C++ iterator::isInlineAsm方法代码示例

MachineBasicBlock::iterator
Filler::findDelayInstr(MachineBasicBlock &MBB,
                       MachineBasicBlock::iterator slot)
{
  SmallSet<unsigned, 32> RegDefs;
  SmallSet<unsigned, 32> RegUses;
  bool sawLoad = false;
  bool sawStore = false;

  if (slot == MBB.begin())
    return MBB.end();

  if (slot->getOpcode() == SP::RET || slot->getOpcode() == SP::TLS_CALL)
    return MBB.end();

  if (slot->getOpcode() == SP::RETL) {
    MachineBasicBlock::iterator J = slot;
    --J;

    if (J->getOpcode() == SP::RESTORErr
        || J->getOpcode() == SP::RESTOREri) {
      // change retl to ret.
      slot->setDesc(TM.getInstrInfo()->get(SP::RET));
      return J;
    }
  }

  // Call's delay filler can def some of call's uses.
  if (slot->isCall())
    insertCallDefsUses(slot, RegDefs, RegUses);
  else
    insertDefsUses(slot, RegDefs, RegUses);

  bool done = false;

  MachineBasicBlock::iterator I = slot;

  while (!done) {
    done = (I == MBB.begin());

    if (!done)
      --I;

    // skip debug value
    if (I->isDebugValue())
      continue;

    if (I->hasUnmodeledSideEffects() || I->isInlineAsm() || I->isPosition() ||
        I->hasDelaySlot() || I->isBundledWithSucc())
      break;

    if (delayHasHazard(I, sawLoad, sawStore, RegDefs, RegUses)) {
      insertDefsUses(I, RegDefs, RegUses);
      continue;
    }

    return I;
  }
  return MBB.end();
}

int PatmosInstrInfo::findPrevDelaySlotEnd(MachineBasicBlock &MBB,
                                          MachineBasicBlock::iterator &II,
                                          int Cycles) const
{
  int cnt = 0;

  int maxDelaySlotSize = PST.getCFLDelaySlotCycles(false);

  while (II != MBB.begin()) {
    --II;
    if (isPseudo(&*II))
      continue;

    // This code assumes that delay slots can not be completely inside other
    // delay slots, i.e., we only need to scan up to the first CFL instruction.

    if (II->isInlineAsm()) {
      break;
    }
    if (II->isBranch() || II->isCall() || II->isReturn()) {
      cnt -= PST.getDelaySlotCycles(&*II);
      break;
    }
    if (Cycles >= 0 && cnt >= Cycles + maxDelaySlotSize)
      break;

    cnt++;
  }

  return Cycles >= 0 && cnt > Cycles ? Cycles : cnt;
}

MachineBasicBlock::iterator
Filler::findDelayInstr(MachineBasicBlock &MBB,
                       MachineBasicBlock::iterator slot)
{
  SmallSet<unsigned, 32> RegDefs;
  SmallSet<unsigned, 32> RegUses;
  bool sawLoad = false;
  bool sawStore = false;

  MachineBasicBlock::iterator I = slot;

  if (slot->getOpcode() == SP::RET)
    return MBB.end();

  if (slot->getOpcode() == SP::RETL) {
    --I;
    if (I->getOpcode() != SP::RESTORErr)
      return MBB.end();
    //change retl to ret
    slot->setDesc(TII->get(SP::RET));
    return I;
  }

  //Call's delay filler can def some of call's uses.
  if (slot->isCall())
    insertCallUses(slot, RegUses);
  else
    insertDefsUses(slot, RegDefs, RegUses);

  bool done = false;

  while (!done) {
    done = (I == MBB.begin());

    if (!done)
      --I;

    // skip debug value
    if (I->isDebugValue())
      continue;


    if (I->hasUnmodeledSideEffects()
        || I->isInlineAsm()
        || I->isLabel()
        || I->hasDelaySlot()
        || isDelayFiller(MBB, I))
      break;

    if (delayHasHazard(I, sawLoad, sawStore, RegDefs, RegUses)) {
      insertDefsUses(I, RegDefs, RegUses);
      continue;
    }

    return I;
  }
  return MBB.end();
}

/// calculateCallsInformation - Calculate the MaxCallFrameSize and AdjustsStack
/// variables for the function's frame information and eliminate call frame
/// pseudo instructions.
void PEI::calculateCallsInformation(MachineFunction &Fn) {
  const TargetRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
  const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo();
  const TargetFrameLowering *TFI = Fn.getTarget().getFrameLowering();
  MachineFrameInfo *MFI = Fn.getFrameInfo();

  unsigned MaxCallFrameSize = 0;
  bool AdjustsStack = MFI->adjustsStack();

  // Get the function call frame set-up and tear-down instruction opcode
  int FrameSetupOpcode   = TII.getCallFrameSetupOpcode();
  int FrameDestroyOpcode = TII.getCallFrameDestroyOpcode();

