示例#1
0
/// Performs the actual liveness calculation for the function.
bool StackMapLiveness::calculateLiveness() {
  bool HasChanged = false;
  // For all basic blocks in the function.
  for (MachineFunction::iterator MBBI = MF->begin(), MBBE = MF->end();
       MBBI != MBBE; ++MBBI) {
    DEBUG(dbgs() << "****** BB " << MBBI->getName() << " ******\n");
    LiveRegs.init(TRI);
    LiveRegs.addLiveOuts(MBBI);
    bool HasStackMap = false;
    // Reverse iterate over all instructions and add the current live register
    // set to an instruction if we encounter a stackmap or patchpoint
    // instruction.
    for (MachineBasicBlock::reverse_iterator I = MBBI->rbegin(),
         E = MBBI->rend(); I != E; ++I) {
      int Opc = I->getOpcode();
      if ((EnableStackMapLiveness && (Opc == TargetOpcode::STACKMAP)) ||
          (EnablePatchPointLiveness && (Opc == TargetOpcode::PATCHPOINT))) {
        addLiveOutSetToMI(*I);
        HasChanged = true;
        HasStackMap = true;
        ++NumStackMaps;
      }
      DEBUG(dbgs() << "   " << LiveRegs << "   " << *I);
      LiveRegs.stepBackward(*I);
    }
    ++NumBBsVisited;
    if (!HasStackMap)
      ++NumBBsHaveNoStackmap;
  }
  return HasChanged;
}
示例#2
0
unsigned MipsInstrInfo::removeBranch(MachineBasicBlock &MBB,
                                     int *BytesRemoved) const {
  assert(!BytesRemoved && "code size not handled");

  MachineBasicBlock::reverse_iterator I = MBB.rbegin(), REnd = MBB.rend();
  unsigned removed;

  // Skip all the debug instructions.
  while (I != REnd && I->isDebugValue())
    ++I;

  if (I == REnd)
    return 0;

  MachineBasicBlock::iterator FirstBr = ++I.getReverse();

  // Up to 2 branches are removed.
  // Note that indirect branches are not removed.
  for (removed = 0; I != REnd && removed < 2; ++I, ++removed)
    if (!getAnalyzableBrOpc(I->getOpcode()))
      break;

  MBB.erase((--I).getReverse(), FirstBr);

  return removed;
}
示例#3
0
unsigned MipsInstrInfo::removeBranch(MachineBasicBlock &MBB,
                                     int *BytesRemoved) const {
  assert(!BytesRemoved && "code size not handled");

  MachineBasicBlock::reverse_iterator I = MBB.rbegin(), REnd = MBB.rend();
  unsigned removed = 0;

  // Up to 2 branches are removed.
  // Note that indirect branches are not removed.
  while (I != REnd && removed < 2) {
    // Skip past debug instructions.
    if (I->isDebugValue()) {
      ++I;
      continue;
    }
    if (!getAnalyzableBrOpc(I->getOpcode()))
      break;
    // Remove the branch.
    I->eraseFromParent();
    I = MBB.rbegin();
    ++removed;
  }

  return removed;
}
示例#4
0
unsigned MipsInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
  MachineBasicBlock::reverse_iterator I = MBB.rbegin(), REnd = MBB.rend();
  MachineBasicBlock::reverse_iterator FirstBr;
  unsigned removed;

  // Skip all the debug instructions.
  while (I != REnd && I->isDebugValue())
    ++I;

  FirstBr = I;

  // Up to 2 branches are removed.
  // Note that indirect branches are not removed.
  for (removed = 0; I != REnd && removed < 2; ++I, ++removed)
    if (!getAnalyzableBrOpc(I->getOpcode()))
      break;

  MBB.erase(I.base(), FirstBr.base());

  return removed;
}