[PM] Rewrite the loop pass manager to use a worklist and augmented run

arguments much like the CGSCC pass manager.

This is a major redesign following the pattern establish for the CGSCC layer to
support updates to the set of loops during the traversal of the loop nest and
to support invalidation of analyses.

An additional significant burden in the loop PM is that so many passes require
access to a large number of function analyses. Manually ensuring these are
cached, available, and preserved has been a long-standing burden in LLVM even
with the help of the automatic scheduling in the old pass manager. And it made
the new pass manager extremely unweildy. With this design, we can package the
common analyses up while in a function pass and make them immediately available
to all the loop passes. While in some cases this is unnecessary, I think the
simplicity afforded is worth it.

This does not (yet) address loop simplified form or LCSSA form, but those are
the next things on my radar and I have a clear plan for them.

While the patch is very large, most of it is either mechanically updating loop
passes to the new API or the new testing for the loop PM. The code for it is
reasonably compact.

I have not yet updated all of the loop passes to correctly leverage the update
mechanisms demonstrated in the unittests. I'll do that in follow-up patches
along with improved FileCheck tests for those passes that ensure things work in
more realistic scenarios. In many cases, there isn't much we can do with these
until the loop simplified form and LCSSA form are in place.

Differential Revision: https://reviews.llvm.org/D28292

llvm-svn: 291651

llvm/include/llvm/Analysis/IVUsers.h

@@ -193,7 +193,8 @@ class IVUsersAnalysis : public AnalysisInfoMixin<IVUsersAnalysis> {
 public:
   typedef IVUsers Result;
 
-  IVUsers run(Loop &L, LoopAnalysisManager &AM);
+  IVUsers run(Loop &L, LoopAnalysisManager &AM,
+              LoopStandardAnalysisResults &AR);
 };
 
 /// Printer pass for the \c IVUsers for a loop.
@@ -202,7 +203,8 @@ class IVUsersPrinterPass : public PassInfoMixin<IVUsersPrinterPass> {
 
 public:
   explicit IVUsersPrinterPass(raw_ostream &OS) : OS(OS) {}
-  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM);
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U);
 };
 }
 

llvm/include/llvm/Analysis/LoopAccessAnalysis.h

@@ -753,8 +753,8 @@ class LoopAccessAnalysis
 
 public:
   typedef LoopAccessInfo Result;
-  Result run(Loop &, LoopAnalysisManager &);
+
-  static StringRef name() { return "LoopAccessAnalysis"; }
+  Result run(Loop &L, LoopAnalysisManager &AM, LoopStandardAnalysisResults &AR);
 };
 
 /// \brief Printer pass for the \c LoopAccessInfo results.
@@ -764,7 +764,8 @@ class LoopAccessInfoPrinterPass
 
 public:
   explicit LoopAccessInfoPrinterPass(raw_ostream &OS) : OS(OS) {}
-  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM);
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U);
 };
 
 inline Instruction *MemoryDepChecker::Dependence::getSource(

llvm/include/llvm/Analysis/LoopInfo.h

@@ -853,17 +853,8 @@ public:
   void getAnalysisUsage(AnalysisUsage &AU) const override;
 };
 
-/// \brief Pass for printing a loop's contents as LLVM's text IR assembly.
+/// Function to print a loop's contents as LLVM's text IR assembly.
-class PrintLoopPass : public PassInfoMixin<PrintLoopPass> {
+void printLoop(Loop &L, raw_ostream &OS, const std::string &Banner = "");
-  raw_ostream &OS;
-  std::string Banner;
-
-public:
-  PrintLoopPass();
-  PrintLoopPass(raw_ostream &OS, const std::string &Banner = "");
-
-  PreservedAnalyses run(Loop &L, AnalysisManager<Loop> &);
-};
 
 } // End llvm namespace
 

llvm/include/llvm/Analysis/LoopPassManager.h

@@ -8,63 +8,342 @@
 //===----------------------------------------------------------------------===//
 /// \file
 ///
-/// This header provides classes for managing passes over loops in LLVM IR.
+/// This header provides classes for managing a pipeline of passes over loops
+/// in LLVM IR.
+///
+/// The primary loop pass pipeline is managed in a very particular way to
+/// provide a set of core guarantees:
+/// 1) Loops are, where possible, in simplified form.
+/// 2) Loops are *always* in LCSSA form.
+/// 3) A collection of Loop-specific analysis results are available:
+///    - LoopInfo
+///    - DominatorTree
+///    - ScalarEvolution
+///    - AAManager
+/// 4) All loop passes preserve #1 (where possible), #2, and #3.
+/// 5) Loop passes run over each loop in the loop nest from the innermost to
+///    the outermost. Specifically, all inner loops are processed before
+///    passes run over outer loops. When running the pipeline across an inner
+///    loop creates new inner loops, those are added and processed in this
+///    order as well.
+///
+/// This process is designed to facilitate transformations which simplify,
+/// reduce, and remove loops. For passes which are more oriented towards
+/// optimizing loops, especially optimizing loop *nests* instead of single
+/// loops in isolation, this framework is less interesting.
 ///
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_ANALYSIS_LOOPPASSMANAGER_H
 #define LLVM_ANALYSIS_LOOPPASSMANAGER_H
 
+#include "llvm/ADT/PostOrderIterator.h"
+#include "llvm/ADT/PriorityWorklist.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Analysis/BasicAliasAnalysis.h"
+#include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/ScalarEvolution.h"
+#include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/PassManager.h"
 
 namespace llvm {
 
-extern template class PassManager<Loop>;
+// Forward declarations of a update tracking and analysis result tracking
-/// \brief The loop pass manager.
+// structures used in the API of loop passes that work within this
-///
+// infrastructure.
-/// See the documentation for the PassManager template for details. It runs a
+class LPMUpdater;
-/// sequency of loop passes over each loop that the manager is run over. This
+struct LoopStandardAnalysisResults;
-/// typedef serves as a convenient way to refer to this construct.
-typedef PassManager<Loop> LoopPassManager;
 
-extern template class AnalysisManager<Loop>;
+/// Extern template declaration for the analysis set for this IR unit.
+extern template class AllAnalysesOn<Loop>;
+
+extern template class AnalysisManager<Loop, LoopStandardAnalysisResults &>;
 /// \brief The loop analysis manager.
 ///
 /// See the documentation for the AnalysisManager template for detail
 /// documentation. This typedef serves as a convenient way to refer to this
 /// construct in the adaptors and proxies used to integrate this into the larger
 /// pass manager infrastructure.
-typedef AnalysisManager<Loop> LoopAnalysisManager;
+typedef AnalysisManager<Loop, LoopStandardAnalysisResults &>
+    LoopAnalysisManager;
+
+// 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 &>;
+
+/// \brief The Loop pass manager.
+///
+/// See the documentation for the PassManager template for details. It runs
+/// a sequence of Loop passes over each Loop that the manager is run over. This
+/// typedef serves as a convenient way to refer to this construct.
+typedef PassManager<Loop, LoopAnalysisManager, LoopStandardAnalysisResults &,
+                    LPMUpdater &>
+    LoopPassManager;
+
+/// A partial specialization of the require analysis template pass to forward
+/// the extra parameters from a transformation's run method to the
+/// AnalysisManager's getResult.
+template <typename AnalysisT>
+struct RequireAnalysisPass<AnalysisT, Loop, LoopAnalysisManager,
+                           LoopStandardAnalysisResults &, LPMUpdater &>
+    : PassInfoMixin<
+          RequireAnalysisPass<AnalysisT, Loop, LoopAnalysisManager,
+                              LoopStandardAnalysisResults &, LPMUpdater &>> {
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &) {
+    (void)AM.template getResult<AnalysisT>(L, AR);
+    return PreservedAnalyses::all();
+  }
+};
+
+/// An alias template to easily name a require analysis loop pass.
+template <typename AnalysisT>
+using RequireAnalysisLoopPass =
+    RequireAnalysisPass<AnalysisT, Loop, LoopAnalysisManager,
+                        LoopStandardAnalysisResults &, LPMUpdater &>;
 
 /// A proxy from a \c LoopAnalysisManager to a \c Function.
 typedef InnerAnalysisManagerProxy<LoopAnalysisManager, Function>
     LoopAnalysisManagerFunctionProxy;
 