  // Early exit for targets which have no call frame setup/destroy pseudo
  // instructions.
  if (FrameSetupOpcode == -1 && FrameDestroyOpcode == -1)
    return;

  std::vector<MachineBasicBlock::iterator> FrameSDOps;
  for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB)
    for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); ++I)
      if (I->getOpcode() == FrameSetupOpcode ||
          I->getOpcode() == FrameDestroyOpcode) {
        assert(I->getNumOperands() >= 1 && "Call Frame Setup/Destroy Pseudo"
               " instructions should have a single immediate argument!");
        unsigned Size = I->getOperand(0).getImm();
        if (Size > MaxCallFrameSize) MaxCallFrameSize = Size;
        AdjustsStack = true;
        FrameSDOps.push_back(I);
      } else if (I->isInlineAsm()) {
        // Some inline asm's need a stack frame, as indicated by operand 1.
        unsigned ExtraInfo = I->getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
        if (ExtraInfo & InlineAsm::Extra_IsAlignStack)
          AdjustsStack = true;
      }

  MFI->setAdjustsStack(AdjustsStack);
  MFI->setMaxCallFrameSize(MaxCallFrameSize);

  for (std::vector<MachineBasicBlock::iterator>::iterator
         i = FrameSDOps.begin(), e = FrameSDOps.end(); i != e; ++i) {
    MachineBasicBlock::iterator I = *i;

    // If call frames are not being included as part of the stack frame, and
    // the target doesn't indicate otherwise, remove the call frame pseudos
    // here. The sub/add sp instruction pairs are still inserted, but we don't
    // need to track the SP adjustment for frame index elimination.
    if (TFI->canSimplifyCallFramePseudos(Fn))
      RegInfo->eliminateCallFramePseudoInstr(Fn, *I->getParent(), I);
  }
}

/// Calculate the MaxCallFrameSize and AdjustsStack
/// variables for the function's frame information and eliminate call frame
/// pseudo instructions.
void PEI::calculateCallFrameInfo(MachineFunction &MF) {
  const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
  const TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
  MachineFrameInfo &MFI = MF.getFrameInfo();

  unsigned MaxCallFrameSize = 0;
  bool AdjustsStack = MFI.adjustsStack();

  // Get the function call frame set-up and tear-down instruction opcode
  unsigned FrameSetupOpcode = TII.getCallFrameSetupOpcode();
  unsigned FrameDestroyOpcode = TII.getCallFrameDestroyOpcode();

  // Early exit for targets which have no call frame setup/destroy pseudo
  // instructions.
  if (FrameSetupOpcode == ~0u && FrameDestroyOpcode == ~0u)
    return;

  std::vector<MachineBasicBlock::iterator> FrameSDOps;
  for (MachineFunction::iterator BB = MF.begin(), E = MF.end(); BB != E; ++BB)
    for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); ++I)
      if (TII.isFrameInstr(*I)) {
        unsigned Size = TII.getFrameSize(*I);
        if (Size > MaxCallFrameSize) MaxCallFrameSize = Size;
        AdjustsStack = true;
        FrameSDOps.push_back(I);
      } else if (I->isInlineAsm()) {
        // Some inline asm's need a stack frame, as indicated by operand 1.
        unsigned ExtraInfo = I->getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
        if (ExtraInfo & InlineAsm::Extra_IsAlignStack)
          AdjustsStack = true;
      }

  assert(!MFI.isMaxCallFrameSizeComputed() ||
         (MFI.getMaxCallFrameSize() == MaxCallFrameSize &&
          MFI.adjustsStack() == AdjustsStack));
  MFI.setAdjustsStack(AdjustsStack);
  MFI.setMaxCallFrameSize(MaxCallFrameSize);

  for (std::vector<MachineBasicBlock::iterator>::iterator
         i = FrameSDOps.begin(), e = FrameSDOps.end(); i != e; ++i) {
    MachineBasicBlock::iterator I = *i;

    // If call frames are not being included as part of the stack frame, and
    // the target doesn't indicate otherwise, remove the call frame pseudos
    // here. The sub/add sp instruction pairs are still inserted, but we don't
    // need to track the SP adjustment for frame index elimination.
    if (TFI->canSimplifyCallFramePseudos(MF))
      TFI->eliminateCallFramePseudoInstr(MF, *I->getParent(), I);
  }
}

bool PatmosInstrInfo::advanceCycles(MachineBasicBlock &MBB,
                                    MachineBasicBlock::iterator &II,
                                    unsigned Cycles, bool StopOnInlineAsm) const
{
  for (unsigned i = 0; i < Cycles && II != MBB.end(); i++) {

    II = nextNonPseudo(MBB, II);

    if (StopOnInlineAsm && II->isInlineAsm()) {
      // Should we stop on the last non-pseudo instruction instead?
      II++;
      return false;
    }
  }
  return true;
}