diff --git a/lld/COFF/ICF.cpp b/lld/COFF/ICF.cpp
index e3a7d27c39b1440977cb4f5ef4b2437ee32a1db8..3b7cc424f0a256e0f85976c2a8b55ddb521ef45b 100644
--- a/lld/COFF/ICF.cpp
+++ b/lld/COFF/ICF.cpp
@@ -21,9 +21,9 @@
 #include "Chunks.h"
 #include "Error.h"
 #include "Symbols.h"
-#include "lld/Core/Parallel.h"
 #include "llvm/ADT/Hashing.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/Parallel.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <atomic>
diff --git a/lld/COFF/MapFile.cpp b/lld/COFF/MapFile.cpp
index 7df88f38879fdd12c753439874a2d83d020843f9..b63d4672c7d5aed578d58029cb6b99a630e493b4 100644
--- a/lld/COFF/MapFile.cpp
+++ b/lld/COFF/MapFile.cpp
@@ -25,7 +25,7 @@
 #include "Symbols.h"
 #include "Writer.h"
 
-#include "lld/Core/Parallel.h"
+#include "llvm/Support/Parallel.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
diff --git a/lld/COFF/Writer.cpp b/lld/COFF/Writer.cpp
index d61d87172f43ab867d819f2b6dc2b0304306a22f..5c9c8375dadc484165242e34e5ee568739bf0f3c 100644
--- a/lld/COFF/Writer.cpp
+++ b/lld/COFF/Writer.cpp
@@ -17,13 +17,13 @@
 #include "PDB.h"
 #include "SymbolTable.h"
 #include "Symbols.h"
-#include "lld/Core/Parallel.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/FileOutputBuffer.h"
+#include "llvm/Support/Parallel.h"
 #include "llvm/Support/RandomNumberGenerator.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
diff --git a/lld/ELF/Threads.h b/lld/ELF/Threads.h
index 0c291c7b703aee2879f8944c92f2e40828bf60f7..e01afd4d3fc90764e3db34833c124c4177b42956 100644
--- a/lld/ELF/Threads.h
+++ b/lld/ELF/Threads.h
@@ -61,7 +61,7 @@
 
 #include "Config.h"
 
-#include "lld/Core/Parallel.h"
+#include "llvm/Support/Parallel.h"
 #include <functional>
 
 namespace lld {
@@ -70,17 +70,17 @@ namespace elf {
 template <class IterTy, class FuncTy>
 void parallelForEach(IterTy Begin, IterTy End, FuncTy Fn) {
   if (Config->Threads)
-    for_each(parallel::par, Begin, End, Fn);
+    for_each(llvm::parallel::par, Begin, End, Fn);
   else
-    for_each(parallel::seq, Begin, End, Fn);
+    for_each(llvm::parallel::seq, Begin, End, Fn);
 }
 
