1 files changed, 0 insertions, 709 deletions

diff --git a/contrib/llvm/lib/Analysis/CGSCCPassManager.cpp b/contrib/llvm/lib/Analysis/CGSCCPassManager.cpp
deleted file mode 100644
index a0b3f83cca6a..000000000000
--- a/contrib/llvm/lib/Analysis/CGSCCPassManager.cpp
+++ /dev/null
@@ -1,709 +0,0 @@
-//===- CGSCCPassManager.cpp - Managing & running CGSCC passes -------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/CGSCCPassManager.h"
-#include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/Optional.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SetVector.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/iterator_range.h"
-#include "llvm/Analysis/LazyCallGraph.h"
-#include "llvm/IR/CallSite.h"
-#include "llvm/IR/Constant.h"
-#include "llvm/IR/InstIterator.h"
-#include "llvm/IR/Instruction.h"
-#include "llvm/IR/PassManager.h"
-#include "llvm/Support/Casting.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-#include <algorithm>
-#include <cassert>
-#include <iterator>
-
-#define DEBUG_TYPE "cgscc"
-
-using namespace llvm;
-
-// Explicit template instantiations and specialization definitions for core
-// template typedefs.
-namespace llvm {
-
-// Explicit instantiations for the core proxy templates.
-template class AllAnalysesOn<LazyCallGraph::SCC>;
-template class AnalysisManager<LazyCallGraph::SCC, LazyCallGraph &>;
-template class PassManager<LazyCallGraph::SCC, CGSCCAnalysisManager,
-                           LazyCallGraph &, CGSCCUpdateResult &>;
-template class InnerAnalysisManagerProxy<CGSCCAnalysisManager, Module>;
-template class OuterAnalysisManagerProxy<ModuleAnalysisManager,
-                                         LazyCallGraph::SCC, LazyCallGraph &>;
-template class OuterAnalysisManagerProxy<CGSCCAnalysisManager, Function>;
-
-/// Explicitly specialize the pass manager run method to handle call graph
-/// updates.
-template <>
-PreservedAnalyses
-PassManager<LazyCallGraph::SCC, CGSCCAnalysisManager, LazyCallGraph &,
-            CGSCCUpdateResult &>::run(LazyCallGraph::SCC &InitialC,
-                                      CGSCCAnalysisManager &AM,
-                                      LazyCallGraph &G, CGSCCUpdateResult &UR) {
-  // Request PassInstrumentation from analysis manager, will use it to run
-  // instrumenting callbacks for the passes later.
-  PassInstrumentation PI =
-      AM.getResult<PassInstrumentationAnalysis>(InitialC, G);
-
-  PreservedAnalyses PA = PreservedAnalyses::all();
-
-  if (DebugLogging)
-    dbgs() << "Starting CGSCC pass manager run.\n";
-
-  // The SCC may be refined while we are running passes over it, so set up
-  // a pointer that we can update.
-  LazyCallGraph::SCC *C = &InitialC;
-
-  for (auto &Pass : Passes) {
-    if (DebugLogging)
-      dbgs() << "Running pass: " << Pass->name() << " on " << *C << "\n";
-
-    // Check the PassInstrumentation's BeforePass callbacks before running the
-    // pass, skip its execution completely if asked to (callback returns false).
-    if (!PI.runBeforePass(*Pass, *C))
-      continue;
-
-    PreservedAnalyses PassPA = Pass->run(*C, AM, G, UR);
-
-    if (UR.InvalidatedSCCs.count(C))
-      PI.runAfterPassInvalidated<LazyCallGraph::SCC>(*Pass);
-    else
-      PI.runAfterPass<LazyCallGraph::SCC>(*Pass, *C);
-
-    // Update the SCC if necessary.
-    C = UR.UpdatedC ? UR.UpdatedC : C;
-
-    // If the CGSCC pass wasn't able to provide a valid updated SCC, the
-    // current SCC may simply need to be skipped if invalid.
