2 files changed, 66 insertions, 0 deletions
diff --git a/llvm/include/llvm/Support/Chrono.h b/llvm/include/llvm/Support/Chrono.h
new file mode 100644
index 00000000000..203439cab91
--- /dev/null
+++ b/llvm/include/llvm/Support/Chrono.h
@@ -0,0 +1,55 @@
+//===- llvm/Support/Chrono.h - Utilities for Timing Manipulation-*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_CHRONO_H
+#define LLVM_SUPPORT_CHRONO_H
+
+#include "llvm/Support/Compiler.h"
+
+#include <chrono>
+#include <ctime>
+
+namespace llvm {
+
+class raw_ostream;
+
+namespace sys {
+
+/// A time point on the system clock. This is provided for two reasons:
+/// - to insulate us agains subtle differences in behavoir to differences in
+///   system clock precision (which is implementation-defined and differs between
+///   platforms).
+/// - to shorten the type name
+/// The default precision is nanoseconds. If need a specific precision specify
+/// it explicitly. If unsure, use the default. If you need a time point on a
+/// clock other than the system_clock, use std::chrono directly.
+template <typename D = std::chrono::nanoseconds>
+using TimePoint = std::chrono::time_point<std::chrono::system_clock, D>;
+
+/// Convert a TimePoint to std::time_t
+LLVM_ATTRIBUTE_ALWAYS_INLINE inline std::time_t toTimeT(TimePoint<> TP) {
+  using namespace std::chrono;
+  return system_clock::to_time_t(
+      time_point_cast<system_clock::time_point::duration>(TP));
+}
+
+/// Convert a std::time_t to a TimePoint
+LLVM_ATTRIBUTE_ALWAYS_INLINE inline TimePoint<std::chrono::seconds>
+toTimePoint(std::time_t T) {
+  using namespace std::chrono;
+  return time_point_cast<seconds>(system_clock::from_time_t(T));
+}
+
+} // namespace sys
+
+raw_ostream &operator<<(raw_ostream &OS, sys::TimePoint<> TP);
+
+} // namespace llvm
+
+#endif // LLVM_SUPPORT_CHRONO_H
diff --git a/llvm/include/llvm/Support/TimeValue.h b/llvm/include/llvm/Support/TimeValue.h
index 6bca58b6bc2..4b6dd15c4bb 100644
--- a/llvm/include/llvm/Support/TimeValue.h
+++ b/llvm/include/llvm/Support/TimeValue.h
@@ -14,6 +14,7 @@
 #ifndef LLVM_SUPPORT_TIMEVALUE_H
 #define LLVM_SUPPORT_TIMEVALUE_H
 
+#include "llvm/Support/Chrono.h"
 #include "llvm/Support/DataTypes.h"
 #include <string>
 
@@ -112,6 +113,11 @@ namespace sys {
       this->normalize();
     }
 
+    template<typename D>
+    TimeValue(TimePoint<D> TP)
+        : seconds_(sys::toTimeT(TP) + PosixZeroTimeSeconds),
+          nanos_((TimePoint<>(TP).time_since_epoch() % std::chrono::seconds(1)).count()) {}
+
     /// This is a static constructor that returns a TimeValue that represents
     /// the current time.
     /// @brief Creates a TimeValue with the current time (UTC).
@@ -121,6 +127,11 @@ namespace sys {
   /// @name Operators
   /// @{
   public:
+    operator TimePoint<>() const {
+      return toTimePoint(seconds_ - PosixZeroTimeSeconds) +
+             std::chrono::nanoseconds(nanos_);
+    }
+
     /// Add \p that to \p this.
     /// @returns this
     /// @brief Incrementing assignment operator.