 inline void parallelForEachN(size_t Begin, size_t End,
                              std::function<void(size_t)> Fn) {
   if (Config->Threads)
-    for_each_n(parallel::par, Begin, End, Fn);
+    for_each_n(llvm::parallel::par, Begin, End, Fn);
   else
-    for_each_n(parallel::seq, Begin, End, Fn);
+    for_each_n(llvm::parallel::seq, Begin, End, Fn);
 }
 }
 }
diff --git a/lld/include/lld/Core/TaskGroup.h b/lld/include/lld/Core/TaskGroup.h
deleted file mode 100644
index 6cd173ebbbb69cc1e9ba5aae0718e1a2a6fa5f41..0000000000000000000000000000000000000000
--- a/lld/include/lld/Core/TaskGroup.h
+++ /dev/null
@@ -1,65 +0,0 @@
-//===- lld/Core/TaskGroup.h - Task Group ----------------------------------===//
-//
-//                             The LLVM Linker
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLD_CORE_TASKGROUP_H
-#define LLD_CORE_TASKGROUP_H
-
-#include "lld/Core/LLVM.h"
-
-#include <condition_variable>
-#include <functional>
-#include <mutex>
-
-namespace lld {
-/// \brief Allows one or more threads to wait on a potentially unknown number of
-///   events.
-///
-/// A latch starts at \p count. inc() increments this, and dec() decrements it.
-/// All calls to sync() will block while the count is not 0.
-///
-/// Calling dec() on a Latch with a count of 0 has undefined behaivor.
-class Latch {
-  uint32_t Count;
-  mutable std::mutex Mutex;
-  mutable std::condition_variable Cond;
-
-public:
-  explicit Latch(uint32_t count = 0) : Count(count) {}
-  ~Latch() { sync(); }
-
-  void inc() {
-    std::unique_lock<std::mutex> lock(Mutex);
-    ++Count;
-  }
-
-  void dec() {
-    std::unique_lock<std::mutex> lock(Mutex);
-    if (--Count == 0)
-      Cond.notify_all();
-  }
-
-  void sync() const {
-    std::unique_lock<std::mutex> lock(Mutex);
-    Cond.wait(lock, [&] { return Count == 0; });
-  }
-};
-
-/// \brief Allows launching a number of tasks and waiting for them to finish
-///   either explicitly via sync() or implicitly on destruction.
-class TaskGroup {
-  Latch L;
-
-public:
-  void spawn(std::function<void()> F);
-
-  void sync() const { L.sync(); }
-};
-}
-
-#endif
diff --git a/lld/lib/Core/CMakeLists.txt b/lld/lib/Core/CMakeLists.txt
index cdd4e679ffa23c23c99bd4533eaed6fed057e0a0..f2bf905092952e1b1fdfc7de85baf68a4a1721e9 100644
--- a/lld/lib/Core/CMakeLists.txt
+++ b/lld/lib/Core/CMakeLists.txt
@@ -12,7 +12,6 @@ add_lld_library(lldCore
   Resolver.cpp
   SymbolTable.cpp
   TargetOptionsCommandFlags.cpp
-  TaskGroup.cpp
   Writer.cpp
 
   ADDITIONAL_HEADER_DIRS
diff --git a/lld/lib/ReaderWriter/MachO/LayoutPass.cpp b/lld/lib/ReaderWriter/MachO/LayoutPass.cpp
index 2b5a46cc98fb7d45c0bb20eb3bf99fb77e27db4a..7bca07eb16d629d1473ba5697f753107d4566b54 100644
--- a/lld/lib/ReaderWriter/MachO/LayoutPass.cpp
+++ b/lld/lib/ReaderWriter/MachO/LayoutPass.cpp
@@ -9,12 +9,12 @@
 
 #include "LayoutPass.h"
 #include "lld/Core/Instrumentation.h"
-#include "lld/Core/Parallel.h"
 #include "lld/Core/PassManager.h"
 #include "lld/ReaderWriter/MachOLinkingContext.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/Parallel.h"
 #include <algorithm>
 #include <set>
 #include <utility>
@@ -461,7 +461,7 @@ llvm::Error LayoutPass::perform(SimpleFile &mergedFile) {
   });
 
   std::vector<LayoutPass::SortKey> vec = decorate(atomRange);
-  sort(parallel::par, vec.begin(), vec.end(),
+  sort(llvm::parallel::par, vec.begin(), vec.end(),
        [&](const LayoutPass::SortKey &l, const LayoutPass::SortKey &r) -> bool {
          return compareAtoms(l, r, _customSorter);
        });
diff --git a/lld/unittests/CMakeLists.txt b/lld/unittests/CMakeLists.txt
index 9cd085398c379d6d1c7cd3956daf4c14e9b53714..84d35d43f4e877473651292d0bafe93d991df5bb 100644
--- a/lld/unittests/CMakeLists.txt
+++ b/lld/unittests/CMakeLists.txt
@@ -12,6 +12,5 @@ function(add_lld_unittest test_dirname)
   target_link_libraries(${test_dirname} ${LLVM_COMMON_LIBS})
 endfunction()
 
