diff --git a/llvm/include/llvm/Analysis/LoopNestAnalysis.h b/llvm/include/llvm/Analysis/LoopNestAnalysis.h
--- a/llvm/include/llvm/Analysis/LoopNestAnalysis.h
+++ b/llvm/include/llvm/Analysis/LoopNestAnalysis.h
@@ -128,6 +128,8 @@
                         [](const Loop *L) { return L->isLoopSimplifyForm(); });
   }
 
+  StringRef getName() const { return Loops.front()->getName(); }
+
 protected:
   const unsigned MaxPerfectDepth; // maximum perfect nesting depth level.
   LoopVectorTy Loops; // the loops in the nest (in breadth first order).
diff --git a/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h b/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
--- a/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
+++ b/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
@@ -44,6 +44,7 @@
 #include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/Analysis/LoopAnalysisManager.h"
 #include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/LoopNestAnalysis.h"
 #include "llvm/Analysis/MemorySSA.h"
 #include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
@@ -61,17 +62,136 @@
 // Forward declarations of an update tracking API used in the pass manager.
 class LPMUpdater;
 
+namespace detail {
+
+// SFINAE helper class that distinguish loop passes and loop-nest passes.
+template <typename PassT, typename SFINAE = void>
+struct IsLoopPass : std::false_type {};
+
+template <typename PassT>
+struct IsLoopPass<
+    PassT,
+    std::enable_if_t<std::is_same<
+        PreservedAnalyses,
+        decltype(std::declval<PassT>().run(
+            std::declval<Loop &>(), std::declval<LoopAnalysisManager &>(),
+            std::declval<LoopStandardAnalysisResults &>(),
+            std::declval<LPMUpdater &>()))>::value>> : std::true_type {};
+
+} // namespace detail
+
 // Explicit specialization and instantiation declarations for the pass manager.
 // See the comments on the definition of the specialization for details on how
 // it differs from the primary template.
 template <>
-PreservedAnalyses
-PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &,
-            LPMUpdater &>::run(Loop &InitialL, LoopAnalysisManager &AM,
-                               LoopStandardAnalysisResults &AnalysisResults,
-                               LPMUpdater &U);
-extern template class PassManager<Loop, LoopAnalysisManager,
-                                  LoopStandardAnalysisResults &, LPMUpdater &>;
+class PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &,
+                  LPMUpdater &>
+    : public PassInfoMixin<
+          PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &,
+                      LPMUpdater &>> {
+public:
+  /// Construct a pass manager.
+  ///
+  /// If \p DebugLogging is true, we'll log our progress to llvm::dbgs().
+  explicit PassManager(bool DebugLogging = false)
+      : DebugLogging(DebugLogging) {}
+
+  // FIXME: These are equivalent to the default move constructor/move
+  // assignment. However, using = default triggers linker errors due to the
+  // explicit instantiations below. Find away to use the default and remove the
+  // duplicated code here.
+  PassManager(PassManager &&Arg)
+      : PassCategories(std::move(Arg.PassCategories)),
+        LoopPasses(std::move(Arg.LoopPasses)),
+        LoopNestPasses(std::move(Arg.LoopNestPasses)),
+        DebugLogging(std::move(Arg.DebugLogging)) {}
+
+  PassManager &operator=(PassManager &&RHS) {
+    PassCategories = std::move(RHS.PassCategories);
+    LoopPasses = std::move(RHS.LoopPasses);
+    LoopNestPasses = std::move(RHS.LoopNestPasses);
+    DebugLogging = std::move(RHS.DebugLogging);
+    return *this;
+  }
+
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U);
+
+  template <typename PassT>
+  std::enable_if_t<detail::IsLoopPass<PassT>::value> addPass(PassT Pass) {
+    using LoopPassModelT =
+        detail::PassModel<Loop, PassT, PreservedAnalyses, LoopAnalysisManager,
+                          LoopStandardAnalysisResults &, LPMUpdater &>;
+    PassCategories.push_back(false);
+    LoopPasses.emplace_back(new LoopPassModelT(std::move(Pass)));
+  }
+
+  template <typename PassT>
