"expected tf_executor.island";

    // Move inner ops in island to before the outer graph.
    auto& island_body = island_op.GetBody().getOperations();
    parent_block->getOperations().splice(graph_position, island_body,
                                         island_body.begin(),
                                         std::prev(island_body.end()));

  for (Block& block : region->getBlocks()) {
    for (Operation& op : block.getOperations()) {
      if (op.hasTrait<OpTrait::ReturnLike>()) result = &op;
    }
  }
  return result;
}

void EraseReturnOperands(Region* region, llvm::BitVector& erase) {
  for (Block& block : region->getBlocks()) {
    for (Operation& op : block.getOperations()) {
      if (!op.hasTrait<OpTrait::ReturnLike>()) continue;

  // Move all inner ops of the launch to the block containing the launch.
  auto body = launch.GetBody().without_terminator();
  Operation* launch_op = launch.getOperation();
  launch_op->getBlock()->getOperations().splice(
      launch_op->getIterator(), launch.GetBody().getOperations(), body.begin(),
      body.end());

  launch.erase();

  return success();
}

void LaunchToDeviceAttributePass::runOnOperation() {

  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

std::unique_ptr<OperationPass<ModuleOp>>

    to_fetch = to_fetch.drop_back();
  }
  builder.create<tf_executor::FetchOp>(loc, to_fetch);
  // Build Island.
  island.getBody().push_back(new Block);
  island.getBody().front().getOperations().splice(
      island.getBody().front().begin(), body.getOperations(),
      copy_range.begin(), copy_range.end());
  builder.setInsertionPointToEnd(&island.getBody().front());
  builder.create<tf_executor::YieldOp>(loc, return_op.getOperands());

        }
        if (constant.hasOneUse()) {
          LLVM_DEBUG(llvm::dbgs() << "Moved constant " << constant << "\n");
          const_op.getOperation()->moveBefore(&body.begin()->front());
          return;
        }
        map_entry.first->getSecond() = const_op.clone();
        body.begin()->getOperations().insert(body.begin()->begin(),
                                             map_entry.first->getSecond());

         llvm::zip(block.getArguments(), op->getOperands())) {
      std::get<0>(arg_mapping).replaceAllUsesWith(std::get<1>(arg_mapping));
    }
    op->getBlock()->getOperations().splice(op->getIterator(),
                                           block.getOperations(), block.begin(),
                                           std::prev(block.end()));
    Operation &return_op = block.front();
    for (auto ret_mapping :

    replaceAllUsesInRegionWith(std::get<0>(p), std::get<1>(p), op_region);
  }

  // Move all instructions in cluster_op into outlined_function's only block.
  auto& op_body = op.GetBody().getOperations();
  outlined_func_block->getOperations().splice(
      outlined_func_block->end(), op_body, op_body.begin(), op_body.end());

  // Replace `tf_device.return` terminator with `std.return` in function
  // body.
  auto return_op =

  func::FuncOp callee = from.lookup<func::FuncOp>(symbol_ref.getValue());
  callee.getOperation()->getBlock()->getOperations().remove(
      callee.getOperation());
  to.insert(callee);
}

void TPUBridgeExecutorIslandOutlining::runOnOperation() {
  MLIRContext *ctx = &getContext();

  SymbolTable symbol_table(getOperation());
  if (Operation *nested_module = symbol_table.lookup(kNestedModule)) {

  // operation list from module_out to module_in.
  auto& module_in_ops = module_in.getBody()->getOperations();
  module_in_ops.clear();
  module_in_ops.splice(module_in_ops.end(),
                       module_out->getBody()->getOperations());
}

// Returns a vector of passes from their names. If a pass is not found, then the
// corresponding return entry is null.