Remove LLVM 8.0.1 files.

1 files changed, 0 insertions, 4592 deletions

diff --git a/gnu/llvm/lib/Transforms/Scalar/SROA.cpp b/gnu/llvm/lib/Transforms/Scalar/SROA.cpp
deleted file mode 100644
index 68ca6c47c8f..00000000000
--- a/gnu/llvm/lib/Transforms/Scalar/SROA.cpp
+++ /dev/null
@@ -1,4592 +0,0 @@
-//===- SROA.cpp - Scalar Replacement Of Aggregates ------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-/// \file
-/// This transformation implements the well known scalar replacement of
-/// aggregates transformation. It tries to identify promotable elements of an
-/// aggregate alloca, and promote them to registers. It will also try to
-/// convert uses of an element (or set of elements) of an alloca into a vector
-/// or bitfield-style integer scalar if appropriate.
-///
-/// It works to do this with minimal slicing of the alloca so that regions
-/// which are merely transferred in and out of external memory remain unchanged
-/// and are not decomposed to scalar code.
-///
-/// Because this also performs alloca promotion, it can be thought of as also
-/// serving the purpose of SSA formation. The algorithm iterates on the
-/// function until all opportunities for promotion have been realized.
-///
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Transforms/Scalar/SROA.h"
-#include "llvm/ADT/APInt.h"
-#include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/PointerIntPair.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SetVector.h"
-#include "llvm/ADT/SmallBitVector.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/ADT/StringRef.h"
-#include "llvm/ADT/Twine.h"
-#include "llvm/ADT/iterator.h"
-#include "llvm/ADT/iterator_range.h"
-#include "llvm/Analysis/AssumptionCache.h"
-#include "llvm/Analysis/GlobalsModRef.h"
-#include "llvm/Analysis/Loads.h"
-#include "llvm/Analysis/PtrUseVisitor.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Config/llvm-config.h"
-#include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/Constant.h"
-#include "llvm/IR/ConstantFolder.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/DIBuilder.h"
-#include "llvm/IR/DataLayout.h"
-#include "llvm/IR/DebugInfoMetadata.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/Dominators.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/GetElementPtrTypeIterator.h"
-#include "llvm/IR/GlobalAlias.h"
-#include "llvm/IR/IRBuilder.h"
-#include "llvm/IR/InstVisitor.h"
-#include "llvm/IR/InstrTypes.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/Metadata.h"
-#include "llvm/IR/Module.h"
-#include "llvm/IR/Operator.h"
-#include "llvm/IR/PassManager.h"
-#include "llvm/IR/Type.h"
-#include "llvm/IR/Use.h"
-#include "llvm/IR/User.h"
-#include "llvm/IR/Value.h"
-#include "llvm/Pass.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/MathExtras.h"
-#include "llvm/Support/raw_ostream.h"
-#include "llvm/Transforms/Scalar.h"
-#include "llvm/Transforms/Utils/PromoteMemToReg.h"
-#include <algorithm>
-#include <cassert>
-#include <chrono>
-#include <cstddef>
-#include <cstdint>
-#include <cstring>
-#include <iterator>
-#include <string>
-#include <tuple>
-#include <utility>
-#include <vector>
-
-#ifndef NDEBUG
-// We only use this for a debug check.
-#include <random>
-#endif
-
-using namespace llvm;
-using namespace llvm::sroa;
-
-#define DEBUG_TYPE "sroa"
-
-STATISTIC(NumAllocasAnalyzed, "Number of allocas analyzed for replacement");
-STATISTIC(NumAllocaPartitions, "Number of alloca partitions formed");
-STATISTIC(MaxPartitionsPerAlloca, "Maximum number of partitions per alloca");
-STATISTIC(NumAllocaPartitionUses, "Number of alloca partition uses rewritten");
-STATISTIC(MaxUsesPerAllocaPartition, "Maximum number of uses of a partition");
-STATISTIC(NumNewAllocas, "Number of new, smaller allocas introduced");
-STATISTIC(NumPromoted, "Number of allocas promoted to SSA values");
-STATISTIC(NumLoadsSpeculated, "Number of loads speculated to allow promotion");
-STATISTIC(NumDeleted, "Number of instructions deleted");
-STATISTIC(NumVectorized, "Number of vectorized aggregates");
-
-/// Hidden option to enable randomly shuffling the slices to help uncover
-/// instability in their order.
-static cl::opt<bool> SROARandomShuffleSlices("sroa-random-shuffle-slices",
-                                             cl::init(false), cl::Hidden);
-
-/// Hidden option to experiment with completely strict handling of inbounds
-/// GEPs.
-static cl::opt<bool> SROAStrictInbounds("sroa-strict-inbounds", cl::init(false),
-                                        cl::Hidden);
-
-namespace {
-
-/// A custom IRBuilder inserter which prefixes all names, but only in
-/// Assert builds.
-class IRBuilderPrefixedInserter : public IRBuilderDefaultInserter {
-  std::string Prefix;
-
-  const Twine getNameWithPrefix(const Twine &Name) const {
-    return Name.isTriviallyEmpty() ? Name : Prefix + Name;
-  }
-
-public:
-  void SetNamePrefix(const Twine &P) { Prefix = P.str(); }
-
-protected:
-  void InsertHelper(Instruction *I, const Twine &Name, BasicBlock *BB,
-                    BasicBlock::iterator InsertPt) const {
-    IRBuilderDefaultInserter::InsertHelper(I, getNameWithPrefix(Name), BB,
-                                           InsertPt);
-  }
-};
-
-/// Provide a type for IRBuilder that drops names in release builds.
-using IRBuilderTy = IRBuilder<ConstantFolder, IRBuilderPrefixedInserter>;
-
-/// A used slice of an alloca.
-///
-/// This structure represents a slice of an alloca used by some instruction. It
-/// stores both the begin and end offsets of this use, a pointer to the use
-/// itself, and a flag indicating whether we can classify the use as splittable
-/// or not when forming partitions of the alloca.
-class Slice {
-  /// The beginning offset of the range.
-  uint64_t BeginOffset = 0;
-
-  /// The ending offset, not included in the range.
-  uint64_t EndOffset = 0;
-
-  /// Storage for both the use of this slice and whether it can be
-  /// split.
-  PointerIntPair<Use *, 1, bool> UseAndIsSplittable;
-
-public:
-  Slice() = default;
-
-  Slice(uint64_t BeginOffset, uint64_t EndOffset, Use *U, bool IsSplittable)
-      : BeginOffset(BeginOffset), EndOffset(EndOffset),
-        UseAndIsSplittable(U, IsSplittable) {}
-
-  uint64_t beginOffset() const { return BeginOffset; }
-  uint64_t endOffset() const { return EndOffset; }
-
-  bool isSplittable() const { return UseAndIsSplittable.getInt(); }
-  void makeUnsplittable() { UseAndIsSplittable.setInt(false); }
-
-  Use *getUse() const { return UseAndIsSplittable.getPointer(); }
-
-  bool isDead() const { return getUse() == nullptr; }
-  void kill() { UseAndIsSplittable.setPointer(nullptr); }
-
-  /// Support for ordering ranges.
-  ///
-  /// This provides an ordering over ranges such that start offsets are
-  /// always increasing, and within equal start offsets, the end offsets are
-  /// decreasing. Thus the spanning range comes first in a cluster with the
-  /// same start position.
-  bool operator<(const Slice &RHS) const {
-    if (beginOffset() < RHS.beginOffset())
-      return true;
-    if (beginOffset() > RHS.beginOffset())
-      return false;
-    if (isSplittable() != RHS.isSplittable())
-      return !isSplittable();
-    if (endOffset() > RHS.endOffset())
-      return true;
-    return false;
-  }
-
-  /// Support comparison with a single offset to allow binary searches.
-  friend LLVM_ATTRIBUTE_UNUSED bool operator<(const Slice &LHS,
-                                              uint64_t RHSOffset) {
-    return LHS.beginOffset() < RHSOffset;
-  }
-  friend LLVM_ATTRIBUTE_UNUSED bool operator<(uint64_t LHSOffset,
-                                              const Slice &RHS) {
-    return LHSOffset < RHS.beginOffset();
-  }
-
-  bool operator==(const Slice &RHS) const {
-    return isSplittable() == RHS.isSplittable() &&
-           beginOffset() == RHS.beginOffset() && endOffset() == RHS.endOffset();
-  }
-  bool operator!=(const Slice &RHS) const { return !operator==(RHS); }
-};
-
-} // end anonymous namespace
-
-namespace llvm {
-
-template <typename T> struct isPodLike;
-template <> struct isPodLike<Slice> { static const bool value = true; };
-
-} // end namespace llvm
-
-/// Representation of the alloca slices.
-///
-/// This class represents the slices of an alloca which are formed by its
-/// various uses. If a pointer escapes, we can't fully build a representation
-/// for the slices used and we reflect that in this structure. The uses are
-/// stored, sorted by increasing beginning offset and with unsplittable slices
-/// starting at a particular offset before splittable slices.
-class llvm::sroa::AllocaSlices {
-public:
-  /// Construct the slices of a particular alloca.
-  AllocaSlices(const DataLayout &DL, AllocaInst &AI);
-
-  /// Test whether a pointer to the allocation escapes our analysis.
-  ///
-  /// If this is true, the slices are never fully built and should be
-  /// ignored.
-  bool isEscaped() const { return PointerEscapingInstr; }
-
-  /// Support for iterating over the slices.
-  /// @{
-  using iterator = SmallVectorImpl<Slice>::iterator;
-  using range = iterator_range<iterator>;
-
-  iterator begin() { return Slices.begin(); }
-  iterator end() { return Slices.end(); }
-
-  using const_iterator = SmallVectorImpl<Slice>::const_iterator;
-  using const_range = iterator_range<const_iterator>;
-
-  const_iterator begin() const { return Slices.begin(); }
-  const_iterator end() const { return Slices.end(); }
-  /// @}
-
-  /// Erase a range of slices.
-  void erase(iterator Start, iterator Stop) { Slices.erase(Start, Stop); }
-
-  /// Insert new slices for this alloca.
-  ///
-  /// This moves the slices into the alloca's slices collection, and re-sorts
-  /// everything so that the usual ordering properties of the alloca's slices
-  /// hold.
-  void insert(ArrayRef<Slice> NewSlices) {
-    int OldSize = Slices.size();
-    Slices.append(NewSlices.begin(), NewSlices.end());
-    auto SliceI = Slices.begin() + OldSize;
-    llvm::sort(SliceI, Slices.end());
-    std::inplace_merge(Slices.begin(), SliceI, Slices.end());
-  }
-
-  // Forward declare the iterator and range accessor for walking the
-  // partitions.
-  class partition_iterator;
-  iterator_range<partition_iterator> partitions();
-
-  /// Access the dead users for this alloca.
-  ArrayRef<Instruction *> getDeadUsers() const { return DeadUsers; }
-
-  /// Access the dead operands referring to this alloca.
-  ///
-  /// These are operands which have cannot actually be used to refer to the
-  /// alloca as they are outside its range and the user doesn't correct for
-  /// that. These mostly consist of PHI node inputs and the like which we just
-  /// need to replace with undef.
-  ArrayRef<Use *> getDeadOperands() const { return DeadOperands; }
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-  void print(raw_ostream &OS, const_iterator I, StringRef Indent = "  ") const;
-  void printSlice(raw_ostream &OS, const_iterator I,
-                  StringRef Indent = "  ") const;
-  void printUse(raw_ostream &OS, const_iterator I,
-                StringRef Indent = "  ") const;
-  void print(raw_ostream &OS) const;
-  void dump(const_iterator I) const;
-  void dump() const;
-#endif
-
-private:
-  template <typename DerivedT, typename RetT = void> class BuilderBase;
-  class SliceBuilder;
-
-  friend class AllocaSlices::SliceBuilder;
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-  /// Handle to alloca instruction to simplify method interfaces.
-  AllocaInst &AI;
-#endif
-
-  /// The instruction responsible for this alloca not having a known set
-  /// of slices.
-  ///
-  /// When an instruction (potentially) escapes the pointer to the alloca, we
-  /// store a pointer to that here and abort trying to form slices of the
-  /// alloca. This will be null if the alloca slices are analyzed successfully.
-  Instruction *PointerEscapingInstr;
-
-  /// The slices of the alloca.
-  ///
-  /// We store a vector of the slices formed by uses of the alloca here. This
-  /// vector is sorted by increasing begin offset, and then the unsplittable
-  /// slices before the splittable ones. See the Slice inner class for more
-  /// details.
-  SmallVector<Slice, 8> Slices;
-
-  /// Instructions which will become dead if we rewrite the alloca.
-  ///
-  /// Note that these are not separated by slice. This is because we expect an
-  /// alloca to be completely rewritten or not rewritten at all. If rewritten,
-  /// all these instructions can simply be removed and replaced with undef as
-  /// they come from outside of the allocated space.
-  SmallVector<Instruction *, 8> DeadUsers;
-
-  /// Operands which will become dead if we rewrite the alloca.
-  ///
-  /// These are operands that in their particular use can be replaced with
-  /// undef when we rewrite the alloca. These show up in out-of-bounds inputs
-  /// to PHI nodes and the like. They aren't entirely dead (there might be
-  /// a GEP back into the bounds using it elsewhere) and nor is the PHI, but we
-  /// want to swap this particular input for undef to simplify the use lists of
-  /// the alloca.
-  SmallVector<Use *, 8> DeadOperands;
-};
-
-/// A partition of the slices.
-///
-/// An ephemeral representation for a range of slices which can be viewed as
-/// a partition of the alloca. This range represents a span of the alloca's
-/// memory which cannot be split, and provides access to all of the slices
-/// overlapping some part of the partition.
-///
-/// Objects of this type are produced by traversing the alloca's slices, but
-/// are only ephemeral and not persistent.
-class llvm::sroa::Partition {
-private:
-  friend class AllocaSlices;
-  friend class AllocaSlices::partition_iterator;
-
-  using iterator = AllocaSlices::iterator;
-
-  /// The beginning and ending offsets of the alloca for this
-  /// partition.
-  uint64_t BeginOffset, EndOffset;
-
-  /// The start and end iterators of this partition.
-  iterator SI, SJ;
-
-  /// A collection of split slice tails overlapping the partition.
-  SmallVector<Slice *, 4> SplitTails;
-
-  /// Raw constructor builds an empty partition starting and ending at
-  /// the given iterator.
