STORE_D16: {
    const AMDGPU::ImageDimIntrinsicInfo *Intr =
        AMDGPU::getImageDimIntrinsicInfo(AMDGPU::getIntrinsicID(I));
    assert(Intr && "not an image intrinsic with image pseudo");
    return selectImageIntrinsic(I, Intr);
  }
  case AMDGPU::G_AMDGPU_INTRIN_BVH_INTERSECT_RAY:
    return selectBVHIntrinsic(I);
  case AMDGPU::G_SBFX:
  case AMDGPU::G_UBFX:
    return selectG_SBFX_UBFX(I);
  case AMDGPU::G_SI_CALL:
    I.setDesc(TII.get(AMDGPU::SI_CALL));
    return true;
  case AMDGPU::G_AMDGPU_WAVE_ADDRESS:
    return selectWaveAddress(I);
  case AMDGPU::G_STACKRESTORE:
    return selectStackRestore(I);
  case AMDGPU::G_PHI:
    return selectPHI(I);
  default:
    return selectImpl(I, *CoverageInfo);
  }
  return false;
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVCSRC(MachineOperand &Root) const {
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.add(Root); }
  }};
 
}
 
std::pair<Register, unsigned>
AMDGPUInstructionSelector::selectVOP3ModsImpl(MachineOperand &Root,
                                              bool IsCanonicalizing,
                                              bool AllowAbs, bool OpSel) const {
  Register Src = Root.getReg();
  unsigned Mods = 0;
  MachineInstr *MI = getDefIgnoringCopies(Src, *MRI);
 
  if (MI->getOpcode() == AMDGPU::G_FNEG) {
    Src = MI->getOperand(1).getReg();
    Mods |= SISrcMods::NEG;
    MI = getDefIgnoringCopies(Src, *MRI);
  } else if (MI->getOpcode() == AMDGPU::G_FSUB && IsCanonicalizing) {
    // Fold fsub [+-]0 into fneg. This may not have folded depending on the
    // denormal mode, but we're implicitly canonicalizing in a source operand.
    const ConstantFP *LHS =
        getConstantFPVRegVal(MI->getOperand(1).getReg(), *MRI);
    if (LHS && LHS->isZero()) {
      Mods |= SISrcMods::NEG;
      Src = MI->getOperand(2).getReg();
    }
  }
 
  if (AllowAbs && MI->getOpcode() == AMDGPU::G_FABS) {
    Src = MI->getOperand(1).getReg();
    Mods |= SISrcMods::ABS;
  }
 
  if (OpSel)
    Mods |= SISrcMods::OP_SEL_0;
 
  return std::pair(Src, Mods);
}
 
Register AMDGPUInstructionSelector::copyToVGPRIfSrcFolded(
    Register Src, unsigned Mods, MachineOperand Root, MachineInstr *InsertPt,
    bool ForceVGPR) const {
  if ((Mods != 0 || ForceVGPR) &&
      RBI.getRegBank(Src, *MRI, TRI)->getID() != AMDGPU::VGPRRegBankID) {
 
    // If we looked through copies to find source modifiers on an SGPR operand,
    // we now have an SGPR register source. To avoid potentially violating the
    // constant bus restriction, we need to insert a copy to a VGPR.
    Register VGPRSrc = MRI->cloneVirtualRegister(Root.getReg());
    BuildMI(*InsertPt->getParent(), InsertPt, InsertPt->getDebugLoc(),
            TII.get(AMDGPU::COPY), VGPRSrc)
        .addReg(Src);
    Src = VGPRSrc;
  }
 
  return Src;
}
 
///
/// This will select either an SGPR or VGPR operand and will save us from
/// having to write an extra tablegen pattern.
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVSRC0(MachineOperand &Root) const {
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.add(Root); }
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVOP3Mods0(MachineOperand &Root) const {
  Register Src;
  unsigned Mods;
  std::tie(Src, Mods) = selectVOP3ModsImpl(Root);
 
  return {{
      [=](MachineInstrBuilder &MIB) {
        MIB.addReg(copyToVGPRIfSrcFolded(Src, Mods, Root, MIB));
      },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); }, // src0_mods
      [=](MachineInstrBuilder &MIB) { MIB.addImm(0); },    // clamp
      [=](MachineInstrBuilder &MIB) { MIB.addImm(0); }     // omod
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVOP3BMods0(MachineOperand &Root) const {
  Register Src;
  unsigned Mods;
  std::tie(Src, Mods) = selectVOP3ModsImpl(Root,
                                           /*IsCanonicalizing=*/true,
                                           /*AllowAbs=*/false);
 
  return {{
      [=](MachineInstrBuilder &MIB) {
        MIB.addReg(copyToVGPRIfSrcFolded(Src, Mods, Root, MIB));
      },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); }, // src0_mods
      [=](MachineInstrBuilder &MIB) { MIB.addImm(0); },    // clamp
      [=](MachineInstrBuilder &MIB) { MIB.addImm(0); }     // omod
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVOP3OMods(MachineOperand &Root) const {
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.add(Root); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(0); }, // clamp
      [=](MachineInstrBuilder &MIB) { MIB.addImm(0); }  // omod
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVOP3Mods(MachineOperand &Root) const {
  Register Src;
  unsigned Mods;
  std::tie(Src, Mods) = selectVOP3ModsImpl(Root);
 
  return {{
      [=](MachineInstrBuilder &MIB) {
        MIB.addReg(copyToVGPRIfSrcFolded(Src, Mods, Root, MIB));
      },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); } // src_mods
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVOP3ModsNonCanonicalizing(
    MachineOperand &Root) const {
  Register Src;
  unsigned Mods;
  std::tie(Src, Mods) = selectVOP3ModsImpl(Root, /*IsCanonicalizing=*/false);
 
  return {{
      [=](MachineInstrBuilder &MIB) {
        MIB.addReg(copyToVGPRIfSrcFolded(Src, Mods, Root, MIB));
      },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); } // src_mods
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVOP3BMods(MachineOperand &Root) const {
  Register Src;
  unsigned Mods;
  std::tie(Src, Mods) = selectVOP3ModsImpl(Root, /*IsCanonicalizing=*/true,
                                           /*AllowAbs=*/false);
 
  return {{
      [=](MachineInstrBuilder &MIB) {
        MIB.addReg(copyToVGPRIfSrcFolded(Src, Mods, Root, MIB));
      },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); } // src_mods
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVOP3NoMods(MachineOperand &Root) const {
  Register Reg = Root.getReg();
  const MachineInstr *Def = getDefIgnoringCopies(Reg, *MRI);
  if (Def->getOpcode() == AMDGPU::G_FNEG || Def->getOpcode() == AMDGPU::G_FABS)
    return {};
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(Reg); },
  }};
}
 
std::pair<Register, unsigned>
AMDGPUInstructionSelector::selectVOP3PModsImpl(
  Register Src, const MachineRegisterInfo &MRI, bool IsDOT) const {
  unsigned Mods = 0;
  MachineInstr *MI = MRI.getVRegDef(Src);
 
  if (MI && MI->getOpcode() == AMDGPU::G_FNEG &&
      // It's possible to see an f32 fneg here, but unlikely.
      // TODO: Treat f32 fneg as only high bit.
      MRI.getType(Src) == LLT::fixed_vector(2, 16)) {
    Mods ^= (SISrcMods::NEG | SISrcMods::NEG_HI);
    Src = MI->getOperand(1).getReg();
    MI = MRI.getVRegDef(Src);
  }
 
  // TODO: Handle G_FSUB 0 as fneg
 
  // TODO: Match op_sel through g_build_vector_trunc and g_shuffle_vector.
  (void)IsDOT; // DOTs do not use OPSEL on gfx940+, check ST.hasDOTOpSelHazard()
 
  // Packed instructions do not have abs modifiers.
  Mods |= SISrcMods::OP_SEL_1;
 
  return std::pair(Src, Mods);
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVOP3PMods(MachineOperand &Root) const {
  MachineRegisterInfo &MRI
    = Root.getParent()->getParent()->getParent()->getRegInfo();
 
  Register Src;
  unsigned Mods;
  std::tie(Src, Mods) = selectVOP3PModsImpl(Root.getReg(), MRI);
 
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); }  // src_mods
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVOP3PModsDOT(MachineOperand &Root) const {
  MachineRegisterInfo &MRI
    = Root.getParent()->getParent()->getParent()->getRegInfo();
 
  Register Src;
  unsigned Mods;
  std::tie(Src, Mods) = selectVOP3PModsImpl(Root.getReg(), MRI, true);
 
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); }  // src_mods
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVOP3PModsNeg(MachineOperand &Root) const {
  // Literal i1 value set in intrinsic, represents SrcMods for the next operand.
  // Value is in Imm operand as i1 sign extended to int64_t.
  // 1(-1) promotes packed values to signed, 0 treats them as unsigned.
  assert((Root.isImm() && (Root.getImm() == -1 || Root.getImm() == 0)) &&
         "expected i1 value");
  unsigned Mods = SISrcMods::OP_SEL_1;
  if (Root.getImm() == -1)
    Mods ^= SISrcMods::NEG;
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); } // src_mods
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectWMMAOpSelVOP3PMods(
    MachineOperand &Root) const {
  assert((Root.isImm() && (Root.getImm() == -1 || Root.getImm() == 0)) &&
         "expected i1 value");
  unsigned Mods = SISrcMods::OP_SEL_1;
  if (Root.getImm() != 0)
    Mods |= SISrcMods::OP_SEL_0;
 
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); } // src_mods
  }};
}
 
static Register buildRegSequence(SmallVectorImpl<Register> &Elts,
                                 MachineInstr *InsertPt,
                                 MachineRegisterInfo &MRI) {
  const TargetRegisterClass *DstRegClass;
  switch (Elts.size()) {
  case 8:
    DstRegClass = &AMDGPU::VReg_256RegClass;
    break;
  case 4:
    DstRegClass = &AMDGPU::VReg_128RegClass;
    break;
  case 2:
    DstRegClass = &AMDGPU::VReg_64RegClass;
    break;
  default:
    llvm_unreachable("unhandled Reg sequence size");
  }
 
