xla::HloFunctionImporter::ImportInstructions(
          *hlo_module->entry_computation(), arguments, symbol_table, &builder));

  mhlo::TupleOp root_tuple =
      mlir::dyn_cast_or_null<mhlo::TupleOp>(root_value.getDefiningOp());
  if (!root_tuple) {
    return tsl::errors::InvalidArgument(
        "Imported XLA Root Value is not a tuple op");
  }

  return root_tuple;
}

LogicalResult Tf2XlaRewriter::PrepareParams() {

          "Func must have ReturnOp as last op and must return 1 value");
    }
    auto def_op = return_op.getOperand(0).getDefiningOp();
    auto fold_results = ConstantFoldOpIfPossible(def_op);
    if (fold_results.size() != 1 ||
        !llvm::isa<TF::ConstOp>(fold_results[0].getDefiningOp())) {
      return absl::InternalError("Failed to evaluate TF ops");
    }

    // Convert output tensor back to xla::Literal.

  std::stack<Operation*> op_stack;
  while (!value_queue.empty()) {
    Value current_value = value_queue.front();
    value_queue.pop();

    Operation* defining_node = current_value.getDefiningOp();
    if (defining_node == nullptr) continue;
    op_stack.push(defining_node);
    for (Value arg : defining_node->getOperands()) {
      if (!argument_set.contains(arg.getImpl())) {
        value_queue.push(arg);

                   llvm::SmallPtrSet<Operation*, 4>* skipped = nullptr) {
  while (auto result = mlir::dyn_cast<OpResult>(v)) {
    if (!(allow_other_use || v.hasOneUse())) break;
    auto op = result.getDefiningOp();
    if (!llvm::isa<TF::IdentityOp, TF::IdentityNOp>(op)) {
      break;
    }
    v = op->getOperand(result.getResultNumber());
    if (skipped) skipped->insert(op);
  }
  return v;
}

  // we set its value as a const tensor of specified size and value 0.
  EXPECT_TRUE(
      mlir::cast<ElementsAttr>(mlir::cast<mlir::arith::ConstantOp>(
                                   it->getOpOperand(15).get().getDefiningOp())
                                   .getValue())
          .getValues<FloatAttr>()[0]
          .getValue()
          .isExactlyValue(0.0f));

  EXPECT_EQ(fused_lstm_func_.getFunctionType().getNumResults(), 1);

      continue;
    }

    // The index is valid for the call_op.
    Value input = call_op.getOperand(operand.index());
    Operation* input_op = input.getDefiningOp();
    auto input_tfr_type =
        signature.getFunctionType().getInputs()[operand.index()];

    // There are three cases for the preceding input_op:

                         FunctionCallOpType::TFXlaCallModuleOp,
                         "composite_dot_general_fn", operands, results,
                         attributes)[0]
          .getDefiningOp();
  const auto entry_function_symbol_ref =
      lifted_op->getAttrOfType<FlatSymbolRefAttr>("_entry_function");
  SymbolTable symbol_table(*module_op);
  auto entry_func = dyn_cast_or_null<func::FuncOp>(

        operand.value().get().getDefiningOp());
    if (!read_op) continue;
    if (check_same_region &&
        read_op->getParentRegion() != execute_parent->getParentRegion())
      continue;

    auto resource = read_op.getResource();
    if (check_device) {
      // TODO(lyandy): Wrap resource ops in tf_device.launch.
      if (auto* resource_op = resource.getDefiningOp()) {

      return cond;

  OpBuilder builder(op);
  Value to_bool = builder.create<TF::ToBoolOp>(op->getLoc(), cond);
  CopyDeviceAndUnderscoredAttributes(op, to_bool.getDefiningOp());
  return to_bool;
}

// Transform a functional IfOp to a region based IfRegionOp.
LogicalResult ConvertIfOp(IfOp if_op) {
  Value cond = ConvertConditionToBoolean(if_op, if_op.getCond());

    if (mlir::isa<tf_executor::ControlType>(operand.getType())) break;

    if (is_switch &&
        llvm::isa_and_nonnull<tf_executor::LoopCondOp>(operand.getDefiningOp()))
      continue;

    auto it = value_to_device.find(operand);
    if (it == value_to_device.end()) return llvm::StringRef();

    if (new_device.empty()) {
      new_device = it->getSecond();