-/// Specialization of the invalidate method for the \c
+/// A specialized result for the \c LoopAnalysisManagerFunctionProxy which
-/// LoopAnalysisManagerFunctionProxy's result.
+/// retains a \c LoopInfo reference.
-template <>
+///
-bool LoopAnalysisManagerFunctionProxy::Result::invalidate(
+/// This allows it to collect loop objects for which analysis results may be
-    Function &F, const PreservedAnalyses &PA,
+/// cached in the \c LoopAnalysisManager.
+template <> class LoopAnalysisManagerFunctionProxy::Result {
+public:
+  explicit Result(LoopAnalysisManager &InnerAM, LoopInfo &LI)
+      : InnerAM(&InnerAM), LI(&LI) {}
+  Result(Result &&Arg) : InnerAM(std::move(Arg.InnerAM)), LI(Arg.LI) {
+    // We have to null out the analysis manager in the moved-from state
+    // because we are taking ownership of the responsibilty to clear the
+    // analysis state.
+    Arg.InnerAM = nullptr;
+  }
+  Result &operator=(Result &&RHS) {
+    InnerAM = RHS.InnerAM;
+    LI = RHS.LI;
+    // We have to null out the analysis manager in the moved-from state
+    // because we are taking ownership of the responsibilty to clear the
+    // analysis state.
+    RHS.InnerAM = nullptr;
+    return *this;
+  }
+  ~Result() {
+    // InnerAM is cleared in a moved from state where there is nothing to do.
+    if (!InnerAM)
+      return;
+
+    // Clear out the analysis manager if we're being destroyed -- it means we
+    // didn't even see an invalidate call when we got invalidated.
+    InnerAM->clear();
+  }
+
+  /// Accessor for the analysis manager.
+  LoopAnalysisManager &getManager() { return *InnerAM; }
+
+  /// Handler for invalidation of the proxy for a particular function.
+  ///
+  /// If the proxy, \c LoopInfo, and associated analyses are preserved, this
+  /// will merely forward the invalidation event to any cached loop analysis
+  /// results for loops within this function.
+  ///
+  /// If the necessary loop infrastructure is not preserved, this will forcibly
+  /// clear all of the cached analysis results that are keyed on the \c
+  /// LoopInfo for this function.
+  bool invalidate(Function &F, const PreservedAnalyses &PA,
                   FunctionAnalysisManager::Invalidator &Inv);
 
+private:
+  LoopAnalysisManager *InnerAM;
+  LoopInfo *LI;
+};
+
+/// Provide a specialized run method for the \c LoopAnalysisManagerFunctionProxy
+/// so it can pass the \c LoopInfo to the result.
+template <>
+LoopAnalysisManagerFunctionProxy::Result
+LoopAnalysisManagerFunctionProxy::run(Function &F, FunctionAnalysisManager &AM);
+
 // Ensure the \c LoopAnalysisManagerFunctionProxy is provided as an extern
 // template.
 extern template class InnerAnalysisManagerProxy<LoopAnalysisManager, Function>;
 
-extern template class OuterAnalysisManagerProxy<FunctionAnalysisManager, Loop>;
+extern template class OuterAnalysisManagerProxy<FunctionAnalysisManager, Loop,
+                                                LoopStandardAnalysisResults &>;
 /// A proxy from a \c FunctionAnalysisManager to a \c Loop.
-typedef OuterAnalysisManagerProxy<FunctionAnalysisManager, Loop>
+typedef OuterAnalysisManagerProxy<FunctionAnalysisManager, Loop,
+                                  LoopStandardAnalysisResults &>
     FunctionAnalysisManagerLoopProxy;
 
 /// Returns the minimum set of Analyses that all loop passes must preserve.
 PreservedAnalyses getLoopPassPreservedAnalyses();
 
+namespace internal {
+/// Helper to implement appending of loops onto a worklist.
+///
+/// We want to process loops in postorder, but the worklist is a LIFO data
+/// structure, so we append to it in *reverse* postorder.
+///
+/// For trees, a preorder traversal is a viable reverse postorder, so we
+/// actually append using a preorder walk algorithm.
+template <typename RangeT>
+inline void appendLoopsToWorklist(RangeT &&Loops,
+                                  SmallPriorityWorklist<Loop *, 4> &Worklist) {
+  // We use an internal worklist to build up the preorder traversal without
+  // recursion.
+  SmallVector<Loop *, 4> PreOrderLoops, PreOrderWorklist;
+
+  // We walk the initial sequence of loops in reverse because we generally want
+  // to visit defs before uses and the worklist is LIFO.
+  for (Loop *RootL : reverse(Loops)) {
+    assert(PreOrderLoops.empty() && "Must start with an empty preorder walk.");
+    assert(PreOrderWorklist.empty() &&
+           "Must start with an empty preorder walk worklist.");
+    PreOrderWorklist.push_back(RootL);
+    do {
+      Loop *L = PreOrderWorklist.pop_back_val();
+      PreOrderWorklist.append(L->begin(), L->end());
+      PreOrderLoops.push_back(L);
+    } while (!PreOrderWorklist.empty());
+
+    Worklist.insert(std::move(PreOrderLoops));
+    PreOrderLoops.clear();
+  }
+}
+}
+
+/// The adaptor from a function pass to a loop pass directly computes
+/// a standard set of analyses that are especially useful to loop passes and
+/// makes them available in the API. Loop passes are also expected to update
+/// all of these so that they remain correct across the entire loop pipeline.
+struct LoopStandardAnalysisResults {
+  AAResults &AA;
+  AssumptionCache &AC;
+  DominatorTree &DT;
+  LoopInfo &LI;
+  ScalarEvolution &SE;
+  TargetLibraryInfo &TLI;
+  TargetTransformInfo &TTI;
+};
+
+template <typename LoopPassT> class FunctionToLoopPassAdaptor;
+
+/// This class provides an interface for updating the loop pass manager based
+/// on mutations to the loop nest.
+///
+/// A reference to an instance of this class is passed as an argument to each
+/// Loop pass, and Loop passes should use it to update LPM infrastructure if
+/// they modify the loop nest structure.
+class LPMUpdater {
+public:
+  /// This can be queried by loop passes which run other loop passes (like pass
+  /// managers) to know whether the loop needs to be skipped due to updates to
+  /// the loop nest.
+  ///
+  /// If this returns true, the loop object may have been deleted, so passes
+  /// should take care not to touch the object.
+  bool skipCurrentLoop() const { return SkipCurrentLoop; }
+
+  /// Loop passes should use this method to indicate they have deleted a loop
+  /// from the nest.
+  ///
+  /// Note that this loop must either be the current loop or a subloop of the
+  /// current loop. This routine must be called prior to removing the loop from
+  /// the loop nest.
+  ///
+  /// If this is called for the current loop, in addition to clearing any
+  /// state, this routine will mark that the current loop should be skipped by
+  /// the rest of the pass management infrastructure.
+  void markLoopAsDeleted(Loop &L) {
+    LAM.clear(L);
+    assert(CurrentL->contains(&L) && "Cannot delete a loop outside of the "
+                                     "subloop tree currently being processed.");
+    if (&L == CurrentL)
+      SkipCurrentLoop = true;
+  }
+
+  /// Loop passes should use this method to indicate they have added new child
+  /// loops of the current loop.
+  ///
+  /// \p NewChildLoops must contain only the immediate children. Any nested
+  /// loops within them will be visited in postorder as usual for the loop pass
+  /// manager.
+  void addChildLoops(ArrayRef<Loop *> NewChildLoops) {
+    // Insert ourselves back into the worklist first, as this loop should be
+    // revisited after all the children have been processed.
+    Worklist.insert(CurrentL);
+
+#ifndef NDEBUG
+    for (Loop *NewL : NewChildLoops)
+      assert(NewL->getParentLoop() == CurrentL && "All of the new loops must "
+                                                  "be immediate children of "
+                                                  "the current loop!");
+#endif
+
+    internal::appendLoopsToWorklist(NewChildLoops, Worklist);
+
+    // Also skip further processing of the current loop--it will be revisited
+    // after all of its newly added children are accounted for.
+    SkipCurrentLoop = true;
+  }
+
+  /// Loop passes should use this method to indicate they have added new
+  /// sibling loops to the current loop.
+  ///
+  /// \p NewSibLoops must only contain the immediate sibling loops. Any nested
+  /// loops within them will be visited in postorder as usual for the loop pass
+  /// manager.
+  void addSiblingLoops(ArrayRef<Loop *> NewSibLoops) {
+#ifndef NDEBUG
+    for (Loop *NewL : NewSibLoops)
+      assert(NewL->getParentLoop() == ParentL &&
+             "All of the new loops must be siblings of the current loop!");
+#endif
+
+    internal::appendLoopsToWorklist(NewSibLoops, Worklist);
+
+    // No need to skip the current loop or revisit it, as sibling loops
+    // shouldn't impact anything.
+  }
+
+private:
+  template <typename LoopPassT> friend class llvm::FunctionToLoopPassAdaptor;
+
+  /// The \c FunctionToLoopPassAdaptor's worklist of loops to process.
+  SmallPriorityWorklist<Loop *, 4> &Worklist;
+
+  /// The analysis manager for use in the current loop nest.
+  LoopAnalysisManager &LAM;
+
+  Loop *CurrentL;
+  bool SkipCurrentLoop;
+
+#ifndef NDEBUG
+  // In debug builds we also track the parent loop to implement asserts even in
+  // the face of loop deletion.
+  Loop *ParentL;
+#endif
+
+  LPMUpdater(SmallPriorityWorklist<Loop *, 4> &Worklist,
+             LoopAnalysisManager &LAM)
+      : Worklist(Worklist), LAM(LAM) {}
+};
+
 /// \brief Adaptor that maps from a function to its loops.
 ///
 /// Designed to allow composition of a LoopPass(Manager) and a
@@ -87,42 +366,61 @@ public:
     // Get the loop structure for this function
     LoopInfo &LI = AM.getResult<LoopAnalysis>(F);
 
