--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/unittests/Support/ParallelTest.cpp	Fri Oct 27 17:07:41 2017 +0900
@@ -0,0 +1,53 @@
+//===- llvm/unittest/Support/ParallelTest.cpp -----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// \brief Parallel.h unit tests.
+///
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/Parallel.h"
+#include "gtest/gtest.h"
+#include <array>
+#include <random>
+
+uint32_t array[1024 * 1024];
+
+using namespace llvm;
+
+// Tests below are hanging up on mingw. Investigating.
+#if !defined(__MINGW32__)
+
+TEST(Parallel, sort) {
+  std::mt19937 randEngine;
+  std::uniform_int_distribution<uint32_t> dist;
+
+  for (auto &i : array)
+    i = dist(randEngine);
+
+  sort(parallel::par, std::begin(array), std::end(array));
+  ASSERT_TRUE(std::is_sorted(std::begin(array), std::end(array)));
+}
+
+TEST(Parallel, parallel_for) {
+  // We need to test the case with a TaskSize > 1. We are white-box testing
+  // here. The TaskSize is calculated as (End - Begin) / 1024 at the time of
+  // writing.
+  uint32_t range[2050];
+  std::fill(range, range + 2050, 1);
+  for_each_n(parallel::par, 0, 2049, [&range](size_t I) { ++range[I]; });
+
+  uint32_t expected[2049];
+  std::fill(expected, expected + 2049, 2);
+  ASSERT_TRUE(std::equal(range, range + 2049, expected));
+  // Check that we don't write past the end of the requested range.
+  ASSERT_EQ(range[2049], 1u);
+}
+
+#endif