  MachineIRBuilder B(*InsertPt);
  auto MIB = B.buildInstr(AMDGPU::REG_SEQUENCE)
                 .addDef(MRI.createVirtualRegister(DstRegClass));
  for (unsigned i = 0; i < Elts.size(); ++i) {
    MIB.addReg(Elts[i]);
    MIB.addImm(SIRegisterInfo::getSubRegFromChannel(i));
  }
  return MIB->getOperand(0).getReg();
}
 
static void selectWMMAModsNegAbs(unsigned ModOpcode, unsigned &Mods,
                                 SmallVectorImpl<Register> &Elts, Register &Src,
                                 MachineInstr *InsertPt,
                                 MachineRegisterInfo &MRI) {
  if (ModOpcode == TargetOpcode::G_FNEG) {
    Mods |= SISrcMods::NEG;
    // Check if all elements also have abs modifier
    SmallVector<Register, 8> NegAbsElts;
    for (auto El : Elts) {
      Register FabsSrc;
      if (!mi_match(El, MRI, m_GFabs(m_Reg(FabsSrc))))
        break;
      NegAbsElts.push_back(FabsSrc);
    }
    if (Elts.size() != NegAbsElts.size()) {
      // Neg
      Src = buildRegSequence(Elts, InsertPt, MRI);
    } else {
      // Neg and Abs
      Mods |= SISrcMods::NEG_HI;
      Src = buildRegSequence(NegAbsElts, InsertPt, MRI);
    }
  } else {
    assert(ModOpcode == TargetOpcode::G_FABS);
    // Abs
    Mods |= SISrcMods::NEG_HI;
    Src = buildRegSequence(Elts, InsertPt, MRI);
  }
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectWMMAModsF32NegAbs(MachineOperand &Root) const {
  Register Src = Root.getReg();
  unsigned Mods = SISrcMods::OP_SEL_1;
  SmallVector<Register, 8> EltsF32;
 
  if (GBuildVector *BV = dyn_cast<GBuildVector>(MRI->getVRegDef(Src))) {
    assert(BV->getNumSources() > 0);
    // Based on first element decide which mod we match, neg or abs
    MachineInstr *ElF32 = MRI->getVRegDef(BV->getSourceReg(0));
    unsigned ModOpcode = (ElF32->getOpcode() == AMDGPU::G_FNEG)
                             ? AMDGPU::G_FNEG
                             : AMDGPU::G_FABS;
    for (unsigned i = 0; i < BV->getNumSources(); ++i) {
      ElF32 = MRI->getVRegDef(BV->getSourceReg(i));
      if (ElF32->getOpcode() != ModOpcode)
        break;
      EltsF32.push_back(ElF32->getOperand(1).getReg());
    }
 
    // All elements had ModOpcode modifier
    if (BV->getNumSources() == EltsF32.size()) {
      selectWMMAModsNegAbs(ModOpcode, Mods, EltsF32, Src, Root.getParent(),
                           *MRI);
    }
  }
 
  return {{[=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
           [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); }}};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectWMMAModsF16Neg(MachineOperand &Root) const {
  Register Src = Root.getReg();
  unsigned Mods = SISrcMods::OP_SEL_1;
  SmallVector<Register, 8> EltsV2F16;
 
  if (GConcatVectors *CV = dyn_cast<GConcatVectors>(MRI->getVRegDef(Src))) {
    for (unsigned i = 0; i < CV->getNumSources(); ++i) {
      Register FNegSrc;
      if (!mi_match(CV->getSourceReg(i), *MRI, m_GFNeg(m_Reg(FNegSrc))))
        break;
      EltsV2F16.push_back(FNegSrc);
    }
 
    // All elements had ModOpcode modifier
    if (CV->getNumSources() == EltsV2F16.size()) {
      Mods |= SISrcMods::NEG;
      Mods |= SISrcMods::NEG_HI;
      Src = buildRegSequence(EltsV2F16, Root.getParent(), *MRI);
    }
  }
 
  return {{[=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
           [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); }}};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectWMMAModsF16NegAbs(MachineOperand &Root) const {
  Register Src = Root.getReg();
  unsigned Mods = SISrcMods::OP_SEL_1;
  SmallVector<Register, 8> EltsV2F16;
 
  if (GConcatVectors *CV = dyn_cast<GConcatVectors>(MRI->getVRegDef(Src))) {
    assert(CV->getNumSources() > 0);
    MachineInstr *ElV2F16 = MRI->getVRegDef(CV->getSourceReg(0));
    // Based on first element decide which mod we match, neg or abs
    unsigned ModOpcode = (ElV2F16->getOpcode() == AMDGPU::G_FNEG)
                             ? AMDGPU::G_FNEG
                             : AMDGPU::G_FABS;
 
    for (unsigned i = 0; i < CV->getNumSources(); ++i) {
      ElV2F16 = MRI->getVRegDef(CV->getSourceReg(i));
      if (ElV2F16->getOpcode() != ModOpcode)
        break;
      EltsV2F16.push_back(ElV2F16->getOperand(1).getReg());
    }
 
    // All elements had ModOpcode modifier
    if (CV->getNumSources() == EltsV2F16.size()) {
      MachineIRBuilder B(*Root.getParent());
      selectWMMAModsNegAbs(ModOpcode, Mods, EltsV2F16, Src, Root.getParent(),
                           *MRI);
    }
  }
 
  return {{[=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
           [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); }}};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectWMMAVISrc(MachineOperand &Root) const {
  std::optional<FPValueAndVReg> FPValReg;
  if (mi_match(Root.getReg(), *MRI, m_GFCstOrSplat(FPValReg))) {
    if (TII.isInlineConstant(FPValReg->Value)) {
      return {{[=](MachineInstrBuilder &MIB) {
        MIB.addImm(FPValReg->Value.bitcastToAPInt().getSExtValue());
      }}};
    }
    // Non-inlineable splat floats should not fall-through for integer immediate
    // checks.
    return {};
  }
 
  APInt ICst;
  if (mi_match(Root.getReg(), *MRI, m_ICstOrSplat(ICst))) {
    if (TII.isInlineConstant(ICst)) {
      return {
          {[=](MachineInstrBuilder &MIB) { MIB.addImm(ICst.getSExtValue()); }}};
    }
  }
 
  return {};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectSWMMACIndex8(MachineOperand &Root) const {
  Register Src =
      getDefIgnoringCopies(Root.getReg(), *MRI)->getOperand(0).getReg();
  unsigned Key = 0;
 
  Register ShiftSrc;
  std::optional<ValueAndVReg> ShiftAmt;
  if (mi_match(Src, *MRI, m_GLShr(m_Reg(ShiftSrc), m_GCst(ShiftAmt))) &&
      MRI->getType(ShiftSrc).getSizeInBits() == 32 &&
      ShiftAmt->Value.getZExtValue() % 8 == 0) {
    Key = ShiftAmt->Value.getZExtValue() / 8;
    Src = ShiftSrc;
  }
 
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Key); } // index_key
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectSWMMACIndex16(MachineOperand &Root) const {
 
  Register Src =
      getDefIgnoringCopies(Root.getReg(), *MRI)->getOperand(0).getReg();
  unsigned Key = 0;
 
  Register ShiftSrc;
  std::optional<ValueAndVReg> ShiftAmt;
  if (mi_match(Src, *MRI, m_GLShr(m_Reg(ShiftSrc), m_GCst(ShiftAmt))) &&
      MRI->getType(ShiftSrc).getSizeInBits() == 32 &&
      ShiftAmt->Value.getZExtValue() == 16) {
    Src = ShiftSrc;
    Key = 1;
  }
 
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Key); } // index_key
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVOP3OpSelMods(MachineOperand &Root) const {
  Register Src;
  unsigned Mods;
  std::tie(Src, Mods) = selectVOP3ModsImpl(Root);
 
  // FIXME: Handle op_sel
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); } // src_mods
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVINTERPMods(MachineOperand &Root) const {
  Register Src;
  unsigned Mods;
  std::tie(Src, Mods) = selectVOP3ModsImpl(Root,
                                           /*IsCanonicalizing=*/true,
                                           /*AllowAbs=*/false,
                                           /*OpSel=*/false);
 
  return {{
      [=](MachineInstrBuilder &MIB) {
        MIB.addReg(
            copyToVGPRIfSrcFolded(Src, Mods, Root, MIB, /* ForceVGPR */ true));
      },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); }, // src0_mods
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVINTERPModsHi(MachineOperand &Root) const {
  Register Src;
  unsigned Mods;
  std::tie(Src, Mods) = selectVOP3ModsImpl(Root,
                                           /*IsCanonicalizing=*/true,
                                           /*AllowAbs=*/false,
                                           /*OpSel=*/true);
 
  return {{
      [=](MachineInstrBuilder &MIB) {
        MIB.addReg(
            copyToVGPRIfSrcFolded(Src, Mods, Root, MIB, /* ForceVGPR */ true));
      },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); }, // src0_mods
  }};
}
 
bool AMDGPUInstructionSelector::selectSmrdOffset(MachineOperand &Root,
                                                 Register &Base,
                                                 Register *SOffset,
                                                 int64_t *Offset) const {
  MachineInstr *MI = Root.getParent();
  MachineBasicBlock *MBB = MI->getParent();
 
  // FIXME: We should shrink the GEP if the offset is known to be <= 32-bits,
  // then we can select all ptr + 32-bit offsets.
  SmallVector<GEPInfo, 4> AddrInfo;
  getAddrModeInfo(*MI, *MRI, AddrInfo);
 
  if (AddrInfo.empty())
    return false;
 
  const GEPInfo &GEPI = AddrInfo[0];
  std::optional<int64_t> EncodedImm;
 
  if (SOffset && Offset) {
    EncodedImm = AMDGPU::getSMRDEncodedOffset(STI, GEPI.Imm, /*IsBuffer=*/false,
                                              /*HasSOffset=*/true);
    if (GEPI.SgprParts.size() == 1 && GEPI.Imm != 0 && EncodedImm &&
        AddrInfo.size() > 1) {
      const GEPInfo &GEPI2 = AddrInfo[1];
      if (GEPI2.SgprParts.size() == 2 && GEPI2.Imm == 0) {
        if (Register OffsetReg =
                matchZeroExtendFromS32(*MRI, GEPI2.SgprParts[1])) {
          Base = GEPI2.SgprParts[0];
          *SOffset = OffsetReg;
          *Offset = *EncodedImm;
          if (*Offset >= 0 || !AMDGPU::hasSMRDSignedImmOffset(STI))
            return true;
 