-    // Also precompute all of the function analyses used by loop passes.
+    // If there are no loops, there is nothing to do here.
-    // FIXME: These should be handed into the loop passes when the loop pass
+    if (LI.empty())
-    // management layer is reworked to follow the design of CGSCC.
+      return PreservedAnalyses::all();
-    (void)AM.getResult<AAManager>(F);
+
-    (void)AM.getResult<DominatorTreeAnalysis>(F);
+    // Get the analysis results needed by loop passes.
-    (void)AM.getResult<ScalarEvolutionAnalysis>(F);
+    LoopStandardAnalysisResults LAR = {AM.getResult<AAManager>(F),
-    (void)AM.getResult<TargetLibraryAnalysis>(F);
+                                       AM.getResult<AssumptionAnalysis>(F),
+                                       AM.getResult<DominatorTreeAnalysis>(F),
+                                       AM.getResult<LoopAnalysis>(F),
+                                       AM.getResult<ScalarEvolutionAnalysis>(F),
+                                       AM.getResult<TargetLibraryAnalysis>(F),
+                                       AM.getResult<TargetIRAnalysis>(F)};
 
     PreservedAnalyses PA = PreservedAnalyses::all();
 
-    // We want to visit the loops in reverse post-order. We'll build the stack
+    // A postorder worklist of loops to process.
-    // of loops to visit in Loops by first walking the loops in pre-order.
+    SmallPriorityWorklist<Loop *, 4> Worklist;
-    SmallVector<Loop *, 2> Loops;
-    SmallVector<Loop *, 2> WorkList(LI.begin(), LI.end());
-    while (!WorkList.empty()) {
-      Loop *L = WorkList.pop_back_val();
-      WorkList.insert(WorkList.end(), L->begin(), L->end());
-      Loops.push_back(L);
-    }
 
-    // Now pop each element off of the stack to visit the loops in reverse
+    // Register the worklist and loop analysis manager so that loop passes can
-    // post-order.
+    // update them when they mutate the loop nest structure.
-    for (auto *L : reverse(Loops)) {
+    LPMUpdater Updater(Worklist, LAM);
-      PreservedAnalyses PassPA = Pass.run(*L, LAM);
+
+    // Add the loop nests in the reverse order of LoopInfo. For some reason,
+    // they are stored in RPO w.r.t. the control flow graph in LoopInfo. For
+    // the purpose of unrolling, loop deletion, and LICM, we largely want to
+    // work forward across the CFG so that we visit defs before uses and can
+    // propagate simplifications from one loop nest into the next.
+    // FIXME: Consider changing the order in LoopInfo.
+    internal::appendLoopsToWorklist(reverse(LI), Worklist);
+
+    do {
+      Loop *L = Worklist.pop_back_val();
+
+      // Reset the update structure for this loop.
+      Updater.CurrentL = L;
+      Updater.SkipCurrentLoop = false;
+#ifndef NDEBUG
+      Updater.ParentL = L->getParentLoop();
+#endif
+
+      PreservedAnalyses PassPA = Pass.run(*L, LAM, LAR, Updater);
       // FIXME: We should verify the set of analyses relevant to Loop passes
       // are preserved.
 
-      // We know that the loop pass couldn't have invalidated any other loop's
+      // If the loop hasn't been deleted, we need to handle invalidation here.
-      // analyses (that's the contract of a loop pass), so directly handle the
+      if (!Updater.skipCurrentLoop())
-      // loop analysis manager's invalidation here.
+        // We know that the loop pass couldn't have invalidated any other
+        // loop's analyses (that's the contract of a loop pass), so directly
+        // handle the loop analysis manager's invalidation here.
         LAM.invalidate(*L, PassPA);
 
       // Then intersect the preserved set so that invalidation of module
       // analyses will eventually occur when the module pass completes.
       PA.intersect(std::move(PassPA));
-    }
+    } while (!Worklist.empty());
 
     // By definition we preserve the proxy. We also preserve all analyses on
     // Loops. This precludes *any* invalidation of loop analyses by the proxy,
@@ -130,6 +428,17 @@ public:
     // loop analysis manager incrementally above.
     PA.preserveSet<AllAnalysesOn<Loop>>();
     PA.preserve<LoopAnalysisManagerFunctionProxy>();
+    // We also preserve the set of standard analyses.
+    PA.preserve<AssumptionAnalysis>();
+    PA.preserve<DominatorTreeAnalysis>();
+    PA.preserve<LoopAnalysis>();
+    PA.preserve<ScalarEvolutionAnalysis>();
+    // FIXME: What we really want to do here is preserve an AA category, but
+    // that concept doesn't exist yet.
+    PA.preserve<AAManager>();
+    PA.preserve<BasicAA>();
+    PA.preserve<GlobalsAA>();
+    PA.preserve<SCEVAA>();
     return PA;
   }
 
@@ -144,6 +453,19 @@ FunctionToLoopPassAdaptor<LoopPassT>
 createFunctionToLoopPassAdaptor(LoopPassT Pass) {
   return FunctionToLoopPassAdaptor<LoopPassT>(std::move(Pass));
 }
+
+/// \brief Pass for printing a loop's contents as textual IR.
+class PrintLoopPass : public PassInfoMixin<PrintLoopPass> {
+  raw_ostream &OS;
+  std::string Banner;
+
+public:
+  PrintLoopPass();
+  PrintLoopPass(raw_ostream &OS, const std::string &Banner = "");
+
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &,
+                        LoopStandardAnalysisResults &, LPMUpdater &);
+};
 }
 
