--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/include/llvm/Support/TimeProfiler.h	Wed Aug 14 16:55:33 2019 +0900
@@ -0,0 +1,76 @@
+//===- llvm/Support/TimeProfiler.h - Hierarchical Time Profiler -*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_TIME_PROFILER_H
+#define LLVM_SUPPORT_TIME_PROFILER_H
+
+#include "llvm/Support/raw_ostream.h"
+
+namespace llvm {
+
+struct TimeTraceProfiler;
+extern TimeTraceProfiler *TimeTraceProfilerInstance;
+
+/// Initialize the time trace profiler.
+/// This sets up the global \p TimeTraceProfilerInstance
+/// variable to be the profiler instance.
+void timeTraceProfilerInitialize(unsigned TimeTraceGranularity);
+
+/// Cleanup the time trace profiler, if it was initialized.
+void timeTraceProfilerCleanup();
+
+/// Is the time trace profiler enabled, i.e. initialized?
+inline bool timeTraceProfilerEnabled() {
+  return TimeTraceProfilerInstance != nullptr;
+}
+
+/// Write profiling data to output file.
+/// Data produced is JSON, in Chrome "Trace Event" format, see
+/// https://docs.google.com/document/d/1CvAClvFfyA5R-PhYUmn5OOQtYMH4h6I0nSsKchNAySU/preview
+void timeTraceProfilerWrite(raw_pwrite_stream &OS);
+
+/// Manually begin a time section, with the given \p Name and \p Detail.
+/// Profiler copies the string data, so the pointers can be given into
+/// temporaries. Time sections can be hierarchical; every Begin must have a
+/// matching End pair but they can nest.
+void timeTraceProfilerBegin(StringRef Name, StringRef Detail);
+void timeTraceProfilerBegin(StringRef Name,
+                            llvm::function_ref<std::string()> Detail);
+
+/// Manually end the last time section.
+void timeTraceProfilerEnd();
+
+/// The TimeTraceScope is a helper class to call the begin and end functions
+/// of the time trace profiler.  When the object is constructed, it begins
+/// the section; and when it is destroyed, it stops it. If the time profiler
+/// is not initialized, the overhead is a single branch.
+struct TimeTraceScope {
+
+  TimeTraceScope() = delete;
+  TimeTraceScope(const TimeTraceScope &) = delete;
+  TimeTraceScope &operator=(const TimeTraceScope &) = delete;
+  TimeTraceScope(TimeTraceScope &&) = delete;
+  TimeTraceScope &operator=(TimeTraceScope &&) = delete;
+
+  TimeTraceScope(StringRef Name, StringRef Detail) {
+    if (TimeTraceProfilerInstance != nullptr)
+      timeTraceProfilerBegin(Name, Detail);
+  }
+  TimeTraceScope(StringRef Name, llvm::function_ref<std::string()> Detail) {
+    if (TimeTraceProfilerInstance != nullptr)
+      timeTraceProfilerBegin(Name, Detail);
+  }
+  ~TimeTraceScope() {
+    if (TimeTraceProfilerInstance != nullptr)
+      timeTraceProfilerEnd();
+  }
+};
+
+} // end namespace llvm
+
+#endif