-  Partition(iterator SI) : SI(SI), SJ(SI) {}
-
-public:
-  /// The start offset of this partition.
-  ///
-  /// All of the contained slices start at or after this offset.
-  uint64_t beginOffset() const { return BeginOffset; }
-
-  /// The end offset of this partition.
-  ///
-  /// All of the contained slices end at or before this offset.
-  uint64_t endOffset() const { return EndOffset; }
-
-  /// The size of the partition.
-  ///
-  /// Note that this can never be zero.
-  uint64_t size() const {
-    assert(BeginOffset < EndOffset && "Partitions must span some bytes!");
-    return EndOffset - BeginOffset;
-  }
-
-  /// Test whether this partition contains no slices, and merely spans
-  /// a region occupied by split slices.
-  bool empty() const { return SI == SJ; }
-
-  /// \name Iterate slices that start within the partition.
-  /// These may be splittable or unsplittable. They have a begin offset >= the
-  /// partition begin offset.
-  /// @{
-  // FIXME: We should probably define a "concat_iterator" helper and use that
-  // to stitch together pointee_iterators over the split tails and the
-  // contiguous iterators of the partition. That would give a much nicer
-  // interface here. We could then additionally expose filtered iterators for
-  // split, unsplit, and unsplittable splices based on the usage patterns.
-  iterator begin() const { return SI; }
-  iterator end() const { return SJ; }
-  /// @}
-
-  /// Get the sequence of split slice tails.
-  ///
-  /// These tails are of slices which start before this partition but are
-  /// split and overlap into the partition. We accumulate these while forming
-  /// partitions.
-  ArrayRef<Slice *> splitSliceTails() const { return SplitTails; }
-};
-
-/// An iterator over partitions of the alloca's slices.
-///
-/// This iterator implements the core algorithm for partitioning the alloca's
-/// slices. It is a forward iterator as we don't support backtracking for
-/// efficiency reasons, and re-use a single storage area to maintain the
-/// current set of split slices.
-///
-/// It is templated on the slice iterator type to use so that it can operate
-/// with either const or non-const slice iterators.
-class AllocaSlices::partition_iterator
-    : public iterator_facade_base<partition_iterator, std::forward_iterator_tag,
-                                  Partition> {
-  friend class AllocaSlices;
-
-  /// Most of the state for walking the partitions is held in a class
-  /// with a nice interface for examining them.
-  Partition P;
-
-  /// We need to keep the end of the slices to know when to stop.
-  AllocaSlices::iterator SE;
-
-  /// We also need to keep track of the maximum split end offset seen.
-  /// FIXME: Do we really?
-  uint64_t MaxSplitSliceEndOffset = 0;
-
-  /// Sets the partition to be empty at given iterator, and sets the
-  /// end iterator.
-  partition_iterator(AllocaSlices::iterator SI, AllocaSlices::iterator SE)
-      : P(SI), SE(SE) {
-    // If not already at the end, advance our state to form the initial
-    // partition.
-    if (SI != SE)
-      advance();
-  }
-
-  /// Advance the iterator to the next partition.
-  ///
-  /// Requires that the iterator not be at the end of the slices.
-  void advance() {
-    assert((P.SI != SE || !P.SplitTails.empty()) &&
-           "Cannot advance past the end of the slices!");
-
-    // Clear out any split uses which have ended.
-    if (!P.SplitTails.empty()) {
-      if (P.EndOffset >= MaxSplitSliceEndOffset) {
-        // If we've finished all splits, this is easy.
-        P.SplitTails.clear();
-        MaxSplitSliceEndOffset = 0;
-      } else {
-        // Remove the uses which have ended in the prior partition. This
-        // cannot change the max split slice end because we just checked that
-        // the prior partition ended prior to that max.
-        P.SplitTails.erase(llvm::remove_if(P.SplitTails,
-                                           [&](Slice *S) {
-                                             return S->endOffset() <=
-                                                    P.EndOffset;
-                                           }),
-                           P.SplitTails.end());
-        assert(llvm::any_of(P.SplitTails,
-                            [&](Slice *S) {
-                              return S->endOffset() == MaxSplitSliceEndOffset;
-                            }) &&
-               "Could not find the current max split slice offset!");
-        assert(llvm::all_of(P.SplitTails,
-                            [&](Slice *S) {
-                              return S->endOffset() <= MaxSplitSliceEndOffset;
-                            }) &&
-               "Max split slice end offset is not actually the max!");
-      }
-    }
-
-    // If P.SI is already at the end, then we've cleared the split tail and
-    // now have an end iterator.
-    if (P.SI == SE) {
-      assert(P.SplitTails.empty() && "Failed to clear the split slices!");
-      return;
-    }
-
-    // If we had a non-empty partition previously, set up the state for
-    // subsequent partitions.
-    if (P.SI != P.SJ) {
-      // Accumulate all the splittable slices which started in the old
-      // partition into the split list.
-      for (Slice &S : P)
-        if (S.isSplittable() && S.endOffset() > P.EndOffset) {
-          P.SplitTails.push_back(&S);
-          MaxSplitSliceEndOffset =
-              std::max(S.endOffset(), MaxSplitSliceEndOffset);
-        }
-
-      // Start from the end of the previous partition.
-      P.SI = P.SJ;
-
-      // If P.SI is now at the end, we at most have a tail of split slices.
-      if (P.SI == SE) {
-        P.BeginOffset = P.EndOffset;
-        P.EndOffset = MaxSplitSliceEndOffset;
-        return;
-      }
-
-      // If the we have split slices and the next slice is after a gap and is
-      // not splittable immediately form an empty partition for the split
-      // slices up until the next slice begins.
-      if (!P.SplitTails.empty() && P.SI->beginOffset() != P.EndOffset &&
-          !P.SI->isSplittable()) {
-        P.BeginOffset = P.EndOffset;
-        P.EndOffset = P.SI->beginOffset();
-        return;
-      }
-    }
-
-    // OK, we need to consume new slices. Set the end offset based on the
-    // current slice, and step SJ past it. The beginning offset of the
-    // partition is the beginning offset of the next slice unless we have
-    // pre-existing split slices that are continuing, in which case we begin
-    // at the prior end offset.
-    P.BeginOffset = P.SplitTails.empty() ? P.SI->beginOffset() : P.EndOffset;
-    P.EndOffset = P.SI->endOffset();
-    ++P.SJ;
-
-    // There are two strategies to form a partition based on whether the
-    // partition starts with an unsplittable slice or a splittable slice.
-    if (!P.SI->isSplittable()) {
-      // When we're forming an unsplittable region, it must always start at
-      // the first slice and will extend through its end.
-      assert(P.BeginOffset == P.SI->beginOffset());
-
-      // Form a partition including all of the overlapping slices with this
-      // unsplittable slice.
-      while (P.SJ != SE && P.SJ->beginOffset() < P.EndOffset) {
-        if (!P.SJ->isSplittable())
-          P.EndOffset = std::max(P.EndOffset, P.SJ->endOffset());
-        ++P.SJ;
-      }
-
-      // We have a partition across a set of overlapping unsplittable
-      // partitions.
-      return;
-    }
-
-    // If we're starting with a splittable slice, then we need to form
-    // a synthetic partition spanning it and any other overlapping splittable
-    // splices.
-    assert(P.SI->isSplittable() && "Forming a splittable partition!");
-
-    // Collect all of the overlapping splittable slices.
-    while (P.SJ != SE && P.SJ->beginOffset() < P.EndOffset &&
-           P.SJ->isSplittable()) {
-      P.EndOffset = std::max(P.EndOffset, P.SJ->endOffset());
-      ++P.SJ;
-    }
-
-    // Back upiP.EndOffset if we ended the span early when encountering an
-    // unsplittable slice. This synthesizes the early end offset of
-    // a partition spanning only splittable slices.
-    if (P.SJ != SE && P.SJ->beginOffset() < P.EndOffset) {
-      assert(!P.SJ->isSplittable());
-      P.EndOffset = P.SJ->beginOffset();
-    }
-  }
-
-public:
-  bool operator==(const partition_iterator &RHS) const {
-    assert(SE == RHS.SE &&
-           "End iterators don't match between compared partition iterators!");
-
-    // The observed positions of partitions is marked by the P.SI iterator and
-    // the emptiness of the split slices. The latter is only relevant when
-    // P.SI == SE, as the end iterator will additionally have an empty split
-    // slices list, but the prior may have the same P.SI and a tail of split
-    // slices.
-    if (P.SI == RHS.P.SI && P.SplitTails.empty() == RHS.P.SplitTails.empty()) {
-      assert(P.SJ == RHS.P.SJ &&
-             "Same set of slices formed two different sized partitions!");
-      assert(P.SplitTails.size() == RHS.P.SplitTails.size() &&
-             "Same slice position with differently sized non-empty split "
-             "slice tails!");
-      return true;
-    }
-    return false;
-  }
-
-  partition_iterator &operator++() {
-    advance();
-    return *this;
-  }
-
-  Partition &operator*() { return P; }
-};
-
-/// A forward range over the partitions of the alloca's slices.
-///
-/// This accesses an iterator range over the partitions of the alloca's
-/// slices. It computes these partitions on the fly based on the overlapping
-/// offsets of the slices and the ability to split them. It will visit "empty"
-/// partitions to cover regions of the alloca only accessed via split
-/// slices.
-iterator_range<AllocaSlices::partition_iterator> AllocaSlices::partitions() {
-  return make_range(partition_iterator(begin(), end()),
-                    partition_iterator(end(), end()));
-}
-
-static Value *foldSelectInst(SelectInst &SI) {
-  // If the condition being selected on is a constant or the same value is
-  // being selected between, fold the select. Yes this does (rarely) happen
-  // early on.
-  if (ConstantInt *CI = dyn_cast<ConstantInt>(SI.getCondition()))
-    return SI.getOperand(1 + CI->isZero());
-  if (SI.getOperand(1) == SI.getOperand(2))
-    return SI.getOperand(1);
-
-  return nullptr;
-}
-
-/// A helper that folds a PHI node or a select.
-static Value *foldPHINodeOrSelectInst(Instruction &I) {
-  if (PHINode *PN = dyn_cast<PHINode>(&I)) {
-    // If PN merges together the same value, return that value.
-    return PN->hasConstantValue();
-  }
-  return foldSelectInst(cast<SelectInst>(I));
-}
-
-/// Builder for the alloca slices.
-///
-/// This class builds a set of alloca slices by recursively visiting the uses
-/// of an alloca and making a slice for each load and store at each offset.
-class AllocaSlices::SliceBuilder : public PtrUseVisitor<SliceBuilder> {
-  friend class PtrUseVisitor<SliceBuilder>;
-  friend class InstVisitor<SliceBuilder>;
-
-  using Base = PtrUseVisitor<SliceBuilder>;
-
-  const uint64_t AllocSize;
-  AllocaSlices &AS;
-
-  SmallDenseMap<Instruction *, unsigned> MemTransferSliceMap;
-  SmallDenseMap<Instruction *, uint64_t> PHIOrSelectSizes;
-
-  /// Set to de-duplicate dead instructions found in the use walk.
-  SmallPtrSet<Instruction *, 4> VisitedDeadInsts;
-
-public:
-  SliceBuilder(const DataLayout &DL, AllocaInst &AI, AllocaSlices &AS)
-      : PtrUseVisitor<SliceBuilder>(DL),
-        AllocSize(DL.getTypeAllocSize(AI.getAllocatedType())), AS(AS) {}
-
-private:
-  void markAsDead(Instruction &I) {
-    if (VisitedDeadInsts.insert(&I).second)
-      AS.DeadUsers.push_back(&I);
-  }
-
-  void insertUse(Instruction &I, const APInt &Offset, uint64_t Size,
-                 bool IsSplittable = false) {
-    // Completely skip uses which have a zero size or start either before or
-    // past the end of the allocation.
-    if (Size == 0 || Offset.uge(AllocSize)) {
-      LLVM_DEBUG(dbgs() << "WARNING: Ignoring " << Size << " byte use @"
-                        << Offset
-                        << " which has zero size or starts outside of the "
-                        << AllocSize << " byte alloca:\n"
-                        << "    alloca: " << AS.AI << "\n"
-                        << "       use: " << I << "\n");
-      return markAsDead(I);
-    }
-
-    uint64_t BeginOffset = Offset.getZExtValue();
-    uint64_t EndOffset = BeginOffset + Size;
-
-    // Clamp the end offset to the end of the allocation. Note that this is
-    // formulated to handle even the case where "BeginOffset + Size" overflows.
-    // This may appear superficially to be something we could ignore entirely,
-    // but that is not so! There may be widened loads or PHI-node uses where
-    // some instructions are dead but not others. We can't completely ignore
-    // them, and so have to record at least the information here.
-    assert(AllocSize >= BeginOffset); // Established above.
-    if (Size > AllocSize - BeginOffset) {
-      LLVM_DEBUG(dbgs() << "WARNING: Clamping a " << Size << " byte use @"
-                        << Offset << " to remain within the " << AllocSize
-                        << " byte alloca:\n"
-                        << "    alloca: " << AS.AI << "\n"
-                        << "       use: " << I << "\n");
-      EndOffset = AllocSize;
-    }
-
-    AS.Slices.push_back(Slice(BeginOffset, EndOffset, U, IsSplittable));
-  }
-
-  void visitBitCastInst(BitCastInst &BC) {
-    if (BC.use_empty())
-      return markAsDead(BC);
-
-    return Base::visitBitCastInst(BC);
-  }
-
-  void visitGetElementPtrInst(GetElementPtrInst &GEPI) {
-    if (GEPI.use_empty())
-      return markAsDead(GEPI);
-
-    if (SROAStrictInbounds && GEPI.isInBounds()) {
-      // FIXME: This is a manually un-factored variant of the basic code inside
-      // of GEPs with checking of the inbounds invariant specified in the
-      // langref in a very strict sense. If we ever want to enable
-      // SROAStrictInbounds, this code should be factored cleanly into
-      // PtrUseVisitor, but it is easier to experiment with SROAStrictInbounds
-      // by writing out the code here where we have the underlying allocation
-      // size readily available.
-      APInt GEPOffset = Offset;
-      const DataLayout &DL = GEPI.getModule()->getDataLayout();
-      for (gep_type_iterator GTI = gep_type_begin(GEPI),
-                             GTE = gep_type_end(GEPI);
-           GTI != GTE; ++GTI) {
-        ConstantInt *OpC = dyn_cast<ConstantInt>(GTI.getOperand());
-        if (!OpC)
-          break;
-
-        // Handle a struct index, which adds its field offset to the pointer.