 #endif // LLVM_ANALYSIS_LOOPPASSMANAGER_H

llvm/include/llvm/Transforms/Scalar/IndVarSimplify.h

@@ -23,7 +23,8 @@ namespace llvm {
 
 class IndVarSimplifyPass : public PassInfoMixin<IndVarSimplifyPass> {
 public:
-  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM);
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U);
 };
 }
 

llvm/include/llvm/Transforms/Scalar/LICM.h

@@ -42,7 +42,8 @@ namespace llvm {
 /// Performs Loop Invariant Code Motion Pass.
 class LICMPass : public PassInfoMixin<LICMPass> {
 public:
-  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM);
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U);
 };
 } // end namespace llvm
 

llvm/include/llvm/Transforms/Scalar/LoopDeletion.h

@@ -24,7 +24,8 @@ namespace llvm {
 class LoopDeletionPass : public PassInfoMixin<LoopDeletionPass> {
 public:
   LoopDeletionPass() {}
-  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM);
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U);
   bool runImpl(Loop *L, DominatorTree &DT, ScalarEvolution &SE,
               LoopInfo &loopInfo);
 

llvm/include/llvm/Transforms/Scalar/LoopIdiomRecognize.h

@@ -25,7 +25,8 @@ namespace llvm {
 /// Performs Loop Idiom Recognize Pass.
 class LoopIdiomRecognizePass : public PassInfoMixin<LoopIdiomRecognizePass> {
 public:
-  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM);
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U);
 };
 } // end namespace llvm
 

llvm/include/llvm/Transforms/Scalar/LoopInstSimplify.h

@@ -23,7 +23,8 @@ namespace llvm {
 /// Performs Loop Inst Simplify Pass.
 class LoopInstSimplifyPass : public PassInfoMixin<LoopInstSimplifyPass> {
 public:
-  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM);
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U);
 };
 } // end namespace llvm
 

llvm/include/llvm/Transforms/Scalar/LoopRotation.h

@@ -24,7 +24,8 @@ namespace llvm {
 class LoopRotatePass : public PassInfoMixin<LoopRotatePass> {
 public:
   LoopRotatePass(bool EnableHeaderDuplication = true);
-  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM);
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U);
 
 private:
   const bool EnableHeaderDuplication;

llvm/include/llvm/Transforms/Scalar/LoopSimplifyCFG.h

@@ -26,7 +26,8 @@ namespace llvm {
 /// Performs basic CFG simplifications to assist other loop passes.
 class LoopSimplifyCFGPass : public PassInfoMixin<LoopSimplifyCFGPass> {
 public:
-  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM);
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U);
 };
 } // end namespace llvm
 

llvm/include/llvm/Transforms/Scalar/LoopStrengthReduce.h

@@ -31,7 +31,8 @@ namespace llvm {
 /// Performs Loop Strength Reduce Pass.
 class LoopStrengthReducePass : public PassInfoMixin<LoopStrengthReducePass> {
 public:
-  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM);
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U);
 };
 } // end namespace llvm
 

llvm/include/llvm/Transforms/Scalar/LoopUnrollPass.h

@@ -23,7 +23,8 @@ struct LoopUnrollPass : public PassInfoMixin<LoopUnrollPass> {
   Optional<bool> ProvidedRuntime;
   Optional<bool> ProvidedUpperBound;
 
-  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM);
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U);
 };
 } // end namespace llvm
 

llvm/lib/Analysis/IVUsers.cpp

@@ -36,19 +36,15 @@ using namespace llvm;
 
 AnalysisKey IVUsersAnalysis::Key;
 
-IVUsers IVUsersAnalysis::run(Loop &L, LoopAnalysisManager &AM) {
+IVUsers IVUsersAnalysis::run(Loop &L, LoopAnalysisManager &AM,
-  const auto &FAM =
+                             LoopStandardAnalysisResults &AR) {
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+  return IVUsers(&L, &AR.AC, &AR.LI, &AR.DT, &AR.SE);
-  Function *F = L.getHeader()->getParent();
-
-  return IVUsers(&L, FAM.getCachedResult<AssumptionAnalysis>(*F),
-                 FAM.getCachedResult<LoopAnalysis>(*F),
-                 FAM.getCachedResult<DominatorTreeAnalysis>(*F),
-                 FAM.getCachedResult<ScalarEvolutionAnalysis>(*F));
 }
 
-PreservedAnalyses IVUsersPrinterPass::run(Loop &L, LoopAnalysisManager &AM) {
+PreservedAnalyses IVUsersPrinterPass::run(Loop &L, LoopAnalysisManager &AM,
-  AM.getResult<IVUsersAnalysis>(L).print(OS);
+                                          LoopStandardAnalysisResults &AR,
+                                          LPMUpdater &U) {
+  AM.getResult<IVUsersAnalysis>(L, AR).print(OS);
   return PreservedAnalyses::all();
 }
 

llvm/lib/Analysis/LoopAccessAnalysis.cpp

@@ -2120,31 +2120,16 @@ INITIALIZE_PASS_END(LoopAccessLegacyAnalysis, LAA_NAME, laa_name, false, true)
 
 AnalysisKey LoopAccessAnalysis::Key;
 
-LoopAccessInfo LoopAccessAnalysis::run(Loop &L, LoopAnalysisManager &AM) {
+LoopAccessInfo LoopAccessAnalysis::run(Loop &L, LoopAnalysisManager &AM,
-  const FunctionAnalysisManager &FAM =
+                                       LoopStandardAnalysisResults &AR) {
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+  return LoopAccessInfo(&L, &AR.SE, &AR.TLI, &AR.AA, &AR.DT, &AR.LI);
-  Function &F = *L.getHeader()->getParent();
-  auto *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(F);
-  auto *TLI = FAM.getCachedResult<TargetLibraryAnalysis>(F);
-  auto *AA = FAM.getCachedResult<AAManager>(F);
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(F);
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(F);
-  if (!SE)
-    report_fatal_error(
-        "ScalarEvolution must have been cached at a higher level");
-  if (!AA)
-    report_fatal_error("AliasAnalysis must have been cached at a higher level");
-  if (!DT)
-    report_fatal_error("DominatorTree must have been cached at a higher level");
-  if (!LI)
-    report_fatal_error("LoopInfo must have been cached at a higher level");
-  return LoopAccessInfo(&L, SE, TLI, AA, DT, LI);
 }
 
-PreservedAnalyses LoopAccessInfoPrinterPass::run(Loop &L,
+PreservedAnalyses
-                                                 LoopAnalysisManager &AM) {
+LoopAccessInfoPrinterPass::run(Loop &L, LoopAnalysisManager &AM,
+                               LoopStandardAnalysisResults &AR, LPMUpdater &) {
   Function &F = *L.getHeader()->getParent();
-  auto &LAI = AM.getResult<LoopAccessAnalysis>(L);
+  auto &LAI = AM.getResult<LoopAccessAnalysis>(L, AR);
   OS << "Loop access info in function '" << F.getName() << "':\n";
   OS.indent(2) << L.getHeader()->getName() << ":\n";
   LAI.print(OS, 4);

llvm/lib/Analysis/LoopInfo.cpp

@@ -689,18 +689,13 @@ PreservedAnalyses LoopPrinterPass::run(Function &F,
   return PreservedAnalyses::all();
 }
 
-PrintLoopPass::PrintLoopPass() : OS(dbgs()) {}
+void llvm::printLoop(Loop &L, raw_ostream &OS, const std::string &Banner) {
-PrintLoopPass::PrintLoopPass(raw_ostream &OS, const std::string &Banner)
-    : OS(OS), Banner(Banner) {}
-
-PreservedAnalyses PrintLoopPass::run(Loop &L, AnalysisManager<Loop> &) {
   OS << Banner;
   for (auto *Block : L.blocks())
     if (Block)
       Block->print(OS);
     else
       OS << "Printing <null> block";
-  return PreservedAnalyses::all();
 }
 
 //===----------------------------------------------------------------------===//

llvm/lib/Analysis/LoopPass.cpp

@@ -32,13 +32,14 @@ namespace {
 /// PrintLoopPass - Print a Function corresponding to a Loop.
 ///
 class PrintLoopPassWrapper : public LoopPass {
-  PrintLoopPass P;
+  raw_ostream &OS;
+  std::string Banner;
 
 public:
   static char ID;
-  PrintLoopPassWrapper() : LoopPass(ID) {}
+  PrintLoopPassWrapper() : LoopPass(ID), OS(dbgs()) {}
   PrintLoopPassWrapper(raw_ostream &OS, const std::string &Banner)
-      : LoopPass(ID), P(OS, Banner) {}
+      : LoopPass(ID), OS(OS), Banner(Banner) {}
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.setPreservesAll();
@@ -49,8 +50,7 @@ public:
                        [](BasicBlock *BB) { return BB; });
     if (BBI != L->blocks().end() &&
         isFunctionInPrintList((*BBI)->getParent()->getName())) {
-      LoopAnalysisManager DummyLAM;
+      printLoop(*L, OS, Banner);
-      P.run(*L, DummyLAM);
     }
     return false;
   }

llvm/lib/Analysis/LoopPassManager.cpp

@@ -20,34 +20,191 @@ using namespace llvm;
 // Explicit template instantiations and specialization defininitions for core
 // template typedefs.
 namespace llvm {
-template class PassManager<Loop>;
+template class AllAnalysesOn<Loop>;
-template class AnalysisManager<Loop>;
+template class AnalysisManager<Loop, LoopStandardAnalysisResults &>;
+template class PassManager<Loop, LoopAnalysisManager,
+                           LoopStandardAnalysisResults &, LPMUpdater &>;
 template class InnerAnalysisManagerProxy<LoopAnalysisManager, Function>;
-template class OuterAnalysisManagerProxy<FunctionAnalysisManager, Loop>;
+template class OuterAnalysisManagerProxy<FunctionAnalysisManager, Loop,
+                                         LoopStandardAnalysisResults &>;
 
