public void mergeInterferenceSet(int reg,IntSet set){
  if (reg < interference.size()) {
    set.merge(interference.get(reg));
  }
}

public void mergeInterferenceSet ( int reg , IntSet set ) { if ( reg < interference . size ( ) ) { set . merge ( interference . get ( reg ) ) ; } }
merges the interference set for a register into a given bit set