          // For unbuffered smem loads, it is illegal for the Immediate Offset
          // to be negative if the resulting (Offset + (M0 or SOffset or zero)
          // is negative. Handle the case where the Immediate Offset + SOffset
          // is negative.
          auto SKnown = KB->getKnownBits(*SOffset);
          if (*Offset + SKnown.getMinValue().getSExtValue() < 0)
            return false;
 
          return true;
        }
      }
    }
    return false;
  }
 
  EncodedImm = AMDGPU::getSMRDEncodedOffset(STI, GEPI.Imm, /*IsBuffer=*/false,
                                            /*HasSOffset=*/false);
  if (Offset && GEPI.SgprParts.size() == 1 && EncodedImm) {
    Base = GEPI.SgprParts[0];
    *Offset = *EncodedImm;
    return true;
  }
 
  // SGPR offset is unsigned.
  if (SOffset && GEPI.SgprParts.size() == 1 && isUInt<32>(GEPI.Imm) &&
      GEPI.Imm != 0) {
    // If we make it this far we have a load with an 32-bit immediate offset.
    // It is OK to select this using a sgpr offset, because we have already
    // failed trying to select this load into one of the _IMM variants since
    // the _IMM Patterns are considered before the _SGPR patterns.
    Base = GEPI.SgprParts[0];
    *SOffset = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
    BuildMI(*MBB, MI, MI->getDebugLoc(), TII.get(AMDGPU::S_MOV_B32), *SOffset)
        .addImm(GEPI.Imm);
    return true;
  }
 
  if (SOffset && GEPI.SgprParts.size() && GEPI.Imm == 0) {
    if (Register OffsetReg = matchZeroExtendFromS32(*MRI, GEPI.SgprParts[1])) {
      Base = GEPI.SgprParts[0];
      *SOffset = OffsetReg;
      return true;
    }
  }
 
  return false;
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectSmrdImm(MachineOperand &Root) const {
  Register Base;
  int64_t Offset;
  if (!selectSmrdOffset(Root, Base, /* SOffset= */ nullptr, &Offset))
    return std::nullopt;
 
  return {{[=](MachineInstrBuilder &MIB) { MIB.addReg(Base); },
           [=](MachineInstrBuilder &MIB) { MIB.addImm(Offset); }}};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectSmrdImm32(MachineOperand &Root) const {
  SmallVector<GEPInfo, 4> AddrInfo;
  getAddrModeInfo(*Root.getParent(), *MRI, AddrInfo);
 
  if (AddrInfo.empty() || AddrInfo[0].SgprParts.size() != 1)
    return std::nullopt;
 
  const GEPInfo &GEPInfo = AddrInfo[0];
  Register PtrReg = GEPInfo.SgprParts[0];
  std::optional<int64_t> EncodedImm =
      AMDGPU::getSMRDEncodedLiteralOffset32(STI, GEPInfo.Imm);
  if (!EncodedImm)
    return std::nullopt;
 
  return {{
    [=](MachineInstrBuilder &MIB) { MIB.addReg(PtrReg); },
    [=](MachineInstrBuilder &MIB) { MIB.addImm(*EncodedImm); }
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectSmrdSgpr(MachineOperand &Root) const {
  Register Base, SOffset;
  if (!selectSmrdOffset(Root, Base, &SOffset, /* Offset= */ nullptr))
    return std::nullopt;
 
  return {{[=](MachineInstrBuilder &MIB) { MIB.addReg(Base); },
           [=](MachineInstrBuilder &MIB) { MIB.addReg(SOffset); }}};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectSmrdSgprImm(MachineOperand &Root) const {
  Register Base, SOffset;
  int64_t Offset;
  if (!selectSmrdOffset(Root, Base, &SOffset, &Offset))
    return std::nullopt;
 
  return {{[=](MachineInstrBuilder &MIB) { MIB.addReg(Base); },
           [=](MachineInstrBuilder &MIB) { MIB.addReg(SOffset); },
           [=](MachineInstrBuilder &MIB) { MIB.addImm(Offset); }}};
}
 
std::pair<Register, int>
AMDGPUInstructionSelector::selectFlatOffsetImpl(MachineOperand &Root,
                                                uint64_t FlatVariant) const {
  MachineInstr *MI = Root.getParent();
 
  auto Default = std::pair(Root.getReg(), 0);
 
  if (!STI.hasFlatInstOffsets())
    return Default;
 
  Register PtrBase;
  int64_t ConstOffset;
  std::tie(PtrBase, ConstOffset) =
      getPtrBaseWithConstantOffset(Root.getReg(), *MRI);
 
  if (ConstOffset == 0 || (FlatVariant == SIInstrFlags::FlatScratch &&
                           !isFlatScratchBaseLegal(Root.getReg())))
    return Default;
 
  unsigned AddrSpace = (*MI->memoperands_begin())->getAddrSpace();
  if (!TII.isLegalFLATOffset(ConstOffset, AddrSpace, FlatVariant))
    return Default;
 
  return std::pair(PtrBase, ConstOffset);
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectFlatOffset(MachineOperand &Root) const {
  auto PtrWithOffset = selectFlatOffsetImpl(Root, SIInstrFlags::FLAT);
 
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(PtrWithOffset.first); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(PtrWithOffset.second); },
    }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectGlobalOffset(MachineOperand &Root) const {
  auto PtrWithOffset = selectFlatOffsetImpl(Root, SIInstrFlags::FlatGlobal);
 
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(PtrWithOffset.first); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(PtrWithOffset.second); },
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectScratchOffset(MachineOperand &Root) const {
  auto PtrWithOffset = selectFlatOffsetImpl(Root, SIInstrFlags::FlatScratch);
 
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(PtrWithOffset.first); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(PtrWithOffset.second); },
    }};
}
 
// Match (64-bit SGPR base) + (zext vgpr offset) + sext(imm offset)
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectGlobalSAddr(MachineOperand &Root) const {
  Register Addr = Root.getReg();
  Register PtrBase;
  int64_t ConstOffset;
  int64_t ImmOffset = 0;
 
  // Match the immediate offset first, which canonically is moved as low as
  // possible.
  std::tie(PtrBase, ConstOffset) = getPtrBaseWithConstantOffset(Addr, *MRI);
 
  if (ConstOffset != 0) {
    if (TII.isLegalFLATOffset(ConstOffset, AMDGPUAS::GLOBAL_ADDRESS,
                              SIInstrFlags::FlatGlobal)) {
      Addr = PtrBase;
      ImmOffset = ConstOffset;
    } else {
      auto PtrBaseDef = getDefSrcRegIgnoringCopies(PtrBase, *MRI);
      if (isSGPR(PtrBaseDef->Reg)) {
        if (ConstOffset > 0) {
          // Offset is too large.
          //
          // saddr + large_offset -> saddr +
          //                         (voffset = large_offset & ~MaxOffset) +
          //                         (large_offset & MaxOffset);
          int64_t SplitImmOffset, RemainderOffset;
          std::tie(SplitImmOffset, RemainderOffset) = TII.splitFlatOffset(
              ConstOffset, AMDGPUAS::GLOBAL_ADDRESS, SIInstrFlags::FlatGlobal);
 
          if (isUInt<32>(RemainderOffset)) {
            MachineInstr *MI = Root.getParent();
            MachineBasicBlock *MBB = MI->getParent();
            Register HighBits =
                MRI->createVirtualRegister(&AMDGPU::VGPR_32RegClass);
 
            BuildMI(*MBB, MI, MI->getDebugLoc(), TII.get(AMDGPU::V_MOV_B32_e32),
                    HighBits)
                .addImm(RemainderOffset);
 
            return {{
                [=](MachineInstrBuilder &MIB) { MIB.addReg(PtrBase); }, // saddr
                [=](MachineInstrBuilder &MIB) {
                  MIB.addReg(HighBits);
                }, // voffset
                [=](MachineInstrBuilder &MIB) { MIB.addImm(SplitImmOffset); },
            }};
          }
        }
 
        // We are adding a 64 bit SGPR and a constant. If constant bus limit
        // is 1 we would need to perform 1 or 2 extra moves for each half of
        // the constant and it is better to do a scalar add and then issue a
        // single VALU instruction to materialize zero. Otherwise it is less
        // instructions to perform VALU adds with immediates or inline literals.
        unsigned NumLiterals =
            !TII.isInlineConstant(APInt(32, ConstOffset & 0xffffffff)) +
            !TII.isInlineConstant(APInt(32, ConstOffset >> 32));
        if (STI.getConstantBusLimit(AMDGPU::V_ADD_U32_e64) > NumLiterals)
          return std::nullopt;
      }
    }
  }
 
  // Match the variable offset.
  auto AddrDef = getDefSrcRegIgnoringCopies(Addr, *MRI);
  if (AddrDef->MI->getOpcode() == AMDGPU::G_PTR_ADD) {
    // Look through the SGPR->VGPR copy.
    Register SAddr =
        getSrcRegIgnoringCopies(AddrDef->MI->getOperand(1).getReg(), *MRI);
 
    if (isSGPR(SAddr)) {
      Register PtrBaseOffset = AddrDef->MI->getOperand(2).getReg();
 
      // It's possible voffset is an SGPR here, but the copy to VGPR will be
      // inserted later.
      if (Register VOffset = matchZeroExtendFromS32(*MRI, PtrBaseOffset)) {
        return {{[=](MachineInstrBuilder &MIB) { // saddr
                   MIB.addReg(SAddr);
                 },
                 [=](MachineInstrBuilder &MIB) { // voffset
                   MIB.addReg(VOffset);
                 },
                 [=](MachineInstrBuilder &MIB) { // offset
                   MIB.addImm(ImmOffset);
                 }}};
      }
    }
  }
 
  // FIXME: We should probably have folded COPY (G_IMPLICIT_DEF) earlier, and
  // drop this.
  if (AddrDef->MI->getOpcode() == AMDGPU::G_IMPLICIT_DEF ||
      AddrDef->MI->getOpcode() == AMDGPU::G_CONSTANT || !isSGPR(AddrDef->Reg))
    return std::nullopt;
 
