namespace mlir {
namespace TFTPU {

namespace {

constexpr char kDeviceAttr[] = "device";
constexpr char kFuncDeviceAttr[] = "tf.device";

// Checks if a function only contains a tf_executor.graph.
bool IsSupportedGraph(func::FuncOp func) {
  if (!llvm::hasSingleElement(func)) return false;

  Block& block = func.front();
  if (!llvm::hasSingleElement(block.without_terminator())) return false;