-        if (StructType *STy = GTI.getStructTypeOrNull()) {
-          unsigned ElementIdx = OpC->getZExtValue();
-          const StructLayout *SL = DL.getStructLayout(STy);
-          GEPOffset +=
-              APInt(Offset.getBitWidth(), SL->getElementOffset(ElementIdx));
-        } else {
-          // For array or vector indices, scale the index by the size of the
-          // type.
-          APInt Index = OpC->getValue().sextOrTrunc(Offset.getBitWidth());
-          GEPOffset += Index * APInt(Offset.getBitWidth(),
-                                     DL.getTypeAllocSize(GTI.getIndexedType()));
-        }
-
-        // If this index has computed an intermediate pointer which is not
-        // inbounds, then the result of the GEP is a poison value and we can
-        // delete it and all uses.
-        if (GEPOffset.ugt(AllocSize))
-          return markAsDead(GEPI);
-      }
-    }
-
-    return Base::visitGetElementPtrInst(GEPI);
-  }
-
-  void handleLoadOrStore(Type *Ty, Instruction &I, const APInt &Offset,
-                         uint64_t Size, bool IsVolatile) {
-    // We allow splitting of non-volatile loads and stores where the type is an
-    // integer type. These may be used to implement 'memcpy' or other "transfer
-    // of bits" patterns.
-    bool IsSplittable = Ty->isIntegerTy() && !IsVolatile;
-
-    insertUse(I, Offset, Size, IsSplittable);
-  }
-
-  void visitLoadInst(LoadInst &LI) {
-    assert((!LI.isSimple() || LI.getType()->isSingleValueType()) &&
-           "All simple FCA loads should have been pre-split");
-
-    if (!IsOffsetKnown)
-      return PI.setAborted(&LI);
-
-    const DataLayout &DL = LI.getModule()->getDataLayout();
-    uint64_t Size = DL.getTypeStoreSize(LI.getType());
-    return handleLoadOrStore(LI.getType(), LI, Offset, Size, LI.isVolatile());
-  }
-
-  void visitStoreInst(StoreInst &SI) {
-    Value *ValOp = SI.getValueOperand();
-    if (ValOp == *U)
-      return PI.setEscapedAndAborted(&SI);
-    if (!IsOffsetKnown)
-      return PI.setAborted(&SI);
-
-    const DataLayout &DL = SI.getModule()->getDataLayout();
-    uint64_t Size = DL.getTypeStoreSize(ValOp->getType());
-
-    // If this memory access can be shown to *statically* extend outside the
-    // bounds of the allocation, it's behavior is undefined, so simply
-    // ignore it. Note that this is more strict than the generic clamping
-    // behavior of insertUse. We also try to handle cases which might run the
-    // risk of overflow.
-    // FIXME: We should instead consider the pointer to have escaped if this
-    // function is being instrumented for addressing bugs or race conditions.
-    if (Size > AllocSize || Offset.ugt(AllocSize - Size)) {
-      LLVM_DEBUG(dbgs() << "WARNING: Ignoring " << Size << " byte store @"
-                        << Offset << " which extends past the end of the "
-                        << AllocSize << " byte alloca:\n"
-                        << "    alloca: " << AS.AI << "\n"
-                        << "       use: " << SI << "\n");
-      return markAsDead(SI);
-    }
-
-    assert((!SI.isSimple() || ValOp->getType()->isSingleValueType()) &&
-           "All simple FCA stores should have been pre-split");
-    handleLoadOrStore(ValOp->getType(), SI, Offset, Size, SI.isVolatile());
-  }
-
-  void visitMemSetInst(MemSetInst &II) {
-    assert(II.getRawDest() == *U && "Pointer use is not the destination?");
-    ConstantInt *Length = dyn_cast<ConstantInt>(II.getLength());
-    if ((Length && Length->getValue() == 0) ||
-        (IsOffsetKnown && Offset.uge(AllocSize)))
-      // Zero-length mem transfer intrinsics can be ignored entirely.
-      return markAsDead(II);
-
-    if (!IsOffsetKnown)
-      return PI.setAborted(&II);
-
-    insertUse(II, Offset, Length ? Length->getLimitedValue()
-                                 : AllocSize - Offset.getLimitedValue(),
-              (bool)Length);
-  }
-
-  void visitMemTransferInst(MemTransferInst &II) {
-    ConstantInt *Length = dyn_cast<ConstantInt>(II.getLength());
-    if (Length && Length->getValue() == 0)
-      // Zero-length mem transfer intrinsics can be ignored entirely.
-      return markAsDead(II);
-
-    // Because we can visit these intrinsics twice, also check to see if the
-    // first time marked this instruction as dead. If so, skip it.
-    if (VisitedDeadInsts.count(&II))
-      return;
-
-    if (!IsOffsetKnown)
-      return PI.setAborted(&II);
-
-    // This side of the transfer is completely out-of-bounds, and so we can
-    // nuke the entire transfer. However, we also need to nuke the other side
-    // if already added to our partitions.
-    // FIXME: Yet another place we really should bypass this when
-    // instrumenting for ASan.
-    if (Offset.uge(AllocSize)) {
-      SmallDenseMap<Instruction *, unsigned>::iterator MTPI =
-          MemTransferSliceMap.find(&II);
-      if (MTPI != MemTransferSliceMap.end())
-        AS.Slices[MTPI->second].kill();
-      return markAsDead(II);
-    }
-
-    uint64_t RawOffset = Offset.getLimitedValue();
-    uint64_t Size = Length ? Length->getLimitedValue() : AllocSize - RawOffset;
-
-    // Check for the special case where the same exact value is used for both
-    // source and dest.
-    if (*U == II.getRawDest() && *U == II.getRawSource()) {
-      // For non-volatile transfers this is a no-op.
-      if (!II.isVolatile())
-        return markAsDead(II);
-
-      return insertUse(II, Offset, Size, /*IsSplittable=*/false);
-    }
-
-    // If we have seen both source and destination for a mem transfer, then
-    // they both point to the same alloca.
-    bool Inserted;
-    SmallDenseMap<Instruction *, unsigned>::iterator MTPI;
-    std::tie(MTPI, Inserted) =
-        MemTransferSliceMap.insert(std::make_pair(&II, AS.Slices.size()));
-    unsigned PrevIdx = MTPI->second;
-    if (!Inserted) {
-      Slice &PrevP = AS.Slices[PrevIdx];
-
-      // Check if the begin offsets match and this is a non-volatile transfer.
-      // In that case, we can completely elide the transfer.
-      if (!II.isVolatile() && PrevP.beginOffset() == RawOffset) {
-        PrevP.kill();
-        return markAsDead(II);
-      }
-
-      // Otherwise we have an offset transfer within the same alloca. We can't
-      // split those.
-      PrevP.makeUnsplittable();
-    }
-
-    // Insert the use now that we've fixed up the splittable nature.
-    insertUse(II, Offset, Size, /*IsSplittable=*/Inserted && Length);
-
-    // Check that we ended up with a valid index in the map.
-    assert(AS.Slices[PrevIdx].getUse()->getUser() == &II &&
-           "Map index doesn't point back to a slice with this user.");
-  }
-
-  // Disable SRoA for any intrinsics except for lifetime invariants.
-  // FIXME: What about debug intrinsics? This matches old behavior, but
-  // doesn't make sense.
-  void visitIntrinsicInst(IntrinsicInst &II) {
-    if (!IsOffsetKnown)
-      return PI.setAborted(&II);
-
-    if (II.isLifetimeStartOrEnd()) {
-      ConstantInt *Length = cast<ConstantInt>(II.getArgOperand(0));
-      uint64_t Size = std::min(AllocSize - Offset.getLimitedValue(),
-                               Length->getLimitedValue());
-      insertUse(II, Offset, Size, true);
-      return;
-    }
-
-    Base::visitIntrinsicInst(II);
-  }
-
-  Instruction *hasUnsafePHIOrSelectUse(Instruction *Root, uint64_t &Size) {
-    // We consider any PHI or select that results in a direct load or store of
-    // the same offset to be a viable use for slicing purposes. These uses
-    // are considered unsplittable and the size is the maximum loaded or stored
-    // size.
-    SmallPtrSet<Instruction *, 4> Visited;
-    SmallVector<std::pair<Instruction *, Instruction *>, 4> Uses;
-    Visited.insert(Root);
-    Uses.push_back(std::make_pair(cast<Instruction>(*U), Root));
-    const DataLayout &DL = Root->getModule()->getDataLayout();
-    // If there are no loads or stores, the access is dead. We mark that as
-    // a size zero access.
-    Size = 0;
-    do {
-      Instruction *I, *UsedI;
-      std::tie(UsedI, I) = Uses.pop_back_val();
-
-      if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
-        Size = std::max(Size, DL.getTypeStoreSize(LI->getType()));
-        continue;
-      }
-      if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
-        Value *Op = SI->getOperand(0);
-        if (Op == UsedI)
-          return SI;
-        Size = std::max(Size, DL.getTypeStoreSize(Op->getType()));
-        continue;
-      }
-
-      if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(I)) {
-        if (!GEP->hasAllZeroIndices())
-          return GEP;
-      } else if (!isa<BitCastInst>(I) && !isa<PHINode>(I) &&
-                 !isa<SelectInst>(I)) {
-        return I;
-      }
-
-      for (User *U : I->users())
-        if (Visited.insert(cast<Instruction>(U)).second)
-          Uses.push_back(std::make_pair(I, cast<Instruction>(U)));
-    } while (!Uses.empty());
-
-    return nullptr;
-  }
-
-  void visitPHINodeOrSelectInst(Instruction &I) {
-    assert(isa<PHINode>(I) || isa<SelectInst>(I));
-    if (I.use_empty())
-      return markAsDead(I);
-
-    // TODO: We could use SimplifyInstruction here to fold PHINodes and
-    // SelectInsts. However, doing so requires to change the current
-    // dead-operand-tracking mechanism. For instance, suppose neither loading
-    // from %U nor %other traps. Then "load (select undef, %U, %other)" does not
-    // trap either.  However, if we simply replace %U with undef using the
-    // current dead-operand-tracking mechanism, "load (select undef, undef,
-    // %other)" may trap because the select may return the first operand
-    // "undef".
-    if (Value *Result = foldPHINodeOrSelectInst(I)) {
-      if (Result == *U)
-        // If the result of the constant fold will be the pointer, recurse
-        // through the PHI/select as if we had RAUW'ed it.
-        enqueueUsers(I);
-      else
-        // Otherwise the operand to the PHI/select is dead, and we can replace
-        // it with undef.
-        AS.DeadOperands.push_back(U);
-
-      return;
-    }
-
-    if (!IsOffsetKnown)
-      return PI.setAborted(&I);
-
-    // See if we already have computed info on this node.
-    uint64_t &Size = PHIOrSelectSizes[&I];
-    if (!Size) {
-      // This is a new PHI/Select, check for an unsafe use of it.
-      if (Instruction *UnsafeI = hasUnsafePHIOrSelectUse(&I, Size))
-        return PI.setAborted(UnsafeI);
-    }
-
-    // For PHI and select operands outside the alloca, we can't nuke the entire
-    // phi or select -- the other side might still be relevant, so we special
-    // case them here and use a separate structure to track the operands
-    // themselves which should be replaced with undef.
-    // FIXME: This should instead be escaped in the event we're instrumenting
-    // for address sanitization.
-    if (Offset.uge(AllocSize)) {
-      AS.DeadOperands.push_back(U);
-      return;
-    }
-
-    insertUse(I, Offset, Size);
-  }
-
-  void visitPHINode(PHINode &PN) { visitPHINodeOrSelectInst(PN); }
-
-  void visitSelectInst(SelectInst &SI) { visitPHINodeOrSelectInst(SI); }
-
-  /// Disable SROA entirely if there are unhandled users of the alloca.
-  void visitInstruction(Instruction &I) { PI.setAborted(&I); }
-};
-
-AllocaSlices::AllocaSlices(const DataLayout &DL, AllocaInst &AI)
-    :
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-      AI(AI),
-#endif
-      PointerEscapingInstr(nullptr) {
-  SliceBuilder PB(DL, AI, *this);
-  SliceBuilder::PtrInfo PtrI = PB.visitPtr(AI);
-  if (PtrI.isEscaped() || PtrI.isAborted()) {
-    // FIXME: We should sink the escape vs. abort info into the caller nicely,
-    // possibly by just storing the PtrInfo in the AllocaSlices.
-    PointerEscapingInstr = PtrI.getEscapingInst() ? PtrI.getEscapingInst()
-                                                  : PtrI.getAbortingInst();
-    assert(PointerEscapingInstr && "Did not track a bad instruction");
-    return;
-  }
-
-  Slices.erase(
-      llvm::remove_if(Slices, [](const Slice &S) { return S.isDead(); }),
-      Slices.end());
-
-#ifndef NDEBUG
-  if (SROARandomShuffleSlices) {
-    std::mt19937 MT(static_cast<unsigned>(
-        std::chrono::system_clock::now().time_since_epoch().count()));
-    std::shuffle(Slices.begin(), Slices.end(), MT);
-  }
-#endif
-
-  // Sort the uses. This arranges for the offsets to be in ascending order,
-  // and the sizes to be in descending order.
-  llvm::sort(Slices);
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-
-void AllocaSlices::print(raw_ostream &OS, const_iterator I,
-                         StringRef Indent) const {
-  printSlice(OS, I, Indent);
-  OS << "\n";
-  printUse(OS, I, Indent);
-}
-
-void AllocaSlices::printSlice(raw_ostream &OS, const_iterator I,
-                              StringRef Indent) const {
-  OS << Indent << "[" << I->beginOffset() << "," << I->endOffset() << ")"
-     << " slice #" << (I - begin())
-     << (I->isSplittable() ? " (splittable)" : "");
-}
-
-void AllocaSlices::printUse(raw_ostream &OS, const_iterator I,
-                            StringRef Indent) const {
-  OS << Indent << "  used by: " << *I->getUse()->getUser() << "\n";
-}
-
-void AllocaSlices::print(raw_ostream &OS) const {
-  if (PointerEscapingInstr) {
-    OS << "Can't analyze slices for alloca: " << AI << "\n"
-       << "  A pointer to this alloca escaped by:\n"
-       << "  " << *PointerEscapingInstr << "\n";
-    return;
-  }
-
-  OS << "Slices of alloca: " << AI << "\n";
-  for (const_iterator I = begin(), E = end(); I != E; ++I)
-    print(OS, I);
-}
-
-LLVM_DUMP_METHOD void AllocaSlices::dump(const_iterator I) const {
-  print(dbgs(), I);
-}
-LLVM_DUMP_METHOD void AllocaSlices::dump() const { print(dbgs()); }
-
-#endif // !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-
-/// Walk the range of a partitioning looking for a common type to cover this
-/// sequence of slices.