  // It's cheaper to materialize a single 32-bit zero for vaddr than the two
  // moves required to copy a 64-bit SGPR to VGPR.
  MachineInstr *MI = Root.getParent();
  MachineBasicBlock *MBB = MI->getParent();
  Register VOffset = MRI->createVirtualRegister(&AMDGPU::VGPR_32RegClass);
 
  BuildMI(*MBB, MI, MI->getDebugLoc(), TII.get(AMDGPU::V_MOV_B32_e32), VOffset)
      .addImm(0);
 
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(AddrDef->Reg); }, // saddr
      [=](MachineInstrBuilder &MIB) { MIB.addReg(VOffset); },      // voffset
      [=](MachineInstrBuilder &MIB) { MIB.addImm(ImmOffset); }     // offset
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectScratchSAddr(MachineOperand &Root) const {
  Register Addr = Root.getReg();
  Register PtrBase;
  int64_t ConstOffset;
  int64_t ImmOffset = 0;
 
  // Match the immediate offset first, which canonically is moved as low as
  // possible.
  std::tie(PtrBase, ConstOffset) = getPtrBaseWithConstantOffset(Addr, *MRI);
 
  if (ConstOffset != 0 && isFlatScratchBaseLegal(Addr) &&
      TII.isLegalFLATOffset(ConstOffset, AMDGPUAS::PRIVATE_ADDRESS,
                            SIInstrFlags::FlatScratch)) {
    Addr = PtrBase;
    ImmOffset = ConstOffset;
  }
 
  auto AddrDef = getDefSrcRegIgnoringCopies(Addr, *MRI);
  if (AddrDef->MI->getOpcode() == AMDGPU::G_FRAME_INDEX) {
    int FI = AddrDef->MI->getOperand(1).getIndex();
    return {{
        [=](MachineInstrBuilder &MIB) { MIB.addFrameIndex(FI); }, // saddr
        [=](MachineInstrBuilder &MIB) { MIB.addImm(ImmOffset); } // offset
    }};
  }
 
  Register SAddr = AddrDef->Reg;
 
  if (AddrDef->MI->getOpcode() == AMDGPU::G_PTR_ADD) {
    Register LHS = AddrDef->MI->getOperand(1).getReg();
    Register RHS = AddrDef->MI->getOperand(2).getReg();
    auto LHSDef = getDefSrcRegIgnoringCopies(LHS, *MRI);
    auto RHSDef = getDefSrcRegIgnoringCopies(RHS, *MRI);
 
    if (LHSDef->MI->getOpcode() == AMDGPU::G_FRAME_INDEX &&
        isSGPR(RHSDef->Reg)) {
      int FI = LHSDef->MI->getOperand(1).getIndex();
      MachineInstr &I = *Root.getParent();
      MachineBasicBlock *BB = I.getParent();
      const DebugLoc &DL = I.getDebugLoc();
      SAddr = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
 
      BuildMI(*BB, &I, DL, TII.get(AMDGPU::S_ADD_I32), SAddr)
          .addFrameIndex(FI)
          .addReg(RHSDef->Reg)
          .setOperandDead(3); // Dead scc
    }
  }
 
  if (!isSGPR(SAddr))
    return std::nullopt;
 
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(SAddr); }, // saddr
      [=](MachineInstrBuilder &MIB) { MIB.addImm(ImmOffset); } // offset
  }};
}
 
// Check whether the flat scratch SVS swizzle bug affects this access.
bool AMDGPUInstructionSelector::checkFlatScratchSVSSwizzleBug(
    Register VAddr, Register SAddr, uint64_t ImmOffset) const {
  if (!Subtarget->hasFlatScratchSVSSwizzleBug())
    return false;
 
  // The bug affects the swizzling of SVS accesses if there is any carry out
  // from the two low order bits (i.e. from bit 1 into bit 2) when adding
  // voffset to (soffset + inst_offset).
  auto VKnown = KB->getKnownBits(VAddr);
  auto SKnown = KnownBits::computeForAddSub(
      /*Add=*/true, /*NSW=*/false, /*NUW=*/false, KB->getKnownBits(SAddr),
      KnownBits::makeConstant(APInt(32, ImmOffset)));
  uint64_t VMax = VKnown.getMaxValue().getZExtValue();
  uint64_t SMax = SKnown.getMaxValue().getZExtValue();
  return (VMax & 3) + (SMax & 3) >= 4;
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectScratchSVAddr(MachineOperand &Root) const {
  Register Addr = Root.getReg();
  Register PtrBase;
  int64_t ConstOffset;
  int64_t ImmOffset = 0;
 
  // Match the immediate offset first, which canonically is moved as low as
  // possible.
  std::tie(PtrBase, ConstOffset) = getPtrBaseWithConstantOffset(Addr, *MRI);
 
  Register OrigAddr = Addr;
  if (ConstOffset != 0 &&
      TII.isLegalFLATOffset(ConstOffset, AMDGPUAS::PRIVATE_ADDRESS, true)) {
    Addr = PtrBase;
    ImmOffset = ConstOffset;
  }
 
  auto AddrDef = getDefSrcRegIgnoringCopies(Addr, *MRI);
  if (AddrDef->MI->getOpcode() != AMDGPU::G_PTR_ADD)
    return std::nullopt;
 
  Register RHS = AddrDef->MI->getOperand(2).getReg();
  if (RBI.getRegBank(RHS, *MRI, TRI)->getID() != AMDGPU::VGPRRegBankID)
    return std::nullopt;
 
  Register LHS = AddrDef->MI->getOperand(1).getReg();
  auto LHSDef = getDefSrcRegIgnoringCopies(LHS, *MRI);
 
  if (OrigAddr != Addr) {
    if (!isFlatScratchBaseLegalSVImm(OrigAddr))
      return std::nullopt;
  } else {
    if (!isFlatScratchBaseLegalSV(OrigAddr))
      return std::nullopt;
  }
 
  if (checkFlatScratchSVSSwizzleBug(RHS, LHS, ImmOffset))
    return std::nullopt;
 
  if (LHSDef->MI->getOpcode() == AMDGPU::G_FRAME_INDEX) {
    int FI = LHSDef->MI->getOperand(1).getIndex();
    return {{
        [=](MachineInstrBuilder &MIB) { MIB.addReg(RHS); }, // vaddr
        [=](MachineInstrBuilder &MIB) { MIB.addFrameIndex(FI); }, // saddr
        [=](MachineInstrBuilder &MIB) { MIB.addImm(ImmOffset); } // offset
    }};
  }
 
  if (!isSGPR(LHS))
    return std::nullopt;
 
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(RHS); }, // vaddr
      [=](MachineInstrBuilder &MIB) { MIB.addReg(LHS); }, // saddr
      [=](MachineInstrBuilder &MIB) { MIB.addImm(ImmOffset); } // offset
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectMUBUFScratchOffen(MachineOperand &Root) const {
  MachineInstr *MI = Root.getParent();
  MachineBasicBlock *MBB = MI->getParent();
  MachineFunction *MF = MBB->getParent();
  const SIMachineFunctionInfo *Info = MF->getInfo<SIMachineFunctionInfo>();
 
  int64_t Offset = 0;
  if (mi_match(Root.getReg(), *MRI, m_ICst(Offset)) &&
      Offset != TM.getNullPointerValue(AMDGPUAS::PRIVATE_ADDRESS)) {
    Register HighBits = MRI->createVirtualRegister(&AMDGPU::VGPR_32RegClass);
 
    // TODO: Should this be inside the render function? The iterator seems to
    // move.
    const uint32_t MaxOffset = SIInstrInfo::getMaxMUBUFImmOffset(*Subtarget);
    BuildMI(*MBB, MI, MI->getDebugLoc(), TII.get(AMDGPU::V_MOV_B32_e32),
            HighBits)
        .addImm(Offset & ~MaxOffset);
 
    return {{[=](MachineInstrBuilder &MIB) { // rsrc
               MIB.addReg(Info->getScratchRSrcReg());
             },
             [=](MachineInstrBuilder &MIB) { // vaddr
               MIB.addReg(HighBits);
             },
             [=](MachineInstrBuilder &MIB) { // soffset
               // Use constant zero for soffset and rely on eliminateFrameIndex
               // to choose the appropriate frame register if need be.
               MIB.addImm(0);
             },
             [=](MachineInstrBuilder &MIB) { // offset
               MIB.addImm(Offset & MaxOffset);
             }}};
  }
 
  assert(Offset == 0 || Offset == -1);
 
  // Try to fold a frame index directly into the MUBUF vaddr field, and any
  // offsets.
  std::optional<int> FI;
  Register VAddr = Root.getReg();
  if (const MachineInstr *RootDef = MRI->getVRegDef(Root.getReg())) {
    Register PtrBase;
    int64_t ConstOffset;
    std::tie(PtrBase, ConstOffset) = getPtrBaseWithConstantOffset(VAddr, *MRI);
    if (ConstOffset != 0) {
      if (TII.isLegalMUBUFImmOffset(ConstOffset) &&
          (!STI.privateMemoryResourceIsRangeChecked() ||
           KB->signBitIsZero(PtrBase))) {
        const MachineInstr *PtrBaseDef = MRI->getVRegDef(PtrBase);
        if (PtrBaseDef->getOpcode() == AMDGPU::G_FRAME_INDEX)
          FI = PtrBaseDef->getOperand(1).getIndex();
        else
          VAddr = PtrBase;
        Offset = ConstOffset;
      }
    } else if (RootDef->getOpcode() == AMDGPU::G_FRAME_INDEX) {
      FI = RootDef->getOperand(1).getIndex();
    }
  }
 
  return {{[=](MachineInstrBuilder &MIB) { // rsrc
             MIB.addReg(Info->getScratchRSrcReg());
           },
           [=](MachineInstrBuilder &MIB) { // vaddr
             if (FI)
               MIB.addFrameIndex(*FI);
             else
               MIB.addReg(VAddr);
           },
           [=](MachineInstrBuilder &MIB) { // soffset
             // Use constant zero for soffset and rely on eliminateFrameIndex
             // to choose the appropriate frame register if need be.
             MIB.addImm(0);
           },
           [=](MachineInstrBuilder &MIB) { // offset
             MIB.addImm(Offset);
           }}};
}
 
bool AMDGPUInstructionSelector::isDSOffsetLegal(Register Base,
                                                int64_t Offset) const {
  if (!isUInt<16>(Offset))
    return false;
 
  if (STI.hasUsableDSOffset() || STI.unsafeDSOffsetFoldingEnabled())
    return true;
 