-    if (UR.InvalidatedSCCs.count(C)) {
-      LLVM_DEBUG(dbgs() << "Skipping invalidated root or island SCC!\n");
-      break;
-    }
-    // Check that we didn't miss any update scenario.
-    assert(C->begin() != C->end() && "Cannot have an empty SCC!");
-
-    // Update the analysis manager as each pass runs and potentially
-    // invalidates analyses.
-    AM.invalidate(*C, 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();
-  }
-
-  // Before we mark all of *this* SCC's analyses as preserved below, intersect
-  // this with the cross-SCC preserved analysis set. This is used to allow
-  // CGSCC passes to mutate ancestor SCCs and still trigger proper invalidation
-  // for them.
-  UR.CrossSCCPA.intersect(PA);
-
-  // Invalidation was handled after each pass in the above loop for the current
-  // SCC. 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.
-  PA.preserveSet<AllAnalysesOn<LazyCallGraph::SCC>>();
-
-  if (DebugLogging)
-    dbgs() << "Finished CGSCC pass manager run.\n";
-
-  return PA;
-}
-
-bool CGSCCAnalysisManagerModuleProxy::Result::invalidate(
-    Module &M, const PreservedAnalyses &PA,
-    ModuleAnalysisManager::Invalidator &Inv) {
-  // If literally everything is preserved, we're done.
-  if (PA.areAllPreserved())
-    return false; // This is still a valid proxy.
-
-  // If this proxy or the call graph is going to be invalidated, we also need
-  // to clear all the keys coming from that analysis.
-  //
-  // We also directly invalidate the FAM's module proxy if necessary, and if
-  // that proxy isn't preserved we can't preserve this proxy either. We rely on
-  // it to handle module -> function analysis invalidation in the face of
-  // structural changes and so if it's unavailable we conservatively clear the
-  // entire SCC layer as well rather than trying to do invalidation ourselves.
-  auto PAC = PA.getChecker<CGSCCAnalysisManagerModuleProxy>();
-  if (!(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Module>>()) ||
-      Inv.invalidate<LazyCallGraphAnalysis>(M, PA) ||
-      Inv.invalidate<FunctionAnalysisManagerModuleProxy>(M, PA)) {
-    InnerAM->clear();
-
-    // And the proxy itself should be marked as invalid so that we can observe
-    // the new call graph. This isn't strictly necessary because we cheat
-    // above, but is still useful.
-    return true;
-  }
-
-  // Directly check if the relevant set is preserved so we can short circuit
-  // invalidating SCCs below.
-  bool AreSCCAnalysesPreserved =
-      PA.allAnalysesInSetPreserved<AllAnalysesOn<LazyCallGraph::SCC>>();
-
-  // Ok, we have a graph, so we can propagate the invalidation down into it.
-  G->buildRefSCCs();
-  for (auto &RC : G->postorder_ref_sccs())
-    for (auto &C : RC) {
-      Optional<PreservedAnalyses> InnerPA;
-
-      // Check to see whether the preserved set needs to be adjusted based on
-      // module-level analysis invalidation triggering deferred invalidation
-      // for this SCC.
-      if (auto *OuterProxy =
-              InnerAM->getCachedResult<ModuleAnalysisManagerCGSCCProxy>(C))
-        for (const auto &OuterInvalidationPair :
-             OuterProxy->getOuterInvalidations()) {
-          AnalysisKey *OuterAnalysisID = OuterInvalidationPair.first;
-          const auto &InnerAnalysisIDs = OuterInvalidationPair.second;
-          if (Inv.invalidate(OuterAnalysisID, M, 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(C, *InnerPA);
-        continue;
-      }
-
-      // Otherwise we only need to do invalidation if the original PA set didn't
-      // preserve all SCC analyses.
-      if (!AreSCCAnalysesPreserved)
-        InnerAM->invalidate(C, PA);
-    }
-
-  // Return false to indicate that this result is still a valid proxy.
-  return false;
-}
-
-template <>
-CGSCCAnalysisManagerModuleProxy::Result
-CGSCCAnalysisManagerModuleProxy::run(Module &M, ModuleAnalysisManager &AM) {
-  // Force the Function analysis manager to also be available so that it can
-  // be accessed in an SCC analysis and proxied onward to function passes.