-static Type *findCommonType(AllocaSlices::const_iterator B,
-                            AllocaSlices::const_iterator E,
-                            uint64_t EndOffset) {
-  Type *Ty = nullptr;
-  bool TyIsCommon = true;
-  IntegerType *ITy = nullptr;
-
-  // Note that we need to look at *every* alloca slice's Use to ensure we
-  // always get consistent results regardless of the order of slices.
-  for (AllocaSlices::const_iterator I = B; I != E; ++I) {
-    Use *U = I->getUse();
-    if (isa<IntrinsicInst>(*U->getUser()))
-      continue;
-    if (I->beginOffset() != B->beginOffset() || I->endOffset() != EndOffset)
-      continue;
-
-    Type *UserTy = nullptr;
-    if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
-      UserTy = LI->getType();
-    } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
-      UserTy = SI->getValueOperand()->getType();
-    }
-
-    if (IntegerType *UserITy = dyn_cast_or_null<IntegerType>(UserTy)) {
-      // If the type is larger than the partition, skip it. We only encounter
-      // this for split integer operations where we want to use the type of the
-      // entity causing the split. Also skip if the type is not a byte width
-      // multiple.
-      if (UserITy->getBitWidth() % 8 != 0 ||
-          UserITy->getBitWidth() / 8 > (EndOffset - B->beginOffset()))
-        continue;
-
-      // Track the largest bitwidth integer type used in this way in case there
-      // is no common type.
-      if (!ITy || ITy->getBitWidth() < UserITy->getBitWidth())
-        ITy = UserITy;
-    }
-
-    // To avoid depending on the order of slices, Ty and TyIsCommon must not
-    // depend on types skipped above.
-    if (!UserTy || (Ty && Ty != UserTy))
-      TyIsCommon = false; // Give up on anything but an iN type.
-    else
-      Ty = UserTy;
-  }
-
-  return TyIsCommon ? Ty : ITy;
-}
-
-/// PHI instructions that use an alloca and are subsequently loaded can be
-/// rewritten to load both input pointers in the pred blocks and then PHI the
-/// results, allowing the load of the alloca to be promoted.
-/// From this:
-///   %P2 = phi [i32* %Alloca, i32* %Other]
-///   %V = load i32* %P2
-/// to:
-///   %V1 = load i32* %Alloca      -> will be mem2reg'd
-///   ...
-///   %V2 = load i32* %Other
-///   ...
-///   %V = phi [i32 %V1, i32 %V2]
-///
-/// We can do this to a select if its only uses are loads and if the operands
-/// to the select can be loaded unconditionally.
-///
-/// FIXME: This should be hoisted into a generic utility, likely in
-/// Transforms/Util/Local.h
-static bool isSafePHIToSpeculate(PHINode &PN) {
-  // For now, we can only do this promotion if the load is in the same block
-  // as the PHI, and if there are no stores between the phi and load.
-  // TODO: Allow recursive phi users.
-  // TODO: Allow stores.
-  BasicBlock *BB = PN.getParent();
-  unsigned MaxAlign = 0;
-  bool HaveLoad = false;
-  for (User *U : PN.users()) {
-    LoadInst *LI = dyn_cast<LoadInst>(U);
-    if (!LI || !LI->isSimple())
-      return false;
-
-    // For now we only allow loads in the same block as the PHI.  This is
-    // a common case that happens when instcombine merges two loads through
-    // a PHI.
-    if (LI->getParent() != BB)
-      return false;
-
-    // Ensure that there are no instructions between the PHI and the load that
-    // could store.
-    for (BasicBlock::iterator BBI(PN); &*BBI != LI; ++BBI)
-      if (BBI->mayWriteToMemory())
-        return false;
-
-    MaxAlign = std::max(MaxAlign, LI->getAlignment());
-    HaveLoad = true;
-  }
-
-  if (!HaveLoad)
-    return false;
-
-  const DataLayout &DL = PN.getModule()->getDataLayout();
-
-  // We can only transform this if it is safe to push the loads into the
-  // predecessor blocks. The only thing to watch out for is that we can't put
-  // a possibly trapping load in the predecessor if it is a critical edge.
-  for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num; ++Idx) {
-    Instruction *TI = PN.getIncomingBlock(Idx)->getTerminator();
-    Value *InVal = PN.getIncomingValue(Idx);
-
-    // If the value is produced by the terminator of the predecessor (an
-    // invoke) or it has side-effects, there is no valid place to put a load
-    // in the predecessor.
-    if (TI == InVal || TI->mayHaveSideEffects())
-      return false;
-
-    // If the predecessor has a single successor, then the edge isn't
-    // critical.
-    if (TI->getNumSuccessors() == 1)
-      continue;
-
-    // If this pointer is always safe to load, or if we can prove that there
-    // is already a load in the block, then we can move the load to the pred
-    // block.
-    if (isSafeToLoadUnconditionally(InVal, MaxAlign, DL, TI))
-      continue;
-
-    return false;
-  }
-
-  return true;
-}
-
-static void speculatePHINodeLoads(PHINode &PN) {
-  LLVM_DEBUG(dbgs() << "    original: " << PN << "\n");
-
-  Type *LoadTy = cast<PointerType>(PN.getType())->getElementType();
-  IRBuilderTy PHIBuilder(&PN);
-  PHINode *NewPN = PHIBuilder.CreatePHI(LoadTy, PN.getNumIncomingValues(),
-                                        PN.getName() + ".sroa.speculated");
-
-  // Get the AA tags and alignment to use from one of the loads.  It doesn't
-  // matter which one we get and if any differ.
-  LoadInst *SomeLoad = cast<LoadInst>(PN.user_back());
-
-  AAMDNodes AATags;
-  SomeLoad->getAAMetadata(AATags);
-  unsigned Align = SomeLoad->getAlignment();
-
-  // Rewrite all loads of the PN to use the new PHI.
-  while (!PN.use_empty()) {
-    LoadInst *LI = cast<LoadInst>(PN.user_back());
-    LI->replaceAllUsesWith(NewPN);
-    LI->eraseFromParent();
-  }
-
-  // Inject loads into all of the pred blocks.
-  DenseMap<BasicBlock*, Value*> InjectedLoads;
-  for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num; ++Idx) {
-    BasicBlock *Pred = PN.getIncomingBlock(Idx);
-    Value *InVal = PN.getIncomingValue(Idx);
-
-    // A PHI node is allowed to have multiple (duplicated) entries for the same
-    // basic block, as long as the value is the same. So if we already injected
-    // a load in the predecessor, then we should reuse the same load for all
-    // duplicated entries.
-    if (Value* V = InjectedLoads.lookup(Pred)) {
-      NewPN->addIncoming(V, Pred);
-      continue;
-    }
-
-    Instruction *TI = Pred->getTerminator();
-    IRBuilderTy PredBuilder(TI);
-
-    LoadInst *Load = PredBuilder.CreateLoad(
-        InVal, (PN.getName() + ".sroa.speculate.load." + Pred->getName()));
-    ++NumLoadsSpeculated;
-    Load->setAlignment(Align);
-    if (AATags)
-      Load->setAAMetadata(AATags);
-    NewPN->addIncoming(Load, Pred);
-    InjectedLoads[Pred] = Load;
-  }
-
-  LLVM_DEBUG(dbgs() << "          speculated to: " << *NewPN << "\n");
-  PN.eraseFromParent();
-}
-
-/// Select instructions that use an alloca and are subsequently loaded can be
-/// rewritten to load both input pointers and then select between the result,
-/// allowing the load of the alloca to be promoted.
-/// From this:
-///   %P2 = select i1 %cond, i32* %Alloca, i32* %Other
-///   %V = load i32* %P2
-/// to:
-///   %V1 = load i32* %Alloca      -> will be mem2reg'd
-///   %V2 = load i32* %Other
-///   %V = select i1 %cond, i32 %V1, i32 %V2
-///
-/// We can do this to a select if its only uses are loads and if the operand
-/// to the select can be loaded unconditionally.
-static bool isSafeSelectToSpeculate(SelectInst &SI) {
-  Value *TValue = SI.getTrueValue();
-  Value *FValue = SI.getFalseValue();
-  const DataLayout &DL = SI.getModule()->getDataLayout();
-
-  for (User *U : SI.users()) {
-    LoadInst *LI = dyn_cast<LoadInst>(U);
-    if (!LI || !LI->isSimple())
-      return false;
-
-    // Both operands to the select need to be dereferenceable, either
-    // absolutely (e.g. allocas) or at this point because we can see other
-    // accesses to it.
-    if (!isSafeToLoadUnconditionally(TValue, LI->getAlignment(), DL, LI))
-      return false;
-    if (!isSafeToLoadUnconditionally(FValue, LI->getAlignment(), DL, LI))
-      return false;
-  }
-
-  return true;
-}
-
-static void speculateSelectInstLoads(SelectInst &SI) {
-  LLVM_DEBUG(dbgs() << "    original: " << SI << "\n");
-
-  IRBuilderTy IRB(&SI);
-  Value *TV = SI.getTrueValue();
-  Value *FV = SI.getFalseValue();
-  // Replace the loads of the select with a select of two loads.
-  while (!SI.use_empty()) {
-    LoadInst *LI = cast<LoadInst>(SI.user_back());
-    assert(LI->isSimple() && "We only speculate simple loads");
-
-    IRB.SetInsertPoint(LI);
-    LoadInst *TL =
-        IRB.CreateLoad(TV, LI->getName() + ".sroa.speculate.load.true");
-    LoadInst *FL =
-        IRB.CreateLoad(FV, LI->getName() + ".sroa.speculate.load.false");
-    NumLoadsSpeculated += 2;
-
-    // Transfer alignment and AA info if present.
-    TL->setAlignment(LI->getAlignment());
-    FL->setAlignment(LI->getAlignment());
-
-    AAMDNodes Tags;
-    LI->getAAMetadata(Tags);
-    if (Tags) {
-      TL->setAAMetadata(Tags);
-      FL->setAAMetadata(Tags);
-    }
-
-    Value *V = IRB.CreateSelect(SI.getCondition(), TL, FL,
-                                LI->getName() + ".sroa.speculated");
-
-    LLVM_DEBUG(dbgs() << "          speculated to: " << *V << "\n");
-    LI->replaceAllUsesWith(V);
-    LI->eraseFromParent();
-  }
-  SI.eraseFromParent();
-}
-
-/// Build a GEP out of a base pointer and indices.
-///
-/// This will return the BasePtr if that is valid, or build a new GEP
-/// instruction using the IRBuilder if GEP-ing is needed.
-static Value *buildGEP(IRBuilderTy &IRB, Value *BasePtr,
-                       SmallVectorImpl<Value *> &Indices, Twine NamePrefix) {
-  if (Indices.empty())
-    return BasePtr;
-
-  // A single zero index is a no-op, so check for this and avoid building a GEP
-  // in that case.
-  if (Indices.size() == 1 && cast<ConstantInt>(Indices.back())->isZero())
-    return BasePtr;
-
-  return IRB.CreateInBoundsGEP(nullptr, BasePtr, Indices,
-                               NamePrefix + "sroa_idx");
-}
-
-/// Get a natural GEP off of the BasePtr walking through Ty toward
-/// TargetTy without changing the offset of the pointer.
-///
-/// This routine assumes we've already established a properly offset GEP with
-/// Indices, and arrived at the Ty type. The goal is to continue to GEP with
-/// zero-indices down through type layers until we find one the same as
-/// TargetTy. If we can't find one with the same type, we at least try to use
-/// one with the same size. If none of that works, we just produce the GEP as
-/// indicated by Indices to have the correct offset.
-static Value *getNaturalGEPWithType(IRBuilderTy &IRB, const DataLayout &DL,
-                                    Value *BasePtr, Type *Ty, Type *TargetTy,
-                                    SmallVectorImpl<Value *> &Indices,
-                                    Twine NamePrefix) {
-  if (Ty == TargetTy)
-    return buildGEP(IRB, BasePtr, Indices, NamePrefix);
-
-  // Offset size to use for the indices.
-  unsigned OffsetSize = DL.getIndexTypeSizeInBits(BasePtr->getType());
-
-  // See if we can descend into a struct and locate a field with the correct
-  // type.
-  unsigned NumLayers = 0;
-  Type *ElementTy = Ty;
-  do {
-    if (ElementTy->isPointerTy())
-      break;
-
-    if (ArrayType *ArrayTy = dyn_cast<ArrayType>(ElementTy)) {
-      ElementTy = ArrayTy->getElementType();
-      Indices.push_back(IRB.getIntN(OffsetSize, 0));
-    } else if (VectorType *VectorTy = dyn_cast<VectorType>(ElementTy)) {
-      ElementTy = VectorTy->getElementType();
-      Indices.push_back(IRB.getInt32(0));
-    } else if (StructType *STy = dyn_cast<StructType>(ElementTy)) {
-      if (STy->element_begin() == STy->element_end())
-        break; // Nothing left to descend into.
-      ElementTy = *STy->element_begin();
-      Indices.push_back(IRB.getInt32(0));
-    } else {
-      break;
-    }
-    ++NumLayers;
-  } while (ElementTy != TargetTy);
-  if (ElementTy != TargetTy)
-    Indices.erase(Indices.end() - NumLayers, Indices.end());
-
-  return buildGEP(IRB, BasePtr, Indices, NamePrefix);
-}
-
-/// Recursively compute indices for a natural GEP.
-///
-/// This is the recursive step for getNaturalGEPWithOffset that walks down the
-/// element types adding appropriate indices for the GEP.
-static Value *getNaturalGEPRecursively(IRBuilderTy &IRB, const DataLayout &DL,
-                                       Value *Ptr, Type *Ty, APInt &Offset,
-                                       Type *TargetTy,
-                                       SmallVectorImpl<Value *> &Indices,
-                                       Twine NamePrefix) {
-  if (Offset == 0)
-    return getNaturalGEPWithType(IRB, DL, Ptr, Ty, TargetTy, Indices,
-                                 NamePrefix);
-
-  // We can't recurse through pointer types.