+  std::enable_if_t<!detail::IsLoopPass<PassT>::value> addPass(PassT Pass) {
+    using LoopNestPassModelT =
+        detail::PassModel<LoopNest, PassT, PreservedAnalyses,
+                          LoopAnalysisManager, LoopStandardAnalysisResults &,
+                          LPMUpdater &>;
+    PassCategories.push_back(true);
+    LoopNestPasses.emplace_back(new LoopNestPassModelT(std::move(Pass)));
+  }
+
+  // Specializations of `addPass` for `RepeatedPass`. These are necessary since
+  // `RepeatedPass` has a templated `run` method that will result in incorrect
+  // behavior of `IsLoopNestPass`.
+  template <typename PassT>
+  std::enable_if_t<detail::IsLoopPass<PassT>::value>
+  addPass(RepeatedPass<PassT> Pass) {
+    using RepeatedLoopPassModelT =
+        detail::PassModel<Loop, RepeatedPass<PassT>, PreservedAnalyses,
+                          LoopAnalysisManager, LoopStandardAnalysisResults &,
+                          LPMUpdater &>;
+    PassCategories.push_back(false);
+    LoopPasses.emplace_back(new RepeatedLoopPassModelT(std::move(Pass)));
+  }
+
+  template <typename PassT>
+  std::enable_if_t<!detail::IsLoopPass<PassT>::value>
+  addPass(RepeatedPass<PassT> Pass) {
+    using RepeatedLoopNestPassModelT =
+        detail::PassModel<LoopNest, RepeatedPass<PassT>, PreservedAnalyses,
+                          LoopAnalysisManager, LoopStandardAnalysisResults &,
+                          LPMUpdater &>;
+    PassCategories.push_back(true);
+    LoopNestPasses.emplace_back(
+        new RepeatedLoopNestPassModelT(std::move(Pass)));
+  }
+
+  static bool isRequired() { return true; }
+
+protected:
+  using LoopPassConceptT =
+      detail::PassConcept<Loop, LoopAnalysisManager,
+                          LoopStandardAnalysisResults &, LPMUpdater &>;
+  using LoopNestPassConceptT =
+      detail::PassConcept<LoopNest, LoopAnalysisManager,
+                          LoopStandardAnalysisResults &, LPMUpdater &>;
+
+  BitVector PassCategories;
+  std::vector<std::unique_ptr<LoopPassConceptT>> LoopPasses;
+  std::vector<std::unique_ptr<LoopNestPassConceptT>> LoopNestPasses;
+
+  /// Flag indicating whether we should do debug logging.
+  bool DebugLogging;
+
+  template <typename IRUnitT, typename PassT>
+  Optional<PreservedAnalyses>
+  runSinglePass(IRUnitT &IR, PassT &Pass, LoopAnalysisManager &AM,
+                LoopStandardAnalysisResults &AR, LPMUpdater &U,
+                PassInstrumentation &PI);
+
+  PreservedAnalyses runWithLoopNestPasses(Loop &L, LoopAnalysisManager &AM,
+                                          LoopStandardAnalysisResults &AR,
+                                          LPMUpdater &U);
+  PreservedAnalyses runWithoutLoopNestPasses(Loop &L, LoopAnalysisManager &AM,
+                                             LoopStandardAnalysisResults &AR,
+                                             LPMUpdater &U);
+};
 
 /// The Loop pass manager.
 ///
@@ -221,6 +341,29 @@
       : Worklist(Worklist), LAM(LAM) {}
 };
 
+template <typename IRUnitT, typename PassT>
+Optional<PreservedAnalyses> LoopPassManager::runSinglePass(
+    IRUnitT &IR, PassT &Pass, LoopAnalysisManager &AM,
+    LoopStandardAnalysisResults &AR, LPMUpdater &U, PassInstrumentation &PI) {
+  // Check the PassInstrumentation's BeforePass callbacks before running the
+  // pass, skip its execution completely if asked to (callback returns false).
+  if (!PI.runBeforePass<IRUnitT>(*Pass, IR))
+    return None;
+
+  PreservedAnalyses PA;
+  {
+    TimeTraceScope TimeScope(Pass->name(), IR.getName());
+    PA = Pass->run(IR, AM, AR, U);
+  }
+
+  // do not pass deleted Loop into the instrumentation
+  if (U.skipCurrentLoop())
+    PI.runAfterPassInvalidated<IRUnitT>(*Pass, PA);
+  else
+    PI.runAfterPass<IRUnitT>(*Pass, IR, PA);
+  return PA;
+}
+
 /// Adaptor that maps from a function to its loops.
 ///
 /// Designed to allow composition of a LoopPass(Manager) and a
diff --git a/llvm/lib/Analysis/LoopNestAnalysis.cpp b/llvm/lib/Analysis/LoopNestAnalysis.cpp
--- a/llvm/lib/Analysis/LoopNestAnalysis.cpp
+++ b/llvm/lib/Analysis/LoopNestAnalysis.cpp
@@ -306,6 +306,8 @@
   return true;
 }
 
