chore: import upstream snapshot with attribution

test/cpp/phi/core/timer.h

@@ -0,0 +1,39 @@
+/* Copyright (c) 2021 PaddlePaddle 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. */
+
+#pragma once
+
+#include <chrono>  // NOLINT
+
+namespace phi {
+namespace tests {
+
+class Timer {
+ public:
+  std::chrono::high_resolution_clock::time_point start;
+  std::chrono::high_resolution_clock::time_point startu;
+
+  void tic() { start = std::chrono::high_resolution_clock::now(); }
+  double toc() {
+    startu = std::chrono::high_resolution_clock::now();
+    std::chrono::duration<double> time_span =
+        std::chrono::duration_cast<std::chrono::duration<double>>(startu -
+                                                                  start);
+    double used_time_ms = static_cast<double>(time_span.count()) * 1000.0;
+    return used_time_ms;
+  }
+};
+
+}  // namespace tests
+}  // namespace phi