Remove LLVM 8.0.1 files.

1 files changed, 0 insertions, 2373 deletions

diff --git a/gnu/llvm/lib/Analysis/MemorySSA.cpp b/gnu/llvm/lib/Analysis/MemorySSA.cpp
deleted file mode 100644
index 6a5567ed765..00000000000
--- a/gnu/llvm/lib/Analysis/MemorySSA.cpp
+++ /dev/null
@@ -1,2373 +0,0 @@
-//===- MemorySSA.cpp - Memory SSA Builder ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the MemorySSA class.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Analysis/MemorySSA.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/DenseMapInfo.h"
-#include "llvm/ADT/DenseSet.h"
-#include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/Hashing.h"
-#include "llvm/ADT/None.h"
-#include "llvm/ADT/Optional.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/iterator.h"
-#include "llvm/ADT/iterator_range.h"
-#include "llvm/Analysis/AliasAnalysis.h"
-#include "llvm/Analysis/IteratedDominanceFrontier.h"
-#include "llvm/Analysis/MemoryLocation.h"
-#include "llvm/Config/llvm-config.h"
-#include "llvm/IR/AssemblyAnnotationWriter.h"
-#include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/Dominators.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/Instruction.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/Intrinsics.h"
-#include "llvm/IR/LLVMContext.h"
-#include "llvm/IR/PassManager.h"
-#include "llvm/IR/Use.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/AtomicOrdering.h"
-#include "llvm/Support/Casting.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Compiler.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/FormattedStream.h"
-#include "llvm/Support/raw_ostream.h"
-#include <algorithm>
-#include <cassert>
-#include <iterator>
-#include <memory>
-#include <utility>
-
-using namespace llvm;
-
-#define DEBUG_TYPE "memoryssa"
-
-INITIALIZE_PASS_BEGIN(MemorySSAWrapperPass, "memoryssa", "Memory SSA", false,
-                      true)
-INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
-INITIALIZE_PASS_END(MemorySSAWrapperPass, "memoryssa", "Memory SSA", false,
-                    true)
-
-INITIALIZE_PASS_BEGIN(MemorySSAPrinterLegacyPass, "print-memoryssa",
-                      "Memory SSA Printer", false, false)
-INITIALIZE_PASS_DEPENDENCY(MemorySSAWrapperPass)
-INITIALIZE_PASS_END(MemorySSAPrinterLegacyPass, "print-memoryssa",
-                    "Memory SSA Printer", false, false)
-
-static cl::opt<unsigned> MaxCheckLimit(
-    "memssa-check-limit", cl::Hidden, cl::init(100),
-    cl::desc("The maximum number of stores/phis MemorySSA"
-             "will consider trying to walk past (default = 100)"));
-
-// Always verify MemorySSA if expensive checking is enabled.
-#ifdef EXPENSIVE_CHECKS
-bool llvm::VerifyMemorySSA = true;
-#else
-bool llvm::VerifyMemorySSA = false;
-#endif
-static cl::opt<bool, true>
-    VerifyMemorySSAX("verify-memoryssa", cl::location(VerifyMemorySSA),
-                     cl::Hidden, cl::desc("Enable verification of MemorySSA."));
-
-namespace llvm {
-
-/// An assembly annotator class to print Memory SSA information in
-/// comments.
-class MemorySSAAnnotatedWriter : public AssemblyAnnotationWriter {
-  friend class MemorySSA;
-
-  const MemorySSA *MSSA;
-
-public:
-  MemorySSAAnnotatedWriter(const MemorySSA *M) : MSSA(M) {}
-
-  void emitBasicBlockStartAnnot(const BasicBlock *BB,
-                                formatted_raw_ostream &OS) override {
-    if (MemoryAccess *MA = MSSA->getMemoryAccess(BB))
-      OS << "; " << *MA << "\n";
-  }
-
-  void emitInstructionAnnot(const Instruction *I,
-                            formatted_raw_ostream &OS) override {
-    if (MemoryAccess *MA = MSSA->getMemoryAccess(I))
-      OS << "; " << *MA << "\n";
-  }
-};
-
-} // end namespace llvm
-
-namespace {
-
-/// Our current alias analysis API differentiates heavily between calls and
-/// non-calls, and functions called on one usually assert on the other.
-/// This class encapsulates the distinction to simplify other code that wants
-/// "Memory affecting instructions and related data" to use as a key.
-/// For example, this class is used as a densemap key in the use optimizer.
-class MemoryLocOrCall {
-public:
-  bool IsCall = false;
-
-  MemoryLocOrCall(MemoryUseOrDef *MUD)
-      : MemoryLocOrCall(MUD->getMemoryInst()) {}
-  MemoryLocOrCall(const MemoryUseOrDef *MUD)
-      : MemoryLocOrCall(MUD->getMemoryInst()) {}
-
-  MemoryLocOrCall(Instruction *Inst) {
-    if (auto *C = dyn_cast<CallBase>(Inst)) {
-      IsCall = true;
-      Call = C;
-    } else {
-      IsCall = false;
-      // There is no such thing as a memorylocation for a fence inst, and it is
-      // unique in that regard.
-      if (!isa<FenceInst>(Inst))
-        Loc = MemoryLocation::get(Inst);
-    }
-  }
-
-  explicit MemoryLocOrCall(const MemoryLocation &Loc) : Loc(Loc) {}
-
-  const CallBase *getCall() const {
-    assert(IsCall);
-    return Call;
-  }
-
-  MemoryLocation getLoc() const {
-    assert(!IsCall);
-    return Loc;
-  }
-
-  bool operator==(const MemoryLocOrCall &Other) const {
-    if (IsCall != Other.IsCall)
-      return false;
-
-    if (!IsCall)
-      return Loc == Other.Loc;
-
-    if (Call->getCalledValue() != Other.Call->getCalledValue())
-      return false;
-
-    return Call->arg_size() == Other.Call->arg_size() &&
-           std::equal(Call->arg_begin(), Call->arg_end(),
-                      Other.Call->arg_begin());
-  }
-
-private:
-  union {
-    const CallBase *Call;
-    MemoryLocation Loc;
-  };
-};
-
-} // end anonymous namespace
-
-namespace llvm {
-
-template <> struct DenseMapInfo<MemoryLocOrCall> {
-  static inline MemoryLocOrCall getEmptyKey() {
-    return MemoryLocOrCall(DenseMapInfo<MemoryLocation>::getEmptyKey());
-  }
-
-  static inline MemoryLocOrCall getTombstoneKey() {
-    return MemoryLocOrCall(DenseMapInfo<MemoryLocation>::getTombstoneKey());
-  }
-
-  static unsigned getHashValue(const MemoryLocOrCall &MLOC) {
-    if (!MLOC.IsCall)
-      return hash_combine(
-          MLOC.IsCall,
-          DenseMapInfo<MemoryLocation>::getHashValue(MLOC.getLoc()));
-
-    hash_code hash =
-        hash_combine(MLOC.IsCall, DenseMapInfo<const Value *>::getHashValue(
-                                      MLOC.getCall()->getCalledValue()));
-
-    for (const Value *Arg : MLOC.getCall()->args())
-      hash = hash_combine(hash, DenseMapInfo<const Value *>::getHashValue(Arg));
-    return hash;
-  }
-
-  static bool isEqual(const MemoryLocOrCall &LHS, const MemoryLocOrCall &RHS) {
-    return LHS == RHS;
-  }
-};
-
-} // end namespace llvm
-
-/// This does one-way checks to see if Use could theoretically be hoisted above
-/// MayClobber. This will not check the other way around.
-///
-/// This assumes that, for the purposes of MemorySSA, Use comes directly after
-/// MayClobber, with no potentially clobbering operations in between them.
-/// (Where potentially clobbering ops are memory barriers, aliased stores, etc.)
-static bool areLoadsReorderable(const LoadInst *Use,
-                                const LoadInst *MayClobber) {
-  bool VolatileUse = Use->isVolatile();
-  bool VolatileClobber = MayClobber->isVolatile();
-  // Volatile operations may never be reordered with other volatile operations.
-  if (VolatileUse && VolatileClobber)
-    return false;
-  // Otherwise, volatile doesn't matter here. From the language reference:
-  // 'optimizers may change the order of volatile operations relative to
-  // non-volatile operations.'"
-
-  // If a load is seq_cst, it cannot be moved above other loads. If its ordering
-  // is weaker, it can be moved above other loads. We just need to be sure that
-  // MayClobber isn't an acquire load, because loads can't be moved above
-  // acquire loads.
-  //
-  // Note that this explicitly *does* allow the free reordering of monotonic (or
-  // weaker) loads of the same address.
-  bool SeqCstUse = Use->getOrdering() == AtomicOrdering::SequentiallyConsistent;
-  bool MayClobberIsAcquire = isAtLeastOrStrongerThan(MayClobber->getOrdering(),
-                                                     AtomicOrdering::Acquire);
-  return !(SeqCstUse || MayClobberIsAcquire);
-}
-
-namespace {
-
-struct ClobberAlias {
-  bool IsClobber;
-  Optional<AliasResult> AR;
-};
-
-} // end anonymous namespace
-
-// Return a pair of {IsClobber (bool), AR (AliasResult)}. It relies on AR being
-// ignored if IsClobber = false.
-static ClobberAlias instructionClobbersQuery(const MemoryDef *MD,
-                                             const MemoryLocation &UseLoc,
-                                             const Instruction *UseInst,
-                                             AliasAnalysis &AA) {
-  Instruction *DefInst = MD->getMemoryInst();
-  assert(DefInst && "Defining instruction not actually an instruction");
-  const auto *UseCall = dyn_cast<CallBase>(UseInst);
-  Optional<AliasResult> AR;
-
-  if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(DefInst)) {
-    // These intrinsics will show up as affecting memory, but they are just
-    // markers, mostly.
-    //
-    // FIXME: We probably don't actually want MemorySSA to model these at all
-    // (including creating MemoryAccesses for them): we just end up inventing
-    // clobbers where they don't really exist at all. Please see D43269 for
-    // context.
-    switch (II->getIntrinsicID()) {
-    case Intrinsic::lifetime_start:
-      if (UseCall)
-        return {false, NoAlias};
-      AR = AA.alias(MemoryLocation(II->getArgOperand(1)), UseLoc);
-      return {AR != NoAlias, AR};
-    case Intrinsic::lifetime_end:
-    case Intrinsic::invariant_start:
-    case Intrinsic::invariant_end:
-    case Intrinsic::assume:
-      return {false, NoAlias};
-    default:
-      break;
-    }
-  }
-
-  if (UseCall) {
-    ModRefInfo I = AA.getModRefInfo(DefInst, UseCall);
-    AR = isMustSet(I) ? MustAlias : MayAlias;
-    return {isModOrRefSet(I), AR};
-  }
-
-  if (auto *DefLoad = dyn_cast<LoadInst>(DefInst))
-    if (auto *UseLoad = dyn_cast<LoadInst>(UseInst))
-      return {!areLoadsReorderable(UseLoad, DefLoad), MayAlias};
-
-  ModRefInfo I = AA.getModRefInfo(DefInst, UseLoc);
-  AR = isMustSet(I) ? MustAlias : MayAlias;
-  return {isModSet(I), AR};
-}
-
-static ClobberAlias instructionClobbersQuery(MemoryDef *MD,
-                                             const MemoryUseOrDef *MU,
-                                             const MemoryLocOrCall &UseMLOC,
-                                             AliasAnalysis &AA) {
-  // FIXME: This is a temporary hack to allow a single instructionClobbersQuery
-  // to exist while MemoryLocOrCall is pushed through places.
-  if (UseMLOC.IsCall)
-    return instructionClobbersQuery(MD, MemoryLocation(), MU->getMemoryInst(),
-                                    AA);
-  return instructionClobbersQuery(MD, UseMLOC.getLoc(), MU->getMemoryInst(),
-                                  AA);
-}
-
-// Return true when MD may alias MU, return false otherwise.
-bool MemorySSAUtil::defClobbersUseOrDef(MemoryDef *MD, const MemoryUseOrDef *MU,
-                                        AliasAnalysis &AA) {
-  return instructionClobbersQuery(MD, MU, MemoryLocOrCall(MU), AA).IsClobber;
-}
-
-namespace {
-
-struct UpwardsMemoryQuery {
-  // True if our original query started off as a call
-  bool IsCall = false;
-  // The pointer location we started the query with. This will be empty if
-  // IsCall is true.
