Exemplo n.º 1
0
RegisterBankInfo::InstructionMapping
RegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
    RegisterBankInfo::InstructionMapping Mapping = getInstrMappingImpl(MI);
    if (Mapping.isValid())
      return Mapping;
  llvm_unreachable("The target must implement this");
}
RegisterBankInfo::InstructionMapping
AArch64RegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
  RegisterBankInfo::InstructionMapping Mapping = getInstrMappingImpl(MI);
  if (Mapping.isValid())
    return Mapping;

  // As a top-level guess, vectors go in FPRs, scalars in GPRs. Obviously this
  // won't work for normal floating-point types (or NZCV). When such
  // instructions exist we'll need to look at the MI's opcode.
  LLT Ty = MI.getType();
  unsigned BankID;
  if (Ty.isVector())
    BankID = AArch64::FPRRegBankID;
  else
    BankID = AArch64::GPRRegBankID;

  Mapping = InstructionMapping{1, 1, MI.getNumOperands()};
  int Size = Ty.isSized() ? Ty.getSizeInBits() : 0;
  for (unsigned Idx = 0; Idx < MI.getNumOperands(); ++Idx)
    Mapping.setOperandMapping(Idx, Size, getRegBank(BankID));

  return Mapping;
}
RegisterBankInfo::InstructionMapping
AArch64RegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
  const unsigned Opc = MI.getOpcode();
  const MachineFunction &MF = *MI.getParent()->getParent();
  const MachineRegisterInfo &MRI = MF.getRegInfo();

  // Try the default logic for non-generic instructions that are either copies
  // or already have some operands assigned to banks.
  if (!isPreISelGenericOpcode(Opc)) {
    RegisterBankInfo::InstructionMapping Mapping = getInstrMappingImpl(MI);
    if (Mapping.isValid())
      return Mapping;
  }

  RegisterBankInfo::InstructionMapping Mapping =
      InstructionMapping{DefaultMappingID, 1, MI.getNumOperands()};

  // Track the size and bank of each register.  We don't do partial mappings.
  SmallVector<unsigned, 4> OpBaseIdx(MI.getNumOperands());
  SmallVector<unsigned, 4> OpFinalIdx(MI.getNumOperands());
  for (unsigned Idx = 0; Idx < MI.getNumOperands(); ++Idx) {
    auto &MO = MI.getOperand(Idx);
    if (!MO.isReg())
      continue;

    LLT Ty = MRI.getType(MO.getReg());
    unsigned RBIdx = AArch64::getRegBankBaseIdx(Ty.getSizeInBits());
    OpBaseIdx[Idx] = RBIdx;

    // As a top-level guess, vectors go in FPRs, scalars and pointers in GPRs.
    // For floating-point instructions, scalars go in FPRs.
    if (Ty.isVector() || isPreISelGenericFloatingPointOpcode(Opc)) {
      assert(RBIdx < (AArch64::LastFPR - AArch64::FirstFPR) + 1 &&
             "Index out of bound");
      OpFinalIdx[Idx] = AArch64::FirstFPR + RBIdx;
    } else {
      assert(RBIdx < (AArch64::LastGPR - AArch64::FirstGPR) + 1 &&
             "Index out of bound");
      OpFinalIdx[Idx] = AArch64::FirstGPR + RBIdx;
    }
  }

  // Some of the floating-point instructions have mixed GPR and FPR operands:
  // fine-tune the computed mapping.
  switch (Opc) {
  case TargetOpcode::G_SITOFP:
  case TargetOpcode::G_UITOFP: {
    OpFinalIdx = {OpBaseIdx[0] + AArch64::FirstFPR,
                  OpBaseIdx[1] + AArch64::FirstGPR};
    break;
  }
  case TargetOpcode::G_FPTOSI:
  case TargetOpcode::G_FPTOUI: {
    OpFinalIdx = {OpBaseIdx[0] + AArch64::FirstGPR,
                  OpBaseIdx[1] + AArch64::FirstFPR};
    break;
  }
  case TargetOpcode::G_FCMP: {
    OpFinalIdx = {OpBaseIdx[0] + AArch64::FirstGPR, /* Predicate */ 0,
                  OpBaseIdx[2] + AArch64::FirstFPR,
                  OpBaseIdx[3] + AArch64::FirstFPR};
    break;
  }
  }

  // Finally construct the computed mapping.
  for (unsigned Idx = 0; Idx < MI.getNumOperands(); ++Idx)
    if (MI.getOperand(Idx).isReg())
      Mapping.setOperandMapping(
          Idx, ValueMapping{&AArch64::PartMappings[OpFinalIdx[Idx]], 1});

  return Mapping;
}
Exemplo n.º 4
0
RegisterBankInfo::InstructionMapping
AArch64RegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
  const unsigned Opc = MI.getOpcode();
  const MachineFunction &MF = *MI.getParent()->getParent();
  const MachineRegisterInfo &MRI = MF.getRegInfo();

