private void typeCheckHelper(OPT_IR ir, OPT_AvExCache cache,
private void typeCheckHelper(OPT_IR ir, AvExCache cache,
  private void typeCheckHelper(OPT_IR ir, OPT_AvExCache cache, 			       OPT_Instruction inst) {    // look up the check in the cache    OPT_AvailableExpression ae = cache.find(inst);    if (ae != null) {      // it's a duplicate; blow it away.      inst.remove();    } else {      // did not find a match: insert new entry in cache      cache.insert(inst);    }  }