-  MemoryLocation StartingLoc;
-  // This is the instruction we were querying about.
-  const Instruction *Inst = nullptr;
-  // The MemoryAccess we actually got called with, used to test local domination
-  const MemoryAccess *OriginalAccess = nullptr;
-  Optional<AliasResult> AR = MayAlias;
-  bool SkipSelfAccess = false;
-
-  UpwardsMemoryQuery() = default;
-
-  UpwardsMemoryQuery(const Instruction *Inst, const MemoryAccess *Access)
-      : IsCall(isa<CallBase>(Inst)), Inst(Inst), OriginalAccess(Access) {
-    if (!IsCall)
-      StartingLoc = MemoryLocation::get(Inst);
-  }
-};
-
-} // end anonymous namespace
-
-static bool lifetimeEndsAt(MemoryDef *MD, const MemoryLocation &Loc,
-                           AliasAnalysis &AA) {
-  Instruction *Inst = MD->getMemoryInst();
-  if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst)) {
-    switch (II->getIntrinsicID()) {
-    case Intrinsic::lifetime_end:
-      return AA.isMustAlias(MemoryLocation(II->getArgOperand(1)), Loc);
-    default:
-      return false;
-    }
-  }
-  return false;
-}
-
-static bool isUseTriviallyOptimizableToLiveOnEntry(AliasAnalysis &AA,
-                                                   const Instruction *I) {
-  // If the memory can't be changed, then loads of the memory can't be
-  // clobbered.
-  return isa<LoadInst>(I) && (I->getMetadata(LLVMContext::MD_invariant_load) ||
-                              AA.pointsToConstantMemory(cast<LoadInst>(I)->
-                                                          getPointerOperand()));
-}
-
-/// Verifies that `Start` is clobbered by `ClobberAt`, and that nothing
-/// inbetween `Start` and `ClobberAt` can clobbers `Start`.
-///
-/// This is meant to be as simple and self-contained as possible. Because it
-/// uses no cache, etc., it can be relatively expensive.
-///
-/// \param Start     The MemoryAccess that we want to walk from.
-/// \param ClobberAt A clobber for Start.
-/// \param StartLoc  The MemoryLocation for Start.
-/// \param MSSA      The MemorySSA instance that Start and ClobberAt belong to.
-/// \param Query     The UpwardsMemoryQuery we used for our search.
-/// \param AA        The AliasAnalysis we used for our search.
-/// \param AllowImpreciseClobber Always false, unless we do relaxed verify.
-static void
-checkClobberSanity(const MemoryAccess *Start, MemoryAccess *ClobberAt,
-                   const MemoryLocation &StartLoc, const MemorySSA &MSSA,
-                   const UpwardsMemoryQuery &Query, AliasAnalysis &AA,
-                   bool AllowImpreciseClobber = false) {
-  assert(MSSA.dominates(ClobberAt, Start) && "Clobber doesn't dominate start?");
-
-  if (MSSA.isLiveOnEntryDef(Start)) {
-    assert(MSSA.isLiveOnEntryDef(ClobberAt) &&
-           "liveOnEntry must clobber itself");
-    return;
-  }
-
-  bool FoundClobber = false;
-  DenseSet<ConstMemoryAccessPair> VisitedPhis;
-  SmallVector<ConstMemoryAccessPair, 8> Worklist;
-  Worklist.emplace_back(Start, StartLoc);
-  // Walk all paths from Start to ClobberAt, while looking for clobbers. If one
-  // is found, complain.
-  while (!Worklist.empty()) {
-    auto MAP = Worklist.pop_back_val();
-    // All we care about is that nothing from Start to ClobberAt clobbers Start.
-    // We learn nothing from revisiting nodes.
-    if (!VisitedPhis.insert(MAP).second)
-      continue;
-
-    for (const auto *MA : def_chain(MAP.first)) {
-      if (MA == ClobberAt) {
-        if (const auto *MD = dyn_cast<MemoryDef>(MA)) {
-          // instructionClobbersQuery isn't essentially free, so don't use `|=`,
-          // since it won't let us short-circuit.
-          //
-          // Also, note that this can't be hoisted out of the `Worklist` loop,
-          // since MD may only act as a clobber for 1 of N MemoryLocations.
-          FoundClobber = FoundClobber || MSSA.isLiveOnEntryDef(MD);
-          if (!FoundClobber) {
-            ClobberAlias CA =
-                instructionClobbersQuery(MD, MAP.second, Query.Inst, AA);
-            if (CA.IsClobber) {
-              FoundClobber = true;
-              // Not used: CA.AR;
-            }
-          }
-        }
-        break;
-      }
-
-      // We should never hit liveOnEntry, unless it's the clobber.
-      assert(!MSSA.isLiveOnEntryDef(MA) && "Hit liveOnEntry before clobber?");
-
-      if (const auto *MD = dyn_cast<MemoryDef>(MA)) {
-        // If Start is a Def, skip self.
-        if (MD == Start)
-          continue;
-
-        assert(!instructionClobbersQuery(MD, MAP.second, Query.Inst, AA)
-                    .IsClobber &&
-               "Found clobber before reaching ClobberAt!");
-        continue;
-      }
-
-      if (const auto *MU = dyn_cast<MemoryUse>(MA)) {
-        (void)MU;
-        assert (MU == Start &&
-                "Can only find use in def chain if Start is a use");
-        continue;
-      }
-
-      assert(isa<MemoryPhi>(MA));
-      Worklist.append(
-          upward_defs_begin({const_cast<MemoryAccess *>(MA), MAP.second}),
-          upward_defs_end());
-    }
-  }
-
-  // If the verify is done following an optimization, it's possible that
-  // ClobberAt was a conservative clobbering, that we can now infer is not a
-  // true clobbering access. Don't fail the verify if that's the case.
-  // We do have accesses that claim they're optimized, but could be optimized
-  // further. Updating all these can be expensive, so allow it for now (FIXME).
-  if (AllowImpreciseClobber)
-    return;
-
-  // If ClobberAt is a MemoryPhi, we can assume something above it acted as a
-  // clobber. Otherwise, `ClobberAt` should've acted as a clobber at some point.
-  assert((isa<MemoryPhi>(ClobberAt) || FoundClobber) &&
-         "ClobberAt never acted as a clobber");
-}
-
-namespace {
-
-/// Our algorithm for walking (and trying to optimize) clobbers, all wrapped up
-/// in one class.
-class ClobberWalker {
-  /// Save a few bytes by using unsigned instead of size_t.
-  using ListIndex = unsigned;
-
-  /// Represents a span of contiguous MemoryDefs, potentially ending in a
-  /// MemoryPhi.
-  struct DefPath {
-    MemoryLocation Loc;
-    // Note that, because we always walk in reverse, Last will always dominate
-    // First. Also note that First and Last are inclusive.
-    MemoryAccess *First;
-    MemoryAccess *Last;
-    Optional<ListIndex> Previous;
-
-    DefPath(const MemoryLocation &Loc, MemoryAccess *First, MemoryAccess *Last,
-            Optional<ListIndex> Previous)
-        : Loc(Loc), First(First), Last(Last), Previous(Previous) {}
-
-    DefPath(const MemoryLocation &Loc, MemoryAccess *Init,
-            Optional<ListIndex> Previous)
-        : DefPath(Loc, Init, Init, Previous) {}
-  };
-
-  const MemorySSA &MSSA;
-  AliasAnalysis &AA;
-  DominatorTree &DT;
-  UpwardsMemoryQuery *Query;
-
-  // Phi optimization bookkeeping
-  SmallVector<DefPath, 32> Paths;
-  DenseSet<ConstMemoryAccessPair> VisitedPhis;
-
-  /// Find the nearest def or phi that `From` can legally be optimized to.
-  const MemoryAccess *getWalkTarget(const MemoryPhi *From) const {
-    assert(From->getNumOperands() && "Phi with no operands?");
-
-    BasicBlock *BB = From->getBlock();
-    MemoryAccess *Result = MSSA.getLiveOnEntryDef();
-    DomTreeNode *Node = DT.getNode(BB);
-    while ((Node = Node->getIDom())) {
-      auto *Defs = MSSA.getBlockDefs(Node->getBlock());
-      if (Defs)
-        return &*Defs->rbegin();
-    }
-    return Result;
-  }
-
-  /// Result of calling walkToPhiOrClobber.
-  struct UpwardsWalkResult {
-    /// The "Result" of the walk. Either a clobber, the last thing we walked, or
-    /// both. Include alias info when clobber found.
-    MemoryAccess *Result;
-    bool IsKnownClobber;
-    Optional<AliasResult> AR;
-  };
-
-  /// Walk to the next Phi or Clobber in the def chain starting at Desc.Last.
-  /// This will update Desc.Last as it walks. It will (optionally) also stop at
-  /// StopAt.
-  ///
-  /// This does not test for whether StopAt is a clobber
-  UpwardsWalkResult
-  walkToPhiOrClobber(DefPath &Desc, const MemoryAccess *StopAt = nullptr,
-                     const MemoryAccess *SkipStopAt = nullptr) const {
-    assert(!isa<MemoryUse>(Desc.Last) && "Uses don't exist in my world");
-
-    for (MemoryAccess *Current : def_chain(Desc.Last)) {
-      Desc.Last = Current;
-      if (Current == StopAt || Current == SkipStopAt)
-        return {Current, false, MayAlias};
-
-      if (auto *MD = dyn_cast<MemoryDef>(Current)) {
-        if (MSSA.isLiveOnEntryDef(MD))
-          return {MD, true, MustAlias};
-        ClobberAlias CA =
-            instructionClobbersQuery(MD, Desc.Loc, Query->Inst, AA);
-        if (CA.IsClobber)
-          return {MD, true, CA.AR};
-      }
-    }
-
-    assert(isa<MemoryPhi>(Desc.Last) &&
-           "Ended at a non-clobber that's not a phi?");
-    return {Desc.Last, false, MayAlias};
-  }
-
-  void addSearches(MemoryPhi *Phi, SmallVectorImpl<ListIndex> &PausedSearches,
-                   ListIndex PriorNode) {
-    auto UpwardDefs = make_range(upward_defs_begin({Phi, Paths[PriorNode].Loc}),
-                                 upward_defs_end());
-    for (const MemoryAccessPair &P : UpwardDefs) {
-      PausedSearches.push_back(Paths.size());
-      Paths.emplace_back(P.second, P.first, PriorNode);
-    }
-  }
-
-  /// Represents a search that terminated after finding a clobber. This clobber
-  /// may or may not be present in the path of defs from LastNode..SearchStart,
-  /// since it may have been retrieved from cache.
-  struct TerminatedPath {
-    MemoryAccess *Clobber;
-    ListIndex LastNode;
-  };
-
-  /// Get an access that keeps us from optimizing to the given phi.
-  ///
-  /// PausedSearches is an array of indices into the Paths array. Its incoming
-  /// value is the indices of searches that stopped at the last phi optimization
-  /// target. It's left in an unspecified state.
-  ///
-  /// If this returns None, NewPaused is a vector of searches that terminated
-  /// at StopWhere. Otherwise, NewPaused is left in an unspecified state.
-  Optional<TerminatedPath>
-  getBlockingAccess(const MemoryAccess *StopWhere,
-                    SmallVectorImpl<ListIndex> &PausedSearches,
-                    SmallVectorImpl<ListIndex> &NewPaused,
-                    SmallVectorImpl<TerminatedPath> &Terminated) {
-    assert(!PausedSearches.empty() && "No searches to continue?");
-
-    // BFS vs DFS really doesn't make a difference here, so just do a DFS with
-    // PausedSearches as our stack.
-    while (!PausedSearches.empty()) {
-      ListIndex PathIndex = PausedSearches.pop_back_val();
-      DefPath &Node = Paths[PathIndex];
-
-      // If we've already visited this path with this MemoryLocation, we don't
-      // need to do so again.
-      //
-      // NOTE: That we just drop these paths on the ground makes caching
-      // behavior sporadic. e.g. given a diamond:
-      //  A
-      // B C
-      //  D
-      //
-      // ...If we walk D, B, A, C, we'll only cache the result of phi
-      // optimization for A, B, and D; C will be skipped because it dies here.
-      // This arguably isn't the worst thing ever, since:
-      //   - We generally query things in a top-down order, so if we got below D
-      //     without needing cache entries for {C, MemLoc}, then chances are
-      //     that those cache entries would end up ultimately unused.
-      //   - We still cache things for A, so C only needs to walk up a bit.