+AnalysisKey LoopNestAnalysis::Key;
+
 raw_ostream &llvm::operator<<(raw_ostream &OS, const LoopNest &LN) {
   OS << "IsPerfect=";
   if (LN.getMaxPerfectDepth() == LN.getNestDepth())
diff --git a/llvm/lib/Transforms/Scalar/LoopPassManager.cpp b/llvm/lib/Transforms/Scalar/LoopPassManager.cpp
--- a/llvm/lib/Transforms/Scalar/LoopPassManager.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopPassManager.cpp
@@ -12,58 +12,88 @@
 
 using namespace llvm;
 
-// Explicit template instantiations and specialization defininitions for core
-// template typedefs.
 namespace llvm {
-template class PassManager<Loop, LoopAnalysisManager,
-                           LoopStandardAnalysisResults &, LPMUpdater &>;
 
 /// Explicitly specialize the pass manager's run method to handle loop nest
 /// structure updates.
-template <>
 PreservedAnalyses
 PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &,
             LPMUpdater &>::run(Loop &L, LoopAnalysisManager &AM,
                                LoopStandardAnalysisResults &AR, LPMUpdater &U) {
-  PreservedAnalyses PA = PreservedAnalyses::all();
+  PreservedAnalyses PA;
 
   if (DebugLogging)
     dbgs() << "Starting Loop pass manager run.\n";
 
   // Request PassInstrumentation from analysis manager, will use it to run
   // instrumenting callbacks for the passes later.
-  PassInstrumentation PI = AM.getResult<PassInstrumentationAnalysis>(L, AR);
-  for (auto &Pass : Passes) {
-    // Check the PassInstrumentation's BeforePass callbacks before running the
-    // pass, skip its execution completely if asked to (callback returns false).
-    if (!PI.runBeforePass<Loop>(*Pass, L))
-      continue;
+  if (!L.getParentLoop() && !LoopNestPasses.empty())
+    PA = runWithLoopNestPasses(L, AM, AR, U);
+  else
+    PA = runWithoutLoopNestPasses(L, AM, AR, U);
+
+  // Invalidation for the current loop should be handled above, and other loop
+  // analysis results shouldn't be impacted by runs over this loop. Therefore,
+  // the remaining analysis results in the AnalysisManager are preserved. We
+  // mark this with a set so that we don't need to inspect each one
+  // individually.
+  // FIXME: This isn't correct! This loop and all nested loops' analyses should
+  // be preserved, but unrolling should invalidate the parent loop's analyses.
+  PA.preserveSet<AllAnalysesOn<Loop>>();
+
+  if (DebugLogging)
+    dbgs() << "Finished Loop pass manager run.\n";
+
+  return PA;
+}
 
-    PreservedAnalyses PassPA;
-    {
-      TimeTraceScope TimeScope(Pass->name(), L.getName());
-      PassPA = Pass->run(L, AM, AR, U);
+PreservedAnalyses
+LoopPassManager::runWithLoopNestPasses(Loop &L, LoopAnalysisManager &AM,
+                                       LoopStandardAnalysisResults &AR,
+                                       LPMUpdater &U) {
+  PreservedAnalyses PA = PreservedAnalyses::all();
+  PassInstrumentation PI = AM.getResult<PassInstrumentationAnalysis>(L, AR);
+  
+  unsigned LoopPassIndex = 0, LoopNestPassIndex = 0;
+  std::unique_ptr<LoopNest> LoopNestPtr;
+  bool IsLoopNestPtrValid = false;
+
+  for (size_t I = 0, E = PassCategories.size(); I != E; ++I) {
+    Optional<PreservedAnalyses> PassPA;
+    if (!PassCategories.test(I)) {
+      auto &Pass = LoopPasses[LoopPassIndex++];
+      PassPA = runSinglePass(L, Pass, AM, AR, U, PI);
+    } else {
+      auto &Pass = LoopNestPasses[LoopNestPassIndex++];
+
+      // If the loop-nest object calculated before is no longer valid,
+      // re-calculate it here before running the loop-nest pass.
+      if (!IsLoopNestPtrValid) {
+        LoopNestPtr = LoopNest::getLoopNest(L, AR.SE);
+        IsLoopNestPtrValid = true;
+      }
+      PassPA = runSinglePass(*LoopNestPtr, Pass, AM, AR, U, PI);
     }
 
