Beispiel #1
0
bool RegisterBankInfo::InstructionMapping::verify(
    const MachineInstr &MI) const {
  // Check that all the register operands are properly mapped.
  // Check the constructor invariant.
  // For PHI, we only care about mapping the definition.
  assert(NumOperands == (isCopyLike(MI) ? 1 : MI.getNumOperands()) &&
         "NumOperands must match, see constructor");
  assert(MI.getParent() && MI.getMF() &&
         "MI must be connected to a MachineFunction");
  const MachineFunction &MF = *MI.getMF();
  const RegisterBankInfo *RBI = MF.getSubtarget().getRegBankInfo();
  (void)RBI;

  for (unsigned Idx = 0; Idx < NumOperands; ++Idx) {
    const MachineOperand &MO = MI.getOperand(Idx);
    if (!MO.isReg()) {
      assert(!getOperandMapping(Idx).isValid() &&
             "We should not care about non-reg mapping");
      continue;
    }
    unsigned Reg = MO.getReg();
    if (!Reg)
      continue;
    assert(getOperandMapping(Idx).isValid() &&
           "We must have a mapping for reg operands");
    const RegisterBankInfo::ValueMapping &MOMapping = getOperandMapping(Idx);
    (void)MOMapping;
    // Register size in bits.
    // This size must match what the mapping expects.
    assert(MOMapping.verify(RBI->getSizeInBits(
               Reg, MF.getRegInfo(), *MF.getSubtarget().getRegisterInfo())) &&
           "Value mapping is invalid");
  }
  return true;
}
Beispiel #2
0
void MIPrinter::print(const MachineInstr &MI) {
  const auto *MF = MI.getMF();
  const auto &MRI = MF->getRegInfo();
  const auto &SubTarget = MF->getSubtarget();
  const auto *TRI = SubTarget.getRegisterInfo();
  assert(TRI && "Expected target register info");
  const auto *TII = SubTarget.getInstrInfo();
  assert(TII && "Expected target instruction info");
  if (MI.isCFIInstruction())
    assert(MI.getNumOperands() == 1 && "Expected 1 operand in CFI instruction");

  SmallBitVector PrintedTypes(8);
  bool ShouldPrintRegisterTies = MI.hasComplexRegisterTies();
  unsigned I = 0, E = MI.getNumOperands();
  for (; I < E && MI.getOperand(I).isReg() && MI.getOperand(I).isDef() &&
         !MI.getOperand(I).isImplicit();
       ++I) {
    if (I)
      OS << ", ";
    print(MI, I, TRI, ShouldPrintRegisterTies,
          MI.getTypeToPrint(I, PrintedTypes, MRI),
          /*PrintDef=*/false);
  }

  if (I)
    OS << " = ";
  if (MI.getFlag(MachineInstr::FrameSetup))
    OS << "frame-setup ";
  OS << TII->getName(MI.getOpcode());
  if (I < E)
    OS << ' ';

  bool NeedComma = false;
  for (; I < E; ++I) {
    if (NeedComma)
      OS << ", ";
    print(MI, I, TRI, ShouldPrintRegisterTies,
          MI.getTypeToPrint(I, PrintedTypes, MRI));
    NeedComma = true;
  }

  if (MI.getDebugLoc()) {
    if (NeedComma)
      OS << ',';
    OS << " debug-location ";
    MI.getDebugLoc()->printAsOperand(OS, MST);
  }

  if (!MI.memoperands_empty()) {
    OS << " :: ";
    const LLVMContext &Context = MF->getFunction().getContext();
    bool NeedComma = false;
    for (const auto *Op : MI.memoperands()) {
      if (NeedComma)
        OS << ", ";
      print(Context, *TII, *Op);
      NeedComma = true;
    }
  }
}
Beispiel #3
0
void TargetInstrInfo::genAlternativeCodeSequence(
    MachineInstr &Root, MachineCombinerPattern Pattern,
    SmallVectorImpl<MachineInstr *> &InsInstrs,
    SmallVectorImpl<MachineInstr *> &DelInstrs,
    DenseMap<unsigned, unsigned> &InstIdxForVirtReg) const {
  MachineRegisterInfo &MRI = Root.getMF()->getRegInfo();