-      // If this behavior becomes problematic, we can fix without a ton of extra
-      // work.
-      if (!VisitedPhis.insert({Node.Last, Node.Loc}).second)
-        continue;
-
-      const MemoryAccess *SkipStopWhere = nullptr;
-      if (Query->SkipSelfAccess && Node.Loc == Query->StartingLoc) {
-        assert(isa<MemoryDef>(Query->OriginalAccess));
-        SkipStopWhere = Query->OriginalAccess;
-      }
-
-      UpwardsWalkResult Res = walkToPhiOrClobber(Node, /*StopAt=*/StopWhere,
-                                                 /*SkipStopAt=*/SkipStopWhere);
-      if (Res.IsKnownClobber) {
-        assert(Res.Result != StopWhere && Res.Result != SkipStopWhere);
-        // If this wasn't a cache hit, we hit a clobber when walking. That's a
-        // failure.
-        TerminatedPath Term{Res.Result, PathIndex};
-        if (!MSSA.dominates(Res.Result, StopWhere))
-          return Term;
-
-        // Otherwise, it's a valid thing to potentially optimize to.
-        Terminated.push_back(Term);
-        continue;
-      }
-
-      if (Res.Result == StopWhere || Res.Result == SkipStopWhere) {
-        // We've hit our target. Save this path off for if we want to continue
-        // walking. If we are in the mode of skipping the OriginalAccess, and
-        // we've reached back to the OriginalAccess, do not save path, we've
-        // just looped back to self.
-        if (Res.Result != SkipStopWhere)
-          NewPaused.push_back(PathIndex);
-        continue;
-      }
-
-      assert(!MSSA.isLiveOnEntryDef(Res.Result) && "liveOnEntry is a clobber");
-      addSearches(cast<MemoryPhi>(Res.Result), PausedSearches, PathIndex);
-    }
-
-    return None;
-  }
-
-  template <typename T, typename Walker>
-  struct generic_def_path_iterator
-      : public iterator_facade_base<generic_def_path_iterator<T, Walker>,
-                                    std::forward_iterator_tag, T *> {
-    generic_def_path_iterator() = default;
-    generic_def_path_iterator(Walker *W, ListIndex N) : W(W), N(N) {}
-
-    T &operator*() const { return curNode(); }
-
-    generic_def_path_iterator &operator++() {
-      N = curNode().Previous;
-      return *this;
-    }
-
-    bool operator==(const generic_def_path_iterator &O) const {
-      if (N.hasValue() != O.N.hasValue())
-        return false;
-      return !N.hasValue() || *N == *O.N;
-    }
-
-  private:
-    T &curNode() const { return W->Paths[*N]; }
-
-    Walker *W = nullptr;
-    Optional<ListIndex> N = None;
-  };
-
-  using def_path_iterator = generic_def_path_iterator<DefPath, ClobberWalker>;
-  using const_def_path_iterator =
-      generic_def_path_iterator<const DefPath, const ClobberWalker>;
-
-  iterator_range<def_path_iterator> def_path(ListIndex From) {
-    return make_range(def_path_iterator(this, From), def_path_iterator());
-  }
-
-  iterator_range<const_def_path_iterator> const_def_path(ListIndex From) const {
-    return make_range(const_def_path_iterator(this, From),
-                      const_def_path_iterator());
-  }
-
-  struct OptznResult {
-    /// The path that contains our result.
-    TerminatedPath PrimaryClobber;
-    /// The paths that we can legally cache back from, but that aren't
-    /// necessarily the result of the Phi optimization.
-    SmallVector<TerminatedPath, 4> OtherClobbers;
-  };
-
-  ListIndex defPathIndex(const DefPath &N) const {
-    // The assert looks nicer if we don't need to do &N
-    const DefPath *NP = &N;
-    assert(!Paths.empty() && NP >= &Paths.front() && NP <= &Paths.back() &&
-           "Out of bounds DefPath!");
-    return NP - &Paths.front();
-  }
-
-  /// Try to optimize a phi as best as we can. Returns a SmallVector of Paths
-  /// that act as legal clobbers. Note that this won't return *all* clobbers.
-  ///
-  /// Phi optimization algorithm tl;dr:
-  ///   - Find the earliest def/phi, A, we can optimize to
-  ///   - Find if all paths from the starting memory access ultimately reach A
-  ///     - If not, optimization isn't possible.
-  ///     - Otherwise, walk from A to another clobber or phi, A'.
-  ///       - If A' is a def, we're done.
-  ///       - If A' is a phi, try to optimize it.
-  ///
-  /// A path is a series of {MemoryAccess, MemoryLocation} pairs. A path
-  /// terminates when a MemoryAccess that clobbers said MemoryLocation is found.
-  OptznResult tryOptimizePhi(MemoryPhi *Phi, MemoryAccess *Start,
-                             const MemoryLocation &Loc) {
-    assert(Paths.empty() && VisitedPhis.empty() &&
-           "Reset the optimization state.");
-
-    Paths.emplace_back(Loc, Start, Phi, None);
-    // Stores how many "valid" optimization nodes we had prior to calling
-    // addSearches/getBlockingAccess. Necessary for caching if we had a blocker.
-    auto PriorPathsSize = Paths.size();
-
-    SmallVector<ListIndex, 16> PausedSearches;
-    SmallVector<ListIndex, 8> NewPaused;
-    SmallVector<TerminatedPath, 4> TerminatedPaths;
-
-    addSearches(Phi, PausedSearches, 0);
-
-    // Moves the TerminatedPath with the "most dominated" Clobber to the end of
-    // Paths.
-    auto MoveDominatedPathToEnd = [&](SmallVectorImpl<TerminatedPath> &Paths) {
-      assert(!Paths.empty() && "Need a path to move");
-      auto Dom = Paths.begin();
-      for (auto I = std::next(Dom), E = Paths.end(); I != E; ++I)
-        if (!MSSA.dominates(I->Clobber, Dom->Clobber))
-          Dom = I;
-      auto Last = Paths.end() - 1;
-      if (Last != Dom)
-        std::iter_swap(Last, Dom);
-    };
-
-    MemoryPhi *Current = Phi;
-    while (true) {
-      assert(!MSSA.isLiveOnEntryDef(Current) &&
-             "liveOnEntry wasn't treated as a clobber?");
-
-      const auto *Target = getWalkTarget(Current);
-      // If a TerminatedPath doesn't dominate Target, then it wasn't a legal
-      // optimization for the prior phi.
-      assert(all_of(TerminatedPaths, [&](const TerminatedPath &P) {
-        return MSSA.dominates(P.Clobber, Target);
-      }));
-
-      // FIXME: This is broken, because the Blocker may be reported to be
-      // liveOnEntry, and we'll happily wait for that to disappear (read: never)
-      // For the moment, this is fine, since we do nothing with blocker info.
-      if (Optional<TerminatedPath> Blocker = getBlockingAccess(
-              Target, PausedSearches, NewPaused, TerminatedPaths)) {
-
-        // Find the node we started at. We can't search based on N->Last, since
-        // we may have gone around a loop with a different MemoryLocation.
-        auto Iter = find_if(def_path(Blocker->LastNode), [&](const DefPath &N) {
-          return defPathIndex(N) < PriorPathsSize;
-        });
-        assert(Iter != def_path_iterator());
-
-        DefPath &CurNode = *Iter;
-        assert(CurNode.Last == Current);
-
-        // Two things:
-        // A. We can't reliably cache all of NewPaused back. Consider a case
-        //    where we have two paths in NewPaused; one of which can't optimize
-        //    above this phi, whereas the other can. If we cache the second path
-        //    back, we'll end up with suboptimal cache entries. We can handle
-        //    cases like this a bit better when we either try to find all
-        //    clobbers that block phi optimization, or when our cache starts
-        //    supporting unfinished searches.
-        // B. We can't reliably cache TerminatedPaths back here without doing
-        //    extra checks; consider a case like:
-        //       T
-        //      / \
-        //     D   C
-        //      \ /
-        //       S
-        //    Where T is our target, C is a node with a clobber on it, D is a
-        //    diamond (with a clobber *only* on the left or right node, N), and
-        //    S is our start. Say we walk to D, through the node opposite N
-        //    (read: ignoring the clobber), and see a cache entry in the top
-        //    node of D. That cache entry gets put into TerminatedPaths. We then
-        //    walk up to C (N is later in our worklist), find the clobber, and
-        //    quit. If we append TerminatedPaths to OtherClobbers, we'll cache
-        //    the bottom part of D to the cached clobber, ignoring the clobber
-        //    in N. Again, this problem goes away if we start tracking all
-        //    blockers for a given phi optimization.
-        TerminatedPath Result{CurNode.Last, defPathIndex(CurNode)};
-        return {Result, {}};
-      }
-
-      // If there's nothing left to search, then all paths led to valid clobbers
-      // that we got from our cache; pick the nearest to the start, and allow
-      // the rest to be cached back.
-      if (NewPaused.empty()) {
-        MoveDominatedPathToEnd(TerminatedPaths);
-        TerminatedPath Result = TerminatedPaths.pop_back_val();
-        return {Result, std::move(TerminatedPaths)};
-      }
-
-      MemoryAccess *DefChainEnd = nullptr;
-      SmallVector<TerminatedPath, 4> Clobbers;
-      for (ListIndex Paused : NewPaused) {
-        UpwardsWalkResult WR = walkToPhiOrClobber(Paths[Paused]);
-        if (WR.IsKnownClobber)
-          Clobbers.push_back({WR.Result, Paused});
-        else
-          // Micro-opt: If we hit the end of the chain, save it.
-          DefChainEnd = WR.Result;
-      }
-
-      if (!TerminatedPaths.empty()) {
-        // If we couldn't find the dominating phi/liveOnEntry in the above loop,
-        // do it now.
-        if (!DefChainEnd)
-          for (auto *MA : def_chain(const_cast<MemoryAccess *>(Target)))
-            DefChainEnd = MA;
-
-        // If any of the terminated paths don't dominate the phi we'll try to
-        // optimize, we need to figure out what they are and quit.
-        const BasicBlock *ChainBB = DefChainEnd->getBlock();
-        for (const TerminatedPath &TP : TerminatedPaths) {
-          // Because we know that DefChainEnd is as "high" as we can go, we
-          // don't need local dominance checks; BB dominance is sufficient.
-          if (DT.dominates(ChainBB, TP.Clobber->getBlock()))
-            Clobbers.push_back(TP);
-        }
-      }
-
-      // If we have clobbers in the def chain, find the one closest to Current
-      // and quit.
-      if (!Clobbers.empty()) {
-        MoveDominatedPathToEnd(Clobbers);
-        TerminatedPath Result = Clobbers.pop_back_val();
-        return {Result, std::move(Clobbers)};
-      }
-
-      assert(all_of(NewPaused,
-                    [&](ListIndex I) { return Paths[I].Last == DefChainEnd; }));
-
-      // Because liveOnEntry is a clobber, this must be a phi.
-      auto *DefChainPhi = cast<MemoryPhi>(DefChainEnd);
-
-      PriorPathsSize = Paths.size();
-      PausedSearches.clear();
-      for (ListIndex I : NewPaused)
-        addSearches(DefChainPhi, PausedSearches, I);
-      NewPaused.clear();
-
-      Current = DefChainPhi;
-    }
-  }
-
-  void verifyOptResult(const OptznResult &R) const {
-    assert(all_of(R.OtherClobbers, [&](const TerminatedPath &P) {
-      return MSSA.dominates(P.Clobber, R.PrimaryClobber.Clobber);
-    }));
-  }
-
-  void resetPhiOptznState() {
-    Paths.clear();
-    VisitedPhis.clear();
-  }
-
-public:
-  ClobberWalker(const MemorySSA &MSSA, AliasAnalysis &AA, DominatorTree &DT)
-      : MSSA(MSSA), AA(AA), DT(DT) {}
-
-  /// Finds the nearest clobber for the given query, optimizing phis if
-  /// possible.
