return std::nullopt;

  if (!HasValidHardwareTarget(op)) return std::nullopt;

  auto device = op->getAttrOfType<mlir::StringAttr>(mlir::TFL::tac::kDevice);
  if (device == nullptr) return std::nullopt;

  llvm::StringRef device_name_str = device.getValue();
  return device_name_str.str();
}

std::optional<std::vector<float>> GetPerDeviceCosts(

      task_and_device = {task, device};
    }
  }

  return topology;
}

// Determine execution devices when topology and device assignment are defined.
// With a topology device coordinate to task and device mapping, device
// assignment device coordinates can then be mapped to task and device for TPU
// devices. The device assignment array is also validated.
//

  %0 = "tf.Const"() {device = "/device:CPU:0", value = dense<2> : tensor<i32>} : () -> tensor<i32>
  %1 = "tf.ReadVariableOp"(%arg) {device = "/device:CPU:0", dtype = i32} : (tensor<!tf_type.resource<tensor<i32>>>) -> tensor<i32>
  %2 = "tf.Add"(%1, %0) {device = "/device:CPU:0"} : (tensor<i32>, tensor<i32>) -> tensor<i32>

"909", tf.device = "/job:tpu_host_worker/replica:0/task:0/device:CPU:0"}, %arg7: tensor<*x!tf_type.resource<tensor<25001x64xf32>>> {tf._user_specified_name = "911", tf.device = "/job:tpu_host_worker/replica:0/task:0/device:CPU:0"}, %arg8: tensor<*x!tf_type.resource<tensor<25001x64xf32>>> {tf._user_specified_name = "913", tf.device = "/job:tpu_host_worker/replica:0/task:1/device:CPU:0"}, %arg9: tensor<*x!tf_type.resource<tensor<25001x64xf32>>> {tf._user_specified_name = "915", tf.device = "/job:t...

namespace mlir {
namespace TF {

namespace {

const char kDeviceAttr[] = "device";
const char kDeviceGpu[] = "GPU";

std::optional<std::string> GetOpDevice(mlir::Operation *op) {
  mlir::StringAttr device = op->getAttrOfType<mlir::StringAttr>(kDeviceAttr);
  if (!device || device.getValue().empty()) {
    return std::nullopt;
  }
  tensorflow::DeviceNameUtils::ParsedName parsed_name;

class DeviceInfoCache {
 public:
  bool IsGpu(DeviceId device) const { return is_gpu_[device.id()]; }
  bool IsCpu(DeviceId device) const { return is_cpu_[device.id()]; }

  absl::string_view GetNameFor(DeviceId device) const {
    return names_[device.id()];
  }

  absl::StatusOr<DeviceId> GetIdFor(absl::string_view name);

    %cst = "tf.Const"() <{value = dense<[0, 1]> : tensor<2xi32>}> {device = ""} : () -> tensor<2xi32>
    %cst_0 = "tf.Const"() <{value = dense<1.000000e+01> : tensor<f32>}> {device = ""} : () -> tensor<f32>
    %0 = "tf.Sum"(%arg0, %cst) <{keep_dims = false}> {device = ""} : (tensor<1x4xf32>, tensor<2xi32>) -> tensor<f32>
    %1 = "tf.Greater"(%0, %cst_0) {device = ""} : (tensor<f32>, tensor<f32>) -> tensor<i1>

                             StringPiece tensor_name, Device* device,
                             Tensor* cpu_tensor, StatusCallback done) override;

  void CopyTensorInSameDevice(const Tensor* input_tensor, Device* device,
                              Tensor* output_tensor,
                              StatusCallback done) const override {
    done(errors::Internal("device->device copy not implemented."));
  }

 private:

                                   TF_Status* status) {
    params->device->hardware_name = hardware_name;
    params->device->device_vendor = vendor;
    params->device->pci_bus_id = pci_bus_id;
  };

  device_fns_.get_numa_node = [](const SP_Device* device) { return 123; };
  device_fns_.get_memory_bandwidth = [](const SP_Device* device) -> int64_t {
    return 54;
  };

  %0 = "tf.Conv2D"(%arg0, %arg1) {
    data_format = "NHWC", device = "", dilations = [1, 1, 1, 1], explicit_paddings = [],
    padding = "SAME", strides = [1, 1, 2, 1], use_cudnn_on_gpu = true
  } : (tensor<1x3x4x3xf32>, tensor<2x3x3x2xf32>) -> tensor<*xf32>
  %1 = "tf.BiasAdd"(%0, %cst) {data_format = "NHWC", device = ""} : (tensor<*xf32>, tensor<2xf32>) -> tensor<*xf32>
  %2 = "tf.Relu6"(%1) {device = ""} : (tensor<*xf32>) -> tensor<*xf32>