Add logging and timer implementations for hexagon. Update xtensa comments.

PiperOrigin-RevId: 337377957
Change-Id: I3c842fa1945c174e435418146b01a66b7805fd40

tensorflow/lite/micro/debug_log.cc

@@ -1,4 +1,4 @@
-/* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
+/* Copyright 2020 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.
@@ -36,6 +36,15 @@ limitations under the License.
 
 #include "tensorflow/lite/micro/debug_log.h"
 
+#ifndef TF_LITE_STRIP_ERROR_STRINGS
 #include <cstdio>
+#endif
 
-extern "C" void DebugLog(const char* s) { fprintf(stderr, "%s", s); }
+extern "C" void DebugLog(const char* s) {
+#ifndef TF_LITE_STRIP_ERROR_STRINGS
+  // Reusing TF_LITE_STRIP_ERROR_STRINGS to disable DebugLog completely to get
+  // maximum reduction in binary size. This is because we have DebugLog calls
+  // via TF_LITE_CHECK that are not stubbed out by TF_LITE_REPORT_ERROR.
+  fprintf(stderr, "%s", s);
+#endif
+}

tensorflow/lite/micro/hexagon/micro_time.cc

@@ -0,0 +1,28 @@
+/* Copyright 2020 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.
+==============================================================================*/
+
+// Hexagon timer implementation.
+// To include this with make, add TARGET=hexagon.
+#include "tensorflow/lite/micro/micro_time.h"
+
+#include <time.h>
+
+namespace tflite {
+
+int32_t ticks_per_second() { return CLOCKS_PER_SEC; }
+
+int32_t GetCurrentTimeTicks() { return clock(); }
+
+}  // namespace tflite

tensorflow/lite/micro/xtensa_hifimini/debug_log.cc

@@ -1,50 +0,0 @@
-/* Copyright 2018 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.
-==============================================================================*/
-
-// Reference implementation of the DebugLog() function that's required for a
-// platform to support the TensorFlow Lite for Microcontrollers library. This is
-// the only function that's absolutely required to be available on a target
-// device, since it's used for communicating test results back to the host so
-// that we can verify the implementation is working correctly.
-// It's designed to be as easy as possible to supply an implementation though.
-// On platforms that have a POSIX stack or C library, it can be written as a
-// single call to `fprintf(stderr, "%s", s)` to output a string to the error
-// stream of the console, but if there's no OS or C library available, there's
-// almost always an equivalent way to write out a string to some serial
-// interface that can be used instead. For example on Arm M-series MCUs, calling
-// the `bkpt #0xAB` assembler instruction will output the string in r1 to
-// whatever debug serial connection is available. If you're running mbed, you
-// can do the same by creating `Serial pc(USBTX, USBRX)` and then calling
-// `pc.printf("%s", s)`.
-// To add an equivalent function for your own platform, create your own
-// implementation file, and place it in a subfolder with named after the OS
-// you're targeting. For example, see the Cortex M bare metal version in
-// tensorflow/lite/micro/bluepill/debug_log.cc or the mbed one on
-// tensorflow/lite/micro/mbed/debug_log.cc.
-
-#include "tensorflow/lite/micro/debug_log.h"
-
-#ifndef TF_LITE_STRIP_ERROR_STRINGS
-#include <cstdio>
-#endif
-
-extern "C" void DebugLog(const char* s) {
-#ifndef TF_LITE_STRIP_ERROR_STRINGS
-  // Reusing TF_LITE_STRIP_ERROR_STRINGS to disable DebugLog completely to get
-  // maximum reduction in binary size. This is because we have DebugLog calls
-  // via TF_LITE_CHECK that are not stubbed out by TF_LITE_REPORT_ERROR.
-  fprintf(stderr, "%s", s);
-#endif
-}

tensorflow/lite/micro/xtensa_hifimini/micro_time.cc

@@ -13,8 +13,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 ==============================================================================*/
 
-// Xtensa implementation of micro_timer.
+// Xtensa timer implementation.
-// To include this with make, add TAGS=xtensa-xpg.
+// To include this with make, add TARGET=xtensa_hifimini.
 #include "tensorflow/lite/micro/micro_time.h"
 
 #include <time.h>