-  if (Ty->isPointerTy())
-    return nullptr;
-
-  // We try to analyze GEPs over vectors here, but note that these GEPs are
-  // extremely poorly defined currently. The long-term goal is to remove GEPing
-  // over a vector from the IR completely.
-  if (VectorType *VecTy = dyn_cast<VectorType>(Ty)) {
-    unsigned ElementSizeInBits = DL.getTypeSizeInBits(VecTy->getScalarType());
-    if (ElementSizeInBits % 8 != 0) {
-      // GEPs over non-multiple of 8 size vector elements are invalid.
-      return nullptr;
-    }
-    APInt ElementSize(Offset.getBitWidth(), ElementSizeInBits / 8);
-    APInt NumSkippedElements = Offset.sdiv(ElementSize);
-    if (NumSkippedElements.ugt(VecTy->getNumElements()))
-      return nullptr;
-    Offset -= NumSkippedElements * ElementSize;
-    Indices.push_back(IRB.getInt(NumSkippedElements));
-    return getNaturalGEPRecursively(IRB, DL, Ptr, VecTy->getElementType(),
-                                    Offset, TargetTy, Indices, NamePrefix);
-  }
-
-  if (ArrayType *ArrTy = dyn_cast<ArrayType>(Ty)) {
-    Type *ElementTy = ArrTy->getElementType();
-    APInt ElementSize(Offset.getBitWidth(), DL.getTypeAllocSize(ElementTy));
-    APInt NumSkippedElements = Offset.sdiv(ElementSize);
-    if (NumSkippedElements.ugt(ArrTy->getNumElements()))
-      return nullptr;
-
-    Offset -= NumSkippedElements * ElementSize;
-    Indices.push_back(IRB.getInt(NumSkippedElements));
-    return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
-                                    Indices, NamePrefix);
-  }
-
-  StructType *STy = dyn_cast<StructType>(Ty);
-  if (!STy)
-    return nullptr;
-
-  const StructLayout *SL = DL.getStructLayout(STy);
-  uint64_t StructOffset = Offset.getZExtValue();
-  if (StructOffset >= SL->getSizeInBytes())
-    return nullptr;
-  unsigned Index = SL->getElementContainingOffset(StructOffset);
-  Offset -= APInt(Offset.getBitWidth(), SL->getElementOffset(Index));
-  Type *ElementTy = STy->getElementType(Index);
-  if (Offset.uge(DL.getTypeAllocSize(ElementTy)))
-    return nullptr; // The offset points into alignment padding.
-
-  Indices.push_back(IRB.getInt32(Index));
-  return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
-                                  Indices, NamePrefix);
-}
-
-/// Get a natural GEP from a base pointer to a particular offset and
-/// resulting in a particular type.
-///
-/// The goal is to produce a "natural" looking GEP that works with the existing
-/// composite types to arrive at the appropriate offset and element type for
-/// a pointer. TargetTy is the element type the returned GEP should point-to if
-/// possible. We recurse by decreasing Offset, adding the appropriate index to
-/// Indices, and setting Ty to the result subtype.
-///
-/// If no natural GEP can be constructed, this function returns null.
-static Value *getNaturalGEPWithOffset(IRBuilderTy &IRB, const DataLayout &DL,
-                                      Value *Ptr, APInt Offset, Type *TargetTy,
-                                      SmallVectorImpl<Value *> &Indices,
-                                      Twine NamePrefix) {
-  PointerType *Ty = cast<PointerType>(Ptr->getType());
-
-  // Don't consider any GEPs through an i8* as natural unless the TargetTy is
-  // an i8.
-  if (Ty == IRB.getInt8PtrTy(Ty->getAddressSpace()) && TargetTy->isIntegerTy(8))
-    return nullptr;
-
-  Type *ElementTy = Ty->getElementType();
-  if (!ElementTy->isSized())
-    return nullptr; // We can't GEP through an unsized element.
-  APInt ElementSize(Offset.getBitWidth(), DL.getTypeAllocSize(ElementTy));
-  if (ElementSize == 0)
-    return nullptr; // Zero-length arrays can't help us build a natural GEP.
-  APInt NumSkippedElements = Offset.sdiv(ElementSize);
-
-  Offset -= NumSkippedElements * ElementSize;
-  Indices.push_back(IRB.getInt(NumSkippedElements));
-  return getNaturalGEPRecursively(IRB, DL, Ptr, ElementTy, Offset, TargetTy,
-                                  Indices, NamePrefix);
-}
-
-/// Compute an adjusted pointer from Ptr by Offset bytes where the
-/// resulting pointer has PointerTy.
-///
-/// This tries very hard to compute a "natural" GEP which arrives at the offset
-/// and produces the pointer type desired. Where it cannot, it will try to use
-/// the natural GEP to arrive at the offset and bitcast to the type. Where that
-/// fails, it will try to use an existing i8* and GEP to the byte offset and
-/// bitcast to the type.
-///
-/// The strategy for finding the more natural GEPs is to peel off layers of the
-/// pointer, walking back through bit casts and GEPs, searching for a base
-/// pointer from which we can compute a natural GEP with the desired
-/// properties. The algorithm tries to fold as many constant indices into
-/// a single GEP as possible, thus making each GEP more independent of the
-/// surrounding code.
-static Value *getAdjustedPtr(IRBuilderTy &IRB, const DataLayout &DL, Value *Ptr,
-                             APInt Offset, Type *PointerTy, Twine NamePrefix) {
-  // Even though we don't look through PHI nodes, we could be called on an
-  // instruction in an unreachable block, which may be on a cycle.
-  SmallPtrSet<Value *, 4> Visited;
-  Visited.insert(Ptr);
-  SmallVector<Value *, 4> Indices;
-
-  // We may end up computing an offset pointer that has the wrong type. If we
-  // never are able to compute one directly that has the correct type, we'll
-  // fall back to it, so keep it and the base it was computed from around here.
-  Value *OffsetPtr = nullptr;
-  Value *OffsetBasePtr;
-
-  // Remember any i8 pointer we come across to re-use if we need to do a raw
-  // byte offset.
-  Value *Int8Ptr = nullptr;
-  APInt Int8PtrOffset(Offset.getBitWidth(), 0);
-
-  Type *TargetTy = PointerTy->getPointerElementType();
-
-  do {
-    // First fold any existing GEPs into the offset.
-    while (GEPOperator *GEP = dyn_cast<GEPOperator>(Ptr)) {
-      APInt GEPOffset(Offset.getBitWidth(), 0);
-      if (!GEP->accumulateConstantOffset(DL, GEPOffset))
-        break;
-      Offset += GEPOffset;
-      Ptr = GEP->getPointerOperand();
-      if (!Visited.insert(Ptr).second)
-        break;
-    }
-
-    // See if we can perform a natural GEP here.
-    Indices.clear();
-    if (Value *P = getNaturalGEPWithOffset(IRB, DL, Ptr, Offset, TargetTy,
-                                           Indices, NamePrefix)) {
-      // If we have a new natural pointer at the offset, clear out any old
-      // offset pointer we computed. Unless it is the base pointer or
-      // a non-instruction, we built a GEP we don't need. Zap it.
-      if (OffsetPtr && OffsetPtr != OffsetBasePtr)
-        if (Instruction *I = dyn_cast<Instruction>(OffsetPtr)) {
-          assert(I->use_empty() && "Built a GEP with uses some how!");
-          I->eraseFromParent();
-        }
-      OffsetPtr = P;
-      OffsetBasePtr = Ptr;
-      // If we also found a pointer of the right type, we're done.
-      if (P->getType() == PointerTy)
-        return P;
-    }
-
-    // Stash this pointer if we've found an i8*.
-    if (Ptr->getType()->isIntegerTy(8)) {
-      Int8Ptr = Ptr;
-      Int8PtrOffset = Offset;
-    }
-
-    // Peel off a layer of the pointer and update the offset appropriately.
-    if (Operator::getOpcode(Ptr) == Instruction::BitCast) {
-      Ptr = cast<Operator>(Ptr)->getOperand(0);
-    } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(Ptr)) {
-      if (GA->isInterposable())
-        break;
-      Ptr = GA->getAliasee();
-    } else {
-      break;
-    }
-    assert(Ptr->getType()->isPointerTy() && "Unexpected operand type!");
-  } while (Visited.insert(Ptr).second);
-
-  if (!OffsetPtr) {
-    if (!Int8Ptr) {
-      Int8Ptr = IRB.CreateBitCast(
-          Ptr, IRB.getInt8PtrTy(PointerTy->getPointerAddressSpace()),
-          NamePrefix + "sroa_raw_cast");
-      Int8PtrOffset = Offset;
-    }
-
-    OffsetPtr = Int8PtrOffset == 0
-                    ? Int8Ptr
-                    : IRB.CreateInBoundsGEP(IRB.getInt8Ty(), Int8Ptr,
-                                            IRB.getInt(Int8PtrOffset),
-                                            NamePrefix + "sroa_raw_idx");
-  }
-  Ptr = OffsetPtr;
-
-  // On the off chance we were targeting i8*, guard the bitcast here.
-  if (Ptr->getType() != PointerTy)
-    Ptr = IRB.CreateBitCast(Ptr, PointerTy, NamePrefix + "sroa_cast");
-
-  return Ptr;
-}
-
-/// Compute the adjusted alignment for a load or store from an offset.
-static unsigned getAdjustedAlignment(Instruction *I, uint64_t Offset,
-                                     const DataLayout &DL) {
-  unsigned Alignment;
-  Type *Ty;
-  if (auto *LI = dyn_cast<LoadInst>(I)) {
-    Alignment = LI->getAlignment();
-    Ty = LI->getType();
-  } else if (auto *SI = dyn_cast<StoreInst>(I)) {
-    Alignment = SI->getAlignment();
-    Ty = SI->getValueOperand()->getType();
-  } else {
-    llvm_unreachable("Only loads and stores are allowed!");
-  }
-
-  if (!Alignment)
-    Alignment = DL.getABITypeAlignment(Ty);
-
-  return MinAlign(Alignment, Offset);
-}
-
-/// Test whether we can convert a value from the old to the new type.
-///
-/// This predicate should be used to guard calls to convertValue in order to
-/// ensure that we only try to convert viable values. The strategy is that we
-/// will peel off single element struct and array wrappings to get to an
-/// underlying value, and convert that value.
-static bool canConvertValue(const DataLayout &DL, Type *OldTy, Type *NewTy) {
-  if (OldTy == NewTy)
-    return true;
-
-  // For integer types, we can't handle any bit-width differences. This would
-  // break both vector conversions with extension and introduce endianness
-  // issues when in conjunction with loads and stores.
-  if (isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) {
-    assert(cast<IntegerType>(OldTy)->getBitWidth() !=
-               cast<IntegerType>(NewTy)->getBitWidth() &&
-           "We can't have the same bitwidth for different int types");
-    return false;
-  }
-
-  if (DL.getTypeSizeInBits(NewTy) != DL.getTypeSizeInBits(OldTy))
-    return false;
-  if (!NewTy->isSingleValueType() || !OldTy->isSingleValueType())
-    return false;
-
-  // We can convert pointers to integers and vice-versa. Same for vectors
-  // of pointers and integers.
-  OldTy = OldTy->getScalarType();
-  NewTy = NewTy->getScalarType();
-  if (NewTy->isPointerTy() || OldTy->isPointerTy()) {
-    if (NewTy->isPointerTy() && OldTy->isPointerTy()) {
-      return cast<PointerType>(NewTy)->getPointerAddressSpace() ==
-        cast<PointerType>(OldTy)->getPointerAddressSpace();
-    }
-
-    // We can convert integers to integral pointers, but not to non-integral
-    // pointers.
-    if (OldTy->isIntegerTy())
-      return !DL.isNonIntegralPointerType(NewTy);
-
-    // We can convert integral pointers to integers, but non-integral pointers
-    // need to remain pointers.
-    if (!DL.isNonIntegralPointerType(OldTy))
-      return NewTy->isIntegerTy();
-
-    return false;
-  }
-
-  return true;
-}
-
-/// Generic routine to convert an SSA value to a value of a different
-/// type.
-///
-/// This will try various different casting techniques, such as bitcasts,
-/// inttoptr, and ptrtoint casts. Use the \c canConvertValue predicate to test
-/// two types for viability with this routine.
-static Value *convertValue(const DataLayout &DL, IRBuilderTy &IRB, Value *V,
-                           Type *NewTy) {
-  Type *OldTy = V->getType();
-  assert(canConvertValue(DL, OldTy, NewTy) && "Value not convertable to type");
-
-  if (OldTy == NewTy)
-    return V;
-
-  assert(!(isa<IntegerType>(OldTy) && isa<IntegerType>(NewTy)) &&
-         "Integer types must be the exact same to convert.");
-
-  // See if we need inttoptr for this type pair. A cast involving both scalars
-  // and vectors requires and additional bitcast.
-  if (OldTy->isIntOrIntVectorTy() && NewTy->isPtrOrPtrVectorTy()) {
-    // Expand <2 x i32> to i8* --> <2 x i32> to i64 to i8*
-    if (OldTy->isVectorTy() && !NewTy->isVectorTy())
-      return IRB.CreateIntToPtr(IRB.CreateBitCast(V, DL.getIntPtrType(NewTy)),
-                                NewTy);
-
-    // Expand i128 to <2 x i8*> --> i128 to <2 x i64> to <2 x i8*>
-    if (!OldTy->isVectorTy() && NewTy->isVectorTy())
-      return IRB.CreateIntToPtr(IRB.CreateBitCast(V, DL.getIntPtrType(NewTy)),
-                                NewTy);
-
-    return IRB.CreateIntToPtr(V, NewTy);
-  }
-
-  // See if we need ptrtoint for this type pair. A cast involving both scalars
-  // and vectors requires and additional bitcast.
-  if (OldTy->isPtrOrPtrVectorTy() && NewTy->isIntOrIntVectorTy()) {
-    // Expand <2 x i8*> to i128 --> <2 x i8*> to <2 x i64> to i128
-    if (OldTy->isVectorTy() && !NewTy->isVectorTy())
-      return IRB.CreateBitCast(IRB.CreatePtrToInt(V, DL.getIntPtrType(OldTy)),
-                               NewTy);
-
-    // Expand i8* to <2 x i32> --> i8* to i64 to <2 x i32>
-    if (!OldTy->isVectorTy() && NewTy->isVectorTy())
-      return IRB.CreateBitCast(IRB.CreatePtrToInt(V, DL.getIntPtrType(OldTy)),
-                               NewTy);
-
-    return IRB.CreatePtrToInt(V, NewTy);
-  }
-
-  return IRB.CreateBitCast(V, NewTy);
-}
-
-/// Test whether the given slice use can be promoted to a vector.