  // On Southern Islands instruction with a negative base value and an offset
  // don't seem to work.
  return KB->signBitIsZero(Base);
}
 
bool AMDGPUInstructionSelector::isDSOffset2Legal(Register Base, int64_t Offset0,
                                                 int64_t Offset1,
                                                 unsigned Size) const {
  if (Offset0 % Size != 0 || Offset1 % Size != 0)
    return false;
  if (!isUInt<8>(Offset0 / Size) || !isUInt<8>(Offset1 / Size))
    return false;
 
  if (STI.hasUsableDSOffset() || STI.unsafeDSOffsetFoldingEnabled())
    return true;
 
  // On Southern Islands instruction with a negative base value and an offset
  // don't seem to work.
  return KB->signBitIsZero(Base);
}
 
// Return whether the operation has NoUnsignedWrap property.
static bool isNoUnsignedWrap(MachineInstr *Addr) {
  return Addr->getOpcode() == TargetOpcode::G_OR ||
         (Addr->getOpcode() == TargetOpcode::G_PTR_ADD &&
          Addr->getFlag(MachineInstr::NoUWrap));
}
 
// Check that the base address of flat scratch load/store in the form of `base +
// offset` is legal to be put in SGPR/VGPR (i.e. unsigned per hardware
// requirement). We always treat the first operand as the base address here.
bool AMDGPUInstructionSelector::isFlatScratchBaseLegal(Register Addr) const {
  MachineInstr *AddrMI = getDefIgnoringCopies(Addr, *MRI);
 
  if (isNoUnsignedWrap(AddrMI))
    return true;
 
  // Starting with GFX12, VADDR and SADDR fields in VSCRATCH can use negative
  // values.
  if (STI.hasSignedScratchOffsets())
    return true;
 
  Register LHS = AddrMI->getOperand(1).getReg();
  Register RHS = AddrMI->getOperand(2).getReg();
 
  if (AddrMI->getOpcode() == TargetOpcode::G_PTR_ADD) {
    std::optional<ValueAndVReg> RhsValReg =
        getIConstantVRegValWithLookThrough(RHS, *MRI);
    // If the immediate offset is negative and within certain range, the base
    // address cannot also be negative. If the base is also negative, the sum
    // would be either negative or much larger than the valid range of scratch
    // memory a thread can access.
    if (RhsValReg && RhsValReg->Value.getSExtValue() < 0 &&
        RhsValReg->Value.getSExtValue() > -0x40000000)
      return true;
  }
 
  return KB->signBitIsZero(LHS);
}
 
// Check address value in SGPR/VGPR are legal for flat scratch in the form
// of: SGPR + VGPR.
bool AMDGPUInstructionSelector::isFlatScratchBaseLegalSV(Register Addr) const {
  MachineInstr *AddrMI = getDefIgnoringCopies(Addr, *MRI);
 
  if (isNoUnsignedWrap(AddrMI))
    return true;
 
  // Starting with GFX12, VADDR and SADDR fields in VSCRATCH can use negative
  // values.
  if (STI.hasSignedScratchOffsets())
    return true;
 
  Register LHS = AddrMI->getOperand(1).getReg();
  Register RHS = AddrMI->getOperand(2).getReg();
  return KB->signBitIsZero(RHS) && KB->signBitIsZero(LHS);
}
 
// Check address value in SGPR/VGPR are legal for flat scratch in the form
// of: SGPR + VGPR + Imm.
bool AMDGPUInstructionSelector::isFlatScratchBaseLegalSVImm(
    Register Addr) const {
  // Starting with GFX12, VADDR and SADDR fields in VSCRATCH can use negative
  // values.
  if (STI.hasSignedScratchOffsets())
    return true;
 
  MachineInstr *AddrMI = getDefIgnoringCopies(Addr, *MRI);
  Register Base = AddrMI->getOperand(1).getReg();
  std::optional<DefinitionAndSourceRegister> BaseDef =
      getDefSrcRegIgnoringCopies(Base, *MRI);
  std::optional<ValueAndVReg> RHSOffset =
      getIConstantVRegValWithLookThrough(AddrMI->getOperand(2).getReg(), *MRI);
  assert(RHSOffset);
 
  // If the immediate offset is negative and within certain range, the base
  // address cannot also be negative. If the base is also negative, the sum
  // would be either negative or much larger than the valid range of scratch
  // memory a thread can access.
  if (isNoUnsignedWrap(BaseDef->MI) &&
      (isNoUnsignedWrap(AddrMI) ||
       (RHSOffset->Value.getSExtValue() < 0 &&
        RHSOffset->Value.getSExtValue() > -0x40000000)))
    return true;
 
  Register LHS = BaseDef->MI->getOperand(1).getReg();
  Register RHS = BaseDef->MI->getOperand(2).getReg();
  return KB->signBitIsZero(RHS) && KB->signBitIsZero(LHS);
}
 
bool AMDGPUInstructionSelector::isUnneededShiftMask(const MachineInstr &MI,
                                                    unsigned ShAmtBits) const {
  assert(MI.getOpcode() == TargetOpcode::G_AND);
 
  std::optional<APInt> RHS =
      getIConstantVRegVal(MI.getOperand(2).getReg(), *MRI);
  if (!RHS)
    return false;
 
  if (RHS->countr_one() >= ShAmtBits)
    return true;
 
  const APInt &LHSKnownZeros = KB->getKnownZeroes(MI.getOperand(1).getReg());
  return (LHSKnownZeros | *RHS).countr_one() >= ShAmtBits;
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectMUBUFScratchOffset(
    MachineOperand &Root) const {
  Register Reg = Root.getReg();
  const SIMachineFunctionInfo *Info = MF->getInfo<SIMachineFunctionInfo>();
 
  std::optional<DefinitionAndSourceRegister> Def =
    getDefSrcRegIgnoringCopies(Reg, *MRI);
  assert(Def && "this shouldn't be an optional result");
  Reg = Def->Reg;
 
  if (Register WaveBase = getWaveAddress(Def->MI)) {
    return {{
        [=](MachineInstrBuilder &MIB) { // rsrc
          MIB.addReg(Info->getScratchRSrcReg());
        },
        [=](MachineInstrBuilder &MIB) { // soffset
          MIB.addReg(WaveBase);
        },
        [=](MachineInstrBuilder &MIB) { MIB.addImm(0); } // offset
    }};
  }
 
  int64_t Offset = 0;
 
  // FIXME: Copy check is a hack
  Register BasePtr;
  if (mi_match(Reg, *MRI,
               m_GPtrAdd(m_Reg(BasePtr),
                         m_any_of(m_ICst(Offset), m_Copy(m_ICst(Offset)))))) {
    if (!TII.isLegalMUBUFImmOffset(Offset))
      return {};
    MachineInstr *BasePtrDef = getDefIgnoringCopies(BasePtr, *MRI);
    Register WaveBase = getWaveAddress(BasePtrDef);
    if (!WaveBase)
      return {};
 
    return {{
        [=](MachineInstrBuilder &MIB) { // rsrc
          MIB.addReg(Info->getScratchRSrcReg());
        },
        [=](MachineInstrBuilder &MIB) { // soffset
          MIB.addReg(WaveBase);
        },
        [=](MachineInstrBuilder &MIB) { MIB.addImm(Offset); } // offset
    }};
  }
 
  if (!mi_match(Root.getReg(), *MRI, m_ICst(Offset)) ||
      !TII.isLegalMUBUFImmOffset(Offset))
    return {};
 
  return {{
      [=](MachineInstrBuilder &MIB) { // rsrc
        MIB.addReg(Info->getScratchRSrcReg());
      },
      [=](MachineInstrBuilder &MIB) { // soffset
        MIB.addImm(0);
      },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Offset); } // offset
  }};
}
 
std::pair<Register, unsigned>
AMDGPUInstructionSelector::selectDS1Addr1OffsetImpl(MachineOperand &Root) const {
  const MachineInstr *RootDef = MRI->getVRegDef(Root.getReg());
  if (!RootDef)
    return std::pair(Root.getReg(), 0);
 
  int64_t ConstAddr = 0;
 
  Register PtrBase;
  int64_t Offset;
  std::tie(PtrBase, Offset) =
    getPtrBaseWithConstantOffset(Root.getReg(), *MRI);
 
  if (Offset) {
    if (isDSOffsetLegal(PtrBase, Offset)) {
      // (add n0, c0)
      return std::pair(PtrBase, Offset);
    }
  } else if (RootDef->getOpcode() == AMDGPU::G_SUB) {
    // TODO
 
 
  } else if (mi_match(Root.getReg(), *MRI, m_ICst(ConstAddr))) {
    // TODO
 
  }
 
  return std::pair(Root.getReg(), 0);
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectDS1Addr1Offset(MachineOperand &Root) const {
  Register Reg;
  unsigned Offset;
  std::tie(Reg, Offset) = selectDS1Addr1OffsetImpl(Root);
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(Reg); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Offset); }
    }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectDS64Bit4ByteAligned(MachineOperand &Root) const {
  return selectDSReadWrite2(Root, 4);
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectDS128Bit8ByteAligned(MachineOperand &Root) const {
  return selectDSReadWrite2(Root, 8);
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectDSReadWrite2(MachineOperand &Root,
                                              unsigned Size) const {
  Register Reg;
  unsigned Offset;
  std::tie(Reg, Offset) = selectDSReadWrite2Impl(Root, Size);
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(Reg); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Offset); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Offset+1); }
    }};
}
 
std::pair<Register, unsigned>
AMDGPUInstructionSelector::selectDSReadWrite2Impl(MachineOperand &Root,
                                                  unsigned Size) const {
  const MachineInstr *RootDef = MRI->getVRegDef(Root.getReg());
  if (!RootDef)
    return std::pair(Root.getReg(), 0);
 
  int64_t ConstAddr = 0;
 
  Register PtrBase;
  int64_t Offset;
  std::tie(PtrBase, Offset) =
    getPtrBaseWithConstantOffset(Root.getReg(), *MRI);
 
  if (Offset) {
    int64_t OffsetValue0 = Offset;
    int64_t OffsetValue1 = Offset + Size;
    if (isDSOffset2Legal(PtrBase, OffsetValue0, OffsetValue1, Size)) {
      // (add n0, c0)
      return std::pair(PtrBase, OffsetValue0 / Size);
    }
  } else if (RootDef->getOpcode() == AMDGPU::G_SUB) {
    // TODO
 