-  // FIXME: It is pretty awkward to just drop the result here and assert that
-  // we can find it again later.
-  (void)AM.getResult<FunctionAnalysisManagerModuleProxy>(M);
-
-  return Result(*InnerAM, AM.getResult<LazyCallGraphAnalysis>(M));
-}
-
-AnalysisKey FunctionAnalysisManagerCGSCCProxy::Key;
-
-FunctionAnalysisManagerCGSCCProxy::Result
-FunctionAnalysisManagerCGSCCProxy::run(LazyCallGraph::SCC &C,
-                                       CGSCCAnalysisManager &AM,
-                                       LazyCallGraph &CG) {
-  // Collect the FunctionAnalysisManager from the Module layer and use that to
-  // build the proxy result.
-  //
-  // This allows us to rely on the FunctionAnalysisMangaerModuleProxy to
-  // invalidate the function analyses.
-  auto &MAM = AM.getResult<ModuleAnalysisManagerCGSCCProxy>(C, CG).getManager();
-  Module &M = *C.begin()->getFunction().getParent();
-  auto *FAMProxy = MAM.getCachedResult<FunctionAnalysisManagerModuleProxy>(M);
-  assert(FAMProxy && "The CGSCC pass manager requires that the FAM module "
-                     "proxy is run on the module prior to entering the CGSCC "
-                     "walk.");
-
-  // Note that we special-case invalidation handling of this proxy in the CGSCC
-  // analysis manager's Module proxy. This avoids the need to do anything
-  // special here to recompute all of this if ever the FAM's module proxy goes
-  // away.
-  return Result(FAMProxy->getManager());
-}
-
-bool FunctionAnalysisManagerCGSCCProxy::Result::invalidate(
-    LazyCallGraph::SCC &C, const PreservedAnalyses &PA,
-    CGSCCAnalysisManager::Invalidator &Inv) {
-  // If literally everything is preserved, we're done.
-  if (PA.areAllPreserved())
-    return false; // This is still a valid proxy.
-
-  // If this proxy isn't marked as preserved, then even if the result remains
-  // valid, the key itself may no longer be valid, so we clear everything.
-  //
-  // Note that in order to preserve this proxy, a module pass must ensure that
-  // the FAM has been completely updated to handle the deletion of functions.
-  // Specifically, any FAM-cached results for those functions need to have been
-  // forcibly cleared. When preserved, this proxy will only invalidate results
-  // cached on functions *still in the module* at the end of the module pass.
-  auto PAC = PA.getChecker<FunctionAnalysisManagerCGSCCProxy>();
-  if (!PAC.preserved() && !PAC.preservedSet<AllAnalysesOn<LazyCallGraph::SCC>>()) {
-    for (LazyCallGraph::Node &N : C)
-      FAM->clear(N.getFunction(), N.getFunction().getName());
-
-    return true;
-  }
-
-  // Directly check if the relevant set is preserved.
-  bool AreFunctionAnalysesPreserved =
-      PA.allAnalysesInSetPreserved<AllAnalysesOn<Function>>();
-
-  // Now walk all the functions to see if any inner analysis invalidation is
-  // necessary.
-  for (LazyCallGraph::Node &N : C) {
-    Function &F = N.getFunction();
-    Optional<PreservedAnalyses> FunctionPA;
-
-    // Check to see whether the preserved set needs to be pruned based on
-    // SCC-level analysis invalidation that triggers deferred invalidation
-    // registered with the outer analysis manager proxy for this function.