-///
-/// This function is called to test each entry in a partition which is slated
-/// for a single slice.
-static bool isVectorPromotionViableForSlice(Partition &P, const Slice &S,
-                                            VectorType *Ty,
-                                            uint64_t ElementSize,
-                                            const DataLayout &DL) {
-  // First validate the slice offsets.
-  uint64_t BeginOffset =
-      std::max(S.beginOffset(), P.beginOffset()) - P.beginOffset();
-  uint64_t BeginIndex = BeginOffset / ElementSize;
-  if (BeginIndex * ElementSize != BeginOffset ||
-      BeginIndex >= Ty->getNumElements())
-    return false;
-  uint64_t EndOffset =
-      std::min(S.endOffset(), P.endOffset()) - P.beginOffset();
-  uint64_t EndIndex = EndOffset / ElementSize;
-  if (EndIndex * ElementSize != EndOffset || EndIndex > Ty->getNumElements())
-    return false;
-
-  assert(EndIndex > BeginIndex && "Empty vector!");
-  uint64_t NumElements = EndIndex - BeginIndex;
-  Type *SliceTy = (NumElements == 1)
-                      ? Ty->getElementType()
-                      : VectorType::get(Ty->getElementType(), NumElements);
-
-  Type *SplitIntTy =
-      Type::getIntNTy(Ty->getContext(), NumElements * ElementSize * 8);
-
-  Use *U = S.getUse();
-
-  if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(U->getUser())) {
-    if (MI->isVolatile())
-      return false;
-    if (!S.isSplittable())
-      return false; // Skip any unsplittable intrinsics.
-  } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U->getUser())) {
-    if (!II->isLifetimeStartOrEnd())
-      return false;
-  } else if (U->get()->getType()->getPointerElementType()->isStructTy()) {
-    // Disable vector promotion when there are loads or stores of an FCA.
-    return false;
-  } else if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
-    if (LI->isVolatile())
-      return false;
-    Type *LTy = LI->getType();
-    if (P.beginOffset() > S.beginOffset() || P.endOffset() < S.endOffset()) {
-      assert(LTy->isIntegerTy());
-      LTy = SplitIntTy;
-    }
-    if (!canConvertValue(DL, SliceTy, LTy))
-      return false;
-  } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
-    if (SI->isVolatile())
-      return false;
-    Type *STy = SI->getValueOperand()->getType();
-    if (P.beginOffset() > S.beginOffset() || P.endOffset() < S.endOffset()) {
-      assert(STy->isIntegerTy());
-      STy = SplitIntTy;
-    }
-    if (!canConvertValue(DL, STy, SliceTy))
-      return false;
-  } else {
-    return false;
-  }
-
-  return true;
-}
-
-/// Test whether the given alloca partitioning and range of slices can be
-/// promoted to a vector.
-///
-/// This is a quick test to check whether we can rewrite a particular alloca
-/// partition (and its newly formed alloca) into a vector alloca with only
-/// whole-vector loads and stores such that it could be promoted to a vector
-/// SSA value. We only can ensure this for a limited set of operations, and we
-/// don't want to do the rewrites unless we are confident that the result will
-/// be promotable, so we have an early test here.
-static VectorType *isVectorPromotionViable(Partition &P, const DataLayout &DL) {
-  // Collect the candidate types for vector-based promotion. Also track whether
-  // we have different element types.
-  SmallVector<VectorType *, 4> CandidateTys;
-  Type *CommonEltTy = nullptr;
-  bool HaveCommonEltTy = true;
-  auto CheckCandidateType = [&](Type *Ty) {
-    if (auto *VTy = dyn_cast<VectorType>(Ty)) {
-      CandidateTys.push_back(VTy);
-      if (!CommonEltTy)
-        CommonEltTy = VTy->getElementType();
-      else if (CommonEltTy != VTy->getElementType())
-        HaveCommonEltTy = false;
-    }
-  };
-  // Consider any loads or stores that are the exact size of the slice.
-  for (const Slice &S : P)
-    if (S.beginOffset() == P.beginOffset() &&
-        S.endOffset() == P.endOffset()) {
-      if (auto *LI = dyn_cast<LoadInst>(S.getUse()->getUser()))
-        CheckCandidateType(LI->getType());
-      else if (auto *SI = dyn_cast<StoreInst>(S.getUse()->getUser()))
-        CheckCandidateType(SI->getValueOperand()->getType());
-    }
-
-  // If we didn't find a vector type, nothing to do here.
-  if (CandidateTys.empty())
-    return nullptr;
-
-  // Remove non-integer vector types if we had multiple common element types.
-  // FIXME: It'd be nice to replace them with integer vector types, but we can't
-  // do that until all the backends are known to produce good code for all
-  // integer vector types.
-  if (!HaveCommonEltTy) {
-    CandidateTys.erase(
-        llvm::remove_if(CandidateTys,
-                        [](VectorType *VTy) {
-                          return !VTy->getElementType()->isIntegerTy();
-                        }),
-        CandidateTys.end());
-
-    // If there were no integer vector types, give up.
-    if (CandidateTys.empty())
-      return nullptr;
-
-    // Rank the remaining candidate vector types. This is easy because we know
-    // they're all integer vectors. We sort by ascending number of elements.
-    auto RankVectorTypes = [&DL](VectorType *RHSTy, VectorType *LHSTy) {
-      (void)DL;
-      assert(DL.getTypeSizeInBits(RHSTy) == DL.getTypeSizeInBits(LHSTy) &&
-             "Cannot have vector types of different sizes!");
-      assert(RHSTy->getElementType()->isIntegerTy() &&
-             "All non-integer types eliminated!");
-      assert(LHSTy->getElementType()->isIntegerTy() &&
-             "All non-integer types eliminated!");
-      return RHSTy->getNumElements() < LHSTy->getNumElements();
-    };
-    llvm::sort(CandidateTys, RankVectorTypes);
-    CandidateTys.erase(
-        std::unique(CandidateTys.begin(), CandidateTys.end(), RankVectorTypes),
-        CandidateTys.end());
-  } else {
-// The only way to have the same element type in every vector type is to
-// have the same vector type. Check that and remove all but one.
-#ifndef NDEBUG
-    for (VectorType *VTy : CandidateTys) {
-      assert(VTy->getElementType() == CommonEltTy &&
-             "Unaccounted for element type!");
-      assert(VTy == CandidateTys[0] &&
-             "Different vector types with the same element type!");
-    }
-#endif
-    CandidateTys.resize(1);
-  }
-
-  // Try each vector type, and return the one which works.
-  auto CheckVectorTypeForPromotion = [&](VectorType *VTy) {
-    uint64_t ElementSize = DL.getTypeSizeInBits(VTy->getElementType());
-
-    // While the definition of LLVM vectors is bitpacked, we don't support sizes
-    // that aren't byte sized.
-    if (ElementSize % 8)
-      return false;
-    assert((DL.getTypeSizeInBits(VTy) % 8) == 0 &&
-           "vector size not a multiple of element size?");
-    ElementSize /= 8;
-
-    for (const Slice &S : P)
-      if (!isVectorPromotionViableForSlice(P, S, VTy, ElementSize, DL))
-        return false;
-
-    for (const Slice *S : P.splitSliceTails())
-      if (!isVectorPromotionViableForSlice(P, *S, VTy, ElementSize, DL))
-        return false;
-
-    return true;
-  };
-  for (VectorType *VTy : CandidateTys)
-    if (CheckVectorTypeForPromotion(VTy))
-      return VTy;
-
-  return nullptr;
-}
-
-/// Test whether a slice of an alloca is valid for integer widening.
-///
-/// This implements the necessary checking for the \c isIntegerWideningViable
-/// test below on a single slice of the alloca.
-static bool isIntegerWideningViableForSlice(const Slice &S,
-                                            uint64_t AllocBeginOffset,
-                                            Type *AllocaTy,
-                                            const DataLayout &DL,
-                                            bool &WholeAllocaOp) {
-  uint64_t Size = DL.getTypeStoreSize(AllocaTy);
-
-  uint64_t RelBegin = S.beginOffset() - AllocBeginOffset;
-  uint64_t RelEnd = S.endOffset() - AllocBeginOffset;
-
-  // We can't reasonably handle cases where the load or store extends past
-  // the end of the alloca's type and into its padding.
-  if (RelEnd > Size)
-    return false;
-
-  Use *U = S.getUse();
-
-  if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
-    if (LI->isVolatile())
-      return false;
-    // We can't handle loads that extend past the allocated memory.
-    if (DL.getTypeStoreSize(LI->getType()) > Size)
-      return false;
-    // So far, AllocaSliceRewriter does not support widening split slice tails
-    // in rewriteIntegerLoad.
-    if (S.beginOffset() < AllocBeginOffset)
-      return false;
-    // Note that we don't count vector loads or stores as whole-alloca
-    // operations which enable integer widening because we would prefer to use
-    // vector widening instead.
-    if (!isa<VectorType>(LI->getType()) && RelBegin == 0 && RelEnd == Size)
-      WholeAllocaOp = true;
-    if (IntegerType *ITy = dyn_cast<IntegerType>(LI->getType())) {
-      if (ITy->getBitWidth() < DL.getTypeStoreSizeInBits(ITy))
-        return false;
-    } else if (RelBegin != 0 || RelEnd != Size ||
-               !canConvertValue(DL, AllocaTy, LI->getType())) {
-      // Non-integer loads need to be convertible from the alloca type so that
-      // they are promotable.
-      return false;
-    }
-  } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
-    Type *ValueTy = SI->getValueOperand()->getType();
-    if (SI->isVolatile())
-      return false;
-    // We can't handle stores that extend past the allocated memory.
-    if (DL.getTypeStoreSize(ValueTy) > Size)
-      return false;
-    // So far, AllocaSliceRewriter does not support widening split slice tails
-    // in rewriteIntegerStore.
-    if (S.beginOffset() < AllocBeginOffset)
-      return false;
-    // Note that we don't count vector loads or stores as whole-alloca
-    // operations which enable integer widening because we would prefer to use
-    // vector widening instead.
-    if (!isa<VectorType>(ValueTy) && RelBegin == 0 && RelEnd == Size)
-      WholeAllocaOp = true;
-    if (IntegerType *ITy = dyn_cast<IntegerType>(ValueTy)) {
-      if (ITy->getBitWidth() < DL.getTypeStoreSizeInBits(ITy))
-        return false;
-    } else if (RelBegin != 0 || RelEnd != Size ||
-               !canConvertValue(DL, ValueTy, AllocaTy)) {
-      // Non-integer stores need to be convertible to the alloca type so that
-      // they are promotable.
-      return false;
-    }
-  } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(U->getUser())) {
-    if (MI->isVolatile() || !isa<Constant>(MI->getLength()))
-      return false;
-    if (!S.isSplittable())
-      return false; // Skip any unsplittable intrinsics.
-  } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U->getUser())) {
-    if (!II->isLifetimeStartOrEnd())
-      return false;
-  } else {
-    return false;
-  }
-
-  return true;
-}
-
-/// Test whether the given alloca partition's integer operations can be
-/// widened to promotable ones.
-///
-/// This is a quick test to check whether we can rewrite the integer loads and
-/// stores to a particular alloca into wider loads and stores and be able to
-/// promote the resulting alloca.
-static bool isIntegerWideningViable(Partition &P, Type *AllocaTy,
-                                    const DataLayout &DL) {
-  uint64_t SizeInBits = DL.getTypeSizeInBits(AllocaTy);
-  // Don't create integer types larger than the maximum bitwidth.
-  if (SizeInBits > IntegerType::MAX_INT_BITS)
-    return false;
-
-  // Don't try to handle allocas with bit-padding.
-  if (SizeInBits != DL.getTypeStoreSizeInBits(AllocaTy))
-    return false;
-
-  // We need to ensure that an integer type with the appropriate bitwidth can
-  // be converted to the alloca type, whatever that is. We don't want to force
-  // the alloca itself to have an integer type if there is a more suitable one.
-  Type *IntTy = Type::getIntNTy(AllocaTy->getContext(), SizeInBits);
-  if (!canConvertValue(DL, AllocaTy, IntTy) ||
-      !canConvertValue(DL, IntTy, AllocaTy))
-    return false;
-
-  // While examining uses, we ensure that the alloca has a covering load or
-  // store. We don't want to widen the integer operations only to fail to
-  // promote due to some other unsplittable entry (which we may make splittable
-  // later). However, if there are only splittable uses, go ahead and assume
-  // that we cover the alloca.
-  // FIXME: We shouldn't consider split slices that happen to start in the
-  // partition here...
