OPT_AvailableExpression ae = cache.find(inst);
AvailableExpression ae = cache.find(inst);
  private void storeHelper (OPT_AvExCache cache, OPT_Instruction inst) {    // look up the expression in the cache    OPT_AvailableExpression ae = cache.find(inst);    if (ae == null) {      // did not find a match: insert new entry in cache      cache.insert(inst);    }  }