-    if (auto *OuterProxy =
-            FAM->getCachedResult<CGSCCAnalysisManagerFunctionProxy>(F))
-      for (const auto &OuterInvalidationPair :
-           OuterProxy->getOuterInvalidations()) {
-        AnalysisKey *OuterAnalysisID = OuterInvalidationPair.first;
-        const auto &InnerAnalysisIDs = OuterInvalidationPair.second;
-        if (Inv.invalidate(OuterAnalysisID, C, PA)) {
-          if (!FunctionPA)
-            FunctionPA = PA;
-          for (AnalysisKey *InnerAnalysisID : InnerAnalysisIDs)
-            FunctionPA->abandon(InnerAnalysisID);
-        }
-      }
-
-    // Check if we needed a custom PA set, and if so we'll need to run the
-    // inner invalidation.
-    if (FunctionPA) {
-      FAM->invalidate(F, *FunctionPA);
-      continue;
-    }
-
-    // Otherwise we only need to do invalidation if the original PA set didn't
-    // preserve all function analyses.
-    if (!AreFunctionAnalysesPreserved)
-      FAM->invalidate(F, PA);
-  }
-
-  // Return false to indicate that this result is still a valid proxy.
-  return false;
-}
-
-} // end namespace llvm
-
-/// When a new SCC is created for the graph and there might be function
-/// analysis results cached for the functions now in that SCC two forms of
-/// updates are required.
-///
-/// First, a proxy from the SCC to the FunctionAnalysisManager needs to be
-/// created so that any subsequent invalidation events to the SCC are
-/// propagated to the function analysis results cached for functions within it.
-///
-/// Second, if any of the functions within the SCC have analysis results with
-/// outer analysis dependencies, then those dependencies would point to the
-/// *wrong* SCC's analysis result. We forcibly invalidate the necessary
-/// function analyses so that they don't retain stale handles.
-static void updateNewSCCFunctionAnalyses(LazyCallGraph::SCC &C,
-                                         LazyCallGraph &G,
-                                         CGSCCAnalysisManager &AM) {
-  // Get the relevant function analysis manager.
-  auto &FAM =
-      AM.getResult<FunctionAnalysisManagerCGSCCProxy>(C, G).getManager();
-
-  // Now walk the functions in this SCC and invalidate any function analysis
-  // results that might have outer dependencies on an SCC analysis.
-  for (LazyCallGraph::Node &N : C) {
-    Function &F = N.getFunction();
-
-    auto *OuterProxy =
-        FAM.getCachedResult<CGSCCAnalysisManagerFunctionProxy>(F);
-    if (!OuterProxy)
-      // No outer analyses were queried, nothing to do.
-      continue;
-
-    // Forcibly abandon all the inner analyses with dependencies, but
-    // invalidate nothing else.
-    auto PA = PreservedAnalyses::all();
-    for (const auto &OuterInvalidationPair :
-         OuterProxy->getOuterInvalidations()) {
-      const auto &InnerAnalysisIDs = OuterInvalidationPair.second;
-      for (AnalysisKey *InnerAnalysisID : InnerAnalysisIDs)
-        PA.abandon(InnerAnalysisID);
-    }
-
-    // Now invalidate anything we found.
-    FAM.invalidate(F, PA);
-  }
-}
-
-/// Helper function to update both the \c CGSCCAnalysisManager \p AM and the \c
-/// CGSCCPassManager's \c CGSCCUpdateResult \p UR based on a range of newly
-/// added SCCs.
-///
-/// The range of new SCCs must be in postorder already. The SCC they were split
-/// out of must be provided as \p C. The current node being mutated and
-/// triggering updates must be passed as \p N.
-///
-/// This function returns the SCC containing \p N. This will be either \p C if
-/// no new SCCs have been split out, or it will be the new SCC containing \p N.
-template <typename SCCRangeT>
-static LazyCallGraph::SCC *
-incorporateNewSCCRange(const SCCRangeT &NewSCCRange, LazyCallGraph &G,
-                       LazyCallGraph::Node &N, LazyCallGraph::SCC *C,
-                       CGSCCAnalysisManager &AM, CGSCCUpdateResult &UR) {
-  using SCC = LazyCallGraph::SCC;
-
-  if (NewSCCRange.begin() == NewSCCRange.end())
-    return C;
-
-  // Add the current SCC to the worklist as its shape has changed.
