Modify TF Lite benchmark to print names of available NNAPI accelerators when --use_nnapi=true

PiperOrigin-RevId: 266040746

tensorflow/lite/delegates/nnapi/BUILD

@@ -34,6 +34,7 @@ cc_library(
         "//tensorflow/lite/c:c_api_internal",
         "//tensorflow/lite/kernels:kernel_util",
         "//tensorflow/lite/nnapi:nnapi_implementation",
+        "//tensorflow/lite/nnapi:nnapi_util",
     ],
 )
 

tensorflow/lite/delegates/nnapi/nnapi_delegate.cc

@@ -51,6 +51,7 @@ limitations under the License.
 #include "tensorflow/lite/kernels/kernel_util.h"
 #include "tensorflow/lite/minimal_logging.h"
 #include "tensorflow/lite/nnapi/nnapi_implementation.h"
+#include "tensorflow/lite/nnapi/nnapi_util.h"
 #include "tensorflow/lite/util.h"
 
 namespace tflite {
@@ -297,21 +298,6 @@ static size_t getNumPaddingBytes(size_t byte_size) {
   return num_padding_bytes;
 }
 
-std::string SimpleJoin(const std::vector<const char*>& elements,
-                       const char* separator) {
-  // Note that we avoid use of sstream to avoid binary size bloat.
-  std::string joined_elements;
-  for (auto it = elements.begin(); it != elements.end(); ++it) {
-    if (separator && it != elements.begin()) {
-      joined_elements += separator;
-    }
-    if (*it) {
-      joined_elements += *it;
-    }
-  }
-  return joined_elements;
-}
-
 // Return NNAPI device handle with the provided null-terminated device name. If
 // no matching device could be found, nullptr will be returned.
 ANeuralNetworksDevice* GetDeviceHandle(TfLiteContext* context,
@@ -322,7 +308,6 @@ ANeuralNetworksDevice* GetDeviceHandle(TfLiteContext* context,
   uint32_t num_devices = 0;
   NnApiImplementation()->ANeuralNetworks_getDeviceCount(&num_devices);
 
-  std::vector<const char*> device_names;
   for (uint32_t i = 0; i < num_devices; i++) {
     ANeuralNetworksDevice* device = nullptr;
     const char* buffer = nullptr;
@@ -332,14 +317,13 @@ ANeuralNetworksDevice* GetDeviceHandle(TfLiteContext* context,
       device_handle = device;
       break;
     }
-    device_names.push_back(buffer);
   }
   if (!device_handle) {
     context->ReportError(context,
                          "Could not find the specified NNAPI accelerator: %s. "
                          "Must be one of: {%s}.",
                          device_name_ptr,
-                         SimpleJoin(device_names, ",").c_str());
+                         nnapi::GetStringDeviceNamesList().c_str());
   }
   return device_handle;
 }

tensorflow/lite/nnapi/BUILD

@@ -61,6 +61,17 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "nnapi_util",
+    srcs = ["nnapi_util.cc"],
+    hdrs = ["nnapi_util.h"],
+    deps = [
+        ":nnapi_implementation",
+        "//tensorflow/lite:util",
+        "//tensorflow/lite/c:c_api_internal",
+    ],
+)
+
 cc_test(
     name = "nnapi_implementation_test",
     srcs = ["nnapi_implementation_test.cc"],

tensorflow/lite/nnapi/nnapi_util.cc

@@ -0,0 +1,73 @@
+/* Copyright 2019 The TensorFlow Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+
+#include "tensorflow/lite/nnapi/nnapi_util.h"
+
+#include <string>
+#include <vector>
+
+#include "tensorflow/lite/nnapi/nnapi_implementation.h"
+#include "tensorflow/lite/util.h"
+
+namespace tflite {
+namespace nnapi {
+
+namespace {
+std::string SimpleJoin(const std::vector<const char*>& elements,
+                       const char* separator) {
+  // Note that we avoid use of sstream to avoid binary size bloat.
+  std::string joined_elements;
+  for (auto it = elements.begin(); it != elements.end(); ++it) {
+    if (separator && it != elements.begin()) {
+      joined_elements += separator;
+    }
+    if (*it) {
+      joined_elements += *it;
+    }
+  }
+  return joined_elements;
+}
+
+}  // namespace
+
+std::vector<const char*> GetDeviceNamesList() {
+  std::vector<const char*> device_names;
+
+  // Only build the list if NnApiImplementation has the methods we need,
+  // leaving it empty otherwise.
+  if (NnApiImplementation()->ANeuralNetworks_getDeviceCount != nullptr) {
+    uint32_t num_devices = 0;
+
+    NnApiImplementation()->ANeuralNetworks_getDeviceCount(&num_devices);
+
+    for (uint32_t i = 0; i < num_devices; i++) {
+      ANeuralNetworksDevice* device = nullptr;
+      const char* buffer = nullptr;
+      NnApiImplementation()->ANeuralNetworks_getDevice(i, &device);
+      NnApiImplementation()->ANeuralNetworksDevice_getName(device, &buffer);
+      device_names.push_back(buffer);
+    }
+  }
+
+  return device_names;
+}
+
+std::string GetStringDeviceNamesList() {
+  std::vector<const char*> device_names = GetDeviceNamesList();
+  return SimpleJoin(device_names, ",");
+}
+
+}  // namespace nnapi
+}  // namespace tflite