  // Try the default logic for non-generic instructions that are either copies
  // or already have some operands assigned to banks.
  if (!isPreISelGenericOpcode(Opc)) {
    RegisterBankInfo::InstructionMapping Mapping = getInstrMappingImpl(MI);
    if (Mapping.isValid())
      return Mapping;
  }

  switch (Opc) {
    // G_{F|S|U}REM are not listed because they are not legal.
    // Arithmetic ops.
  case TargetOpcode::G_ADD:
  case TargetOpcode::G_SUB:
  case TargetOpcode::G_GEP:
  case TargetOpcode::G_MUL:
  case TargetOpcode::G_SDIV:
  case TargetOpcode::G_UDIV:
    // Bitwise ops.
  case TargetOpcode::G_AND:
  case TargetOpcode::G_OR:
  case TargetOpcode::G_XOR:
    // Shifts.
  case TargetOpcode::G_SHL:
  case TargetOpcode::G_LSHR:
  case TargetOpcode::G_ASHR:
    // Floating point ops.
  case TargetOpcode::G_FADD:
  case TargetOpcode::G_FSUB:
  case TargetOpcode::G_FMUL:
  case TargetOpcode::G_FDIV:
    return getSameKindOfOperandsMapping(MI);
  case TargetOpcode::G_BITCAST: {
    LLT DstTy = MRI.getType(MI.getOperand(0).getReg());
    LLT SrcTy = MRI.getType(MI.getOperand(1).getReg());
    unsigned Size = DstTy.getSizeInBits();
    bool DstIsGPR = !DstTy.isVector();
    bool SrcIsGPR = !SrcTy.isVector();
    const RegisterBank &DstRB =
        DstIsGPR ? AArch64::GPRRegBank : AArch64::FPRRegBank;
    const RegisterBank &SrcRB =
        SrcIsGPR ? AArch64::GPRRegBank : AArch64::FPRRegBank;
    return InstructionMapping{
        DefaultMappingID, copyCost(DstRB, SrcRB, Size),
        getCopyMapping(DstRB.getID(), SrcRB.getID(), Size),
        /*NumOperands*/ 2};
  }
  case TargetOpcode::G_SEQUENCE:
    // FIXME: support this, but the generic code is really not going to do
    // anything sane.
    return InstructionMapping();
  default:
    break;
  }

  unsigned NumOperands = MI.getNumOperands();

  // Track the size and bank of each register.  We don't do partial mappings.
  SmallVector<unsigned, 4> OpSize(NumOperands);
  SmallVector<PartialMappingIdx, 4> OpRegBankIdx(NumOperands);
  for (unsigned Idx = 0; Idx < NumOperands; ++Idx) {
    auto &MO = MI.getOperand(Idx);
    if (!MO.isReg() || !MO.getReg())
      continue;

    LLT Ty = MRI.getType(MO.getReg());
    OpSize[Idx] = Ty.getSizeInBits();

    // As a top-level guess, vectors go in FPRs, scalars and pointers in GPRs.
    // For floating-point instructions, scalars go in FPRs.
    if (Ty.isVector() || isPreISelGenericFloatingPointOpcode(Opc))
      OpRegBankIdx[Idx] = PMI_FirstFPR;
    else
      OpRegBankIdx[Idx] = PMI_FirstGPR;
  }

  unsigned Cost = 1;
  // Some of the floating-point instructions have mixed GPR and FPR operands:
  // fine-tune the computed mapping.
  switch (Opc) {
  case TargetOpcode::G_SITOFP:
  case TargetOpcode::G_UITOFP:
    OpRegBankIdx = {PMI_FirstFPR, PMI_FirstGPR};
    break;
  case TargetOpcode::G_FPTOSI:
  case TargetOpcode::G_FPTOUI:
    OpRegBankIdx = {PMI_FirstGPR, PMI_FirstFPR};
    break;
  case TargetOpcode::G_FCMP:
    OpRegBankIdx = {PMI_FirstGPR,
                    /* Predicate */ PMI_None, PMI_FirstFPR, PMI_FirstFPR};
    break;
  case TargetOpcode::G_BITCAST:
    // This is going to be a cross register bank copy and this is expensive.
    if (OpRegBankIdx[0] != OpRegBankIdx[1])
      Cost = copyCost(
          *AArch64GenRegisterBankInfo::PartMappings[OpRegBankIdx[0]].RegBank,
          *AArch64GenRegisterBankInfo::PartMappings[OpRegBankIdx[1]].RegBank,
          OpSize[0]);
    break;
  case TargetOpcode::G_LOAD:
    // Loading in vector unit is slightly more expensive.
    // This is actually only true for the LD1R and co instructions,
    // but anyway for the fast mode this number does not matter and
    // for the greedy mode the cost of the cross bank copy will
    // offset this number.
    // FIXME: Should be derived from the scheduling model.
    if (OpRegBankIdx[0] >= PMI_FirstFPR)
      Cost = 2;
    break;
  }

  // Finally construct the computed mapping.
  RegisterBankInfo::InstructionMapping Mapping =
      InstructionMapping{DefaultMappingID, Cost, nullptr, NumOperands};
  SmallVector<const ValueMapping *, 8> OpdsMapping(NumOperands);
  for (unsigned Idx = 0; Idx < NumOperands; ++Idx) {
    if (MI.getOperand(Idx).isReg() && MI.getOperand(Idx).getReg()) {
      auto Mapping = getValueMapping(OpRegBankIdx[Idx], OpSize[Idx]);
      if (!Mapping->isValid())
        return InstructionMapping();

      OpdsMapping[Idx] = Mapping;
    }
  }

  Mapping.setOperandsMapping(getOperandsMapping(OpdsMapping));
  return Mapping;
}