LiveIntervalAnalysis.cpp

         E = mri_->reg_end(); I != E; ++I) {
    MachineOperand &O = I.getOperand();
    MachineInstr *MI = O.getParent();
    unsigned Index = getInstructionIndex(MI);
    if (pli.liveAt(Index))
      ++NumConflicts;
  }
  return NumConflicts;
}

/// spillPhysRegAroundRegDefsUses - Spill the specified physical register
/// around all defs and uses of the specified interval.
void LiveIntervals::spillPhysRegAroundRegDefsUses(const LiveInterval &li,
                                            unsigned PhysReg, VirtRegMap &vrm) {
  unsigned SpillReg = getRepresentativeReg(PhysReg);

  for (const unsigned *AS = tri_->getAliasSet(PhysReg); *AS; ++AS)
    // If there are registers which alias PhysReg, but which are not a
    // sub-register of the chosen representative super register. Assert
    // since we can't handle it yet.
    assert(*AS == SpillReg || !allocatableRegs_[*AS] ||
           tri_->isSuperRegister(*AS, SpillReg));

  LiveInterval &pli = getInterval(SpillReg);
  SmallPtrSet<MachineInstr*, 8> SeenMIs;
  for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(li.reg),
         E = mri_->reg_end(); I != E; ++I) {
    MachineOperand &O = I.getOperand();
    MachineInstr *MI = O.getParent();
    if (SeenMIs.count(MI))
      continue;
    SeenMIs.insert(MI);
    unsigned Index = getInstructionIndex(MI);
    if (pli.liveAt(Index)) {
      vrm.addEmergencySpill(SpillReg, MI);
      pli.removeRange(getLoadIndex(Index), getStoreIndex(Index)+1);
      for (const unsigned* AS = tri_->getSubRegisters(SpillReg); *AS; ++AS) {
        if (!hasInterval(*AS))
          continue;
        LiveInterval &spli = getInterval(*AS);
        if (spli.liveAt(Index))
          spli.removeRange(getLoadIndex(Index), getStoreIndex(Index)+1);
      }
    }
  }
}

LiveRange LiveIntervals::addLiveRangeToEndOfBlock(unsigned reg,
                                                   MachineInstr* startInst) {
  LiveInterval& Interval = getOrCreateInterval(reg);
  VNInfo* VN = Interval.getNextValue(
            getInstructionIndex(startInst) + InstrSlots::DEF,
            startInst, getVNInfoAllocator());
  VN->hasPHIKill = true;
  VN->kills.push_back(getMBBEndIdx(startInst->getParent()));
  LiveRange LR(getInstructionIndex(startInst) + InstrSlots::DEF,
               getMBBEndIdx(startInst->getParent()) + 1, VN);
  Interval.addRange(LR);
  
  return LR;
}