+/// 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();
+
+  if (DebugLogging)
+    dbgs() << "Starting Loop pass manager run.\n";
+
+  for (auto &Pass : Passes) {
+    if (DebugLogging)
+      dbgs() << "Running pass: " << Pass->name() << " on " << L;
+
+    PreservedAnalyses PassPA = Pass->run(L, AM, AR, U);
+
+    // 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();
+  }
+
+  // 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;
+}
+
 bool LoopAnalysisManagerFunctionProxy::Result::invalidate(
     Function &F, const PreservedAnalyses &PA,
     FunctionAnalysisManager::Invalidator &Inv) {
-  // If this proxy isn't marked as preserved, the set of Function objects in
+  // First compute the sequence of IR units covered by this proxy. We will want
-  // the module may have changed. We therefore can't call
+  // to visit this in postorder, but because this is a tree structure we can do
-  // InnerAM->invalidate(), because any pointers to Functions it has may be
+  // this by building a preorder sequence and walking it in reverse.
-  // stale.
+  SmallVector<Loop *, 4> PreOrderLoops, PreOrderWorklist;
-  auto PAC = PA.getChecker<LoopAnalysisManagerFunctionProxy>();
+  // Note that we want to walk the roots in reverse order because we will end
-  if (!PAC.preserved() && !PAC.preservedSet<AllAnalysesOn<Loop>>())
+  // up reversing the preorder sequence. However, it happens that the loop nest
-    InnerAM->clear();
+  // roots are in reverse order within the LoopInfo object. So we just walk
+  // forward here.
+  // FIXME: If we change the order of LoopInfo we will want to add a reverse
+  // here.
+  for (Loop *RootL : *LI) {
+    assert(PreOrderWorklist.empty() &&
+           "Must start with an empty preorder walk worklist.");
+    PreOrderWorklist.push_back(RootL);
+    do {
+      Loop *L = PreOrderWorklist.pop_back_val();
+      PreOrderWorklist.append(L->begin(), L->end());
+      PreOrderLoops.push_back(L);
+    } while (!PreOrderWorklist.empty());
+  }
 
-  // FIXME: Proper suppor for invalidation isn't yet implemented for the LPM.
+  // If this proxy or the loop info is going to be invalidated, we also need
+  // to clear all the keys coming from that analysis. We also completely blow
+  // away the loop analyses if any of the standard analyses provided by the
+  // loop pass manager go away so that loop analyses can freely use these
+  // without worrying about declaring dependencies on them etc.
+  // FIXME: It isn't clear if this is the right tradeoff. We could instead make
+  // loop analyses declare any dependencies on these and use the more general
+  // invalidation logic below to act on that.
+  auto PAC = PA.getChecker<LoopAnalysisManagerFunctionProxy>();
+  if (!(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Function>>()) ||
+      Inv.invalidate<AAManager>(F, PA) ||
+      Inv.invalidate<AssumptionAnalysis>(F, PA) ||
+      Inv.invalidate<DominatorTreeAnalysis>(F, PA) ||
+      Inv.invalidate<LoopAnalysis>(F, PA) ||
+      Inv.invalidate<ScalarEvolutionAnalysis>(F, PA)) {
+    // Note that the LoopInfo may be stale at this point, however the loop
+    // objects themselves remain the only viable keys that could be in the
+    // analysis manager's cache. So we just walk the keys and forcibly clear
+    // those results. Note that the order doesn't matter here as this will just
+    // directly destroy the results without calling methods on them.
+    for (Loop *L : PreOrderLoops)
+      InnerAM->clear(*L);
+
+    // We also need to null out the inner AM so that when the object gets
+    // destroyed as invalid we don't try to clear the inner AM again. At that
+    // point we won't be able to reliably walk the loops for this function and
+    // only clear results associated with those loops the way we do here.
+    // FIXME: Making InnerAM null at this point isn't very nice. Most analyses
+    // try to remain valid during invalidation. Maybe we should add an
+    // `IsClean` flag?
+    InnerAM = nullptr;
+
+    // Now return true to indicate this *is* invalid and a fresh proxy result
+    // needs to be built. This is especially important given the null InnerAM.
+    return true;
+  }
+
+  // Directly check if the relevant set is preserved so we can short circuit
+  // invalidating loops.
+  bool AreLoopAnalysesPreserved =
+      PA.allAnalysesInSetPreserved<AllAnalysesOn<Loop>>();
+
+  // Since we have a valid LoopInfo we can actually leave the cached results in
+  // the analysis manager associated with the Loop keys, but we need to
+  // propagate any necessary invalidation logic into them. We'd like to
+  // invalidate things in roughly the same order as they were put into the
+  // cache and so we walk the preorder list in reverse to form a valid
+  // postorder.
+  for (Loop *L : reverse(PreOrderLoops)) {
+    Optional<PreservedAnalyses> InnerPA;
+
+    // Check to see whether the preserved set needs to be adjusted based on
+    // function-level analysis invalidation triggering deferred invalidation
+    // for this loop.
+    if (auto *OuterProxy =
+            InnerAM->getCachedResult<FunctionAnalysisManagerLoopProxy>(*L))
+      for (const auto &OuterInvalidationPair :
+           OuterProxy->getOuterInvalidations()) {
+        AnalysisKey *OuterAnalysisID = OuterInvalidationPair.first;
+        const auto &InnerAnalysisIDs = OuterInvalidationPair.second;
+        if (Inv.invalidate(OuterAnalysisID, F, PA)) {
+          if (!InnerPA)
+            InnerPA = PA;
+          for (AnalysisKey *InnerAnalysisID : InnerAnalysisIDs)
+            InnerPA->abandon(InnerAnalysisID);
+        }
+      }
+
+    // Check if we needed a custom PA set. If so we'll need to run the inner
+    // invalidation.
+    if (InnerPA) {
+      InnerAM->invalidate(*L, *InnerPA);
+      continue;
+    }
+
+    // Otherwise we only need to do invalidation if the original PA set didn't
+    // preserve all Loop analyses.
+    if (!AreLoopAnalysesPreserved)
+      InnerAM->invalidate(*L, PA);
+  }
 
   // Return false to indicate that this result is still a valid proxy.
   return false;
 }
+
+template <>
+LoopAnalysisManagerFunctionProxy::Result
+LoopAnalysisManagerFunctionProxy::run(Function &F,
+                                      FunctionAnalysisManager &AM) {
+  return Result(*InnerAM, AM.getResult<LoopAnalysis>(F));
+}
 }
 
 PreservedAnalyses llvm::getLoopPassPreservedAnalyses() {
   PreservedAnalyses PA;
+  PA.preserve<AssumptionAnalysis>();
   PA.preserve<DominatorTreeAnalysis>();
   PA.preserve<LoopAnalysis>();
+  PA.preserve<LoopAnalysisManagerFunctionProxy>();
   PA.preserve<ScalarEvolutionAnalysis>();
   // TODO: What we really want to do here is preserve an AA category, but that
   // concept doesn't exist yet.
@@ -57,3 +214,14 @@ PreservedAnalyses llvm::getLoopPassPreservedAnalyses() {
   PA.preserve<SCEVAA>();
   return PA;
 }
+
+PrintLoopPass::PrintLoopPass() : OS(dbgs()) {}
+PrintLoopPass::PrintLoopPass(raw_ostream &OS, const std::string &Banner)
+    : OS(OS), Banner(Banner) {}
+
+PreservedAnalyses PrintLoopPass::run(Loop &L, LoopAnalysisManager &,
+                                     LoopStandardAnalysisResults &,
+                                     LPMUpdater &) {
+  printLoop(L, OS, Banner);
+  return PreservedAnalyses::all();
+}

llvm/lib/Passes/PassBuilder.cpp

@@ -38,6 +38,7 @@
 #include "llvm/Analysis/LazyValueInfo.h"
 #include "llvm/Analysis/LoopAccessAnalysis.h"
 #include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/LoopPassManager.h"
 #include "llvm/Analysis/MemoryDependenceAnalysis.h"
 #include "llvm/Analysis/ModuleSummaryAnalysis.h"
 #include "llvm/Analysis/OptimizationDiagnosticInfo.h"
@@ -220,7 +221,8 @@ public:
 