  } else if (mi_match(Root.getReg(), *MRI, m_ICst(ConstAddr))) {
    // TODO
 
  }
 
  return std::pair(Root.getReg(), 0);
}
 
/// If \p Root is a G_PTR_ADD with a G_CONSTANT on the right hand side, return
/// the base value with the constant offset. There may be intervening copies
/// between \p Root and the identified constant. Returns \p Root, 0 if this does
/// not match the pattern.
std::pair<Register, int64_t>
AMDGPUInstructionSelector::getPtrBaseWithConstantOffset(
  Register Root, const MachineRegisterInfo &MRI) const {
  MachineInstr *RootI = getDefIgnoringCopies(Root, MRI);
  if (RootI->getOpcode() != TargetOpcode::G_PTR_ADD)
    return {Root, 0};
 
  MachineOperand &RHS = RootI->getOperand(2);
  std::optional<ValueAndVReg> MaybeOffset =
      getIConstantVRegValWithLookThrough(RHS.getReg(), MRI);
  if (!MaybeOffset)
    return {Root, 0};
  return {RootI->getOperand(1).getReg(), MaybeOffset->Value.getSExtValue()};
}
 
static void addZeroImm(MachineInstrBuilder &MIB) {
  MIB.addImm(0);
}
 
/// Return a resource descriptor for use with an arbitrary 64-bit pointer. If \p
/// BasePtr is not valid, a null base pointer will be used.
static Register buildRSRC(MachineIRBuilder &B, MachineRegisterInfo &MRI,
                          uint32_t FormatLo, uint32_t FormatHi,
                          Register BasePtr) {
  Register RSrc2 = MRI.createVirtualRegister(&AMDGPU::SReg_32RegClass);
  Register RSrc3 = MRI.createVirtualRegister(&AMDGPU::SReg_32RegClass);
  Register RSrcHi = MRI.createVirtualRegister(&AMDGPU::SReg_64RegClass);
  Register RSrc = MRI.createVirtualRegister(&AMDGPU::SGPR_128RegClass);
 
  B.buildInstr(AMDGPU::S_MOV_B32)
    .addDef(RSrc2)
    .addImm(FormatLo);
  B.buildInstr(AMDGPU::S_MOV_B32)
    .addDef(RSrc3)
    .addImm(FormatHi);
 
  // Build the half of the subregister with the constants before building the
  // full 128-bit register. If we are building multiple resource descriptors,
  // this will allow CSEing of the 2-component register.
  B.buildInstr(AMDGPU::REG_SEQUENCE)
    .addDef(RSrcHi)
    .addReg(RSrc2)
    .addImm(AMDGPU::sub0)
    .addReg(RSrc3)
    .addImm(AMDGPU::sub1);
 
  Register RSrcLo = BasePtr;
  if (!BasePtr) {
    RSrcLo = MRI.createVirtualRegister(&AMDGPU::SReg_64RegClass);
    B.buildInstr(AMDGPU::S_MOV_B64)
      .addDef(RSrcLo)
      .addImm(0);
  }
 
  B.buildInstr(AMDGPU::REG_SEQUENCE)
    .addDef(RSrc)
    .addReg(RSrcLo)
    .addImm(AMDGPU::sub0_sub1)
    .addReg(RSrcHi)
    .addImm(AMDGPU::sub2_sub3);
 
  return RSrc;
}
 
static Register buildAddr64RSrc(MachineIRBuilder &B, MachineRegisterInfo &MRI,
                                const SIInstrInfo &TII, Register BasePtr) {
  uint64_t DefaultFormat = TII.getDefaultRsrcDataFormat();
 
  // FIXME: Why are half the "default" bits ignored based on the addressing
  // mode?
  return buildRSRC(B, MRI, 0, Hi_32(DefaultFormat), BasePtr);
}
 
static Register buildOffsetSrc(MachineIRBuilder &B, MachineRegisterInfo &MRI,
                               const SIInstrInfo &TII, Register BasePtr) {
  uint64_t DefaultFormat = TII.getDefaultRsrcDataFormat();
 
  // FIXME: Why are half the "default" bits ignored based on the addressing
  // mode?
  return buildRSRC(B, MRI, -1, Hi_32(DefaultFormat), BasePtr);
}
 
AMDGPUInstructionSelector::MUBUFAddressData
AMDGPUInstructionSelector::parseMUBUFAddress(Register Src) const {
  MUBUFAddressData Data;
  Data.N0 = Src;
 
  Register PtrBase;
  int64_t Offset;
 
  std::tie(PtrBase, Offset) = getPtrBaseWithConstantOffset(Src, *MRI);
  if (isUInt<32>(Offset)) {
    Data.N0 = PtrBase;
    Data.Offset = Offset;
  }
 
  if (MachineInstr *InputAdd
      = getOpcodeDef(TargetOpcode::G_PTR_ADD, Data.N0, *MRI)) {
    Data.N2 = InputAdd->getOperand(1).getReg();
    Data.N3 = InputAdd->getOperand(2).getReg();
 
    // FIXME: Need to fix extra SGPR->VGPRcopies inserted
    // FIXME: Don't know this was defined by operand 0
    //
    // TODO: Remove this when we have copy folding optimizations after
    // RegBankSelect.
    Data.N2 = getDefIgnoringCopies(Data.N2, *MRI)->getOperand(0).getReg();
    Data.N3 = getDefIgnoringCopies(Data.N3, *MRI)->getOperand(0).getReg();
  }
 
  return Data;
}
 
/// Return if the addr64 mubuf mode should be used for the given address.
bool AMDGPUInstructionSelector::shouldUseAddr64(MUBUFAddressData Addr) const {
  // (ptr_add N2, N3) -> addr64, or
  // (ptr_add (ptr_add N2, N3), C1) -> addr64
  if (Addr.N2)
    return true;
 
  const RegisterBank *N0Bank = RBI.getRegBank(Addr.N0, *MRI, TRI);
  return N0Bank->getID() == AMDGPU::VGPRRegBankID;
}
 
/// Split an immediate offset \p ImmOffset depending on whether it fits in the
/// immediate field. Modifies \p ImmOffset and sets \p SOffset to the variable
/// component.
void AMDGPUInstructionSelector::splitIllegalMUBUFOffset(
  MachineIRBuilder &B, Register &SOffset, int64_t &ImmOffset) const {
  if (TII.isLegalMUBUFImmOffset(ImmOffset))
    return;
 
  // Illegal offset, store it in soffset.
  SOffset = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
  B.buildInstr(AMDGPU::S_MOV_B32)
    .addDef(SOffset)
    .addImm(ImmOffset);
  ImmOffset = 0;
}
 
bool AMDGPUInstructionSelector::selectMUBUFAddr64Impl(
  MachineOperand &Root, Register &VAddr, Register &RSrcReg,
  Register &SOffset, int64_t &Offset) const {
  // FIXME: Predicates should stop this from reaching here.
  // addr64 bit was removed for volcanic islands.
  if (!STI.hasAddr64() || STI.useFlatForGlobal())
    return false;
 
  MUBUFAddressData AddrData = parseMUBUFAddress(Root.getReg());
  if (!shouldUseAddr64(AddrData))
    return false;
 
  Register N0 = AddrData.N0;
  Register N2 = AddrData.N2;
  Register N3 = AddrData.N3;
  Offset = AddrData.Offset;
 
  // Base pointer for the SRD.
  Register SRDPtr;
 
  if (N2) {
    if (RBI.getRegBank(N2, *MRI, TRI)->getID() == AMDGPU::VGPRRegBankID) {
      assert(N3);
      if (RBI.getRegBank(N3, *MRI, TRI)->getID() == AMDGPU::VGPRRegBankID) {
        // Both N2 and N3 are divergent. Use N0 (the result of the add) as the
        // addr64, and construct the default resource from a 0 address.
        VAddr = N0;
      } else {
        SRDPtr = N3;
        VAddr = N2;
      }
    } else {
      // N2 is not divergent.
      SRDPtr = N2;
      VAddr = N3;
    }
  } else if (RBI.getRegBank(N0, *MRI, TRI)->getID() == AMDGPU::VGPRRegBankID) {
    // Use the default null pointer in the resource
    VAddr = N0;
  } else {
    // N0 -> offset, or
    // (N0 + C1) -> offset
    SRDPtr = N0;
  }
 
  MachineIRBuilder B(*Root.getParent());
  RSrcReg = buildAddr64RSrc(B, *MRI, TII, SRDPtr);
  splitIllegalMUBUFOffset(B, SOffset, Offset);
  return true;
}
 
bool AMDGPUInstructionSelector::selectMUBUFOffsetImpl(
  MachineOperand &Root, Register &RSrcReg, Register &SOffset,
  int64_t &Offset) const {
 
  // FIXME: Pattern should not reach here.
  if (STI.useFlatForGlobal())
    return false;
 
  MUBUFAddressData AddrData = parseMUBUFAddress(Root.getReg());
  if (shouldUseAddr64(AddrData))
    return false;
 
  // N0 -> offset, or
  // (N0 + C1) -> offset
  Register SRDPtr = AddrData.N0;
  Offset = AddrData.Offset;
 
  // TODO: Look through extensions for 32-bit soffset.
  MachineIRBuilder B(*Root.getParent());
 
  RSrcReg = buildOffsetSrc(B, *MRI, TII, SRDPtr);
  splitIllegalMUBUFOffset(B, SOffset, Offset);
  return true;
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectMUBUFAddr64(MachineOperand &Root) const {
  Register VAddr;
  Register RSrcReg;
  Register SOffset;
  int64_t Offset = 0;
 
  if (!selectMUBUFAddr64Impl(Root, VAddr, RSrcReg, SOffset, Offset))
    return {};
 