  // Select the previous instruction in the sequence based on the input pattern.
  MachineInstr *Prev = nullptr;
  switch (Pattern) {
  case MachineCombinerPattern::REASSOC_AX_BY:
  case MachineCombinerPattern::REASSOC_XA_BY:
    Prev = MRI.getUniqueVRegDef(Root.getOperand(1).getReg());
    break;
  case MachineCombinerPattern::REASSOC_AX_YB:
  case MachineCombinerPattern::REASSOC_XA_YB:
    Prev = MRI.getUniqueVRegDef(Root.getOperand(2).getReg());
    break;
  default:
    break;
  }

  assert(Prev && "Unknown pattern for machine combiner");

  reassociateOps(Root, *Prev, Pattern, InsInstrs, DelInstrs, InstIdxForVirtReg);
}
Beispiel #4
0
void MIPrinter::print(const MachineInstr &MI, unsigned OpIdx,
                      const TargetRegisterInfo *TRI,
                      bool ShouldPrintRegisterTies, LLT TypeToPrint,
                      bool PrintDef) {
  const MachineOperand &Op = MI.getOperand(OpIdx);
  switch (Op.getType()) {
  case MachineOperand::MO_Immediate:
    if (MI.isOperandSubregIdx(OpIdx)) {
      MachineOperand::printTargetFlags(OS, Op);
      MachineOperand::printSubRegIdx(OS, Op.getImm(), TRI);
      break;
    }
    LLVM_FALLTHROUGH;
  case MachineOperand::MO_Register:
  case MachineOperand::MO_CImmediate:
  case MachineOperand::MO_FPImmediate:
  case MachineOperand::MO_MachineBasicBlock:
  case MachineOperand::MO_ConstantPoolIndex:
  case MachineOperand::MO_TargetIndex:
  case MachineOperand::MO_JumpTableIndex:
  case MachineOperand::MO_ExternalSymbol:
  case MachineOperand::MO_GlobalAddress:
  case MachineOperand::MO_RegisterLiveOut:
  case MachineOperand::MO_Metadata:
  case MachineOperand::MO_MCSymbol:
  case MachineOperand::MO_CFIIndex:
  case MachineOperand::MO_IntrinsicID:
  case MachineOperand::MO_Predicate:
  case MachineOperand::MO_BlockAddress: {
    unsigned TiedOperandIdx = 0;
    if (ShouldPrintRegisterTies && Op.isReg() && Op.isTied() && !Op.isDef())
      TiedOperandIdx = Op.getParent()->findTiedOperandIdx(OpIdx);
    const TargetIntrinsicInfo *TII = MI.getMF()->getTarget().getIntrinsicInfo();
    Op.print(OS, MST, TypeToPrint, PrintDef, /*IsStandalone=*/false,
             ShouldPrintRegisterTies, TiedOperandIdx, TRI, TII);
    break;
  }
  case MachineOperand::MO_FrameIndex:
    printStackObjectReference(Op.getIndex());
    break;
  case MachineOperand::MO_RegisterMask: {
    auto RegMaskInfo = RegisterMaskIds.find(Op.getRegMask());
    if (RegMaskInfo != RegisterMaskIds.end())
      OS << StringRef(TRI->getRegMaskNames()[RegMaskInfo->second]).lower();
    else
      printCustomRegMask(Op.getRegMask(), OS, TRI);
    break;
  }
  }
}
Beispiel #5
0
void GCNRPTracker::reset(const MachineInstr &MI,
                         const LiveRegSet *LiveRegsCopy,
                         bool After) {
  const MachineFunction &MF = *MI.getMF();
  MRI = &MF.getRegInfo();
  if (LiveRegsCopy) {
    if (&LiveRegs != LiveRegsCopy)
      LiveRegs = *LiveRegsCopy;
  } else {
    LiveRegs = After ? getLiveRegsAfter(MI, LIS)
                     : getLiveRegsBefore(MI, LIS);
  }