-  bool WholeAllocaOp =
-      P.begin() != P.end() ? false : DL.isLegalInteger(SizeInBits);
-
-  for (const Slice &S : P)
-    if (!isIntegerWideningViableForSlice(S, P.beginOffset(), AllocaTy, DL,
-                                         WholeAllocaOp))
-      return false;
-
-  for (const Slice *S : P.splitSliceTails())
-    if (!isIntegerWideningViableForSlice(*S, P.beginOffset(), AllocaTy, DL,
-                                         WholeAllocaOp))
-      return false;
-
-  return WholeAllocaOp;
-}
-
-static Value *extractInteger(const DataLayout &DL, IRBuilderTy &IRB, Value *V,
-                             IntegerType *Ty, uint64_t Offset,
-                             const Twine &Name) {
-  LLVM_DEBUG(dbgs() << "       start: " << *V << "\n");
-  IntegerType *IntTy = cast<IntegerType>(V->getType());
-  assert(DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) &&
-         "Element extends past full value");
-  uint64_t ShAmt = 8 * Offset;
-  if (DL.isBigEndian())
-    ShAmt = 8 * (DL.getTypeStoreSize(IntTy) - DL.getTypeStoreSize(Ty) - Offset);
-  if (ShAmt) {
-    V = IRB.CreateLShr(V, ShAmt, Name + ".shift");
-    LLVM_DEBUG(dbgs() << "     shifted: " << *V << "\n");
-  }
-  assert(Ty->getBitWidth() <= IntTy->getBitWidth() &&
-         "Cannot extract to a larger integer!");
-  if (Ty != IntTy) {
-    V = IRB.CreateTrunc(V, Ty, Name + ".trunc");
-    LLVM_DEBUG(dbgs() << "     trunced: " << *V << "\n");
-  }
-  return V;
-}
-
-static Value *insertInteger(const DataLayout &DL, IRBuilderTy &IRB, Value *Old,
-                            Value *V, uint64_t Offset, const Twine &Name) {
-  IntegerType *IntTy = cast<IntegerType>(Old->getType());
-  IntegerType *Ty = cast<IntegerType>(V->getType());
-  assert(Ty->getBitWidth() <= IntTy->getBitWidth() &&
-         "Cannot insert a larger integer!");
-  LLVM_DEBUG(dbgs() << "       start: " << *V << "\n");
-  if (Ty != IntTy) {
-    V = IRB.CreateZExt(V, IntTy, Name + ".ext");
-    LLVM_DEBUG(dbgs() << "    extended: " << *V << "\n");
-  }
-  assert(DL.getTypeStoreSize(Ty) + Offset <= DL.getTypeStoreSize(IntTy) &&
-         "Element store outside of alloca store");
-  uint64_t ShAmt = 8 * Offset;
-  if (DL.isBigEndian())
-    ShAmt = 8 * (DL.getTypeStoreSize(IntTy) - DL.getTypeStoreSize(Ty) - Offset);
-  if (ShAmt) {
-    V = IRB.CreateShl(V, ShAmt, Name + ".shift");
-    LLVM_DEBUG(dbgs() << "     shifted: " << *V << "\n");
-  }
-
-  if (ShAmt || Ty->getBitWidth() < IntTy->getBitWidth()) {
-    APInt Mask = ~Ty->getMask().zext(IntTy->getBitWidth()).shl(ShAmt);
-    Old = IRB.CreateAnd(Old, Mask, Name + ".mask");
-    LLVM_DEBUG(dbgs() << "      masked: " << *Old << "\n");
-    V = IRB.CreateOr(Old, V, Name + ".insert");
-    LLVM_DEBUG(dbgs() << "    inserted: " << *V << "\n");
-  }
-  return V;
-}
-
-static Value *extractVector(IRBuilderTy &IRB, Value *V, unsigned BeginIndex,
-                            unsigned EndIndex, const Twine &Name) {
-  VectorType *VecTy = cast<VectorType>(V->getType());
-  unsigned NumElements = EndIndex - BeginIndex;
-  assert(NumElements <= VecTy->getNumElements() && "Too many elements!");
-
-  if (NumElements == VecTy->getNumElements())
-    return V;
-
-  if (NumElements == 1) {
-    V = IRB.CreateExtractElement(V, IRB.getInt32(BeginIndex),
-                                 Name + ".extract");
-    LLVM_DEBUG(dbgs() << "     extract: " << *V << "\n");
-    return V;
-  }
-
-  SmallVector<Constant *, 8> Mask;
-  Mask.reserve(NumElements);
-  for (unsigned i = BeginIndex; i != EndIndex; ++i)
-    Mask.push_back(IRB.getInt32(i));
-  V = IRB.CreateShuffleVector(V, UndefValue::get(V->getType()),
-                              ConstantVector::get(Mask), Name + ".extract");
-  LLVM_DEBUG(dbgs() << "     shuffle: " << *V << "\n");
-  return V;
-}
-
-static Value *insertVector(IRBuilderTy &IRB, Value *Old, Value *V,
-                           unsigned BeginIndex, const Twine &Name) {
-  VectorType *VecTy = cast<VectorType>(Old->getType());
-  assert(VecTy && "Can only insert a vector into a vector");
-
-  VectorType *Ty = dyn_cast<VectorType>(V->getType());
-  if (!Ty) {
-    // Single element to insert.
-    V = IRB.CreateInsertElement(Old, V, IRB.getInt32(BeginIndex),
-                                Name + ".insert");
-    LLVM_DEBUG(dbgs() << "     insert: " << *V << "\n");
-    return V;
-  }
-
-  assert(Ty->getNumElements() <= VecTy->getNumElements() &&
-         "Too many elements!");
-  if (Ty->getNumElements() == VecTy->getNumElements()) {
-    assert(V->getType() == VecTy && "Vector type mismatch");
-    return V;
-  }
-  unsigned EndIndex = BeginIndex + Ty->getNumElements();
-
-  // When inserting a smaller vector into the larger to store, we first
-  // use a shuffle vector to widen it with undef elements, and then
-  // a second shuffle vector to select between the loaded vector and the
-  // incoming vector.
-  SmallVector<Constant *, 8> Mask;
-  Mask.reserve(VecTy->getNumElements());
-  for (unsigned i = 0; i != VecTy->getNumElements(); ++i)
-    if (i >= BeginIndex && i < EndIndex)
-      Mask.push_back(IRB.getInt32(i - BeginIndex));
-    else
-      Mask.push_back(UndefValue::get(IRB.getInt32Ty()));
-  V = IRB.CreateShuffleVector(V, UndefValue::get(V->getType()),
-                              ConstantVector::get(Mask), Name + ".expand");
-  LLVM_DEBUG(dbgs() << "    shuffle: " << *V << "\n");
-
-  Mask.clear();
-  for (unsigned i = 0; i != VecTy->getNumElements(); ++i)
-    Mask.push_back(IRB.getInt1(i >= BeginIndex && i < EndIndex));
-
-  V = IRB.CreateSelect(ConstantVector::get(Mask), V, Old, Name + "blend");
-
-  LLVM_DEBUG(dbgs() << "    blend: " << *V << "\n");
-  return V;
-}
-
-/// Visitor to rewrite instructions using p particular slice of an alloca
-/// to use a new alloca.
-///
-/// Also implements the rewriting to vector-based accesses when the partition
-/// passes the isVectorPromotionViable predicate. Most of the rewriting logic
-/// lives here.
-class llvm::sroa::AllocaSliceRewriter
-    : public InstVisitor<AllocaSliceRewriter, bool> {
-  // Befriend the base class so it can delegate to private visit methods.
-  friend class InstVisitor<AllocaSliceRewriter, bool>;
-
-  using Base = InstVisitor<AllocaSliceRewriter, bool>;
-
-  const DataLayout &DL;
-  AllocaSlices &AS;
-  SROA &Pass;
-  AllocaInst &OldAI, &NewAI;
-  const uint64_t NewAllocaBeginOffset, NewAllocaEndOffset;
-  Type *NewAllocaTy;
-
-  // This is a convenience and flag variable that will be null unless the new
-  // alloca's integer operations should be widened to this integer type due to
-  // passing isIntegerWideningViable above. If it is non-null, the desired
-  // integer type will be stored here for easy access during rewriting.
-  IntegerType *IntTy;
-
-  // If we are rewriting an alloca partition which can be written as pure
-  // vector operations, we stash extra information here. When VecTy is
-  // non-null, we have some strict guarantees about the rewritten alloca:
-  //   - The new alloca is exactly the size of the vector type here.
-  //   - The accesses all either map to the entire vector or to a single
-  //     element.
-  //   - The set of accessing instructions is only one of those handled above
-  //     in isVectorPromotionViable. Generally these are the same access kinds
-  //     which are promotable via mem2reg.
-  VectorType *VecTy;
-  Type *ElementTy;
-  uint64_t ElementSize;
-
-  // The original offset of the slice currently being rewritten relative to
-  // the original alloca.
-  uint64_t BeginOffset = 0;
-  uint64_t EndOffset = 0;
-
-  // The new offsets of the slice currently being rewritten relative to the
-  // original alloca.
-  uint64_t NewBeginOffset, NewEndOffset;
-
-  uint64_t SliceSize;
-  bool IsSplittable = false;
-  bool IsSplit = false;
-  Use *OldUse = nullptr;
-  Instruction *OldPtr = nullptr;
-
-  // Track post-rewrite users which are PHI nodes and Selects.
-  SmallSetVector<PHINode *, 8> &PHIUsers;
-  SmallSetVector<SelectInst *, 8> &SelectUsers;
-
-  // Utility IR builder, whose name prefix is setup for each visited use, and
-  // the insertion point is set to point to the user.
-  IRBuilderTy IRB;
-
-public:
-  AllocaSliceRewriter(const DataLayout &DL, AllocaSlices &AS, SROA &Pass,
-                      AllocaInst &OldAI, AllocaInst &NewAI,
-                      uint64_t NewAllocaBeginOffset,
-                      uint64_t NewAllocaEndOffset, bool IsIntegerPromotable,
-                      VectorType *PromotableVecTy,
-                      SmallSetVector<PHINode *, 8> &PHIUsers,
-                      SmallSetVector<SelectInst *, 8> &SelectUsers)
-      : DL(DL), AS(AS), Pass(Pass), OldAI(OldAI), NewAI(NewAI),
-        NewAllocaBeginOffset(NewAllocaBeginOffset),
-        NewAllocaEndOffset(NewAllocaEndOffset),
-        NewAllocaTy(NewAI.getAllocatedType()),
-        IntTy(IsIntegerPromotable
-                  ? Type::getIntNTy(
-                        NewAI.getContext(),
-                        DL.getTypeSizeInBits(NewAI.getAllocatedType()))
-                  : nullptr),
-        VecTy(PromotableVecTy),
-        ElementTy(VecTy ? VecTy->getElementType() : nullptr),
-        ElementSize(VecTy ? DL.getTypeSizeInBits(ElementTy) / 8 : 0),
-        PHIUsers(PHIUsers), SelectUsers(SelectUsers),
-        IRB(NewAI.getContext(), ConstantFolder()) {
-    if (VecTy) {
-      assert((DL.getTypeSizeInBits(ElementTy) % 8) == 0 &&
-             "Only multiple-of-8 sized vector elements are viable");
-      ++NumVectorized;
-    }
-    assert((!IntTy && !VecTy) || (IntTy && !VecTy) || (!IntTy && VecTy));
-  }
-
-  bool visit(AllocaSlices::const_iterator I) {
-    bool CanSROA = true;
-    BeginOffset = I->beginOffset();
-    EndOffset = I->endOffset();
-    IsSplittable = I->isSplittable();
-    IsSplit =
-        BeginOffset < NewAllocaBeginOffset || EndOffset > NewAllocaEndOffset;
-    LLVM_DEBUG(dbgs() << "  rewriting " << (IsSplit ? "split " : ""));
-    LLVM_DEBUG(AS.printSlice(dbgs(), I, ""));
-    LLVM_DEBUG(dbgs() << "\n");
-
-    // Compute the intersecting offset range.
-    assert(BeginOffset < NewAllocaEndOffset);
-    assert(EndOffset > NewAllocaBeginOffset);
-    NewBeginOffset = std::max(BeginOffset, NewAllocaBeginOffset);
-    NewEndOffset = std::min(EndOffset, NewAllocaEndOffset);
-
-    SliceSize = NewEndOffset - NewBeginOffset;
-
-    OldUse = I->getUse();
-    OldPtr = cast<Instruction>(OldUse->get());
-
-    Instruction *OldUserI = cast<Instruction>(OldUse->getUser());
-    IRB.SetInsertPoint(OldUserI);
-    IRB.SetCurrentDebugLocation(OldUserI->getDebugLoc());
-    IRB.SetNamePrefix(Twine(NewAI.getName()) + "." + Twine(BeginOffset) + ".");
-
-    CanSROA &= visit(cast<Instruction>(OldUse->getUser()));
-    if (VecTy || IntTy)
-      assert(CanSROA);
-    return CanSROA;
-  }
-
-private:
-  // Make sure the other visit overloads are visible.
-  using Base::visit;
-
-  // Every instruction which can end up as a user must have a rewrite rule.
-  bool visitInstruction(Instruction &I) {
-    LLVM_DEBUG(dbgs() << "    !!!! Cannot rewrite: " << I << "\n");
-    llvm_unreachable("No rewrite rule for this instruction!");
-  }
-
-  Value *getNewAllocaSlicePtr(IRBuilderTy &IRB, Type *PointerTy) {
-    // Note that the offset computation can use BeginOffset or NewBeginOffset
-    // interchangeably for unsplit slices.
-    assert(IsSplit || BeginOffset == NewBeginOffset);
-    uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
-
-#ifndef NDEBUG
-    StringRef OldName = OldPtr->getName();
-    // Skip through the last '.sroa.' component of the name.
-    size_t LastSROAPrefix = OldName.rfind(".sroa.");
-    if (LastSROAPrefix != StringRef::npos) {
-      OldName = OldName.substr(LastSROAPrefix + strlen(".sroa."));
-      // Look for an SROA slice index.
-      size_t IndexEnd = OldName.find_first_not_of("0123456789");
-      if (IndexEnd != StringRef::npos && OldName[IndexEnd] == '.') {
-        // Strip the index and look for the offset.
-        OldName = OldName.substr(IndexEnd + 1);
-        size_t OffsetEnd = OldName.find_first_not_of("0123456789");
-        if (OffsetEnd != StringRef::npos && OldName[OffsetEnd] == '.')
-          // Strip the offset.
-          OldName = OldName.substr(OffsetEnd + 1);
-      }
-    }
-    // Strip any SROA suffixes as well.
-    OldName = OldName.substr(0, OldName.find(".sroa_"));
-#endif
-
-    return getAdjustedPtr(IRB, DL, &NewAI,
-                          APInt(DL.getIndexTypeSizeInBits(PointerTy), Offset),
-                          PointerTy,
-#ifndef NDEBUG
-                          Twine(OldName) + "."
-#else
-                          Twine()
-#endif
-                          );
-  }
-
-  /// Compute suitable alignment to access this slice of the *new*
-  /// alloca.
-  ///
-  /// You can optionally pass a type to this routine and if that type's ABI
-  /// alignment is itself suitable, this will return zero.