  // FIXME: Use defaulted operands for trailing 0s and remove from the complex
  // pattern.
  return {{
      [=](MachineInstrBuilder &MIB) {  // rsrc
        MIB.addReg(RSrcReg);
      },
      [=](MachineInstrBuilder &MIB) { // vaddr
        MIB.addReg(VAddr);
      },
      [=](MachineInstrBuilder &MIB) { // soffset
        if (SOffset)
          MIB.addReg(SOffset);
        else if (STI.hasRestrictedSOffset())
          MIB.addReg(AMDGPU::SGPR_NULL);
        else
          MIB.addImm(0);
      },
      [=](MachineInstrBuilder &MIB) { // offset
        MIB.addImm(Offset);
      },
      addZeroImm, //  cpol
      addZeroImm, //  tfe
      addZeroImm  //  swz
    }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectMUBUFOffset(MachineOperand &Root) const {
  Register RSrcReg;
  Register SOffset;
  int64_t Offset = 0;
 
  if (!selectMUBUFOffsetImpl(Root, RSrcReg, SOffset, Offset))
    return {};
 
  return {{
      [=](MachineInstrBuilder &MIB) {  // rsrc
        MIB.addReg(RSrcReg);
      },
      [=](MachineInstrBuilder &MIB) { // soffset
        if (SOffset)
          MIB.addReg(SOffset);
        else if (STI.hasRestrictedSOffset())
          MIB.addReg(AMDGPU::SGPR_NULL);
        else
          MIB.addImm(0);
      },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Offset); }, // offset
      addZeroImm, //  cpol
      addZeroImm, //  tfe
      addZeroImm, //  swz
    }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectBUFSOffset(MachineOperand &Root) const {
 
  Register SOffset = Root.getReg();
 
  if (STI.hasRestrictedSOffset() && mi_match(SOffset, *MRI, m_ZeroInt()))
    SOffset = AMDGPU::SGPR_NULL;
 
  return {{[=](MachineInstrBuilder &MIB) { MIB.addReg(SOffset); }}};
}
 
/// Get an immediate that must be 32-bits, and treated as zero extended.
static std::optional<uint64_t>
getConstantZext32Val(Register Reg, const MachineRegisterInfo &MRI) {
  // getIConstantVRegVal sexts any values, so see if that matters.
  std::optional<int64_t> OffsetVal = getIConstantVRegSExtVal(Reg, MRI);
  if (!OffsetVal || !isInt<32>(*OffsetVal))
    return std::nullopt;
  return Lo_32(*OffsetVal);
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectSMRDBufferImm(MachineOperand &Root) const {
  std::optional<uint64_t> OffsetVal = getConstantZext32Val(Root.getReg(), *MRI);
  if (!OffsetVal)
    return {};
 
  std::optional<int64_t> EncodedImm =
      AMDGPU::getSMRDEncodedOffset(STI, *OffsetVal, true);
  if (!EncodedImm)
    return {};
 
  return {{ [=](MachineInstrBuilder &MIB) { MIB.addImm(*EncodedImm); }  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectSMRDBufferImm32(MachineOperand &Root) const {
  assert(STI.getGeneration() == AMDGPUSubtarget::SEA_ISLANDS);
 
  std::optional<uint64_t> OffsetVal = getConstantZext32Val(Root.getReg(), *MRI);
  if (!OffsetVal)
    return {};
 
  std::optional<int64_t> EncodedImm =
      AMDGPU::getSMRDEncodedLiteralOffset32(STI, *OffsetVal);
  if (!EncodedImm)
    return {};
 
  return {{ [=](MachineInstrBuilder &MIB) { MIB.addImm(*EncodedImm); }  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectSMRDBufferSgprImm(MachineOperand &Root) const {
  // Match the (soffset + offset) pair as a 32-bit register base and
  // an immediate offset.
  Register SOffset;
  unsigned Offset;
  std::tie(SOffset, Offset) = AMDGPU::getBaseWithConstantOffset(
      *MRI, Root.getReg(), KB, /*CheckNUW*/ true);
  if (!SOffset)
    return std::nullopt;
 
  std::optional<int64_t> EncodedOffset =
      AMDGPU::getSMRDEncodedOffset(STI, Offset, /* IsBuffer */ true);
  if (!EncodedOffset)
    return std::nullopt;
 
  assert(MRI->getType(SOffset) == LLT::scalar(32));
  return {{[=](MachineInstrBuilder &MIB) { MIB.addReg(SOffset); },
           [=](MachineInstrBuilder &MIB) { MIB.addImm(*EncodedOffset); }}};
}
 
// Variant of stripBitCast that returns the instruction instead of a
// MachineOperand.
static MachineInstr *stripBitCast(MachineInstr *MI, MachineRegisterInfo &MRI) {
  if (MI->getOpcode() == AMDGPU::G_BITCAST)
    return getDefIgnoringCopies(MI->getOperand(1).getReg(), MRI);
  return MI;
}
 
// Figure out if this is really an extract of the high 16-bits of a dword,
// returns nullptr if it isn't.
static MachineInstr *isExtractHiElt(MachineInstr *Inst,
                                    MachineRegisterInfo &MRI) {
  Inst = stripBitCast(Inst, MRI);
 
  if (Inst->getOpcode() != AMDGPU::G_TRUNC)
    return nullptr;
 
  MachineInstr *TruncOp =
      getDefIgnoringCopies(Inst->getOperand(1).getReg(), MRI);
  TruncOp = stripBitCast(TruncOp, MRI);
 
  // G_LSHR x, (G_CONSTANT i32 16)
  if (TruncOp->getOpcode() == AMDGPU::G_LSHR) {
    auto SrlAmount = getIConstantVRegValWithLookThrough(
        TruncOp->getOperand(2).getReg(), MRI);
    if (SrlAmount && SrlAmount->Value.getZExtValue() == 16) {
      MachineInstr *SrlOp =
          getDefIgnoringCopies(TruncOp->getOperand(1).getReg(), MRI);
      return stripBitCast(SrlOp, MRI);
    }
  }
 
  // G_SHUFFLE_VECTOR x, y, shufflemask(1, 1|0)
  //    1, 0 swaps the low/high 16 bits.
  //    1, 1 sets the high 16 bits to be the same as the low 16.
  // in any case, it selects the high elts.
  if (TruncOp->getOpcode() == AMDGPU::G_SHUFFLE_VECTOR) {
    assert(MRI.getType(TruncOp->getOperand(0).getReg()) ==
           LLT::fixed_vector(2, 16));
 
    ArrayRef<int> Mask = TruncOp->getOperand(3).getShuffleMask();
    assert(Mask.size() == 2);
 
    if (Mask[0] == 1 && Mask[1] <= 1) {
      MachineInstr *LHS =
          getDefIgnoringCopies(TruncOp->getOperand(1).getReg(), MRI);
      return stripBitCast(LHS, MRI);
    }
  }
 
  return nullptr;
}
 
std::pair<Register, unsigned>
AMDGPUInstructionSelector::selectVOP3PMadMixModsImpl(MachineOperand &Root,
                                                     bool &Matched) const {
  Matched = false;
 
  Register Src;
  unsigned Mods;
  std::tie(Src, Mods) = selectVOP3ModsImpl(Root);
 
  MachineInstr *MI = getDefIgnoringCopies(Src, *MRI);
  if (MI->getOpcode() == AMDGPU::G_FPEXT) {
    MachineOperand *MO = &MI->getOperand(1);
    Src = MO->getReg();
    MI = getDefIgnoringCopies(Src, *MRI);
 
    assert(MRI->getType(Src) == LLT::scalar(16));
 
    // See through bitcasts.
    // FIXME: Would be nice to use stripBitCast here.
    if (MI->getOpcode() == AMDGPU::G_BITCAST) {
      MO = &MI->getOperand(1);
      Src = MO->getReg();
      MI = getDefIgnoringCopies(Src, *MRI);
    }
 
    const auto CheckAbsNeg = [&]() {
      // Be careful about folding modifiers if we already have an abs. fneg is
      // applied last, so we don't want to apply an earlier fneg.
      if ((Mods & SISrcMods::ABS) == 0) {
        unsigned ModsTmp;
        std::tie(Src, ModsTmp) = selectVOP3ModsImpl(*MO);
        MI = getDefIgnoringCopies(Src, *MRI);
 
        if ((ModsTmp & SISrcMods::NEG) != 0)
          Mods ^= SISrcMods::NEG;
 
        if ((ModsTmp & SISrcMods::ABS) != 0)
          Mods |= SISrcMods::ABS;
      }
    };
 
    CheckAbsNeg();
 
    // op_sel/op_sel_hi decide the source type and source.
    // If the source's op_sel_hi is set, it indicates to do a conversion from
    // fp16. If the sources's op_sel is set, it picks the high half of the
    // source register.
 
    Mods |= SISrcMods::OP_SEL_1;
 
    if (MachineInstr *ExtractHiEltMI = isExtractHiElt(MI, *MRI)) {
      Mods |= SISrcMods::OP_SEL_0;
      MI = ExtractHiEltMI;
      MO = &MI->getOperand(0);
      Src = MO->getReg();
 
      CheckAbsNeg();
    }
 
    Matched = true;
  }
 
  return {Src, Mods};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVOP3PMadMixModsExt(
    MachineOperand &Root) const {
  Register Src;
  unsigned Mods;
  bool Matched;
  std::tie(Src, Mods) = selectVOP3PMadMixModsImpl(Root, Matched);
  if (!Matched)
    return {};
 
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); } // src_mods
  }};
}
 
InstructionSelector::ComplexRendererFns
AMDGPUInstructionSelector::selectVOP3PMadMixMods(MachineOperand &Root) const {
  Register Src;
  unsigned Mods;
  bool Matched;
  std::tie(Src, Mods) = selectVOP3PMadMixModsImpl(Root, Matched);
 
  return {{
      [=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
      [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); } // src_mods
  }};
}
 
bool AMDGPUInstructionSelector::selectSBarrierSignalIsfirst(
    MachineInstr &I, Intrinsic::ID IntrID) const {
  MachineBasicBlock *MBB = I.getParent();
  const DebugLoc &DL = I.getDebugLoc();
  Register CCReg = I.getOperand(0).getReg();
 
  bool HasM0 = IntrID == Intrinsic::amdgcn_s_barrier_signal_isfirst_var;
 
  if (HasM0) {
    auto CopyMIB = BuildMI(*MBB, &I, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
                       .addReg(I.getOperand(2).getReg());
    BuildMI(*MBB, &I, DL, TII.get(AMDGPU::S_BARRIER_SIGNAL_ISFIRST_M0));
    if (!constrainSelectedInstRegOperands(*CopyMIB, TII, TRI, RBI))
      return false;
  } else {
    BuildMI(*MBB, &I, DL, TII.get(AMDGPU::S_BARRIER_SIGNAL_ISFIRST_IMM))
        .addImm(I.getOperand(2).getImm());
  }
 