-  MemoryAccess *findClobber(MemoryAccess *Start, UpwardsMemoryQuery &Q) {
-    Query = &Q;
-
-    MemoryAccess *Current = Start;
-    // This walker pretends uses don't exist. If we're handed one, silently grab
-    // its def. (This has the nice side-effect of ensuring we never cache uses)
-    if (auto *MU = dyn_cast<MemoryUse>(Start))
-      Current = MU->getDefiningAccess();
-
-    DefPath FirstDesc(Q.StartingLoc, Current, Current, None);
-    // Fast path for the overly-common case (no crazy phi optimization
-    // necessary)
-    UpwardsWalkResult WalkResult = walkToPhiOrClobber(FirstDesc);
-    MemoryAccess *Result;
-    if (WalkResult.IsKnownClobber) {
-      Result = WalkResult.Result;
-      Q.AR = WalkResult.AR;
-    } else {
-      OptznResult OptRes = tryOptimizePhi(cast<MemoryPhi>(FirstDesc.Last),
-                                          Current, Q.StartingLoc);
-      verifyOptResult(OptRes);
-      resetPhiOptznState();
-      Result = OptRes.PrimaryClobber.Clobber;
-    }
-
-#ifdef EXPENSIVE_CHECKS
-    if (!Q.SkipSelfAccess)
-      checkClobberSanity(Current, Result, Q.StartingLoc, MSSA, Q, AA);
-#endif
-    return Result;
-  }
-
-  void verify(const MemorySSA *MSSA) { assert(MSSA == &this->MSSA); }
-};
-
-struct RenamePassData {
-  DomTreeNode *DTN;
-  DomTreeNode::const_iterator ChildIt;
-  MemoryAccess *IncomingVal;
-
-  RenamePassData(DomTreeNode *D, DomTreeNode::const_iterator It,
-                 MemoryAccess *M)
-      : DTN(D), ChildIt(It), IncomingVal(M) {}
-
-  void swap(RenamePassData &RHS) {
-    std::swap(DTN, RHS.DTN);
-    std::swap(ChildIt, RHS.ChildIt);
-    std::swap(IncomingVal, RHS.IncomingVal);
-  }
-};
-
-} // end anonymous namespace
-
-namespace llvm {
-
-class MemorySSA::ClobberWalkerBase {
-  ClobberWalker Walker;
-  MemorySSA *MSSA;
-
-public:
-  ClobberWalkerBase(MemorySSA *M, AliasAnalysis *A, DominatorTree *D)
-      : Walker(*M, *A, *D), MSSA(M) {}
-
-  MemoryAccess *getClobberingMemoryAccessBase(MemoryAccess *,
-                                              const MemoryLocation &);
-  // Second argument (bool), defines whether the clobber search should skip the
-  // original queried access. If true, there will be a follow-up query searching
-  // for a clobber access past "self". Note that the Optimized access is not
-  // updated if a new clobber is found by this SkipSelf search. If this
-  // additional query becomes heavily used we may decide to cache the result.
-  // Walker instantiations will decide how to set the SkipSelf bool.
-  MemoryAccess *getClobberingMemoryAccessBase(MemoryAccess *, bool);
-  void verify(const MemorySSA *MSSA) { Walker.verify(MSSA); }
-};
-
-/// A MemorySSAWalker that does AA walks to disambiguate accesses. It no
-/// longer does caching on its own, but the name has been retained for the
-/// moment.
-class MemorySSA::CachingWalker final : public MemorySSAWalker {
-  ClobberWalkerBase *Walker;
-
-public:
-  CachingWalker(MemorySSA *M, ClobberWalkerBase *W)
-      : MemorySSAWalker(M), Walker(W) {}
-  ~CachingWalker() override = default;
-
-  using MemorySSAWalker::getClobberingMemoryAccess;
-
-  MemoryAccess *getClobberingMemoryAccess(MemoryAccess *MA) override;
-  MemoryAccess *getClobberingMemoryAccess(MemoryAccess *MA,
-                                          const MemoryLocation &Loc) override;
-
-  void invalidateInfo(MemoryAccess *MA) override {
-    if (auto *MUD = dyn_cast<MemoryUseOrDef>(MA))
-      MUD->resetOptimized();
-  }
-
-  void verify(const MemorySSA *MSSA) override {
-    MemorySSAWalker::verify(MSSA);
-    Walker->verify(MSSA);
-  }
-};
-
-class MemorySSA::SkipSelfWalker final : public MemorySSAWalker {
-  ClobberWalkerBase *Walker;
-
-public:
-  SkipSelfWalker(MemorySSA *M, ClobberWalkerBase *W)
-      : MemorySSAWalker(M), Walker(W) {}
-  ~SkipSelfWalker() override = default;
-
-  using MemorySSAWalker::getClobberingMemoryAccess;
-
-  MemoryAccess *getClobberingMemoryAccess(MemoryAccess *MA) override;
-  MemoryAccess *getClobberingMemoryAccess(MemoryAccess *MA,
-                                          const MemoryLocation &Loc) override;
-
-  void invalidateInfo(MemoryAccess *MA) override {
-    if (auto *MUD = dyn_cast<MemoryUseOrDef>(MA))
-      MUD->resetOptimized();
-  }
-
-  void verify(const MemorySSA *MSSA) override {
-    MemorySSAWalker::verify(MSSA);
-    Walker->verify(MSSA);
-  }
-};
-
-} // end namespace llvm
-
-void MemorySSA::renameSuccessorPhis(BasicBlock *BB, MemoryAccess *IncomingVal,
-                                    bool RenameAllUses) {
-  // Pass through values to our successors
-  for (const BasicBlock *S : successors(BB)) {
-    auto It = PerBlockAccesses.find(S);
-    // Rename the phi nodes in our successor block
-    if (It == PerBlockAccesses.end() || !isa<MemoryPhi>(It->second->front()))
-      continue;
-    AccessList *Accesses = It->second.get();
-    auto *Phi = cast<MemoryPhi>(&Accesses->front());
-    if (RenameAllUses) {
-      int PhiIndex = Phi->getBasicBlockIndex(BB);
-      assert(PhiIndex != -1 && "Incomplete phi during partial rename");
-      Phi->setIncomingValue(PhiIndex, IncomingVal);
-    } else
-      Phi->addIncoming(IncomingVal, BB);
-  }
-}
-
-/// Rename a single basic block into MemorySSA form.
-/// Uses the standard SSA renaming algorithm.
-/// \returns The new incoming value.
-MemoryAccess *MemorySSA::renameBlock(BasicBlock *BB, MemoryAccess *IncomingVal,
-                                     bool RenameAllUses) {
-  auto It = PerBlockAccesses.find(BB);
-  // Skip most processing if the list is empty.
-  if (It != PerBlockAccesses.end()) {
-    AccessList *Accesses = It->second.get();
-    for (MemoryAccess &L : *Accesses) {
-      if (MemoryUseOrDef *MUD = dyn_cast<MemoryUseOrDef>(&L)) {
-        if (MUD->getDefiningAccess() == nullptr || RenameAllUses)
-          MUD->setDefiningAccess(IncomingVal);
-        if (isa<MemoryDef>(&L))
-          IncomingVal = &L;
-      } else {
-        IncomingVal = &L;
-      }
-    }
-  }
-  return IncomingVal;
-}
-
-/// This is the standard SSA renaming algorithm.
-///
-/// We walk the dominator tree in preorder, renaming accesses, and then filling
-/// in phi nodes in our successors.
-void MemorySSA::renamePass(DomTreeNode *Root, MemoryAccess *IncomingVal,
-                           SmallPtrSetImpl<BasicBlock *> &Visited,
-                           bool SkipVisited, bool RenameAllUses) {
-  SmallVector<RenamePassData, 32> WorkStack;
-  // Skip everything if we already renamed this block and we are skipping.
-  // Note: You can't sink this into the if, because we need it to occur
-  // regardless of whether we skip blocks or not.
-  bool AlreadyVisited = !Visited.insert(Root->getBlock()).second;
-  if (SkipVisited && AlreadyVisited)
-    return;
-
-  IncomingVal = renameBlock(Root->getBlock(), IncomingVal, RenameAllUses);
-  renameSuccessorPhis(Root->getBlock(), IncomingVal, RenameAllUses);
-  WorkStack.push_back({Root, Root->begin(), IncomingVal});
-
-  while (!WorkStack.empty()) {
-    DomTreeNode *Node = WorkStack.back().DTN;
-    DomTreeNode::const_iterator ChildIt = WorkStack.back().ChildIt;
-    IncomingVal = WorkStack.back().IncomingVal;
-
-    if (ChildIt == Node->end()) {
-      WorkStack.pop_back();
-    } else {
-      DomTreeNode *Child = *ChildIt;
-      ++WorkStack.back().ChildIt;
-      BasicBlock *BB = Child->getBlock();
-      // Note: You can't sink this into the if, because we need it to occur
-      // regardless of whether we skip blocks or not.
-      AlreadyVisited = !Visited.insert(BB).second;
-      if (SkipVisited && AlreadyVisited) {
-        // We already visited this during our renaming, which can happen when
-        // being asked to rename multiple blocks. Figure out the incoming val,
-        // which is the last def.
-        // Incoming value can only change if there is a block def, and in that
-        // case, it's the last block def in the list.
-        if (auto *BlockDefs = getWritableBlockDefs(BB))
-          IncomingVal = &*BlockDefs->rbegin();
-      } else
-        IncomingVal = renameBlock(BB, IncomingVal, RenameAllUses);
-      renameSuccessorPhis(BB, IncomingVal, RenameAllUses);
-      WorkStack.push_back({Child, Child->begin(), IncomingVal});
-    }
-  }
-}
-
-/// This handles unreachable block accesses by deleting phi nodes in
-/// unreachable blocks, and marking all other unreachable MemoryAccess's as
-/// being uses of the live on entry definition.
-void MemorySSA::markUnreachableAsLiveOnEntry(BasicBlock *BB) {
-  assert(!DT->isReachableFromEntry(BB) &&
-         "Reachable block found while handling unreachable blocks");
-
-  // Make sure phi nodes in our reachable successors end up with a
-  // LiveOnEntryDef for our incoming edge, even though our block is forward
-  // unreachable.  We could just disconnect these blocks from the CFG fully,
-  // but we do not right now.
-  for (const BasicBlock *S : successors(BB)) {
-    if (!DT->isReachableFromEntry(S))
-      continue;
-    auto It = PerBlockAccesses.find(S);
-    // Rename the phi nodes in our successor block
-    if (It == PerBlockAccesses.end() || !isa<MemoryPhi>(It->second->front()))
-      continue;
-    AccessList *Accesses = It->second.get();
-    auto *Phi = cast<MemoryPhi>(&Accesses->front());
-    Phi->addIncoming(LiveOnEntryDef.get(), BB);
-  }
-
-  auto It = PerBlockAccesses.find(BB);
-  if (It == PerBlockAccesses.end())
-    return;
-
-  auto &Accesses = It->second;
-  for (auto AI = Accesses->begin(), AE = Accesses->end(); AI != AE;) {
-    auto Next = std::next(AI);
-    // If we have a phi, just remove it. We are going to replace all
-    // users with live on entry.
-    if (auto *UseOrDef = dyn_cast<MemoryUseOrDef>(AI))
-      UseOrDef->setDefiningAccess(LiveOnEntryDef.get());
-    else
-      Accesses->erase(AI);
-    AI = Next;
-  }
-}
-
-MemorySSA::MemorySSA(Function &Func, AliasAnalysis *AA, DominatorTree *DT)
-    : AA(AA), DT(DT), F(Func), LiveOnEntryDef(nullptr), Walker(nullptr),
-      SkipWalker(nullptr), NextID(0) {
-  buildMemorySSA();
-}
-
-MemorySSA::~MemorySSA() {
-  // Drop all our references
-  for (const auto &Pair : PerBlockAccesses)
-    for (MemoryAccess &MA : *Pair.second)
-      MA.dropAllReferences();
-}
-
-MemorySSA::AccessList *MemorySSA::getOrCreateAccessList(const BasicBlock *BB) {
-  auto Res = PerBlockAccesses.insert(std::make_pair(BB, nullptr));
-
-  if (Res.second)
-    Res.first->second = llvm::make_unique<AccessList>();
-  return Res.first->second.get();
-}
-
-MemorySSA::DefsList *MemorySSA::getOrCreateDefsList(const BasicBlock *BB) {
-  auto Res = PerBlockDefs.insert(std::make_pair(BB, nullptr));
-
-  if (Res.second)
-    Res.first->second = llvm::make_unique<DefsList>();
-  return Res.first->second.get();
-}
-
-namespace llvm {
-
-/// This class is a batch walker of all MemoryUse's in the program, and points
-/// their defining access at the thing that actually clobbers them.  Because it
-/// is a batch walker that touches everything, it does not operate like the
-/// other walkers.  This walker is basically performing a top-down SSA renaming
-/// pass, where the version stack is used as the cache.  This enables it to be
-/// significantly more time and memory efficient than using the regular walker,
-/// which is walking bottom-up.