  MaxPressure = CurPressure = getRegPressure(*MRI, LiveRegs);
}
Beispiel #6
0
int TargetInstrInfo::getSPAdjust(const MachineInstr &MI) const {
  const MachineFunction *MF = MI.getMF();
  const TargetFrameLowering *TFI = MF->getSubtarget().getFrameLowering();
  bool StackGrowsDown =
    TFI->getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown;

  unsigned FrameSetupOpcode = getCallFrameSetupOpcode();
  unsigned FrameDestroyOpcode = getCallFrameDestroyOpcode();

  if (!isFrameInstr(MI))
    return 0;

  int SPAdj = TFI->alignSPAdjust(getFrameSize(MI));

  if ((!StackGrowsDown && MI.getOpcode() == FrameSetupOpcode) ||
      (StackGrowsDown && MI.getOpcode() == FrameDestroyOpcode))
    SPAdj = -SPAdj;

  return SPAdj;
}
Beispiel #7
0
void MIPrinter::print(const MachineInstr &MI) {
  const auto *MF = MI.getMF();
  const auto &MRI = MF->getRegInfo();
  const auto &SubTarget = MF->getSubtarget();
  const auto *TRI = SubTarget.getRegisterInfo();
  assert(TRI && "Expected target register info");
  const auto *TII = SubTarget.getInstrInfo();
  assert(TII && "Expected target instruction info");
  if (MI.isCFIInstruction())
    assert(MI.getNumOperands() == 1 && "Expected 1 operand in CFI instruction");

  SmallBitVector PrintedTypes(8);
  bool ShouldPrintRegisterTies = MI.hasComplexRegisterTies();
  unsigned I = 0, E = MI.getNumOperands();
  for (; I < E && MI.getOperand(I).isReg() && MI.getOperand(I).isDef() &&
         !MI.getOperand(I).isImplicit();
       ++I) {
    if (I)
      OS << ", ";
    print(MI, I, TRI, ShouldPrintRegisterTies,
          MI.getTypeToPrint(I, PrintedTypes, MRI),
          /*PrintDef=*/false);
  }

  if (I)
    OS << " = ";
  if (MI.getFlag(MachineInstr::FrameSetup))
    OS << "frame-setup ";
  if (MI.getFlag(MachineInstr::FrameDestroy))
    OS << "frame-destroy ";
  if (MI.getFlag(MachineInstr::FmNoNans))
    OS << "nnan ";
  if (MI.getFlag(MachineInstr::FmNoInfs))
    OS << "ninf ";
  if (MI.getFlag(MachineInstr::FmNsz))
    OS << "nsz ";
  if (MI.getFlag(MachineInstr::FmArcp))
    OS << "arcp ";
  if (MI.getFlag(MachineInstr::FmContract))
    OS << "contract ";
  if (MI.getFlag(MachineInstr::FmAfn))
    OS << "afn ";
  if (MI.getFlag(MachineInstr::FmReassoc))
    OS << "reassoc ";
  if (MI.getFlag(MachineInstr::NoUWrap))
    OS << "nuw ";
  if (MI.getFlag(MachineInstr::NoSWrap))
    OS << "nsw ";
  if (MI.getFlag(MachineInstr::IsExact))
    OS << "exact ";

  OS << TII->getName(MI.getOpcode());
  if (I < E)
    OS << ' ';

  bool NeedComma = false;
  for (; I < E; ++I) {
    if (NeedComma)
      OS << ", ";
    print(MI, I, TRI, ShouldPrintRegisterTies,
          MI.getTypeToPrint(I, PrintedTypes, MRI));
    NeedComma = true;
  }