  BuildMI(*MBB, &I, DL, TII.get(AMDGPU::COPY), CCReg).addReg(AMDGPU::SCC);
 
  I.eraseFromParent();
  return RBI.constrainGenericRegister(CCReg, AMDGPU::SReg_32_XM0_XEXECRegClass,
                                      *MRI);
}
 
unsigned getNamedBarrierOp(bool HasInlineConst, Intrinsic::ID IntrID) {
  if (HasInlineConst) {
    switch (IntrID) {
    default:
      llvm_unreachable("not a named barrier op");
    case Intrinsic::amdgcn_s_barrier_init:
      return AMDGPU::S_BARRIER_INIT_IMM;
    case Intrinsic::amdgcn_s_barrier_join:
      return AMDGPU::S_BARRIER_JOIN_IMM;
    case Intrinsic::amdgcn_s_wakeup_barrier:
      return AMDGPU::S_WAKEUP_BARRIER_IMM;
    case Intrinsic::amdgcn_s_get_barrier_state:
      return AMDGPU::S_GET_BARRIER_STATE_IMM;
    };
  } else {
    switch (IntrID) {
    default:
      llvm_unreachable("not a named barrier op");
    case Intrinsic::amdgcn_s_barrier_init:
      return AMDGPU::S_BARRIER_INIT_M0;
    case Intrinsic::amdgcn_s_barrier_join:
      return AMDGPU::S_BARRIER_JOIN_M0;
    case Intrinsic::amdgcn_s_wakeup_barrier:
      return AMDGPU::S_WAKEUP_BARRIER_M0;
    case Intrinsic::amdgcn_s_get_barrier_state:
      return AMDGPU::S_GET_BARRIER_STATE_M0;
    };
  }
}
 
bool AMDGPUInstructionSelector::selectNamedBarrierInst(
    MachineInstr &I, Intrinsic::ID IntrID) const {
  MachineBasicBlock *MBB = I.getParent();
  const DebugLoc &DL = I.getDebugLoc();
  MachineOperand BarOp = IntrID == Intrinsic::amdgcn_s_get_barrier_state
                             ? I.getOperand(2)
                             : I.getOperand(1);
  std::optional<int64_t> BarValImm =
      getIConstantVRegSExtVal(BarOp.getReg(), *MRI);
  Register M0Val;
  Register TmpReg0;
 
  // For S_BARRIER_INIT, member count will always be read from M0[16:22]
  if (IntrID == Intrinsic::amdgcn_s_barrier_init) {
    Register MemberCount = I.getOperand(2).getReg();
    TmpReg0 = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
    // TODO: This should be expanded during legalization so that the the S_LSHL
    // and S_OR can be constant-folded
    BuildMI(*MBB, &I, DL, TII.get(AMDGPU::S_LSHL_B32), TmpReg0)
        .addImm(16)
        .addReg(MemberCount);
    M0Val = TmpReg0;
  }
 
  // If not inlinable, get reference to barrier depending on the instruction
  if (!BarValImm) {
    if (IntrID == Intrinsic::amdgcn_s_barrier_init) {
      // If reference to barrier id is not an inlinable constant then it must be
      // referenced with M0[4:0]. Perform an OR with the member count to include
      // it in M0 for S_BARRIER_INIT.
      Register TmpReg1 = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
      BuildMI(*MBB, &I, DL, TII.get(AMDGPU::S_OR_B32), TmpReg1)
          .addReg(BarOp.getReg())
          .addReg(TmpReg0);
      M0Val = TmpReg1;
    } else {
      M0Val = BarOp.getReg();
    }
  }
 
  // Build copy to M0 if needed. For S_BARRIER_INIT, M0 is always required.
  if (M0Val) {
    auto CopyMIB =
        BuildMI(*MBB, &I, DL, TII.get(AMDGPU::COPY), AMDGPU::M0).addReg(M0Val);
    constrainSelectedInstRegOperands(*CopyMIB, TII, TRI, RBI);
  }
 
  MachineInstrBuilder MIB;
  unsigned Opc = getNamedBarrierOp(BarValImm.has_value(), IntrID);
  MIB = BuildMI(*MBB, &I, DL, TII.get(Opc));
 
  if (IntrID == Intrinsic::amdgcn_s_get_barrier_state)
    MIB.addDef(I.getOperand(0).getReg());
 
  if (BarValImm)
    MIB.addImm(*BarValImm);
 
  I.eraseFromParent();
  return true;
}
 
bool AMDGPUInstructionSelector::selectSBarrierLeave(MachineInstr &I) const {
  MachineBasicBlock *BB = I.getParent();
  const DebugLoc &DL = I.getDebugLoc();
  Register CCReg = I.getOperand(0).getReg();
 
  BuildMI(*BB, &I, DL, TII.get(AMDGPU::S_BARRIER_LEAVE));
  BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), CCReg).addReg(AMDGPU::SCC);
 
  I.eraseFromParent();
  return RBI.constrainGenericRegister(CCReg, AMDGPU::SReg_32_XM0_XEXECRegClass,
                                      *MRI);
}
 
void AMDGPUInstructionSelector::renderTruncImm32(MachineInstrBuilder &MIB,
                                                 const MachineInstr &MI,
                                                 int OpIdx) const {
  assert(MI.getOpcode() == TargetOpcode::G_CONSTANT && OpIdx == -1 &&
         "Expected G_CONSTANT");
  MIB.addImm(MI.getOperand(1).getCImm()->getSExtValue());
}
 
void AMDGPUInstructionSelector::renderNegateImm(MachineInstrBuilder &MIB,
                                                const MachineInstr &MI,
                                                int OpIdx) const {
  assert(MI.getOpcode() == TargetOpcode::G_CONSTANT && OpIdx == -1 &&
         "Expected G_CONSTANT");
  MIB.addImm(-MI.getOperand(1).getCImm()->getSExtValue());
}
 
void AMDGPUInstructionSelector::renderBitcastImm(MachineInstrBuilder &MIB,
                                                 const MachineInstr &MI,
                                                 int OpIdx) const {
  assert(OpIdx == -1);
 
  const MachineOperand &Op = MI.getOperand(1);
  if (MI.getOpcode() == TargetOpcode::G_FCONSTANT)
    MIB.addImm(Op.getFPImm()->getValueAPF().bitcastToAPInt().getZExtValue());
  else {
    assert(MI.getOpcode() == TargetOpcode::G_CONSTANT && "Expected G_CONSTANT");
    MIB.addImm(Op.getCImm()->getSExtValue());
  }
}
 
void AMDGPUInstructionSelector::renderPopcntImm(MachineInstrBuilder &MIB,
                                                const MachineInstr &MI,
                                                int OpIdx) const {
  assert(MI.getOpcode() == TargetOpcode::G_CONSTANT && OpIdx == -1 &&
         "Expected G_CONSTANT");
  MIB.addImm(MI.getOperand(1).getCImm()->getValue().popcount());
}
 
/// This only really exists to satisfy DAG type checking machinery, so is a
/// no-op here.
void AMDGPUInstructionSelector::renderTruncTImm(MachineInstrBuilder &MIB,
                                                const MachineInstr &MI,
                                                int OpIdx) const {
  MIB.addImm(MI.getOperand(OpIdx).getImm());
}
 
void AMDGPUInstructionSelector::renderOpSelTImm(MachineInstrBuilder &MIB,
                                                const MachineInstr &MI,
                                                int OpIdx) const {
  assert(OpIdx >= 0 && "expected to match an immediate operand");
  MIB.addImm(MI.getOperand(OpIdx).getImm() ? (int64_t)SISrcMods::OP_SEL_0 : 0);
}
 
void AMDGPUInstructionSelector::renderExtractCPol(MachineInstrBuilder &MIB,
                                                  const MachineInstr &MI,
                                                  int OpIdx) const {
  assert(OpIdx >= 0 && "expected to match an immediate operand");
  MIB.addImm(MI.getOperand(OpIdx).getImm() &
             (AMDGPU::isGFX12Plus(STI) ? AMDGPU::CPol::ALL
                                       : AMDGPU::CPol::ALL_pregfx12));
}
 
void AMDGPUInstructionSelector::renderExtractSWZ(MachineInstrBuilder &MIB,
                                                 const MachineInstr &MI,
                                                 int OpIdx) const {
  assert(OpIdx >= 0 && "expected to match an immediate operand");
  const bool Swizzle = MI.getOperand(OpIdx).getImm() &
                       (AMDGPU::isGFX12Plus(STI) ? AMDGPU::CPol::SWZ
                                                 : AMDGPU::CPol::SWZ_pregfx12);
  MIB.addImm(Swizzle);
}
 
void AMDGPUInstructionSelector::renderExtractCpolSetGLC(
    MachineInstrBuilder &MIB, const MachineInstr &MI, int OpIdx) const {
  assert(OpIdx >= 0 && "expected to match an immediate operand");
  const uint32_t Cpol = MI.getOperand(OpIdx).getImm() &
                        (AMDGPU::isGFX12Plus(STI) ? AMDGPU::CPol::ALL
                                                  : AMDGPU::CPol::ALL_pregfx12);
  MIB.addImm(Cpol | AMDGPU::CPol::GLC);
}
 
void AMDGPUInstructionSelector::renderFrameIndex(MachineInstrBuilder &MIB,
                                                 const MachineInstr &MI,
                                                 int OpIdx) const {
  MIB.addFrameIndex(MI.getOperand(1).getIndex());
}
 
void AMDGPUInstructionSelector::renderFPPow2ToExponent(MachineInstrBuilder &MIB,
                                                       const MachineInstr &MI,
                                                       int OpIdx) const {
  const APFloat &APF = MI.getOperand(1).getFPImm()->getValueAPF();
  int ExpVal = APF.getExactLog2Abs();
  assert(ExpVal != INT_MIN);
  MIB.addImm(ExpVal);
}
 
bool AMDGPUInstructionSelector::isInlineImmediate(const APInt &Imm) const {
  return TII.isInlineConstant(Imm);
}
 
bool AMDGPUInstructionSelector::isInlineImmediate(const APFloat &Imm) const {
  return TII.isInlineConstant(Imm);
}