-  UR.CWorklist.insert(C);
-  LLVM_DEBUG(dbgs() << "Enqueuing the existing SCC in the worklist:" << *C
-                    << "\n");
-
-  SCC *OldC = C;
-
-  // Update the current SCC. Note that if we have new SCCs, this must actually
-  // change the SCC.
-  assert(C != &*NewSCCRange.begin() &&
-         "Cannot insert new SCCs without changing current SCC!");
-  C = &*NewSCCRange.begin();
-  assert(G.lookupSCC(N) == C && "Failed to update current SCC!");
-
-  // If we had a cached FAM proxy originally, we will want to create more of
-  // them for each SCC that was split off.
-  bool NeedFAMProxy =
-      AM.getCachedResult<FunctionAnalysisManagerCGSCCProxy>(*OldC) != nullptr;
-
-  // We need to propagate an invalidation call to all but the newly current SCC
-  // because the outer pass manager won't do that for us after splitting them.
-  // FIXME: We should accept a PreservedAnalysis from the CG updater so that if
-  // there are preserved analysis we can avoid invalidating them here for
-  // split-off SCCs.
-  // We know however that this will preserve any FAM proxy so go ahead and mark
-  // that.
-  PreservedAnalyses PA;
-  PA.preserve<FunctionAnalysisManagerCGSCCProxy>();
-  AM.invalidate(*OldC, PA);
-
-  // Ensure the now-current SCC's function analyses are updated.
-  if (NeedFAMProxy)
-    updateNewSCCFunctionAnalyses(*C, G, AM);
-
-  for (SCC &NewC : llvm::reverse(make_range(std::next(NewSCCRange.begin()),
-                                            NewSCCRange.end()))) {
-    assert(C != &NewC && "No need to re-visit the current SCC!");
-    assert(OldC != &NewC && "Already handled the original SCC!");
-    UR.CWorklist.insert(&NewC);
-    LLVM_DEBUG(dbgs() << "Enqueuing a newly formed SCC:" << NewC << "\n");
-
-    // Ensure new SCCs' function analyses are updated.
-    if (NeedFAMProxy)
-      updateNewSCCFunctionAnalyses(NewC, G, AM);
-
-    // Also propagate a normal invalidation to the new SCC as only the current
-    // will get one from the pass manager infrastructure.
-    AM.invalidate(NewC, PA);
-  }
-  return C;
-}
-
-LazyCallGraph::SCC &llvm::updateCGAndAnalysisManagerForFunctionPass(
-    LazyCallGraph &G, LazyCallGraph::SCC &InitialC, LazyCallGraph::Node &N,
-    CGSCCAnalysisManager &AM, CGSCCUpdateResult &UR) {
-  using Node = LazyCallGraph::Node;
-  using Edge = LazyCallGraph::Edge;
-  using SCC = LazyCallGraph::SCC;
-  using RefSCC = LazyCallGraph::RefSCC;
-
-  RefSCC &InitialRC = InitialC.getOuterRefSCC();
-  SCC *C = &InitialC;
-  RefSCC *RC = &InitialRC;
-  Function &F = N.getFunction();
-
-  // Walk the function body and build up the set of retained, promoted, and
-  // demoted edges.
-  SmallVector<Constant *, 16> Worklist;
-  SmallPtrSet<Constant *, 16> Visited;
-  SmallPtrSet<Node *, 16> RetainedEdges;
-  SmallSetVector<Node *, 4> PromotedRefTargets;
-  SmallSetVector<Node *, 4> DemotedCallTargets;
-
-  // First walk the function and handle all called functions. We do this first
-  // because if there is a single call edge, whether there are ref edges is
-  // irrelevant.
-  for (Instruction &I : instructions(F))
-    if (auto CS = CallSite(&I))
-      if (Function *Callee = CS.getCalledFunction())
-        if (Visited.insert(Callee).second && !Callee->isDeclaration()) {
-          Node &CalleeN = *G.lookup(*Callee);
-          Edge *E = N->lookup(CalleeN);
-          // FIXME: We should really handle adding new calls. While it will
-          // make downstream usage more complex, there is no fundamental
-          // limitation and it will allow passes within the CGSCC to be a bit
-          // more flexible in what transforms they can do. Until then, we
-          // verify that new calls haven't been introduced.