  // Print any optional symbols attached to this instruction as-if they were
  // operands.
  if (MCSymbol *PreInstrSymbol = MI.getPreInstrSymbol()) {
    if (NeedComma)
      OS << ',';
    OS << " pre-instr-symbol ";
    MachineOperand::printSymbol(OS, *PreInstrSymbol);
    NeedComma = true;
  }
  if (MCSymbol *PostInstrSymbol = MI.getPostInstrSymbol()) {
    if (NeedComma)
      OS << ',';
    OS << " post-instr-symbol ";
    MachineOperand::printSymbol(OS, *PostInstrSymbol);
    NeedComma = true;
  }

  if (const DebugLoc &DL = MI.getDebugLoc()) {
    if (NeedComma)
      OS << ',';
    OS << " debug-location ";
    DL->printAsOperand(OS, MST);
  }

  if (!MI.memoperands_empty()) {
    OS << " :: ";
    const LLVMContext &Context = MF->getFunction().getContext();
    const MachineFrameInfo &MFI = MF->getFrameInfo();
    bool NeedComma = false;
    for (const auto *Op : MI.memoperands()) {
      if (NeedComma)
        OS << ", ";
      Op->print(OS, MST, SSNs, Context, &MFI, TII);
      NeedComma = true;
    }
  }
}
Beispiel #8
0
bool TargetInstrInfo::isReallyTriviallyReMaterializableGeneric(
    const MachineInstr &MI, AliasAnalysis *AA) const {
  const MachineFunction &MF = *MI.getMF();
  const MachineRegisterInfo &MRI = MF.getRegInfo();

  // Remat clients assume operand 0 is the defined register.
  if (!MI.getNumOperands() || !MI.getOperand(0).isReg())
    return false;
  unsigned DefReg = MI.getOperand(0).getReg();

  // A sub-register definition can only be rematerialized if the instruction
  // doesn't read the other parts of the register.  Otherwise it is really a
  // read-modify-write operation on the full virtual register which cannot be
  // moved safely.
  if (TargetRegisterInfo::isVirtualRegister(DefReg) &&
      MI.getOperand(0).getSubReg() && MI.readsVirtualRegister(DefReg))
    return false;

  // A load from a fixed stack slot can be rematerialized. This may be
  // redundant with subsequent checks, but it's target-independent,
  // simple, and a common case.
  int FrameIdx = 0;
  if (isLoadFromStackSlot(MI, FrameIdx) &&
      MF.getFrameInfo().isImmutableObjectIndex(FrameIdx))
    return true;

  // Avoid instructions obviously unsafe for remat.
  if (MI.isNotDuplicable() || MI.mayStore() || MI.hasUnmodeledSideEffects())
    return false;

  // Don't remat inline asm. We have no idea how expensive it is
  // even if it's side effect free.
  if (MI.isInlineAsm())
    return false;

  // Avoid instructions which load from potentially varying memory.
  if (MI.mayLoad() && !MI.isDereferenceableInvariantLoad(AA))
    return false;

  // If any of the registers accessed are non-constant, conservatively assume
  // the instruction is not rematerializable.
  for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
    const MachineOperand &MO = MI.getOperand(i);
    if (!MO.isReg()) continue;
    unsigned Reg = MO.getReg();
    if (Reg == 0)
      continue;

    // Check for a well-behaved physical register.
    if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
      if (MO.isUse()) {
        // If the physreg has no defs anywhere, it's just an ambient register
        // and we can freely move its uses. Alternatively, if it's allocatable,
        // it could get allocated to something with a def during allocation.
        if (!MRI.isConstantPhysReg(Reg))
          return false;
      } else {
        // A physreg def. We can't remat it.
        return false;
      }
      continue;
    }

    // Only allow one virtual-register def.  There may be multiple defs of the
    // same virtual register, though.
    if (MO.isDef() && Reg != DefReg)
      return false;

    // Don't allow any virtual-register uses. Rematting an instruction with
    // virtual register uses would length the live ranges of the uses, which
    // is not necessarily a good idea, certainly not "trivial".
    if (MO.isUse())
      return false;
  }

