OPT_DominatorsPhase dom = new OPT_DominatorsPhase();
OPT_DominatorsPhase dom = new OPT_DominatorsPhase(true);
  static void staticPerform (OPT_IR ir) {    if (ir.hasReachableExceptionHandlers()) return;    OPT_DominatorsPhase dom = new OPT_DominatorsPhase();    for (;;) {      dom.perform(ir);      if (!turnWhilesIntoUntils(ir))        break;    }        branchOpts.perform(ir, false);    dom.perform(ir);    splitCriticalEdges(ir);    ir.cfg.compactNodeNumbering();  }