-class MemorySSA::OptimizeUses {
-public:
-  OptimizeUses(MemorySSA *MSSA, MemorySSAWalker *Walker, AliasAnalysis *AA,
-               DominatorTree *DT)
-      : MSSA(MSSA), Walker(Walker), AA(AA), DT(DT) {
-    Walker = MSSA->getWalker();
-  }
-
-  void optimizeUses();
-
-private:
-  /// This represents where a given memorylocation is in the stack.
-  struct MemlocStackInfo {
-    // This essentially is keeping track of versions of the stack. Whenever
-    // the stack changes due to pushes or pops, these versions increase.
-    unsigned long StackEpoch;
-    unsigned long PopEpoch;
-    // This is the lower bound of places on the stack to check. It is equal to
-    // the place the last stack walk ended.
-    // Note: Correctness depends on this being initialized to 0, which densemap
-    // does
-    unsigned long LowerBound;
-    const BasicBlock *LowerBoundBlock;
-    // This is where the last walk for this memory location ended.
-    unsigned long LastKill;
-    bool LastKillValid;
-    Optional<AliasResult> AR;
-  };
-
-  void optimizeUsesInBlock(const BasicBlock *, unsigned long &, unsigned long &,
-                           SmallVectorImpl<MemoryAccess *> &,
-                           DenseMap<MemoryLocOrCall, MemlocStackInfo> &);
-
-  MemorySSA *MSSA;
-  MemorySSAWalker *Walker;
-  AliasAnalysis *AA;
-  DominatorTree *DT;
-};
-
-} // end namespace llvm
-
-/// Optimize the uses in a given block This is basically the SSA renaming
-/// algorithm, with one caveat: We are able to use a single stack for all
-/// MemoryUses.  This is because the set of *possible* reaching MemoryDefs is
-/// the same for every MemoryUse.  The *actual* clobbering MemoryDef is just
-/// going to be some position in that stack of possible ones.
-///
-/// We track the stack positions that each MemoryLocation needs
-/// to check, and last ended at.  This is because we only want to check the
-/// things that changed since last time.  The same MemoryLocation should
-/// get clobbered by the same store (getModRefInfo does not use invariantness or
-/// things like this, and if they start, we can modify MemoryLocOrCall to
-/// include relevant data)
-void MemorySSA::OptimizeUses::optimizeUsesInBlock(
-    const BasicBlock *BB, unsigned long &StackEpoch, unsigned long &PopEpoch,
-    SmallVectorImpl<MemoryAccess *> &VersionStack,
-    DenseMap<MemoryLocOrCall, MemlocStackInfo> &LocStackInfo) {
-
-  /// If no accesses, nothing to do.
-  MemorySSA::AccessList *Accesses = MSSA->getWritableBlockAccesses(BB);
-  if (Accesses == nullptr)
-    return;
-
-  // Pop everything that doesn't dominate the current block off the stack,
-  // increment the PopEpoch to account for this.
-  while (true) {
-    assert(
-        !VersionStack.empty() &&
-        "Version stack should have liveOnEntry sentinel dominating everything");
-    BasicBlock *BackBlock = VersionStack.back()->getBlock();
-    if (DT->dominates(BackBlock, BB))
-      break;
-    while (VersionStack.back()->getBlock() == BackBlock)
-      VersionStack.pop_back();
-    ++PopEpoch;
-  }
-
-  for (MemoryAccess &MA : *Accesses) {
-    auto *MU = dyn_cast<MemoryUse>(&MA);
-    if (!MU) {
-      VersionStack.push_back(&MA);
-      ++StackEpoch;
-      continue;
-    }
-
-    if (isUseTriviallyOptimizableToLiveOnEntry(*AA, MU->getMemoryInst())) {
-      MU->setDefiningAccess(MSSA->getLiveOnEntryDef(), true, None);
-      continue;
-    }
-
-    MemoryLocOrCall UseMLOC(MU);
-    auto &LocInfo = LocStackInfo[UseMLOC];
-    // If the pop epoch changed, it means we've removed stuff from top of
-    // stack due to changing blocks. We may have to reset the lower bound or
-    // last kill info.
-    if (LocInfo.PopEpoch != PopEpoch) {
-      LocInfo.PopEpoch = PopEpoch;
-      LocInfo.StackEpoch = StackEpoch;
-      // If the lower bound was in something that no longer dominates us, we
-      // have to reset it.
-      // We can't simply track stack size, because the stack may have had
-      // pushes/pops in the meantime.
-      // XXX: This is non-optimal, but only is slower cases with heavily
-      // branching dominator trees.  To get the optimal number of queries would
-      // be to make lowerbound and lastkill a per-loc stack, and pop it until
-      // the top of that stack dominates us.  This does not seem worth it ATM.
-      // A much cheaper optimization would be to always explore the deepest
-      // branch of the dominator tree first. This will guarantee this resets on
-      // the smallest set of blocks.
-      if (LocInfo.LowerBoundBlock && LocInfo.LowerBoundBlock != BB &&
-          !DT->dominates(LocInfo.LowerBoundBlock, BB)) {
-        // Reset the lower bound of things to check.
-        // TODO: Some day we should be able to reset to last kill, rather than
-        // 0.
-        LocInfo.LowerBound = 0;
-        LocInfo.LowerBoundBlock = VersionStack[0]->getBlock();
-        LocInfo.LastKillValid = false;
-      }
-    } else if (LocInfo.StackEpoch != StackEpoch) {
-      // If all that has changed is the StackEpoch, we only have to check the
-      // new things on the stack, because we've checked everything before.  In
-      // this case, the lower bound of things to check remains the same.
-      LocInfo.PopEpoch = PopEpoch;
-      LocInfo.StackEpoch = StackEpoch;
-    }
-    if (!LocInfo.LastKillValid) {
-      LocInfo.LastKill = VersionStack.size() - 1;
-      LocInfo.LastKillValid = true;
-      LocInfo.AR = MayAlias;
-    }
-
-    // At this point, we should have corrected last kill and LowerBound to be
-    // in bounds.
-    assert(LocInfo.LowerBound < VersionStack.size() &&
-           "Lower bound out of range");
-    assert(LocInfo.LastKill < VersionStack.size() &&
-           "Last kill info out of range");
-    // In any case, the new upper bound is the top of the stack.
-    unsigned long UpperBound = VersionStack.size() - 1;
-
-    if (UpperBound - LocInfo.LowerBound > MaxCheckLimit) {
-      LLVM_DEBUG(dbgs() << "MemorySSA skipping optimization of " << *MU << " ("
-                        << *(MU->getMemoryInst()) << ")"
-                        << " because there are "
-                        << UpperBound - LocInfo.LowerBound
-                        << " stores to disambiguate\n");
-      // Because we did not walk, LastKill is no longer valid, as this may
-      // have been a kill.
-      LocInfo.LastKillValid = false;
-      continue;
-    }
-    bool FoundClobberResult = false;
-    while (UpperBound > LocInfo.LowerBound) {
-      if (isa<MemoryPhi>(VersionStack[UpperBound])) {
-        // For phis, use the walker, see where we ended up, go there
-        Instruction *UseInst = MU->getMemoryInst();
-        MemoryAccess *Result = Walker->getClobberingMemoryAccess(UseInst);
-        // We are guaranteed to find it or something is wrong
-        while (VersionStack[UpperBound] != Result) {
-          assert(UpperBound != 0);
-          --UpperBound;
-        }
-        FoundClobberResult = true;
-        break;
-      }
-
-      MemoryDef *MD = cast<MemoryDef>(VersionStack[UpperBound]);
-      // If the lifetime of the pointer ends at this instruction, it's live on
-      // entry.
-      if (!UseMLOC.IsCall && lifetimeEndsAt(MD, UseMLOC.getLoc(), *AA)) {
-        // Reset UpperBound to liveOnEntryDef's place in the stack
-        UpperBound = 0;
-        FoundClobberResult = true;
-        LocInfo.AR = MustAlias;
-        break;
-      }
-      ClobberAlias CA = instructionClobbersQuery(MD, MU, UseMLOC, *AA);
-      if (CA.IsClobber) {
-        FoundClobberResult = true;
-        LocInfo.AR = CA.AR;
-        break;
-      }
-      --UpperBound;
-    }
-
-    // Note: Phis always have AliasResult AR set to MayAlias ATM.
-
-    // At the end of this loop, UpperBound is either a clobber, or lower bound
-    // PHI walking may cause it to be < LowerBound, and in fact, < LastKill.
-    if (FoundClobberResult || UpperBound < LocInfo.LastKill) {
-      // We were last killed now by where we got to
-      if (MSSA->isLiveOnEntryDef(VersionStack[UpperBound]))
-        LocInfo.AR = None;
-      MU->setDefiningAccess(VersionStack[UpperBound], true, LocInfo.AR);
-      LocInfo.LastKill = UpperBound;
-    } else {
-      // Otherwise, we checked all the new ones, and now we know we can get to
-      // LastKill.
-      MU->setDefiningAccess(VersionStack[LocInfo.LastKill], true, LocInfo.AR);
-    }
-    LocInfo.LowerBound = VersionStack.size() - 1;
-    LocInfo.LowerBoundBlock = BB;
-  }
-}
-
-/// Optimize uses to point to their actual clobbering definitions.
-void MemorySSA::OptimizeUses::optimizeUses() {
-  SmallVector<MemoryAccess *, 16> VersionStack;
-  DenseMap<MemoryLocOrCall, MemlocStackInfo> LocStackInfo;
-  VersionStack.push_back(MSSA->getLiveOnEntryDef());
-
-  unsigned long StackEpoch = 1;
-  unsigned long PopEpoch = 1;
-  // We perform a non-recursive top-down dominator tree walk.
-  for (const auto *DomNode : depth_first(DT->getRootNode()))
-    optimizeUsesInBlock(DomNode->getBlock(), StackEpoch, PopEpoch, VersionStack,
-                        LocStackInfo);
-}
-
-void MemorySSA::placePHINodes(
-    const SmallPtrSetImpl<BasicBlock *> &DefiningBlocks) {
-  // Determine where our MemoryPhi's should go
-  ForwardIDFCalculator IDFs(*DT);
-  IDFs.setDefiningBlocks(DefiningBlocks);
-  SmallVector<BasicBlock *, 32> IDFBlocks;
-  IDFs.calculate(IDFBlocks);
-
-  // Now place MemoryPhi nodes.
-  for (auto &BB : IDFBlocks)
-    createMemoryPhi(BB);
-}
-
-void MemorySSA::buildMemorySSA() {
-  // We create an access to represent "live on entry", for things like
-  // arguments or users of globals, where the memory they use is defined before
-  // the beginning of the function. We do not actually insert it into the IR.
-  // We do not define a live on exit for the immediate uses, and thus our
-  // semantics do *not* imply that something with no immediate uses can simply
-  // be removed.
-  BasicBlock &StartingPoint = F.getEntryBlock();
-  LiveOnEntryDef.reset(new MemoryDef(F.getContext(), nullptr, nullptr,
-                                     &StartingPoint, NextID++));
-
-  // We maintain lists of memory accesses per-block, trading memory for time. We
-  // could just look up the memory access for every possible instruction in the
-  // stream.
-  SmallPtrSet<BasicBlock *, 32> DefiningBlocks;
-  // Go through each block, figure out where defs occur, and chain together all
-  // the accesses.
-  for (BasicBlock &B : F) {
-    bool InsertIntoDef = false;
-    AccessList *Accesses = nullptr;
-    DefsList *Defs = nullptr;
-    for (Instruction &I : B) {
-      MemoryUseOrDef *MUD = createNewAccess(&I);
-      if (!MUD)
-        continue;
-
-      if (!Accesses)
-        Accesses = getOrCreateAccessList(&B);
-      Accesses->push_back(MUD);
-      if (isa<MemoryDef>(MUD)) {
-        InsertIntoDef = true;
-        if (!Defs)
-          Defs = getOrCreateDefsList(&B);
-        Defs->push_back(*MUD);
-      }
-    }
-    if (InsertIntoDef)
-      DefiningBlocks.insert(&B);
-  }
-  placePHINodes(DefiningBlocks);
-
-  // Now do regular SSA renaming on the MemoryDef/MemoryUse. Visited will get
-  // filled in with all blocks.