  // Everything checked out.
  return true;
}
Beispiel #9
0
/// Attempt the reassociation transformation to reduce critical path length.
/// See the above comments before getMachineCombinerPatterns().
void TargetInstrInfo::reassociateOps(
    MachineInstr &Root, MachineInstr &Prev,
    MachineCombinerPattern Pattern,
    SmallVectorImpl<MachineInstr *> &InsInstrs,
    SmallVectorImpl<MachineInstr *> &DelInstrs,
    DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const {
  MachineFunction *MF = Root.getMF();
  MachineRegisterInfo &MRI = MF->getRegInfo();
  const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
  const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
  const TargetRegisterClass *RC = Root.getRegClassConstraint(0, TII, TRI);

  // This array encodes the operand index for each parameter because the
  // operands may be commuted. Each row corresponds to a pattern value,
  // and each column specifies the index of A, B, X, Y.
  unsigned OpIdx[4][4] = {
    { 1, 1, 2, 2 },
    { 1, 2, 2, 1 },
    { 2, 1, 1, 2 },
    { 2, 2, 1, 1 }
  };

  int Row;
  switch (Pattern) {
  case MachineCombinerPattern::REASSOC_AX_BY: Row = 0; break;
  case MachineCombinerPattern::REASSOC_AX_YB: Row = 1; break;
  case MachineCombinerPattern::REASSOC_XA_BY: Row = 2; break;
  case MachineCombinerPattern::REASSOC_XA_YB: Row = 3; break;
  default: llvm_unreachable("unexpected MachineCombinerPattern");
  }

  MachineOperand &OpA = Prev.getOperand(OpIdx[Row][0]);
  MachineOperand &OpB = Root.getOperand(OpIdx[Row][1]);
  MachineOperand &OpX = Prev.getOperand(OpIdx[Row][2]);
  MachineOperand &OpY = Root.getOperand(OpIdx[Row][3]);
  MachineOperand &OpC = Root.getOperand(0);

  unsigned RegA = OpA.getReg();
  unsigned RegB = OpB.getReg();
  unsigned RegX = OpX.getReg();
  unsigned RegY = OpY.getReg();
  unsigned RegC = OpC.getReg();

  if (TargetRegisterInfo::isVirtualRegister(RegA))
    MRI.constrainRegClass(RegA, RC);
  if (TargetRegisterInfo::isVirtualRegister(RegB))
    MRI.constrainRegClass(RegB, RC);
  if (TargetRegisterInfo::isVirtualRegister(RegX))
    MRI.constrainRegClass(RegX, RC);
  if (TargetRegisterInfo::isVirtualRegister(RegY))
    MRI.constrainRegClass(RegY, RC);
  if (TargetRegisterInfo::isVirtualRegister(RegC))
    MRI.constrainRegClass(RegC, RC);

  // Create a new virtual register for the result of (X op Y) instead of
  // recycling RegB because the MachineCombiner's computation of the critical
  // path requires a new register definition rather than an existing one.
  unsigned NewVR = MRI.createVirtualRegister(RC);
  InstrIdxForVirtReg.insert(std::make_pair(NewVR, 0));

  unsigned Opcode = Root.getOpcode();
  bool KillA = OpA.isKill();
  bool KillX = OpX.isKill();
  bool KillY = OpY.isKill();

  // Create new instructions for insertion.
  MachineInstrBuilder MIB1 =
      BuildMI(*MF, Prev.getDebugLoc(), TII->get(Opcode), NewVR)
          .addReg(RegX, getKillRegState(KillX))
          .addReg(RegY, getKillRegState(KillY));
  MachineInstrBuilder MIB2 =
      BuildMI(*MF, Root.getDebugLoc(), TII->get(Opcode), RegC)
          .addReg(RegA, getKillRegState(KillA))
          .addReg(NewVR, getKillRegState(true));

  setSpecialOperandAttr(Root, Prev, *MIB1, *MIB2);

  // Record new instructions for insertion and old instructions for deletion.
  InsInstrs.push_back(MIB1);
  InsInstrs.push_back(MIB2);
  DelInstrs.push_back(&Prev);
  DelInstrs.push_back(&Root);
}