 /// \brief No-op loop pass which does nothing.
 struct NoOpLoopPass {
-  PreservedAnalyses run(Loop &L, LoopAnalysisManager &) {
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &,
+                        LoopStandardAnalysisResults &, LPMUpdater &) {
     return PreservedAnalyses::all();
   }
   static StringRef name() { return "NoOpLoopPass"; }
@@ -233,7 +235,9 @@ class NoOpLoopAnalysis : public AnalysisInfoMixin<NoOpLoopAnalysis> {
 
 public:
   struct Result {};
-  Result run(Loop &, LoopAnalysisManager &) { return Result(); }
+  Result run(Loop &, LoopAnalysisManager &, LoopStandardAnalysisResults &) {
+    return Result();
+  }
   static StringRef name() { return "NoOpLoopAnalysis"; }
 };
 
@@ -1019,7 +1023,9 @@ bool PassBuilder::parseLoopPass(LoopPassManager &LPM, const PipelineElement &E,
 #define LOOP_ANALYSIS(NAME, CREATE_PASS)                                       \
   if (Name == "require<" NAME ">") {                                           \
     LPM.addPass(RequireAnalysisPass<                                           \
-                std::remove_reference<decltype(CREATE_PASS)>::type, Loop>());  \
+                std::remove_reference<decltype(CREATE_PASS)>::type, Loop,      \
+                LoopAnalysisManager, LoopStandardAnalysisResults &,            \
+                LPMUpdater &>());                                              \
     return true;                                                               \
   }                                                                            \
   if (Name == "invalidate<" NAME ">") {                                        \

llvm/lib/Transforms/Scalar/IndVarSimplify.cpp

@@ -2482,23 +2482,13 @@ bool IndVarSimplify::run(Loop *L) {
   return Changed;
 }
 
-PreservedAnalyses IndVarSimplifyPass::run(Loop &L, LoopAnalysisManager &AM) {
+PreservedAnalyses IndVarSimplifyPass::run(Loop &L, LoopAnalysisManager &AM,
-  auto &FAM = AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+                                          LoopStandardAnalysisResults &AR,
+                                          LPMUpdater &) {
   Function *F = L.getHeader()->getParent();
   const DataLayout &DL = F->getParent()->getDataLayout();
 
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
+  IndVarSimplify IVS(&AR.LI, &AR.SE, &AR.DT, DL, &AR.TLI, &AR.TTI);
-  auto *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-
-  assert((LI && SE && DT) &&
-         "Analyses required for indvarsimplify not available!");
-
-  // Optional analyses.
-  auto *TTI = FAM.getCachedResult<TargetIRAnalysis>(*F);
-  auto *TLI = FAM.getCachedResult<TargetLibraryAnalysis>(*F);
-
-  IndVarSimplify IVS(LI, SE, DT, DL, TLI, TTI);
   if (!IVS.run(&L))
     return PreservedAnalyses::all();
 

llvm/lib/Transforms/Scalar/LICM.cpp

@@ -185,23 +185,20 @@ private:
 };
 }
 
-PreservedAnalyses LICMPass::run(Loop &L, LoopAnalysisManager &AM) {
+PreservedAnalyses LICMPass::run(Loop &L, LoopAnalysisManager &AM,
+                                LoopStandardAnalysisResults &AR, LPMUpdater &) {
   const auto &FAM =
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+      AM.getResult<FunctionAnalysisManagerLoopProxy>(L, AR).getManager();
   Function *F = L.getHeader()->getParent();
 
-  auto *AA = FAM.getCachedResult<AAManager>(*F);
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  auto *TLI = FAM.getCachedResult<TargetLibraryAnalysis>(*F);
-  auto *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
   auto *ORE = FAM.getCachedResult<OptimizationRemarkEmitterAnalysis>(*F);
-  assert((AA && LI && DT && TLI && SE && ORE) &&
+  // FIXME: This should probably be optional rather than required.
-         "Analyses for LICM not available");
+  if (!ORE)
+    report_fatal_error("LICM: OptimizationRemarkEmitterAnalysis not "
+                       "cached at a higher level");
 
   LoopInvariantCodeMotion LICM;
-
+  if (!LICM.runOnLoop(&L, &AR.AA, &AR.LI, &AR.DT, &AR.TLI, &AR.SE, ORE, true))
-  if (!LICM.runOnLoop(&L, AA, LI, DT, TLI, SE, ORE, true))
     return PreservedAnalyses::all();
 
   // FIXME: There is no setPreservesCFG in the new PM. When that becomes

llvm/lib/Transforms/Scalar/LoopDeletion.cpp

@@ -215,15 +215,10 @@ bool LoopDeletionPass::runImpl(Loop *L, DominatorTree &DT, ScalarEvolution &SE,
   return Changed;
 }
 
-PreservedAnalyses LoopDeletionPass::run(Loop &L, LoopAnalysisManager &AM) {
+PreservedAnalyses LoopDeletionPass::run(Loop &L, LoopAnalysisManager &AM,
-  auto &FAM = AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+                                        LoopStandardAnalysisResults &AR,
-  Function *F = L.getHeader()->getParent();
+                                        LPMUpdater &) {
-
+  bool Changed = runImpl(&L, AR.DT, AR.SE, AR.LI);
-  auto &DT = *FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  auto &SE = *FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
-  auto &LI = *FAM.getCachedResult<LoopAnalysis>(*F);
-
-  bool Changed = runImpl(&L, DT, SE, LI);
   if (!Changed)
     return PreservedAnalyses::all();
 

llvm/lib/Transforms/Scalar/LoopDistribute.cpp

@@ -946,10 +946,18 @@ PreservedAnalyses LoopDistributePass::run(Function &F,
   auto &SE = AM.getResult<ScalarEvolutionAnalysis>(F);
   auto &ORE = AM.getResult<OptimizationRemarkEmitterAnalysis>(F);
 
+  // We don't directly need these analyses but they're required for loop
+  // analyses so provide them below.
+  auto &AA = AM.getResult<AAManager>(F);
+  auto &AC = AM.getResult<AssumptionAnalysis>(F);
+  auto &TTI = AM.getResult<TargetIRAnalysis>(F);
+  auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
+
   auto &LAM = AM.getResult<LoopAnalysisManagerFunctionProxy>(F).getManager();
   std::function<const LoopAccessInfo &(Loop &)> GetLAA =
       [&](Loop &L) -> const LoopAccessInfo & {
-    return LAM.getResult<LoopAccessAnalysis>(L);
+    LoopStandardAnalysisResults AR = {AA, AC, DT, LI, SE, TLI, TTI};
+    return LAM.getResult<LoopAccessAnalysis>(L, AR);
   };
 
   bool Changed = runImpl(F, &LI, &DT, &SE, &ORE, GetLAA);

llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp

@@ -186,24 +186,12 @@ public:
 };
 } // End anonymous namespace.
 