tensorflow/lite/nnapi/nnapi_util.h

@@ -0,0 +1,38 @@
+/* Copyright 2019 The TensorFlow Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+==============================================================================*/
+
+// This file provides general C++ utility functions for interacting with NNAPI.
+
+#ifndef TENSORFLOW_LITE_NNAPI_NNAPI_UTIL_H_
+#define TENSORFLOW_LITE_NNAPI_NNAPI_UTIL_H_
+
+#include <string>
+#include <vector>
+
+namespace tflite {
+namespace nnapi {
+
+// Return std::vector consisting of pointers to null-terminated device names.
+// These names are guaranteed valid for the lifetime of the application.
+std::vector<const char*> GetDeviceNamesList();
+
+// Return a string containing the names of all available devices.
+// Will take the format: "DeviceA,DeviceB,DeviceC"
+std::string GetStringDeviceNamesList();
+
+}  // namespace nnapi
+}  // namespace tflite
+
+#endif  // TENSORFLOW_LITE_NNAPI_NNAPI_UTIL_H_

tensorflow/lite/tools/benchmark/BUILD

@@ -112,6 +112,7 @@ cc_library(
         "//tensorflow/lite:framework",
         "//tensorflow/lite:string_util",
         "//tensorflow/lite/kernels:builtin_ops",
+        "//tensorflow/lite/nnapi:nnapi_util",
         "//tensorflow/lite/profiling:profile_summarizer",
         "//tensorflow/lite/profiling:profiler",
         "//tensorflow/lite/tools/evaluation:utils",

tensorflow/lite/tools/benchmark/README.md

@@ -38,7 +38,9 @@ and the following optional parameters:
     Whether to use [Android NNAPI](https://developer.android.com/ndk/guides/neuralnetworks/).
     This API is available on recent Android devices. Note that some Android P
     devices will fail to use NNAPI for models in `/data/local/tmp/` and this
-    benchmark tool will not correctly use NNAPI.
+    benchmark tool will not correctly use NNAPI. When on Android Q+, will also
+    print the names of NNAPI accelerators accessible through the
+    `nnapi_accelerator_name` flag.
 *   `nnapi_accelerator_name`: `str` (default="") \
     The name of the NNAPI accelerator to use (requires Android Q+). If left
     blank, NNAPI will automatically select which of the available accelerators

tensorflow/lite/tools/benchmark/benchmark_tflite_model.cc

@@ -23,6 +23,8 @@ limitations under the License.
 #include <unordered_set>
 #include <vector>
 
+#include "tensorflow/lite/nnapi/nnapi_util.h"
+
 #if defined(__ANDROID__)
 #include "tensorflow/lite/delegates/gpu/gl_delegate.h"
 #endif
@@ -302,9 +304,17 @@ void BenchmarkTfLiteModel::LogParams() {
   }
   TFLITE_LOG(INFO) << "Use legacy nnapi : ["
                    << params_.Get<bool>("use_legacy_nnapi") << "]";
-  if (!params_.Get<std::string>("nnapi_accelerator_name").empty()) {
-    TFLITE_LOG(INFO) << "nnapi accelerator name: ["
-                     << params_.Get<string>("nnapi_accelerator_name") << "]";
+  if (params_.Get<bool>("use_nnapi")) {
+    std::string log_string = "nnapi accelerator name: [" +
+                             params_.Get<string>("nnapi_accelerator_name") +
+                             "]";
+
+    std::string string_device_names_list = nnapi::GetStringDeviceNamesList();
+    // Print available devices when possible
+    if (!string_device_names_list.empty()) {
+      log_string += " (Available: " + string_device_names_list + ")";
+    }
+    TFLITE_LOG(INFO) << log_string;
   }
   TFLITE_LOG(INFO) << "Use gpu : [" << params_.Get<bool>("use_gpu") << "]";
 #if defined(__ANDROID__)