Exemple #1
0
bool Filler::tryCombineRestoreWithPrevInst(MachineBasicBlock &MBB,
                                        MachineBasicBlock::iterator MBBI)
{
  // No previous instruction.
  if (MBBI == MBB.begin())
    return false;

  // assert that MBBI is a "restore %g0, %g0, %g0".
  assert(MBBI->getOpcode() == SP::RESTORErr
         && MBBI->getOperand(0).getReg() == SP::G0
         && MBBI->getOperand(1).getReg() == SP::G0
         && MBBI->getOperand(2).getReg() == SP::G0);

  MachineBasicBlock::iterator PrevInst = std::prev(MBBI);

  // It cannot be combined with a bundled instruction.
  if (PrevInst->isBundledWithSucc())
    return false;

  const TargetInstrInfo *TII = TM.getInstrInfo();

  switch (PrevInst->getOpcode()) {
  default: break;
  case SP::ADDrr:
  case SP::ADDri: return combineRestoreADD(MBBI, PrevInst, TII); break;
  case SP::ORrr:
  case SP::ORri:  return combineRestoreOR(MBBI, PrevInst, TII); break;
  case SP::SETHIi: return combineRestoreSETHIi(MBBI, PrevInst, TII); break;
  }
  // It cannot combine with the previous instruction.
  return false;
}
Exemple #2
0
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();
}