-PreservedAnalyses LoopIdiomRecognizePass::run(Loop &L,
+PreservedAnalyses LoopIdiomRecognizePass::run(Loop &L, LoopAnalysisManager &AM,
-                                              LoopAnalysisManager &AM) {
+                                              LoopStandardAnalysisResults &AR,
-  const auto &FAM =
+                                              LPMUpdater &) {
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
-  Function *F = L.getHeader()->getParent();
-
-  // Use getCachedResult because Loop pass cannot trigger a function analysis.
-  auto *AA = FAM.getCachedResult<AAManager>(*F);
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  auto *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
-  auto *TLI = FAM.getCachedResult<TargetLibraryAnalysis>(*F);
-  const auto *TTI = FAM.getCachedResult<TargetIRAnalysis>(*F);
   const auto *DL = &L.getHeader()->getModule()->getDataLayout();
-  assert((AA && DT && LI && SE && TLI && TTI && DL) &&
-         "Analyses for Loop Idiom Recognition not available");
 
-  LoopIdiomRecognize LIR(AA, DT, LI, SE, TLI, TTI, DL);
+  LoopIdiomRecognize LIR(&AR.AA, &AR.DT, &AR.LI, &AR.SE, &AR.TLI, &AR.TTI, DL);
   if (!LIR.runOnLoop(&L))
     return PreservedAnalyses::all();
 

llvm/lib/Transforms/Scalar/LoopInstSimplify.cpp

@@ -183,20 +183,10 @@ public:
 };
 }
 
-PreservedAnalyses LoopInstSimplifyPass::run(Loop &L,
+PreservedAnalyses LoopInstSimplifyPass::run(Loop &L, LoopAnalysisManager &AM,
-                                            LoopAnalysisManager &AM) {
+                                            LoopStandardAnalysisResults &AR,
-  const auto &FAM =
+                                            LPMUpdater &) {
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+  if (!SimplifyLoopInst(&L, &AR.DT, &AR.LI, &AR.AC, &AR.TLI))
-  Function *F = L.getHeader()->getParent();
-
-  // Use getCachedResult because Loop pass cannot trigger a function analysis.
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  auto *AC = FAM.getCachedResult<AssumptionAnalysis>(*F);
-  const auto *TLI = FAM.getCachedResult<TargetLibraryAnalysis>(*F);
-  assert((LI && AC && TLI) && "Analyses for Loop Inst Simplify not available");
-
-  if (!SimplifyLoopInst(&L, DT, LI, AC, TLI))
     return PreservedAnalyses::all();
 
   return getLoopPassPreservedAnalyses();

llvm/lib/Transforms/Scalar/LoopRotation.cpp

@@ -625,20 +625,11 @@ bool LoopRotate::processLoop(Loop *L) {
 LoopRotatePass::LoopRotatePass(bool EnableHeaderDuplication)
     : EnableHeaderDuplication(EnableHeaderDuplication) {}
 
-PreservedAnalyses LoopRotatePass::run(Loop &L, LoopAnalysisManager &AM) {
+PreservedAnalyses LoopRotatePass::run(Loop &L, LoopAnalysisManager &AM,
-  auto &FAM = AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+                                      LoopStandardAnalysisResults &AR,
-  Function *F = L.getHeader()->getParent();
+                                      LPMUpdater &) {
-
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  const auto *TTI = FAM.getCachedResult<TargetIRAnalysis>(*F);
-  auto *AC = FAM.getCachedResult<AssumptionAnalysis>(*F);
-  assert((LI && TTI && AC) && "Analyses for loop rotation not available");
-
-  // Optional analyses.
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  auto *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
   int Threshold = EnableHeaderDuplication ? DefaultRotationThreshold : 0;
-  LoopRotate LR(Threshold, LI, TTI, AC, DT, SE);
+  LoopRotate LR(Threshold, &AR.LI, &AR.TTI, &AR.AC, &AR.DT, &AR.SE);
 
   bool Changed = LR.processLoop(&L);
   if (!Changed)

llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp

@@ -64,16 +64,10 @@ static bool simplifyLoopCFG(Loop &L, DominatorTree &DT, LoopInfo &LI) {
   return Changed;
 }
 
-PreservedAnalyses LoopSimplifyCFGPass::run(Loop &L, LoopAnalysisManager &AM) {
+PreservedAnalyses LoopSimplifyCFGPass::run(Loop &L, LoopAnalysisManager &AM,
-  const auto &FAM =
+                                           LoopStandardAnalysisResults &AR,
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+                                           LPMUpdater &) {
-  Function *F = L.getHeader()->getParent();
+  if (!simplifyLoopCFG(L, AR.DT, AR.LI))
-
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  assert((LI && DT) && "Analyses for LoopSimplifyCFG not available");
-
-  if (!simplifyLoopCFG(L, *DT, *LI))
     return PreservedAnalyses::all();
   return getLoopPassPreservedAnalyses();
 }

llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp

@@ -5052,21 +5052,11 @@ bool LoopStrengthReduce::runOnLoop(Loop *L, LPPassManager & /*LPM*/) {
   return ReduceLoopStrength(L, IU, SE, DT, LI, TTI);
 }
 
-PreservedAnalyses LoopStrengthReducePass::run(Loop &L,
+PreservedAnalyses LoopStrengthReducePass::run(Loop &L, LoopAnalysisManager &AM,
-                                              LoopAnalysisManager &AM) {
+                                              LoopStandardAnalysisResults &AR,
-  const auto &FAM =
+                                              LPMUpdater &) {
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+  if (!ReduceLoopStrength(&L, AM.getResult<IVUsersAnalysis>(L, AR), AR.SE,
-  Function *F = L.getHeader()->getParent();
+                          AR.DT, AR.LI, AR.TTI))
-
-  auto &IU = AM.getResult<IVUsersAnalysis>(L);
-  auto *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
-  auto *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  auto *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  auto *TTI = FAM.getCachedResult<TargetIRAnalysis>(*F);
-  assert((SE && DT && LI && TTI) &&
-         "Analyses for Loop Strength Reduce not available");
-
-  if (!ReduceLoopStrength(&L, IU, *SE, *DT, *LI, *TTI))
     return PreservedAnalyses::all();
 
   return getLoopPassPreservedAnalyses();

llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp

@@ -1111,40 +1111,22 @@ Pass *llvm::createSimpleLoopUnrollPass() {
   return llvm::createLoopUnrollPass(-1, -1, 0, 0, 0);
 }
 
-PreservedAnalyses LoopUnrollPass::run(Loop &L, LoopAnalysisManager &AM) {
+PreservedAnalyses LoopUnrollPass::run(Loop &L, LoopAnalysisManager &AM,
+                                      LoopStandardAnalysisResults &AR,
+                                      LPMUpdater &) {
   const auto &FAM =
-      AM.getResult<FunctionAnalysisManagerLoopProxy>(L).getManager();
+      AM.getResult<FunctionAnalysisManagerLoopProxy>(L, AR).getManager();
   Function *F = L.getHeader()->getParent();
 
-
-  DominatorTree *DT = FAM.getCachedResult<DominatorTreeAnalysis>(*F);
-  LoopInfo *LI = FAM.getCachedResult<LoopAnalysis>(*F);
-  ScalarEvolution *SE = FAM.getCachedResult<ScalarEvolutionAnalysis>(*F);
-  auto *TTI = FAM.getCachedResult<TargetIRAnalysis>(*F);
-  auto *AC = FAM.getCachedResult<AssumptionAnalysis>(*F);
   auto *ORE = FAM.getCachedResult<OptimizationRemarkEmitterAnalysis>(*F);
-  if (!DT)
+  // FIXME: This should probably be optional rather than required.
-    report_fatal_error(
-        "LoopUnrollPass: DominatorTreeAnalysis not cached at a higher level");
-  if (!LI)
-    report_fatal_error(
-        "LoopUnrollPass: LoopAnalysis not cached at a higher level");
-  if (!SE)
-    report_fatal_error(
-        "LoopUnrollPass: ScalarEvolutionAnalysis not cached at a higher level");
-  if (!TTI)
-    report_fatal_error(
-        "LoopUnrollPass: TargetIRAnalysis not cached at a higher level");
-  if (!AC)
-    report_fatal_error(
-        "LoopUnrollPass: AssumptionAnalysis not cached at a higher level");
   if (!ORE)
     report_fatal_error("LoopUnrollPass: OptimizationRemarkEmitterAnalysis not "
                        "cached at a higher level");
 
-  bool Changed =
+  bool Changed = tryToUnrollLoop(&L, AR.DT, &AR.LI, &AR.SE, AR.TTI, AR.AC, *ORE,
-      tryToUnrollLoop(&L, *DT, LI, SE, *TTI, *AC, *ORE, /*PreserveLCSSA*/ true,
+                                 /*PreserveLCSSA*/ true, ProvidedCount,
-                      ProvidedCount, ProvidedThreshold, ProvidedAllowPartial,
+                                 ProvidedThreshold, ProvidedAllowPartial,
                                  ProvidedRuntime, ProvidedUpperBound);
 
   if (!Changed)