-          assert(E && "No function transformations should introduce *new* "
-                      "call edges! Any new calls should be modeled as "
-                      "promoted existing ref edges!");
-          bool Inserted = RetainedEdges.insert(&CalleeN).second;
-          (void)Inserted;
-          assert(Inserted && "We should never visit a function twice.");
-          if (!E->isCall())
-            PromotedRefTargets.insert(&CalleeN);
-        }
-
-  // Now walk all references.
-  for (Instruction &I : instructions(F))
-    for (Value *Op : I.operand_values())
-      if (auto *C = dyn_cast<Constant>(Op))
-        if (Visited.insert(C).second)
-          Worklist.push_back(C);
-
-  auto VisitRef = [&](Function &Referee) {
-    Node &RefereeN = *G.lookup(Referee);
-    Edge *E = N->lookup(RefereeN);
-    // FIXME: Similarly to new calls, we also currently preclude
-    // introducing new references. See above for details.
-    assert(E && "No function transformations should introduce *new* ref "
-                "edges! Any new ref edges would require IPO which "
-                "function passes aren't allowed to do!");
-    bool Inserted = RetainedEdges.insert(&RefereeN).second;
-    (void)Inserted;
-    assert(Inserted && "We should never visit a function twice.");
-    if (E->isCall())
-      DemotedCallTargets.insert(&RefereeN);
-  };
-  LazyCallGraph::visitReferences(Worklist, Visited, VisitRef);
-
-  // Include synthetic reference edges to known, defined lib functions.
-  for (auto *F : G.getLibFunctions())
-    // While the list of lib functions doesn't have repeats, don't re-visit
-    // anything handled above.
-    if (!Visited.count(F))
-      VisitRef(*F);
-
-  // First remove all of the edges that are no longer present in this function.
-  // The first step makes these edges uniformly ref edges and accumulates them
-  // into a separate data structure so removal doesn't invalidate anything.
-  SmallVector<Node *, 4> DeadTargets;
-  for (Edge &E : *N) {
-    if (RetainedEdges.count(&E.getNode()))
-      continue;
-
-    SCC &TargetC = *G.lookupSCC(E.getNode());
-    RefSCC &TargetRC = TargetC.getOuterRefSCC();
-    if (&TargetRC == RC && E.isCall()) {
-      if (C != &TargetC) {
-        // For separate SCCs this is trivial.
-        RC->switchTrivialInternalEdgeToRef(N, E.getNode());
-      } else {
-        // Now update the call graph.
-        C = incorporateNewSCCRange(RC->switchInternalEdgeToRef(N, E.getNode()),
-                                   G, N, C, AM, UR);
-      }
-    }
-
-    // Now that this is ready for actual removal, put it into our list.
-    DeadTargets.push_back(&E.getNode());
-  }
-  // Remove the easy cases quickly and actually pull them out of our list.
-  DeadTargets.erase(
-      llvm::remove_if(DeadTargets,
-                      [&](Node *TargetN) {
-                        SCC &TargetC = *G.lookupSCC(*TargetN);
-                        RefSCC &TargetRC = TargetC.getOuterRefSCC();
-
-                        // We can't trivially remove internal targets, so skip
-                        // those.
-                        if (&TargetRC == RC)
-                          return false;
-
-                        RC->removeOutgoingEdge(N, *TargetN);
-                        LLVM_DEBUG(dbgs() << "Deleting outgoing edge from '"
-                                          << N << "' to '" << TargetN << "'\n");
-                        return true;
-                      }),
-      DeadTargets.end());
-
-  // Now do a batch removal of the internal ref edges left.
-  auto NewRefSCCs = RC->removeInternalRefEdge(N, DeadTargets);
-  if (!NewRefSCCs.empty()) {
-    // The old RefSCC is dead, mark it as such.