-add_subdirectory(CoreTests)
 add_subdirectory(DriverTests)
 add_subdirectory(MachOTests)
diff --git a/lld/unittests/CoreTests/CMakeLists.txt b/lld/unittests/CoreTests/CMakeLists.txt
deleted file mode 100644
index 9f68f56a6c03c590c5db8b3a6b1c56972ef8a5d1..0000000000000000000000000000000000000000
--- a/lld/unittests/CoreTests/CMakeLists.txt
+++ /dev/null
@@ -1,7 +0,0 @@
-add_lld_unittest(CoreTests
-  ParallelTest.cpp
-  )
-
-target_link_libraries(CoreTests
-  lldCore ${LLVM_PTHREAD_LIB}
-  )
diff --git a/lld/include/lld/Core/Parallel.h b/llvm/include/llvm/Support/Parallel.h
similarity index 85%
rename from lld/include/lld/Core/Parallel.h
rename to llvm/include/llvm/Support/Parallel.h
index 20b774112ca58ee079323df185349fe30d98ff4a..aca972eb490cebe69304a36b9e334d6283619478 100644
--- a/lld/include/lld/Core/Parallel.h
+++ b/llvm/include/llvm/Support/Parallel.h
@@ -1,29 +1,70 @@
-//===- lld/Core/Parallel.h - Parallel utilities ---------------------------===//
+//===- llvm/Support/Parallel.h - Parallel algorithms ----------------------===//
 //
-//                             The LLVM Linker
+//                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLD_CORE_PARALLEL_H
-#define LLD_CORE_PARALLEL_H
+#ifndef LLVM_SUPPORT_PARALLEL_H
+#define LLVM_SUPPORT_PARALLEL_H
 
-#include "lld/Core/LLVM.h"
-#include "lld/Core/TaskGroup.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Config/llvm-config.h"
 #include "llvm/Support/MathExtras.h"
 
 #include <algorithm>
+#include <condition_variable>
+#include <functional>
+#include <mutex>
 
 #if defined(_MSC_VER) && LLVM_ENABLE_THREADS
+#pragma warning(push)
+#pragma warning(disable : 4530)
 #include <concrt.h>
 #include <ppl.h>
+#pragma warning(pop)
 #endif
 
-namespace lld {
+namespace llvm {
+
+namespace detail {
+class Latch {
+  uint32_t Count;
+  mutable std::mutex Mutex;
+  mutable std::condition_variable Cond;
+
+public:
+  explicit Latch(uint32_t count = 0) : Count(Count) {}
+  ~Latch() { sync(); }
+
+  void inc() {
+    std::unique_lock<std::mutex> lock(Mutex);
+    ++Count;
+  }
+
+  void dec() {
+    std::unique_lock<std::mutex> lock(Mutex);
+    if (--Count == 0)
+      Cond.notify_all();
+  }
+
+  void sync() const {
+    std::unique_lock<std::mutex> lock(Mutex);
+    Cond.wait(lock, [&] { return Count == 0; });
+  }
+};
+
+class TaskGroup {
+  Latch L;
+
+public:
+  void spawn(std::function<void()> f);
+
+  void sync() const { L.sync(); }
+};
+}
 
 namespace parallel {
 struct sequential_execution_policy {};
@@ -205,6 +246,6 @@ void for_each_n(parallel_execution_policy policy, IndexTy Begin, IndexTy End,
 #endif
 
 } // namespace parallel
-} // End namespace lld
+} // namespace llvm
 
-#endif // LLD_CORE_PARALLEL_H
+#endif // LLVM_SUPPORT_PARALLEL_H
diff --git a/llvm/lib/Support/CMakeLists.txt b/llvm/lib/Support/CMakeLists.txt
index 63c440037c22425d76dcc1a1e104488014d6abb8..83376284548f5d54686112fe975335804568db9d 100644
--- a/llvm/lib/Support/CMakeLists.txt
+++ b/llvm/lib/Support/CMakeLists.txt
@@ -81,6 +81,7 @@ add_llvm_library(LLVMSupport
   MD5.cpp
   NativeFormatting.cpp
   Options.cpp
+  Parallel.cpp
   PluginLoader.cpp
   PrettyStackTrace.cpp
   RandomNumberGenerator.cpp
diff --git a/lld/lib/Core/TaskGroup.cpp b/llvm/lib/Support/Parallel.cpp
similarity index 90%
rename from lld/lib/Core/TaskGroup.cpp
rename to llvm/lib/Support/Parallel.cpp
index 6cd5d22b7e8e345d0f7bc39d13e2a1933baa1ce2..04fb1c95533cef8bb75b1217aa9efaec2535d81c 100644
--- a/lld/lib/Core/TaskGroup.cpp
+++ b/llvm/lib/Support/Parallel.cpp
@@ -1,25 +1,20 @@
-//===- lld/Core/TaskGroup.cpp - Task Group --------------------------------===//
+//===- llvm/Support/Parallel.cpp - Parallel algorithms --------------------===//
 //
-//                             The LLVM Linker
+//                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
-#include "lld/Core/TaskGroup.h"
+#include "llvm/Support/Parallel.h"
 #include "llvm/Config/llvm-config.h"
 