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -7641,7 +7641,7 @@ PreservedAnalyses LoopVectorizePass::run(Function &F,
     auto &TTI = AM.getResult<TargetIRAnalysis>(F);
     auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
     auto &BFI = AM.getResult<BlockFrequencyAnalysis>(F);
-    auto *TLI = AM.getCachedResult<TargetLibraryAnalysis>(F);
+    auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
     auto &AA = AM.getResult<AAManager>(F);
     auto &AC = AM.getResult<AssumptionAnalysis>(F);
     auto &DB = AM.getResult<DemandedBitsAnalysis>(F);
@@ -7650,10 +7650,11 @@ PreservedAnalyses LoopVectorizePass::run(Function &F,
     auto &LAM = AM.getResult<LoopAnalysisManagerFunctionProxy>(F).getManager();
     std::function<const LoopAccessInfo &(Loop &)> GetLAA =
         [&](Loop &L) -> const LoopAccessInfo & {
-      return LAM.getResult<LoopAccessAnalysis>(L);
+      LoopStandardAnalysisResults AR = {AA, AC, DT, LI, SE, TLI, TTI};
+      return LAM.getResult<LoopAccessAnalysis>(L, AR);
     };
     bool Changed =
-        runImpl(F, SE, LI, TTI, DT, BFI, TLI, DB, AA, AC, GetLAA, ORE);
+        runImpl(F, SE, LI, TTI, DT, BFI, &TLI, DB, AA, AC, GetLAA, ORE);
     if (!Changed)
       return PreservedAnalyses::all();
     PreservedAnalyses PA;

llvm/test/Other/loop-pass-ordering.ll

@@ -8,11 +8,12 @@
 ;      /      \        \
 ; loop.0.0  loop.0.1  loop.1.0
 ;
-; CHECK: Running pass: NoOpLoopPass on loop.1.0
+; CHECK: Running pass: NoOpLoopPass on Loop at depth 2 containing: %loop.0.0
-; CHECK: Running pass: NoOpLoopPass on loop.1
+; CHECK: Running pass: NoOpLoopPass on Loop at depth 2 containing: %loop.0.1
-; CHECK: Running pass: NoOpLoopPass on loop.0.0
+; CHECK: Running pass: NoOpLoopPass on Loop at depth 1 containing: %loop.0
-; CHECK: Running pass: NoOpLoopPass on loop.0.1
+; CHECK: Running pass: NoOpLoopPass on Loop at depth 2 containing: %loop.1.0
-; CHECK: Running pass: NoOpLoopPass on loop.0
+; CHECK: Running pass: NoOpLoopPass on Loop at depth 1 containing: %loop.1
+
 define void @f() {
 entry:
   br label %loop.0

llvm/test/Other/new-pass-manager.ll

@@ -433,12 +433,12 @@
 ; CHECK-O: Running pass: TailCallElimPass
 ; CHECK-O: Running pass: SimplifyCFGPass
 ; CHECK-O: Running pass: ReassociatePass
-; CHECK-O: Starting llvm::Loop pass manager run.
+; CHECK-O: Starting Loop pass manager run.
-; CHECK-O: Finished llvm::Loop pass manager run.
+; CHECK-O: Finished Loop pass manager run.
 ; CHECK-O: Running pass: SimplifyCFGPass
 ; CHECK-O: Running pass: InstCombinePass
-; CHECK-O: Starting llvm::Loop pass manager run.
+; CHECK-O: Starting Loop pass manager run.
-; CHECK-O: Finished llvm::Loop pass manager run.
+; CHECK-O: Finished Loop pass manager run.
 ; CHECK-O: Running pass: MemCpyOptPass
 ; CHECK-O: Running pass: SCCPPass
 ; CHECK-O: Running pass: BDCEPass
@@ -544,20 +544,21 @@
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: DominatorTreeAnalysis
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: AAManager
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: TargetLibraryAnalysis
-; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: ScalarEvolutionAnalysis
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: AssumptionAnalysis
-; CHECK-REPEAT-LOOP-PASS-NEXT: Starting llvm::Loop pass manager run
+; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: ScalarEvolutionAnalysis
+; CHECK-REPEAT-LOOP-PASS-NEXT: Running analysis: TargetIRAnalysis
+; CHECK-REPEAT-LOOP-PASS-NEXT: Starting Loop pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running pass: RepeatedPass
-; CHECK-REPEAT-LOOP-PASS-NEXT: Starting llvm::Loop pass manager run
+; CHECK-REPEAT-LOOP-PASS-NEXT: Starting Loop pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running pass: NoOpLoopPass
-; CHECK-REPEAT-LOOP-PASS-NEXT: Finished llvm::Loop pass manager run
+; CHECK-REPEAT-LOOP-PASS-NEXT: Finished Loop pass manager run
-; CHECK-REPEAT-LOOP-PASS-NEXT: Starting llvm::Loop pass manager run
+; CHECK-REPEAT-LOOP-PASS-NEXT: Starting Loop pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running pass: NoOpLoopPass
-; CHECK-REPEAT-LOOP-PASS-NEXT: Finished llvm::Loop pass manager run
+; CHECK-REPEAT-LOOP-PASS-NEXT: Finished Loop pass manager run
-; CHECK-REPEAT-LOOP-PASS-NEXT: Starting llvm::Loop pass manager run
+; CHECK-REPEAT-LOOP-PASS-NEXT: Starting Loop pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Running pass: NoOpLoopPass
-; CHECK-REPEAT-LOOP-PASS-NEXT: Finished llvm::Loop pass manager run
+; CHECK-REPEAT-LOOP-PASS-NEXT: Finished Loop pass manager run
-; CHECK-REPEAT-LOOP-PASS-NEXT: Finished llvm::Loop pass manager run
+; CHECK-REPEAT-LOOP-PASS-NEXT: Finished Loop pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Finished llvm::Function pass manager run
 ; CHECK-REPEAT-LOOP-PASS-NEXT: Finished llvm::Module pass manager run
 

llvm/test/Other/pass-pipeline-parsing.ll

@@ -144,10 +144,10 @@
 ; CHECK-TWO-NOOP-LOOP: Running pass: ModuleToFunctionPassAdaptor
 ; CHECK-TWO-NOOP-LOOP: Starting llvm::Function pass manager run
 ; CHECK-TWO-NOOP-LOOP: Running pass: FunctionToLoopPassAdaptor
-; CHECK-TWO-NOOP-LOOP: Starting llvm::Loop pass manager run
+; CHECK-TWO-NOOP-LOOP: Starting Loop pass manager run
 ; CHECK-TWO-NOOP-LOOP: Running pass: NoOpLoopPass
 ; CHECK-TWO-NOOP-LOOP: Running pass: NoOpLoopPass
-; CHECK-TWO-NOOP-LOOP: Finished llvm::Loop pass manager run
+; CHECK-TWO-NOOP-LOOP: Finished Loop pass manager run
 ; CHECK-TWO-NOOP-LOOP: Finished llvm::Function pass manager run
 ; CHECK-TWO-NOOP-LOOP: Finished llvm::Module pass manager run
 
@@ -167,9 +167,9 @@
 ; CHECK-NESTED-FP-LP: Running pass: ModuleToFunctionPassAdaptor
 ; CHECK-NESTED-FP-LP: Starting llvm::Function pass manager run
 ; CHECK-NESTED-FP-LP: Running pass: FunctionToLoopPassAdaptor
-; CHECK-NESTED-FP-LP: Starting llvm::Loop pass manager run
+; CHECK-NESTED-FP-LP: Starting Loop pass manager run
 ; CHECK-NESTED-FP-LP: Running pass: NoOpLoopPass
-; CHECK-NESTED-FP-LP: Finished llvm::Loop pass manager run
+; CHECK-NESTED-FP-LP: Finished Loop pass manager run
 ; CHECK-NESTED-FP-LP: Finished llvm::Function pass manager run
 ; CHECK-NESTED-FP-LP: Finished llvm::Module pass manager run