-  SmallPtrSet<BasicBlock *, 16> Visited;
-  renamePass(DT->getRootNode(), LiveOnEntryDef.get(), Visited);
-
-  CachingWalker *Walker = getWalkerImpl();
-
-  OptimizeUses(this, Walker, AA, DT).optimizeUses();
-
-  // Mark the uses in unreachable blocks as live on entry, so that they go
-  // somewhere.
-  for (auto &BB : F)
-    if (!Visited.count(&BB))
-      markUnreachableAsLiveOnEntry(&BB);
-}
-
-MemorySSAWalker *MemorySSA::getWalker() { return getWalkerImpl(); }
-
-MemorySSA::CachingWalker *MemorySSA::getWalkerImpl() {
-  if (Walker)
-    return Walker.get();
-
-  if (!WalkerBase)
-    WalkerBase = llvm::make_unique<ClobberWalkerBase>(this, AA, DT);
-
-  Walker = llvm::make_unique<CachingWalker>(this, WalkerBase.get());
-  return Walker.get();
-}
-
-MemorySSAWalker *MemorySSA::getSkipSelfWalker() {
-  if (SkipWalker)
-    return SkipWalker.get();
-
-  if (!WalkerBase)
-    WalkerBase = llvm::make_unique<ClobberWalkerBase>(this, AA, DT);
-
-  SkipWalker = llvm::make_unique<SkipSelfWalker>(this, WalkerBase.get());
-  return SkipWalker.get();
- }
-
-
-// This is a helper function used by the creation routines. It places NewAccess
-// into the access and defs lists for a given basic block, at the given
-// insertion point.
-void MemorySSA::insertIntoListsForBlock(MemoryAccess *NewAccess,
-                                        const BasicBlock *BB,
-                                        InsertionPlace Point) {
-  auto *Accesses = getOrCreateAccessList(BB);
-  if (Point == Beginning) {
-    // If it's a phi node, it goes first, otherwise, it goes after any phi
-    // nodes.
-    if (isa<MemoryPhi>(NewAccess)) {
-      Accesses->push_front(NewAccess);
-      auto *Defs = getOrCreateDefsList(BB);
-      Defs->push_front(*NewAccess);
-    } else {
-      auto AI = find_if_not(
-          *Accesses, [](const MemoryAccess &MA) { return isa<MemoryPhi>(MA); });
-      Accesses->insert(AI, NewAccess);
-      if (!isa<MemoryUse>(NewAccess)) {
-        auto *Defs = getOrCreateDefsList(BB);
-        auto DI = find_if_not(
-            *Defs, [](const MemoryAccess &MA) { return isa<MemoryPhi>(MA); });
-        Defs->insert(DI, *NewAccess);
-      }
-    }
-  } else {
-    Accesses->push_back(NewAccess);
-    if (!isa<MemoryUse>(NewAccess)) {
-      auto *Defs = getOrCreateDefsList(BB);
-      Defs->push_back(*NewAccess);
-    }
-  }
-  BlockNumberingValid.erase(BB);
-}
-
-void MemorySSA::insertIntoListsBefore(MemoryAccess *What, const BasicBlock *BB,
-                                      AccessList::iterator InsertPt) {
-  auto *Accesses = getWritableBlockAccesses(BB);
-  bool WasEnd = InsertPt == Accesses->end();
-  Accesses->insert(AccessList::iterator(InsertPt), What);
-  if (!isa<MemoryUse>(What)) {
-    auto *Defs = getOrCreateDefsList(BB);
-    // If we got asked to insert at the end, we have an easy job, just shove it
-    // at the end. If we got asked to insert before an existing def, we also get
-    // an iterator. If we got asked to insert before a use, we have to hunt for
-    // the next def.
-    if (WasEnd) {
-      Defs->push_back(*What);
-    } else if (isa<MemoryDef>(InsertPt)) {
-      Defs->insert(InsertPt->getDefsIterator(), *What);
-    } else {
-      while (InsertPt != Accesses->end() && !isa<MemoryDef>(InsertPt))
-        ++InsertPt;
-      // Either we found a def, or we are inserting at the end
-      if (InsertPt == Accesses->end())
-        Defs->push_back(*What);
-      else
-        Defs->insert(InsertPt->getDefsIterator(), *What);
-    }
-  }
-  BlockNumberingValid.erase(BB);
-}
-
-void MemorySSA::prepareForMoveTo(MemoryAccess *What, BasicBlock *BB) {
-  // Keep it in the lookup tables, remove from the lists
-  removeFromLists(What, false);
-
-  // Note that moving should implicitly invalidate the optimized state of a
-  // MemoryUse (and Phis can't be optimized). However, it doesn't do so for a
-  // MemoryDef.
-  if (auto *MD = dyn_cast<MemoryDef>(What))
-    MD->resetOptimized();
-  What->setBlock(BB);
-}
-
-// Move What before Where in the IR.  The end result is that What will belong to
-// the right lists and have the right Block set, but will not otherwise be
-// correct. It will not have the right defining access, and if it is a def,
-// things below it will not properly be updated.
-void MemorySSA::moveTo(MemoryUseOrDef *What, BasicBlock *BB,
-                       AccessList::iterator Where) {
-  prepareForMoveTo(What, BB);
-  insertIntoListsBefore(What, BB, Where);
-}
-
-void MemorySSA::moveTo(MemoryAccess *What, BasicBlock *BB,
-                       InsertionPlace Point) {
-  if (isa<MemoryPhi>(What)) {
-    assert(Point == Beginning &&
-           "Can only move a Phi at the beginning of the block");
-    // Update lookup table entry
-    ValueToMemoryAccess.erase(What->getBlock());
-    bool Inserted = ValueToMemoryAccess.insert({BB, What}).second;
-    (void)Inserted;
-    assert(Inserted && "Cannot move a Phi to a block that already has one");
-  }
-
-  prepareForMoveTo(What, BB);
-  insertIntoListsForBlock(What, BB, Point);
-}
-
-MemoryPhi *MemorySSA::createMemoryPhi(BasicBlock *BB) {
-  assert(!getMemoryAccess(BB) && "MemoryPhi already exists for this BB");
-  MemoryPhi *Phi = new MemoryPhi(BB->getContext(), BB, NextID++);
-  // Phi's always are placed at the front of the block.
-  insertIntoListsForBlock(Phi, BB, Beginning);
-  ValueToMemoryAccess[BB] = Phi;
-  return Phi;
-}
-
-MemoryUseOrDef *MemorySSA::createDefinedAccess(Instruction *I,
-                                               MemoryAccess *Definition,
-                                               const MemoryUseOrDef *Template) {
-  assert(!isa<PHINode>(I) && "Cannot create a defined access for a PHI");
-  MemoryUseOrDef *NewAccess = createNewAccess(I, Template);
-  assert(
-      NewAccess != nullptr &&
-      "Tried to create a memory access for a non-memory touching instruction");
-  NewAccess->setDefiningAccess(Definition);
-  return NewAccess;
-}
-
-// Return true if the instruction has ordering constraints.
-// Note specifically that this only considers stores and loads
-// because others are still considered ModRef by getModRefInfo.
-static inline bool isOrdered(const Instruction *I) {
-  if (auto *SI = dyn_cast<StoreInst>(I)) {
-    if (!SI->isUnordered())
-      return true;
-  } else if (auto *LI = dyn_cast<LoadInst>(I)) {
-    if (!LI->isUnordered())
-      return true;
-  }
-  return false;
-}
-
-/// Helper function to create new memory accesses
-MemoryUseOrDef *MemorySSA::createNewAccess(Instruction *I,
-                                           const MemoryUseOrDef *Template) {
-  // The assume intrinsic has a control dependency which we model by claiming
-  // that it writes arbitrarily. Ignore that fake memory dependency here.
-  // FIXME: Replace this special casing with a more accurate modelling of
-  // assume's control dependency.
-  if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I))
-    if (II->getIntrinsicID() == Intrinsic::assume)
-      return nullptr;
-
-  bool Def, Use;
-  if (Template) {
-    Def = dyn_cast_or_null<MemoryDef>(Template) != nullptr;
-    Use = dyn_cast_or_null<MemoryUse>(Template) != nullptr;
-#if !defined(NDEBUG)
-    ModRefInfo ModRef = AA->getModRefInfo(I, None);
-    bool DefCheck, UseCheck;
-    DefCheck = isModSet(ModRef) || isOrdered(I);
-    UseCheck = isRefSet(ModRef);
-    assert(Def == DefCheck && (Def || Use == UseCheck) && "Invalid template");
-#endif
-  } else {
-    // Find out what affect this instruction has on memory.
-    ModRefInfo ModRef = AA->getModRefInfo(I, None);
-    // The isOrdered check is used to ensure that volatiles end up as defs
-    // (atomics end up as ModRef right now anyway).  Until we separate the
-    // ordering chain from the memory chain, this enables people to see at least
-    // some relative ordering to volatiles.  Note that getClobberingMemoryAccess
-    // will still give an answer that bypasses other volatile loads.  TODO:
-    // Separate memory aliasing and ordering into two different chains so that
-    // we can precisely represent both "what memory will this read/write/is
-    // clobbered by" and "what instructions can I move this past".
-    Def = isModSet(ModRef) || isOrdered(I);
-    Use = isRefSet(ModRef);
-  }
-
-  // It's possible for an instruction to not modify memory at all. During
-  // construction, we ignore them.
-  if (!Def && !Use)
-    return nullptr;
-
-  MemoryUseOrDef *MUD;
-  if (Def)
-    MUD = new MemoryDef(I->getContext(), nullptr, I, I->getParent(), NextID++);
-  else
-    MUD = new MemoryUse(I->getContext(), nullptr, I, I->getParent());
-  ValueToMemoryAccess[I] = MUD;
-  return MUD;
-}
-
-/// Returns true if \p Replacer dominates \p Replacee .
-bool MemorySSA::dominatesUse(const MemoryAccess *Replacer,
-                             const MemoryAccess *Replacee) const {
-  if (isa<MemoryUseOrDef>(Replacee))
-    return DT->dominates(Replacer->getBlock(), Replacee->getBlock());
-  const auto *MP = cast<MemoryPhi>(Replacee);
-  // For a phi node, the use occurs in the predecessor block of the phi node.
-  // Since we may occur multiple times in the phi node, we have to check each
-  // operand to ensure Replacer dominates each operand where Replacee occurs.
-  for (const Use &Arg : MP->operands()) {
-    if (Arg.get() != Replacee &&
-        !DT->dominates(Replacer->getBlock(), MP->getIncomingBlock(Arg)))
-      return false;
-  }
-  return true;
-}
-
-/// Properly remove \p MA from all of MemorySSA's lookup tables.
-void MemorySSA::removeFromLookups(MemoryAccess *MA) {
-  assert(MA->use_empty() &&
-         "Trying to remove memory access that still has uses");
-  BlockNumbering.erase(MA);
-  if (auto *MUD = dyn_cast<MemoryUseOrDef>(MA))
-    MUD->setDefiningAccess(nullptr);
-  // Invalidate our walker's cache if necessary
-  if (!isa<MemoryUse>(MA))
-    Walker->invalidateInfo(MA);
-
-  Value *MemoryInst;
-  if (const auto *MUD = dyn_cast<MemoryUseOrDef>(MA))
-    MemoryInst = MUD->getMemoryInst();
-  else
-    MemoryInst = MA->getBlock();
-
-  auto VMA = ValueToMemoryAccess.find(MemoryInst);
-  if (VMA->second == MA)
-    ValueToMemoryAccess.erase(VMA);
-}
-
-/// Properly remove \p MA from all of MemorySSA's lists.
-///
-/// Because of the way the intrusive list and use lists work, it is important to
-/// do removal in the right order.
-/// ShouldDelete defaults to true, and will cause the memory access to also be
-/// deleted, not just removed.
-void MemorySSA::removeFromLists(MemoryAccess *MA, bool ShouldDelete) {
-  BasicBlock *BB = MA->getBlock();
-  // The access list owns the reference, so we erase it from the non-owning list
-  // first.
-  if (!isa<MemoryUse>(MA)) {
-    auto DefsIt = PerBlockDefs.find(BB);
-    std::unique_ptr<DefsList> &Defs = DefsIt->second;
-    Defs->remove(*MA);
-    if (Defs->empty())
-      PerBlockDefs.erase(DefsIt);
-  }
-
-  // The erase call here will delete it. If we don't want it deleted, we call
-  // remove instead.
