auto func_op_quant_scale_spec = GetStableHloQuantConstraints;

  for (auto func_op : module_op.getOps<func::FuncOp>()) {
    // The function might contain more stats ops than required, and it will
    // introduce requantize if the calibration stats have conflicts. This tries
    // to remove all the redundant stats ops.
    RemoveRedundantStatsOps(func_op, func_op_quant_spec,
                            func_op_quant_scale_spec);

  Block &nested_block = nested_module->getRegion(0).front();
  for (func::FuncOp func_op :
       llvm::make_early_inc_range(nested_block.getOps<func::FuncOp>())) {
    if (!symbol_table.lookupSymbolIn(getOperation(), func_op.getName())) {
      nested_block.getOperations().remove(func_op.getOperation());
      symbol_table.insert(func_op.getOperation());
    }
  }
  nested_module->erase();
}

}  // namespace

  }

  Value func_input_arg;
  // Creates a function.
  func::FuncOp func_op = PrepareFunctionRegister(
      rewriter, input_val, result_type, unique_func_name, func_input_arg);

  // Fills the body.
  Operation* last_op_in_func =
      quantization_operations_func(rewriter, func_op.getOperation(),
                                   func_input_arg, result_type, quant_type);

  }
};

// Returns true iff func_op has either no Region or the body has no Blocks.
bool IsFuncOpEmpty(func::FuncOp func_op) {
  return func_op->getNumRegions() == 0 || func_op.getBody().empty();
}

// Gets the GraphOp from the function op. Returns an empty op iff it doesn't
// exist.
GraphOp GetGraphOpFromFuncOp(func::FuncOp func_op) {
  if (IsFuncOpEmpty(func_op)) return {};

using ::tensorflow::kDefaultServingSignatureDefKey;
using ::tensorflow::kImportModelDefaultGraphFuncName;

// Returns true iff the function's symbol is public.
bool IsPublicFuncOp(func::FuncOp func_op) {
  return SymbolTable::getSymbolVisibility(&*func_op) ==
         SymbolTable::Visibility::Public;
}

}  // namespace

func::FuncOp FindMainFuncOp(ModuleOp module_op) {
  if (const auto main_func_op = module_op.lookupSymbol<func::FuncOp>(

  OpPassManager &func_pm = pm.nest<func::FuncOp>();

  // First operates on the executor dialect:
  // - remove dead islands.
  // - fuse islands as much as possible.
  // - materialize the eventual "pass-through" ops by inlining their content.
  func_pm.addPass(tf_executor::CreateTFExecutorGraphPruningPass());
  func_pm.addPass(tf_executor::CreateTFExecutorIslandCoarseningPass());

 public:
  void runOnOperation() override;
};

void InferenceMetricsPass::runOnOperation() {
  bool has_tpu_partitioned_call = false;
  ModuleOp module = getOperation();

  for (auto func_op : module.getOps<func::FuncOp>()) {
    func_op->walk(
        [&](TF::TPUPartitionedCallOp op) { has_tpu_partitioned_call = true; });

    if (has_tpu_partitioned_call) break;
  }

  std::string has_tpu_partitioned_call_str =

    return false;  // not a call
  func::FuncOp func_op = dyn_cast<func::FuncOp>(call.resolveCallable(
      &symbol_table_collection_));
  return IsPureFunction(func_op);
}

bool OpSideEffectCollector::IsPureFunction(func::FuncOp func_op) const {
  auto it = is_pure_function_.find(func_op);
  if (it == is_pure_function_.end()) {
    bool is_pure = true;
    is_pure_function_[func_op] = is_pure;  // prevent infinite recursion

    return_operands.push_back(cloned_output);
  }
  function_builder.create<mlir::func::ReturnOp>(new_func.getLoc(),
                                                return_operands);
  ops_added.func_op = new_func;
  module.push_back(new_func);
  return new_func;
}

void ExtractSubgraphToFunc(const Subgraph& subgraph, OpBuilder& builder,
                           ModuleOp& module, OpsAdded& ops_added) {

    : tfr_module_(tfr_module), pm_(tfr_module_.getContext()) {
  mlir::OpPassManager& func_pm = pm_.nest<mlir::func::FuncOp>();

  // Prepare the imported graph.
  func_pm.addPass(mlir::CreateExecutorDialectToFunctionalConversionPass());

  // Run TFR lowering, inlining and raising to tf.
  func_pm.addPass(mlir::TFR::CreateDecomposeTFOpsPass(tfr_module_));
  func_pm.addPass(mlir::TFR::CreateRaiseToTFOpsPass(