Fix MicroProfiler bug with ClearEvents().

Add pre-inference profiling to the Generic Benchmark.

tensorflow/lite/micro/micro_profiler.cc

@@ -86,14 +86,14 @@ void MicroProfiler::LogTicksPerTagCsv() {
     TFLITE_DCHECK(tags_[i] != nullptr);
     int position = FindExistingOrNextPosition(tags_[i]);
     TFLITE_DCHECK(position >= 0);
-    total_ticks_per_tag[position].tag = tags_[i];
-    total_ticks_per_tag[position].ticks =
-        total_ticks_per_tag[position].ticks + ticks;
+    total_ticks_per_tag_[position].tag = tags_[i];
+    total_ticks_per_tag_[position].ticks =
+        total_ticks_per_tag_[position].ticks + ticks;
     total_ticks += ticks;
   }
 
   for (int i = 0; i < num_events_; ++i) {
-    TicksPerTag each_tag_entry = total_ticks_per_tag[i];
+    TicksPerTag each_tag_entry = total_ticks_per_tag_[i];
     if (each_tag_entry.tag == nullptr) {
       break;
     }
@@ -112,12 +112,21 @@ void MicroProfiler::LogTicksPerTagCsv() {
 int MicroProfiler::FindExistingOrNextPosition(const char* tag_name) {
   int pos = 0;
   for (; pos < num_events_; pos++) {
-    TicksPerTag each_tag_entry = total_ticks_per_tag[pos];
+    TicksPerTag each_tag_entry = total_ticks_per_tag_[pos];
     if (each_tag_entry.tag == nullptr ||
         strcmp(each_tag_entry.tag, tag_name) == 0) {
       return pos;
     }
   }
   return pos < num_events_ ? pos : -1;
 }
+
+void MicroProfiler::ClearEvents() {
+  for (int i = 0; i < num_events_; i++) {
+    total_ticks_per_tag_[i].tag = nullptr;
+  }
+
+  num_events_ = 0;
+}
+
 }  // namespace tflite

tensorflow/lite/micro/micro_profiler.h

@@ -1,4 +1,4 @@
-/* Copyright 2022 The TensorFlow Authors. All Rights Reserved.
+/* Copyright 2024 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.
@@ -45,7 +45,7 @@ class MicroProfiler : public MicroProfilerInterface {
   virtual void EndEvent(uint32_t event_handle) override;
 
   // Clears all the events that have been currently profiled.
-  void ClearEvents() { num_events_ = 0; }
+  void ClearEvents();
 
   // Returns the sum of the ticks taken across all the events. This number
   // is only meaningful if all of the events are disjoint (the end time of
@@ -83,7 +83,7 @@ class MicroProfiler : public MicroProfilerInterface {
   // In practice, the number of tags will be much lower than the number of
   // events. But it is theoretically possible that each event to be unique and
   // hence we allow total_ticks_per_tag to have kMaxEvents entries.
-  TicksPerTag total_ticks_per_tag[kMaxEvents] = {};
+  TicksPerTag total_ticks_per_tag_[kMaxEvents] = {};
 
   int FindExistingOrNextPosition(const char* tag_name);
 

tensorflow/lite/micro/tools/benchmarking/generic_model_benchmark.cc

@@ -182,24 +182,35 @@ int Benchmark(const uint8_t* model_data, tflite::PrettyPrintType print_type) {
   constexpr bool using_compression = false;
 #endif  // USE_TFLM_COMPRESSION
 
+  [[maybe_unused]]
   alignas(16) static uint8_t tensor_arena[kTensorArenaSize];
 
-  uint32_t event_handle = profiler.BeginEvent("TfliteGetModel");
+  uint32_t event_handle = profiler.BeginEvent("tflite::GetModel");
   const tflite::Model* model = tflite::GetModel(model_data);
   profiler.EndEvent(event_handle);
 
+  event_handle = profiler.BeginEvent("tflite::CreateOpResolver");
   TflmOpResolver op_resolver;
   TF_LITE_ENSURE_STATUS(CreateOpResolver(op_resolver));
+  profiler.EndEvent(event_handle);
 
+  event_handle = profiler.BeginEvent("tflite::RecordingMicroAllocator::Create");
   tflite::RecordingMicroAllocator* allocator(
-      tflite::RecordingMicroAllocator::Create(tensor_arena, kTensorArenaSize));
+      tflite::RecordingMicroAllocator::Create(
+          reinterpret_cast<uint8_t*>(0xe1000000), kTensorArenaSize));
+  profiler.EndEvent(event_handle);
+  event_handle = profiler.BeginEvent("tflite::MicroInterpreter instantiation");
   tflite::RecordingMicroInterpreter interpreter(
       model, op_resolver, allocator,
       tflite::MicroResourceVariables::Create(allocator, kNumResourceVariable),
       &profiler);
+  profiler.EndEvent(event_handle);
+  event_handle =
+      profiler.BeginEvent("tflite::MicroInterpreter::AllocateTensors");
   TF_LITE_ENSURE_STATUS(interpreter.AllocateTensors());
+  profiler.EndEvent(event_handle);
 
-  profiler.Log();
+  profiler.LogTicksPerTagCsv();
   profiler.ClearEvents();
 
   if (using_compression) {