-  auto AccessIt = PerBlockAccesses.find(BB);
-  std::unique_ptr<AccessList> &Accesses = AccessIt->second;
-  if (ShouldDelete)
-    Accesses->erase(MA);
-  else
-    Accesses->remove(MA);
-
-  if (Accesses->empty()) {
-    PerBlockAccesses.erase(AccessIt);
-    BlockNumberingValid.erase(BB);
-  }
-}
-
-void MemorySSA::print(raw_ostream &OS) const {
-  MemorySSAAnnotatedWriter Writer(this);
-  F.print(OS, &Writer);
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-LLVM_DUMP_METHOD void MemorySSA::dump() const { print(dbgs()); }
-#endif
-
-void MemorySSA::verifyMemorySSA() const {
-  verifyDefUses(F);
-  verifyDomination(F);
-  verifyOrdering(F);
-  verifyDominationNumbers(F);
-  Walker->verify(this);
-  verifyClobberSanity(F);
-}
-
-/// Check sanity of the clobbering instruction for access MA.
-void MemorySSA::checkClobberSanityAccess(const MemoryAccess *MA) const {
-  if (const auto *MUD = dyn_cast<MemoryUseOrDef>(MA)) {
-    if (!MUD->isOptimized())
-      return;
-    auto *I = MUD->getMemoryInst();
-    auto Loc = MemoryLocation::getOrNone(I);
-    if (Loc == None)
-      return;
-    auto *Clobber = MUD->getOptimized();
-    UpwardsMemoryQuery Q(I, MUD);
-    checkClobberSanity(MUD, Clobber, *Loc, *this, Q, *AA, true);
-  }
-}
-
-void MemorySSA::verifyClobberSanity(const Function &F) const {
-#if !defined(NDEBUG) && defined(EXPENSIVE_CHECKS)
-  for (const BasicBlock &BB : F) {
-    const AccessList *Accesses = getBlockAccesses(&BB);
-    if (!Accesses)
-      continue;
-    for (const MemoryAccess &MA : *Accesses)
-      checkClobberSanityAccess(&MA);
-  }
-#endif
-}
-
-/// Verify that all of the blocks we believe to have valid domination numbers
-/// actually have valid domination numbers.
-void MemorySSA::verifyDominationNumbers(const Function &F) const {
-#ifndef NDEBUG
-  if (BlockNumberingValid.empty())
-    return;
-
-  SmallPtrSet<const BasicBlock *, 16> ValidBlocks = BlockNumberingValid;
-  for (const BasicBlock &BB : F) {
-    if (!ValidBlocks.count(&BB))
-      continue;
-
-    ValidBlocks.erase(&BB);
-
-    const AccessList *Accesses = getBlockAccesses(&BB);
-    // It's correct to say an empty block has valid numbering.
-    if (!Accesses)
-      continue;
-
-    // Block numbering starts at 1.
-    unsigned long LastNumber = 0;
-    for (const MemoryAccess &MA : *Accesses) {
-      auto ThisNumberIter = BlockNumbering.find(&MA);
-      assert(ThisNumberIter != BlockNumbering.end() &&
-             "MemoryAccess has no domination number in a valid block!");
-
-      unsigned long ThisNumber = ThisNumberIter->second;
-      assert(ThisNumber > LastNumber &&
-             "Domination numbers should be strictly increasing!");
-      LastNumber = ThisNumber;
-    }
-  }
-
-  assert(ValidBlocks.empty() &&
-         "All valid BasicBlocks should exist in F -- dangling pointers?");
-#endif
-}
-
-/// Verify that the order and existence of MemoryAccesses matches the
-/// order and existence of memory affecting instructions.
-void MemorySSA::verifyOrdering(Function &F) const {
-#ifndef NDEBUG
-  // Walk all the blocks, comparing what the lookups think and what the access
-  // lists think, as well as the order in the blocks vs the order in the access
-  // lists.
-  SmallVector<MemoryAccess *, 32> ActualAccesses;
-  SmallVector<MemoryAccess *, 32> ActualDefs;
-  for (BasicBlock &B : F) {
-    const AccessList *AL = getBlockAccesses(&B);
-    const auto *DL = getBlockDefs(&B);
-    MemoryAccess *Phi = getMemoryAccess(&B);
-    if (Phi) {
-      ActualAccesses.push_back(Phi);
-      ActualDefs.push_back(Phi);
-    }
-
-    for (Instruction &I : B) {
-      MemoryAccess *MA = getMemoryAccess(&I);
-      assert((!MA || (AL && (isa<MemoryUse>(MA) || DL))) &&
-             "We have memory affecting instructions "
-             "in this block but they are not in the "
-             "access list or defs list");
-      if (MA) {
-        ActualAccesses.push_back(MA);
-        if (isa<MemoryDef>(MA))
-          ActualDefs.push_back(MA);
-      }
-    }
-    // Either we hit the assert, really have no accesses, or we have both
-    // accesses and an access list.
-    // Same with defs.
-    if (!AL && !DL)
-      continue;
-    assert(AL->size() == ActualAccesses.size() &&
-           "We don't have the same number of accesses in the block as on the "
-           "access list");
-    assert((DL || ActualDefs.size() == 0) &&
-           "Either we should have a defs list, or we should have no defs");
-    assert((!DL || DL->size() == ActualDefs.size()) &&
-           "We don't have the same number of defs in the block as on the "
-           "def list");
-    auto ALI = AL->begin();
-    auto AAI = ActualAccesses.begin();
-    while (ALI != AL->end() && AAI != ActualAccesses.end()) {
-      assert(&*ALI == *AAI && "Not the same accesses in the same order");
-      ++ALI;
-      ++AAI;
-    }
-    ActualAccesses.clear();
-    if (DL) {
-      auto DLI = DL->begin();
-      auto ADI = ActualDefs.begin();
-      while (DLI != DL->end() && ADI != ActualDefs.end()) {
-        assert(&*DLI == *ADI && "Not the same defs in the same order");
-        ++DLI;
-        ++ADI;
-      }
-    }
-    ActualDefs.clear();
-  }
-#endif
-}
-
-/// Verify the domination properties of MemorySSA by checking that each
-/// definition dominates all of its uses.
-void MemorySSA::verifyDomination(Function &F) const {
-#ifndef NDEBUG
-  for (BasicBlock &B : F) {
-    // Phi nodes are attached to basic blocks
-    if (MemoryPhi *MP = getMemoryAccess(&B))
-      for (const Use &U : MP->uses())
-        assert(dominates(MP, U) && "Memory PHI does not dominate it's uses");
-
-    for (Instruction &I : B) {
-      MemoryAccess *MD = dyn_cast_or_null<MemoryDef>(getMemoryAccess(&I));
-      if (!MD)
-        continue;
-
-      for (const Use &U : MD->uses())
-        assert(dominates(MD, U) && "Memory Def does not dominate it's uses");
-    }
-  }
-#endif
-}
-
-/// Verify the def-use lists in MemorySSA, by verifying that \p Use
-/// appears in the use list of \p Def.
-void MemorySSA::verifyUseInDefs(MemoryAccess *Def, MemoryAccess *Use) const {
-#ifndef NDEBUG
-  // The live on entry use may cause us to get a NULL def here
-  if (!Def)
-    assert(isLiveOnEntryDef(Use) &&
-           "Null def but use not point to live on entry def");
-  else
-    assert(is_contained(Def->users(), Use) &&
-           "Did not find use in def's use list");
-#endif
-}
-
-/// Verify the immediate use information, by walking all the memory
-/// accesses and verifying that, for each use, it appears in the
-/// appropriate def's use list
-void MemorySSA::verifyDefUses(Function &F) const {
-#ifndef NDEBUG
-  for (BasicBlock &B : F) {
-    // Phi nodes are attached to basic blocks
-    if (MemoryPhi *Phi = getMemoryAccess(&B)) {
-      assert(Phi->getNumOperands() == static_cast<unsigned>(std::distance(
-                                          pred_begin(&B), pred_end(&B))) &&
-             "Incomplete MemoryPhi Node");
-      for (unsigned I = 0, E = Phi->getNumIncomingValues(); I != E; ++I) {
-        verifyUseInDefs(Phi->getIncomingValue(I), Phi);
-        assert(find(predecessors(&B), Phi->getIncomingBlock(I)) !=
-                   pred_end(&B) &&
-               "Incoming phi block not a block predecessor");
-      }
-    }
-
-    for (Instruction &I : B) {
-      if (MemoryUseOrDef *MA = getMemoryAccess(&I)) {
-        verifyUseInDefs(MA->getDefiningAccess(), MA);
-      }
-    }
-  }
-#endif
-}
-
-/// Perform a local numbering on blocks so that instruction ordering can be
-/// determined in constant time.
-/// TODO: We currently just number in order.  If we numbered by N, we could
-/// allow at least N-1 sequences of insertBefore or insertAfter (and at least
-/// log2(N) sequences of mixed before and after) without needing to invalidate
-/// the numbering.
-void MemorySSA::renumberBlock(const BasicBlock *B) const {
-  // The pre-increment ensures the numbers really start at 1.
-  unsigned long CurrentNumber = 0;
-  const AccessList *AL = getBlockAccesses(B);
-  assert(AL != nullptr && "Asking to renumber an empty block");
-  for (const auto &I : *AL)
-    BlockNumbering[&I] = ++CurrentNumber;
-  BlockNumberingValid.insert(B);
-}
-
-/// Determine, for two memory accesses in the same block,
-/// whether \p Dominator dominates \p Dominatee.
-/// \returns True if \p Dominator dominates \p Dominatee.
-bool MemorySSA::locallyDominates(const MemoryAccess *Dominator,
-                                 const MemoryAccess *Dominatee) const {
-  const BasicBlock *DominatorBlock = Dominator->getBlock();
-
-  assert((DominatorBlock == Dominatee->getBlock()) &&
-         "Asking for local domination when accesses are in different blocks!");
-  // A node dominates itself.
-  if (Dominatee == Dominator)
-    return true;
-
-  // When Dominatee is defined on function entry, it is not dominated by another
-  // memory access.
-  if (isLiveOnEntryDef(Dominatee))
-    return false;
-
-  // When Dominator is defined on function entry, it dominates the other memory
-  // access.
-  if (isLiveOnEntryDef(Dominator))
-    return true;
-
-  if (!BlockNumberingValid.count(DominatorBlock))
-    renumberBlock(DominatorBlock);
-
-  unsigned long DominatorNum = BlockNumbering.lookup(Dominator);
-  // All numbers start with 1
-  assert(DominatorNum != 0 && "Block was not numbered properly");
-  unsigned long DominateeNum = BlockNumbering.lookup(Dominatee);
-  assert(DominateeNum != 0 && "Block was not numbered properly");
-  return DominatorNum < DominateeNum;
-}
-
-bool MemorySSA::dominates(const MemoryAccess *Dominator,
-                          const MemoryAccess *Dominatee) const {
-  if (Dominator == Dominatee)
-    return true;
-
-  if (isLiveOnEntryDef(Dominatee))
-    return false;
-
-  if (Dominator->getBlock() != Dominatee->getBlock())
-    return DT->dominates(Dominator->getBlock(), Dominatee->getBlock());
-  return locallyDominates(Dominator, Dominatee);
-}
-
-bool MemorySSA::dominates(const MemoryAccess *Dominator,
-                          const Use &Dominatee) const {
-  if (MemoryPhi *MP = dyn_cast<MemoryPhi>(Dominatee.getUser())) {
-    BasicBlock *UseBB = MP->getIncomingBlock(Dominatee);
-    // The def must dominate the incoming block of the phi.
-    if (UseBB != Dominator->getBlock())
-      return DT->dominates(Dominator->getBlock(), UseBB);
-    // If the UseBB and the DefBB are the same, compare locally.
-    return locallyDominates(Dominator, cast<MemoryAccess>(Dominatee));
-  }
-  // If it's not a PHI node use, the normal dominates can already handle it.