-    UR.InvalidatedRefSCCs.insert(RC);
-
-    // Note that we don't bother to invalidate analyses as ref-edge
-    // connectivity is not really observable in any way and is intended
-    // exclusively to be used for ordering of transforms rather than for
-    // analysis conclusions.
-
-    // Update RC to the "bottom".
-    assert(G.lookupSCC(N) == C && "Changed the SCC when splitting RefSCCs!");
-    RC = &C->getOuterRefSCC();
-    assert(G.lookupRefSCC(N) == RC && "Failed to update current RefSCC!");
-
-    // The RC worklist is in reverse postorder, so we enqueue the new ones in
-    // RPO except for the one which contains the source node as that is the
-    // "bottom" we will continue processing in the bottom-up walk.
-    assert(NewRefSCCs.front() == RC &&
-           "New current RefSCC not first in the returned list!");
-    for (RefSCC *NewRC : llvm::reverse(make_range(std::next(NewRefSCCs.begin()),
-                                                  NewRefSCCs.end()))) {
-      assert(NewRC != RC && "Should not encounter the current RefSCC further "
-                            "in the postorder list of new RefSCCs.");
-      UR.RCWorklist.insert(NewRC);
-      LLVM_DEBUG(dbgs() << "Enqueuing a new RefSCC in the update worklist: "
-                        << *NewRC << "\n");
-    }
-  }
-
-  // Next demote all the call edges that are now ref edges. This helps make
-  // the SCCs small which should minimize the work below as we don't want to
-  // form cycles that this would break.
-  for (Node *RefTarget : DemotedCallTargets) {
-    SCC &TargetC = *G.lookupSCC(*RefTarget);
-    RefSCC &TargetRC = TargetC.getOuterRefSCC();
-
-    // The easy case is when the target RefSCC is not this RefSCC. This is
-    // only supported when the target RefSCC is a child of this RefSCC.
-    if (&TargetRC != RC) {
-      assert(RC->isAncestorOf(TargetRC) &&
-             "Cannot potentially form RefSCC cycles here!");
-      RC->switchOutgoingEdgeToRef(N, *RefTarget);
-      LLVM_DEBUG(dbgs() << "Switch outgoing call edge to a ref edge from '" << N
-                        << "' to '" << *RefTarget << "'\n");
-      continue;
-    }
-
-    // We are switching an internal call edge to a ref edge. This may split up
-    // some SCCs.
-    if (C != &TargetC) {
-      // For separate SCCs this is trivial.
-      RC->switchTrivialInternalEdgeToRef(N, *RefTarget);
-      continue;
-    }
-
-    // Now update the call graph.
-    C = incorporateNewSCCRange(RC->switchInternalEdgeToRef(N, *RefTarget), G, N,
-                               C, AM, UR);
-  }
-
-  // Now promote ref edges into call edges.
-  for (Node *CallTarget : PromotedRefTargets) {
-    SCC &TargetC = *G.lookupSCC(*CallTarget);
-    RefSCC &TargetRC = TargetC.getOuterRefSCC();
-
-    // The easy case is when the target RefSCC is not this RefSCC. This is
-    // only supported when the target RefSCC is a child of this RefSCC.
-    if (&TargetRC != RC) {
-      assert(RC->isAncestorOf(TargetRC) &&
-             "Cannot potentially form RefSCC cycles here!");
-      RC->switchOutgoingEdgeToCall(N, *CallTarget);
-      LLVM_DEBUG(dbgs() << "Switch outgoing ref edge to a call edge from '" << N
-                        << "' to '" << *CallTarget << "'\n");
-      continue;
-    }
-    LLVM_DEBUG(dbgs() << "Switch an internal ref edge to a call edge from '"
-                      << N << "' to '" << *CallTarget << "'\n");
-
-    // Otherwise we are switching an internal ref edge to a call edge. This
-    // may merge away some SCCs, and we add those to the UpdateResult. We also
-    // need to make sure to update the worklist in the event SCCs have moved
-    // before the current one in the post-order sequence
-    bool HasFunctionAnalysisProxy = false;
-    auto InitialSCCIndex = RC->find(*C) - RC->begin();
-    bool FormedCycle = RC->switchInternalEdgeToCall(
-        N, *CallTarget, [&](ArrayRef<SCC *> MergedSCCs) {
-          for (SCC *MergedC : MergedSCCs) {
-            assert(MergedC != &TargetC && "Cannot merge away the target SCC!");
-
-            HasFunctionAnalysisProxy |=
-                AM.getCachedResult<FunctionAnalysisManagerCGSCCProxy>(
-                    *MergedC) != nullptr;
-
-            // Mark that this SCC will no longer be valid.