-    // do not pass deleted Loop into the instrumentation
-    if (U.skipCurrentLoop())
-      PI.runAfterPassInvalidated<Loop>(*Pass, PassPA);
-    else
-      PI.runAfterPass<Loop>(*Pass, L, PassPA);
+    if (!PassPA)
+      continue;
 
     // If the loop was deleted, abort the run and return to the outer walk.
     if (U.skipCurrentLoop()) {
-      PA.intersect(std::move(PassPA));
+      PA.intersect(std::move(*PassPA));
       break;
     }
 
     // Update the analysis manager as each pass runs and potentially
     // invalidates analyses.
-    AM.invalidate(L, PassPA);
+    AM.invalidate(L, *PassPA);
 
     // Finally, we intersect the final preserved analyses to compute the
     // aggregate preserved set for this pass manager.
-    PA.intersect(std::move(PassPA));
+    PA.intersect(std::move(*PassPA));
+
+    // Check if the current pass preserved the loop-nest object or not.
+    IsLoopNestPtrValid = PassPA->getChecker<LoopNestAnalysis>().preserved();
 
     // FIXME: Historically, the pass managers all called the LLVM context's
     // yield function here. We don't have a generic way to acquire the
@@ -71,22 +101,43 @@
     // in the new pass manager so it is currently omitted.
     // ...getContext().yield();
   }
+  return PA;
+}
 
-  // Invalidation for the current loop should be handled above, and other loop
-  // analysis results shouldn't be impacted by runs over this loop. Therefore,
-  // the remaining analysis results in the AnalysisManager are preserved. We
-  // mark this with a set so that we don't need to inspect each one
-  // individually.
-  // FIXME: This isn't correct! This loop and all nested loops' analyses should
-  // be preserved, but unrolling should invalidate the parent loop's analyses.
-  PA.preserveSet<AllAnalysesOn<Loop>>();
+PreservedAnalyses
+LoopPassManager::runWithoutLoopNestPasses(Loop &L, LoopAnalysisManager &AM,
+                                          LoopStandardAnalysisResults &AR,
+                                          LPMUpdater &U) {
+  PreservedAnalyses PA = PreservedAnalyses::all();
+  PassInstrumentation PI = AM.getResult<PassInstrumentationAnalysis>(L, AR);
+  for (auto &Pass : LoopPasses) {
+    auto PassPA = runSinglePass(L, Pass, AM, AR, U, PI);
+    if (!PassPA)
+      continue;
 
-  if (DebugLogging)
-    dbgs() << "Finished Loop pass manager run.\n";
+    // If the loop was deleted, abort the run and return to the outer walk.
+    if (U.skipCurrentLoop()) {
+      PA.intersect(std::move(*PassPA));
+      break;
+    }
+
+    // Update the analysis manager as each pass runs and potentially
+    // invalidates analyses.
+    AM.invalidate(L, *PassPA);
+
+    // Finally, we intersect the final preserved analyses to compute the
+    // aggregate preserved set for this pass manager.
+    PA.intersect(std::move(*PassPA));
 
+    // FIXME: Historically, the pass managers all called the LLVM context's
+    // yield function here. We don't have a generic way to acquire the
+    // context and it isn't yet clear what the right pattern is for yielding
+    // in the new pass manager so it is currently omitted.
+    // ...getContext().yield();
+  }
   return PA;
 }
-}
+} // namespace llvm
 
 PrintLoopPass::PrintLoopPass() : OS(dbgs()) {}
 PrintLoopPass::PrintLoopPass(raw_ostream &OS, const std::string &Banner)