-  return dominates(Dominator, cast<MemoryAccess>(Dominatee.getUser()));
-}
-
-const static char LiveOnEntryStr[] = "liveOnEntry";
-
-void MemoryAccess::print(raw_ostream &OS) const {
-  switch (getValueID()) {
-  case MemoryPhiVal: return static_cast<const MemoryPhi *>(this)->print(OS);
-  case MemoryDefVal: return static_cast<const MemoryDef *>(this)->print(OS);
-  case MemoryUseVal: return static_cast<const MemoryUse *>(this)->print(OS);
-  }
-  llvm_unreachable("invalid value id");
-}
-
-void MemoryDef::print(raw_ostream &OS) const {
-  MemoryAccess *UO = getDefiningAccess();
-
-  auto printID = [&OS](MemoryAccess *A) {
-    if (A && A->getID())
-      OS << A->getID();
-    else
-      OS << LiveOnEntryStr;
-  };
-
-  OS << getID() << " = MemoryDef(";
-  printID(UO);
-  OS << ")";
-
-  if (isOptimized()) {
-    OS << "->";
-    printID(getOptimized());
-
-    if (Optional<AliasResult> AR = getOptimizedAccessType())
-      OS << " " << *AR;
-  }
-}
-
-void MemoryPhi::print(raw_ostream &OS) const {
-  bool First = true;
-  OS << getID() << " = MemoryPhi(";
-  for (const auto &Op : operands()) {
-    BasicBlock *BB = getIncomingBlock(Op);
-    MemoryAccess *MA = cast<MemoryAccess>(Op);
-    if (!First)
-      OS << ',';
-    else
-      First = false;
-
-    OS << '{';
-    if (BB->hasName())
-      OS << BB->getName();
-    else
-      BB->printAsOperand(OS, false);
-    OS << ',';
-    if (unsigned ID = MA->getID())
-      OS << ID;
-    else
-      OS << LiveOnEntryStr;
-    OS << '}';
-  }
-  OS << ')';
-}
-
-void MemoryUse::print(raw_ostream &OS) const {
-  MemoryAccess *UO = getDefiningAccess();
-  OS << "MemoryUse(";
-  if (UO && UO->getID())
-    OS << UO->getID();
-  else
-    OS << LiveOnEntryStr;
-  OS << ')';
-
-  if (Optional<AliasResult> AR = getOptimizedAccessType())
-    OS << " " << *AR;
-}
-
-void MemoryAccess::dump() const {
-// Cannot completely remove virtual function even in release mode.
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-  print(dbgs());
-  dbgs() << "\n";
-#endif
-}
-
-char MemorySSAPrinterLegacyPass::ID = 0;
-
-MemorySSAPrinterLegacyPass::MemorySSAPrinterLegacyPass() : FunctionPass(ID) {
-  initializeMemorySSAPrinterLegacyPassPass(*PassRegistry::getPassRegistry());
-}
-
-void MemorySSAPrinterLegacyPass::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.setPreservesAll();
-  AU.addRequired<MemorySSAWrapperPass>();
-}
-
-bool MemorySSAPrinterLegacyPass::runOnFunction(Function &F) {
-  auto &MSSA = getAnalysis<MemorySSAWrapperPass>().getMSSA();
-  MSSA.print(dbgs());
-  if (VerifyMemorySSA)
-    MSSA.verifyMemorySSA();
-  return false;
-}
-
-AnalysisKey MemorySSAAnalysis::Key;
-
-MemorySSAAnalysis::Result MemorySSAAnalysis::run(Function &F,
-                                                 FunctionAnalysisManager &AM) {
-  auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
-  auto &AA = AM.getResult<AAManager>(F);
-  return MemorySSAAnalysis::Result(llvm::make_unique<MemorySSA>(F, &AA, &DT));
-}
-
-PreservedAnalyses MemorySSAPrinterPass::run(Function &F,
-                                            FunctionAnalysisManager &AM) {
-  OS << "MemorySSA for function: " << F.getName() << "\n";
-  AM.getResult<MemorySSAAnalysis>(F).getMSSA().print(OS);
-
-  return PreservedAnalyses::all();
-}
-
-PreservedAnalyses MemorySSAVerifierPass::run(Function &F,
-                                             FunctionAnalysisManager &AM) {
-  AM.getResult<MemorySSAAnalysis>(F).getMSSA().verifyMemorySSA();
-
-  return PreservedAnalyses::all();
-}
-
-char MemorySSAWrapperPass::ID = 0;
-
-MemorySSAWrapperPass::MemorySSAWrapperPass() : FunctionPass(ID) {
-  initializeMemorySSAWrapperPassPass(*PassRegistry::getPassRegistry());
-}
-
-void MemorySSAWrapperPass::releaseMemory() { MSSA.reset(); }
-
-void MemorySSAWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.setPreservesAll();
-  AU.addRequiredTransitive<DominatorTreeWrapperPass>();
-  AU.addRequiredTransitive<AAResultsWrapperPass>();
-}
-
-bool MemorySSAWrapperPass::runOnFunction(Function &F) {
-  auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
-  auto &AA = getAnalysis<AAResultsWrapperPass>().getAAResults();
-  MSSA.reset(new MemorySSA(F, &AA, &DT));
-  return false;
-}
-
-void MemorySSAWrapperPass::verifyAnalysis() const { MSSA->verifyMemorySSA(); }
-
-void MemorySSAWrapperPass::print(raw_ostream &OS, const Module *M) const {
-  MSSA->print(OS);
-}
-
-MemorySSAWalker::MemorySSAWalker(MemorySSA *M) : MSSA(M) {}
-
-/// Walk the use-def chains starting at \p StartingAccess and find
-/// the MemoryAccess that actually clobbers Loc.
-///
-/// \returns our clobbering memory access
-MemoryAccess *MemorySSA::ClobberWalkerBase::getClobberingMemoryAccessBase(
-    MemoryAccess *StartingAccess, const MemoryLocation &Loc) {
-  if (isa<MemoryPhi>(StartingAccess))
-    return StartingAccess;
-
-  auto *StartingUseOrDef = cast<MemoryUseOrDef>(StartingAccess);
-  if (MSSA->isLiveOnEntryDef(StartingUseOrDef))
-    return StartingUseOrDef;
-
-  Instruction *I = StartingUseOrDef->getMemoryInst();
-
-  // Conservatively, fences are always clobbers, so don't perform the walk if we
-  // hit a fence.
-  if (!isa<CallBase>(I) && I->isFenceLike())
-    return StartingUseOrDef;
-
-  UpwardsMemoryQuery Q;
-  Q.OriginalAccess = StartingUseOrDef;
-  Q.StartingLoc = Loc;
-  Q.Inst = I;
-  Q.IsCall = false;
-
-  // Unlike the other function, do not walk to the def of a def, because we are
-  // handed something we already believe is the clobbering access.
-  // We never set SkipSelf to true in Q in this method.
-  MemoryAccess *DefiningAccess = isa<MemoryUse>(StartingUseOrDef)
-                                     ? StartingUseOrDef->getDefiningAccess()
-                                     : StartingUseOrDef;
-
-  MemoryAccess *Clobber = Walker.findClobber(DefiningAccess, Q);
-  LLVM_DEBUG(dbgs() << "Starting Memory SSA clobber for " << *I << " is ");
-  LLVM_DEBUG(dbgs() << *StartingUseOrDef << "\n");
-  LLVM_DEBUG(dbgs() << "Final Memory SSA clobber for " << *I << " is ");
-  LLVM_DEBUG(dbgs() << *Clobber << "\n");
-  return Clobber;
-}
-
-MemoryAccess *
-MemorySSA::ClobberWalkerBase::getClobberingMemoryAccessBase(MemoryAccess *MA,
-                                                            bool SkipSelf) {
-  auto *StartingAccess = dyn_cast<MemoryUseOrDef>(MA);
-  // If this is a MemoryPhi, we can't do anything.
-  if (!StartingAccess)
-    return MA;
-
-  bool IsOptimized = false;
-
-  // If this is an already optimized use or def, return the optimized result.
-  // Note: Currently, we store the optimized def result in a separate field,
-  // since we can't use the defining access.
-  if (StartingAccess->isOptimized()) {
-    if (!SkipSelf || !isa<MemoryDef>(StartingAccess))
-      return StartingAccess->getOptimized();
-    IsOptimized = true;
-  }
-
-  const Instruction *I = StartingAccess->getMemoryInst();
-  // We can't sanely do anything with a fence, since they conservatively clobber
-  // all memory, and have no locations to get pointers from to try to
-  // disambiguate.
-  if (!isa<CallBase>(I) && I->isFenceLike())
-    return StartingAccess;
-
-  UpwardsMemoryQuery Q(I, StartingAccess);
-
-  if (isUseTriviallyOptimizableToLiveOnEntry(*MSSA->AA, I)) {
-    MemoryAccess *LiveOnEntry = MSSA->getLiveOnEntryDef();
-    StartingAccess->setOptimized(LiveOnEntry);
-    StartingAccess->setOptimizedAccessType(None);
-    return LiveOnEntry;
-  }
-
-  MemoryAccess *OptimizedAccess;
-  if (!IsOptimized) {
-    // Start with the thing we already think clobbers this location
-    MemoryAccess *DefiningAccess = StartingAccess->getDefiningAccess();
-
-    // At this point, DefiningAccess may be the live on entry def.
-    // If it is, we will not get a better result.
-    if (MSSA->isLiveOnEntryDef(DefiningAccess)) {
-      StartingAccess->setOptimized(DefiningAccess);
-      StartingAccess->setOptimizedAccessType(None);
-      return DefiningAccess;
-    }
-
-    OptimizedAccess = Walker.findClobber(DefiningAccess, Q);
-    StartingAccess->setOptimized(OptimizedAccess);
-    if (MSSA->isLiveOnEntryDef(OptimizedAccess))
-      StartingAccess->setOptimizedAccessType(None);
-    else if (Q.AR == MustAlias)
-      StartingAccess->setOptimizedAccessType(MustAlias);
-  } else
-    OptimizedAccess = StartingAccess->getOptimized();
-
-  LLVM_DEBUG(dbgs() << "Starting Memory SSA clobber for " << *I << " is ");
-  LLVM_DEBUG(dbgs() << *StartingAccess << "\n");
-  LLVM_DEBUG(dbgs() << "Optimized Memory SSA clobber for " << *I << " is ");
-  LLVM_DEBUG(dbgs() << *OptimizedAccess << "\n");
-
-  MemoryAccess *Result;
-  if (SkipSelf && isa<MemoryPhi>(OptimizedAccess) &&
-      isa<MemoryDef>(StartingAccess)) {
-    assert(isa<MemoryDef>(Q.OriginalAccess));
-    Q.SkipSelfAccess = true;
-    Result = Walker.findClobber(OptimizedAccess, Q);
-  } else
-    Result = OptimizedAccess;
-
-  LLVM_DEBUG(dbgs() << "Result Memory SSA clobber [SkipSelf = " << SkipSelf);
-  LLVM_DEBUG(dbgs() << "] for " << *I << " is " << *Result << "\n");
-
-  return Result;
-}
-
-MemoryAccess *
-MemorySSA::CachingWalker::getClobberingMemoryAccess(MemoryAccess *MA) {
-  return Walker->getClobberingMemoryAccessBase(MA, false);
-}
-
-MemoryAccess *
-MemorySSA::CachingWalker::getClobberingMemoryAccess(MemoryAccess *MA,
-                                                    const MemoryLocation &Loc) {
-  return Walker->getClobberingMemoryAccessBase(MA, Loc);
-}
-
-MemoryAccess *
-MemorySSA::SkipSelfWalker::getClobberingMemoryAccess(MemoryAccess *MA) {
-  return Walker->getClobberingMemoryAccessBase(MA, true);
-}
-
-MemoryAccess *
-MemorySSA::SkipSelfWalker::getClobberingMemoryAccess(MemoryAccess *MA,
-                                                    const MemoryLocation &Loc) {
-  return Walker->getClobberingMemoryAccessBase(MA, Loc);
-}
-
-MemoryAccess *
-DoNothingMemorySSAWalker::getClobberingMemoryAccess(MemoryAccess *MA) {
-  if (auto *Use = dyn_cast<MemoryUseOrDef>(MA))
-    return Use->getDefiningAccess();
-  return MA;
-}
-
-MemoryAccess *DoNothingMemorySSAWalker::getClobberingMemoryAccess(
-    MemoryAccess *StartingAccess, const MemoryLocation &) {
-  if (auto *Use = dyn_cast<MemoryUseOrDef>(StartingAccess))
-    return Use->getDefiningAccess();
-  return StartingAccess;
-}
-
-void MemoryPhi::deleteMe(DerivedUser *Self) {
-  delete static_cast<MemoryPhi *>(Self);
-}
-
-void MemoryDef::deleteMe(DerivedUser *Self) {
-  delete static_cast<MemoryDef *>(Self);
-}
-
-void MemoryUse::deleteMe(DerivedUser *Self) {
-  delete static_cast<MemoryUse *>(Self);
-}