if (needCleanup) { ir.cfg.compactNodeNumbering(); }
  public void perform (OPT_IR ir) {    // (1) Find candidates to split    simpleCandidateSearch(ir);    // (2) Split them    boolean needCleanup = haveCandidates();    while (haveCandidates()) {      splitCandidate(nextCandidate(), ir);    }  }