auto funcs_for_cluster = tpu_funcs.find(cluster);
    assert(funcs_for_cluster != tpu_funcs.end());
    assert(!funcs_for_cluster->second.empty());
    if (funcs_for_cluster->second.size() == 1) return false;
    for (NamedAttribute attr : op->getAttrs()) {
      auto symbol_ref = mlir::dyn_cast<FlatSymbolRefAttr>(attr.getValue());
      if (!symbol_ref) continue;
      func::FuncOp callee =