 #include <atomic>
 #include <stack>
 #include <thread>
 
-#if defined(_MSC_VER) && LLVM_ENABLE_THREADS
-#include <concrt.h>
-#include <ppl.h>
-#endif
-
-using namespace lld;
+using namespace llvm;
 
 namespace {
 
@@ -132,7 +127,7 @@ Executor *Executor::getDefaultExecutor() {
 #endif
 }
 
-void TaskGroup::spawn(std::function<void()> F) {
+void detail::TaskGroup::spawn(std::function<void()> F) {
   L.inc();
   Executor::getDefaultExecutor()->add([&, F] {
     F();
diff --git a/llvm/unittests/Support/CMakeLists.txt b/llvm/unittests/Support/CMakeLists.txt
index 1f677100dcef379cda5b36b63ccc2403d0addba1..f8d3c1c9a8c770ce1f605f63ca8577a0cd32dd79 100644
--- a/llvm/unittests/Support/CMakeLists.txt
+++ b/llvm/unittests/Support/CMakeLists.txt
@@ -36,6 +36,7 @@ add_llvm_unittest(SupportTests
   MemoryBufferTest.cpp
   MemoryTest.cpp
   NativeFormatTests.cpp
+  ParallelTest.cpp
   Path.cpp
   ProcessTest.cpp
   ProgramTest.cpp
diff --git a/lld/unittests/CoreTests/ParallelTest.cpp b/llvm/unittests/Support/ParallelTest.cpp
similarity index 82%
rename from lld/unittests/CoreTests/ParallelTest.cpp
rename to llvm/unittests/Support/ParallelTest.cpp
index 601a2b0839b0130fe9339c23490b68a8676ee5b5..f381631ac3a2dee4fd1863812317ca8b59015581 100644
--- a/lld/unittests/CoreTests/ParallelTest.cpp
+++ b/llvm/unittests/Support/ParallelTest.cpp
@@ -1,4 +1,4 @@
-//===- lld/unittest/ParallelTest.cpp --------------------------------------===//
+//===- llvm/unittest/Support/ParallelTest.cpp -----------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -12,13 +12,15 @@
 ///
 //===----------------------------------------------------------------------===//
 
+#include "llvm/Support/Parallel.h"
 #include "gtest/gtest.h"
-#include "lld/Core/Parallel.h"
 #include <array>
 #include <random>
 
 uint32_t array[1024 * 1024];
 
+using namespace llvm;
+
 TEST(Parallel, sort) {
   std::mt19937 randEngine;
   std::uniform_int_distribution<uint32_t> dist;
@@ -26,7 +28,7 @@ TEST(Parallel, sort) {
   for (auto &i : array)
     i = dist(randEngine);
 
-  sort(lld::parallel::par, std::begin(array), std::end(array));
+  sort(parallel::par, std::begin(array), std::end(array));
   ASSERT_TRUE(std::is_sorted(std::begin(array), std::end(array)));
 }
 
@@ -36,7 +38,7 @@ TEST(Parallel, parallel_for) {
   // writing.
   uint32_t range[2050];
   std::fill(range, range + 2050, 1);
-  for_each_n(lld::parallel::par, 0, 2049, [&range](size_t I) { ++range[I]; });
+  for_each_n(parallel::par, 0, 2049, [&range](size_t I) { ++range[I]; });
 
   uint32_t expected[2049];
   std::fill(expected, expected + 2049, 2);