-            UR.InvalidatedSCCs.insert(MergedC);
-
-            // FIXME: We should really do a 'clear' here to forcibly release
-            // memory, but we don't have a good way of doing that and
-            // preserving the function analyses.
-            auto PA = PreservedAnalyses::allInSet<AllAnalysesOn<Function>>();
-            PA.preserve<FunctionAnalysisManagerCGSCCProxy>();
-            AM.invalidate(*MergedC, PA);
-          }
-        });
-
-    // If we formed a cycle by creating this call, we need to update more data
-    // structures.
-    if (FormedCycle) {
-      C = &TargetC;
-      assert(G.lookupSCC(N) == C && "Failed to update current SCC!");
-
-      // If one of the invalidated SCCs had a cached proxy to a function
-      // analysis manager, we need to create a proxy in the new current SCC as
-      // the invalidated SCCs had their functions moved.
-      if (HasFunctionAnalysisProxy)
-        AM.getResult<FunctionAnalysisManagerCGSCCProxy>(*C, G);
-
-      // Any analyses cached for this SCC are no longer precise as the shape
-      // has changed by introducing this cycle. However, we have taken care to
-      // update the proxies so it remains valide.
-      auto PA = PreservedAnalyses::allInSet<AllAnalysesOn<Function>>();
-      PA.preserve<FunctionAnalysisManagerCGSCCProxy>();
-      AM.invalidate(*C, PA);
-    }
-    auto NewSCCIndex = RC->find(*C) - RC->begin();
-    // If we have actually moved an SCC to be topologically "below" the current
-    // one due to merging, we will need to revisit the current SCC after
-    // visiting those moved SCCs.
-    //
-    // It is critical that we *do not* revisit the current SCC unless we
-    // actually move SCCs in the process of merging because otherwise we may
-    // form a cycle where an SCC is split apart, merged, split, merged and so
-    // on infinitely.
-    if (InitialSCCIndex < NewSCCIndex) {
-      // Put our current SCC back onto the worklist as we'll visit other SCCs
-      // that are now definitively ordered prior to the current one in the
-      // post-order sequence, and may end up observing more precise context to
-      // optimize the current SCC.
-      UR.CWorklist.insert(C);
-      LLVM_DEBUG(dbgs() << "Enqueuing the existing SCC in the worklist: " << *C
-                        << "\n");
-      // Enqueue in reverse order as we pop off the back of the worklist.
-      for (SCC &MovedC : llvm::reverse(make_range(RC->begin() + InitialSCCIndex,
-                                                  RC->begin() + NewSCCIndex))) {
-        UR.CWorklist.insert(&MovedC);
-        LLVM_DEBUG(dbgs() << "Enqueuing a newly earlier in post-order SCC: "
-                          << MovedC << "\n");
-      }
-    }
-  }
-
-  assert(!UR.InvalidatedSCCs.count(C) && "Invalidated the current SCC!");
-  assert(!UR.InvalidatedRefSCCs.count(RC) && "Invalidated the current RefSCC!");
-  assert(&C->getOuterRefSCC() == RC && "Current SCC not in current RefSCC!");
-
-  // Record the current RefSCC and SCC for higher layers of the CGSCC pass
-  // manager now that all the updates have been applied.
-  if (RC != &InitialRC)
-    UR.UpdatedRC = RC;
-  if (C != &InitialC)
-    UR.UpdatedC = C;
-
-  return *C;
-}