-  unsigned getSliceAlign(Type *Ty = nullptr) {
-    unsigned NewAIAlign = NewAI.getAlignment();
-    if (!NewAIAlign)
-      NewAIAlign = DL.getABITypeAlignment(NewAI.getAllocatedType());
-    unsigned Align =
-        MinAlign(NewAIAlign, NewBeginOffset - NewAllocaBeginOffset);
-    return (Ty && Align == DL.getABITypeAlignment(Ty)) ? 0 : Align;
-  }
-
-  unsigned getIndex(uint64_t Offset) {
-    assert(VecTy && "Can only call getIndex when rewriting a vector");
-    uint64_t RelOffset = Offset - NewAllocaBeginOffset;
-    assert(RelOffset / ElementSize < UINT32_MAX && "Index out of bounds");
-    uint32_t Index = RelOffset / ElementSize;
-    assert(Index * ElementSize == RelOffset);
-    return Index;
-  }
-
-  void deleteIfTriviallyDead(Value *V) {
-    Instruction *I = cast<Instruction>(V);
-    if (isInstructionTriviallyDead(I))
-      Pass.DeadInsts.insert(I);
-  }
-
-  Value *rewriteVectorizedLoadInst() {
-    unsigned BeginIndex = getIndex(NewBeginOffset);
-    unsigned EndIndex = getIndex(NewEndOffset);
-    assert(EndIndex > BeginIndex && "Empty vector!");
-
-    Value *V = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
-    return extractVector(IRB, V, BeginIndex, EndIndex, "vec");
-  }
-
-  Value *rewriteIntegerLoad(LoadInst &LI) {
-    assert(IntTy && "We cannot insert an integer to the alloca");
-    assert(!LI.isVolatile());
-    Value *V = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
-    V = convertValue(DL, IRB, V, IntTy);
-    assert(NewBeginOffset >= NewAllocaBeginOffset && "Out of bounds offset");
-    uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
-    if (Offset > 0 || NewEndOffset < NewAllocaEndOffset) {
-      IntegerType *ExtractTy = Type::getIntNTy(LI.getContext(), SliceSize * 8);
-      V = extractInteger(DL, IRB, V, ExtractTy, Offset, "extract");
-    }
-    // It is possible that the extracted type is not the load type. This
-    // happens if there is a load past the end of the alloca, and as
-    // a consequence the slice is narrower but still a candidate for integer
-    // lowering. To handle this case, we just zero extend the extracted
-    // integer.
-    assert(cast<IntegerType>(LI.getType())->getBitWidth() >= SliceSize * 8 &&
-           "Can only handle an extract for an overly wide load");
-    if (cast<IntegerType>(LI.getType())->getBitWidth() > SliceSize * 8)
-      V = IRB.CreateZExt(V, LI.getType());
-    return V;
-  }
-
-  bool visitLoadInst(LoadInst &LI) {
-    LLVM_DEBUG(dbgs() << "    original: " << LI << "\n");
-    Value *OldOp = LI.getOperand(0);
-    assert(OldOp == OldPtr);
-
-    AAMDNodes AATags;
-    LI.getAAMetadata(AATags);
-
-    unsigned AS = LI.getPointerAddressSpace();
-
-    Type *TargetTy = IsSplit ? Type::getIntNTy(LI.getContext(), SliceSize * 8)
-                             : LI.getType();
-    const bool IsLoadPastEnd = DL.getTypeStoreSize(TargetTy) > SliceSize;
-    bool IsPtrAdjusted = false;
-    Value *V;
-    if (VecTy) {
-      V = rewriteVectorizedLoadInst();
-    } else if (IntTy && LI.getType()->isIntegerTy()) {
-      V = rewriteIntegerLoad(LI);
-    } else if (NewBeginOffset == NewAllocaBeginOffset &&
-               NewEndOffset == NewAllocaEndOffset &&
-               (canConvertValue(DL, NewAllocaTy, TargetTy) ||
-                (IsLoadPastEnd && NewAllocaTy->isIntegerTy() &&
-                 TargetTy->isIntegerTy()))) {
-      LoadInst *NewLI = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(),
-                                              LI.isVolatile(), LI.getName());
-      if (AATags)
-        NewLI->setAAMetadata(AATags);
-      if (LI.isVolatile())
-        NewLI->setAtomic(LI.getOrdering(), LI.getSyncScopeID());
-
-      // Any !nonnull metadata or !range metadata on the old load is also valid
-      // on the new load. This is even true in some cases even when the loads
-      // are different types, for example by mapping !nonnull metadata to
-      // !range metadata by modeling the null pointer constant converted to the
-      // integer type.
-      // FIXME: Add support for range metadata here. Currently the utilities
-      // for this don't propagate range metadata in trivial cases from one
-      // integer load to another, don't handle non-addrspace-0 null pointers
-      // correctly, and don't have any support for mapping ranges as the
-      // integer type becomes winder or narrower.
-      if (MDNode *N = LI.getMetadata(LLVMContext::MD_nonnull))
-        copyNonnullMetadata(LI, N, *NewLI);
-
-      // Try to preserve nonnull metadata
-      V = NewLI;
-
-      // If this is an integer load past the end of the slice (which means the
-      // bytes outside the slice are undef or this load is dead) just forcibly
-      // fix the integer size with correct handling of endianness.
-      if (auto *AITy = dyn_cast<IntegerType>(NewAllocaTy))
-        if (auto *TITy = dyn_cast<IntegerType>(TargetTy))
-          if (AITy->getBitWidth() < TITy->getBitWidth()) {
-            V = IRB.CreateZExt(V, TITy, "load.ext");
-            if (DL.isBigEndian())
-              V = IRB.CreateShl(V, TITy->getBitWidth() - AITy->getBitWidth(),
-                                "endian_shift");
-          }
-    } else {
-      Type *LTy = TargetTy->getPointerTo(AS);
-      LoadInst *NewLI = IRB.CreateAlignedLoad(getNewAllocaSlicePtr(IRB, LTy),
-                                              getSliceAlign(TargetTy),
-                                              LI.isVolatile(), LI.getName());
-      if (AATags)
-        NewLI->setAAMetadata(AATags);
-      if (LI.isVolatile())
-        NewLI->setAtomic(LI.getOrdering(), LI.getSyncScopeID());
-
-      V = NewLI;
-      IsPtrAdjusted = true;
-    }
-    V = convertValue(DL, IRB, V, TargetTy);
-
-    if (IsSplit) {
-      assert(!LI.isVolatile());
-      assert(LI.getType()->isIntegerTy() &&
-             "Only integer type loads and stores are split");
-      assert(SliceSize < DL.getTypeStoreSize(LI.getType()) &&
-             "Split load isn't smaller than original load");
-      assert(LI.getType()->getIntegerBitWidth() ==
-                 DL.getTypeStoreSizeInBits(LI.getType()) &&
-             "Non-byte-multiple bit width");
-      // Move the insertion point just past the load so that we can refer to it.
-      IRB.SetInsertPoint(&*std::next(BasicBlock::iterator(&LI)));
-      // Create a placeholder value with the same type as LI to use as the
-      // basis for the new value. This allows us to replace the uses of LI with
-      // the computed value, and then replace the placeholder with LI, leaving
-      // LI only used for this computation.
-      Value *Placeholder =
-          new LoadInst(UndefValue::get(LI.getType()->getPointerTo(AS)));
-      V = insertInteger(DL, IRB, Placeholder, V, NewBeginOffset - BeginOffset,
-                        "insert");
-      LI.replaceAllUsesWith(V);
-      Placeholder->replaceAllUsesWith(&LI);
-      Placeholder->deleteValue();
-    } else {
-      LI.replaceAllUsesWith(V);
-    }
-
-    Pass.DeadInsts.insert(&LI);
-    deleteIfTriviallyDead(OldOp);
-    LLVM_DEBUG(dbgs() << "          to: " << *V << "\n");
-    return !LI.isVolatile() && !IsPtrAdjusted;
-  }
-
-  bool rewriteVectorizedStoreInst(Value *V, StoreInst &SI, Value *OldOp,
-                                  AAMDNodes AATags) {
-    if (V->getType() != VecTy) {
-      unsigned BeginIndex = getIndex(NewBeginOffset);
-      unsigned EndIndex = getIndex(NewEndOffset);
-      assert(EndIndex > BeginIndex && "Empty vector!");
-      unsigned NumElements = EndIndex - BeginIndex;
-      assert(NumElements <= VecTy->getNumElements() && "Too many elements!");
-      Type *SliceTy = (NumElements == 1)
-                          ? ElementTy
-                          : VectorType::get(ElementTy, NumElements);
-      if (V->getType() != SliceTy)
-        V = convertValue(DL, IRB, V, SliceTy);
-
-      // Mix in the existing elements.
-      Value *Old = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
-      V = insertVector(IRB, Old, V, BeginIndex, "vec");
-    }
-    StoreInst *Store = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlignment());
-    if (AATags)
-      Store->setAAMetadata(AATags);
-    Pass.DeadInsts.insert(&SI);
-
-    LLVM_DEBUG(dbgs() << "          to: " << *Store << "\n");
-    return true;
-  }
-
-  bool rewriteIntegerStore(Value *V, StoreInst &SI, AAMDNodes AATags) {
-    assert(IntTy && "We cannot extract an integer from the alloca");
-    assert(!SI.isVolatile());
-    if (DL.getTypeSizeInBits(V->getType()) != IntTy->getBitWidth()) {
-      Value *Old =
-          IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
-      Old = convertValue(DL, IRB, Old, IntTy);
-      assert(BeginOffset >= NewAllocaBeginOffset && "Out of bounds offset");
-      uint64_t Offset = BeginOffset - NewAllocaBeginOffset;
-      V = insertInteger(DL, IRB, Old, SI.getValueOperand(), Offset, "insert");
-    }
-    V = convertValue(DL, IRB, V, NewAllocaTy);
-    StoreInst *Store = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlignment());
-    Store->copyMetadata(SI, {LLVMContext::MD_mem_parallel_loop_access,
-                             LLVMContext::MD_access_group});
-    if (AATags)
-      Store->setAAMetadata(AATags);
-    Pass.DeadInsts.insert(&SI);
-    LLVM_DEBUG(dbgs() << "          to: " << *Store << "\n");
-    return true;
-  }
-
-  bool visitStoreInst(StoreInst &SI) {
-    LLVM_DEBUG(dbgs() << "    original: " << SI << "\n");
-    Value *OldOp = SI.getOperand(1);
-    assert(OldOp == OldPtr);
-
-    AAMDNodes AATags;
-    SI.getAAMetadata(AATags);
-
-    Value *V = SI.getValueOperand();
-
-    // Strip all inbounds GEPs and pointer casts to try to dig out any root
-    // alloca that should be re-examined after promoting this alloca.
-    if (V->getType()->isPointerTy())
-      if (AllocaInst *AI = dyn_cast<AllocaInst>(V->stripInBoundsOffsets()))
-        Pass.PostPromotionWorklist.insert(AI);
-
-    if (SliceSize < DL.getTypeStoreSize(V->getType())) {
-      assert(!SI.isVolatile());
-      assert(V->getType()->isIntegerTy() &&
-             "Only integer type loads and stores are split");
-      assert(V->getType()->getIntegerBitWidth() ==
-                 DL.getTypeStoreSizeInBits(V->getType()) &&
-             "Non-byte-multiple bit width");
-      IntegerType *NarrowTy = Type::getIntNTy(SI.getContext(), SliceSize * 8);
-      V = extractInteger(DL, IRB, V, NarrowTy, NewBeginOffset - BeginOffset,
-                         "extract");
-    }
-
-    if (VecTy)
-      return rewriteVectorizedStoreInst(V, SI, OldOp, AATags);
-    if (IntTy && V->getType()->isIntegerTy())
-      return rewriteIntegerStore(V, SI, AATags);
-
-    const bool IsStorePastEnd = DL.getTypeStoreSize(V->getType()) > SliceSize;
-    StoreInst *NewSI;
-    if (NewBeginOffset == NewAllocaBeginOffset &&
-        NewEndOffset == NewAllocaEndOffset &&
-        (canConvertValue(DL, V->getType(), NewAllocaTy) ||
-         (IsStorePastEnd && NewAllocaTy->isIntegerTy() &&
-          V->getType()->isIntegerTy()))) {
-      // If this is an integer store past the end of slice (and thus the bytes
-      // past that point are irrelevant or this is unreachable), truncate the
-      // value prior to storing.
-      if (auto *VITy = dyn_cast<IntegerType>(V->getType()))
-        if (auto *AITy = dyn_cast<IntegerType>(NewAllocaTy))
-          if (VITy->getBitWidth() > AITy->getBitWidth()) {
-            if (DL.isBigEndian())
-              V = IRB.CreateLShr(V, VITy->getBitWidth() - AITy->getBitWidth(),
-                                 "endian_shift");
-            V = IRB.CreateTrunc(V, AITy, "load.trunc");
-          }
-
-      V = convertValue(DL, IRB, V, NewAllocaTy);
-      NewSI = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlignment(),
-                                     SI.isVolatile());
-    } else {
-      unsigned AS = SI.getPointerAddressSpace();
-      Value *NewPtr = getNewAllocaSlicePtr(IRB, V->getType()->getPointerTo(AS));
-      NewSI = IRB.CreateAlignedStore(V, NewPtr, getSliceAlign(V->getType()),
-                                     SI.isVolatile());
-    }
-    NewSI->copyMetadata(SI, {LLVMContext::MD_mem_parallel_loop_access,
-                             LLVMContext::MD_access_group});
-    if (AATags)
-      NewSI->setAAMetadata(AATags);
-    if (SI.isVolatile())
-      NewSI->setAtomic(SI.getOrdering(), SI.getSyncScopeID());
-    Pass.DeadInsts.insert(&SI);
-    deleteIfTriviallyDead(OldOp);
-
-    LLVM_DEBUG(dbgs() << "          to: " << *NewSI << "\n");
-    return NewSI->getPointerOperand() == &NewAI && !SI.isVolatile();
-  }
-
-  /// Compute an integer value from splatting an i8 across the given
-  /// number of bytes.
-  ///
-  /// Note that this routine assumes an i8 is a byte. If that isn't true, don't
-  /// call this routine.
-  /// FIXME: Heed the advice above.
-  ///
-  /// \param V The i8 value to splat.
-  /// \param Size The number of bytes in the output (assuming i8 is one byte)
-  Value *getIntegerSplat(Value *V, unsigned Size) {
-    assert(Size > 0 && "Expected a positive number of bytes.");
-    IntegerType *VTy = cast<IntegerType>(V->getType());
-    assert(VTy->getBitWidth() == 8 && "Expected an i8 value for the byte");
-    if (Size == 1)
-      return V;
-
-    Type *SplatIntTy = Type::getIntNTy(VTy->getContext(), Size * 8);
-    V = IRB.CreateMul(
-        IRB.CreateZExt(V, SplatIntTy, "zext"),
-        ConstantExpr::getUDiv(
-            Constant::getAllOnesValue(SplatIntTy),
-            ConstantExpr::getZExt(Constant::getAllOnesValue(V->getType()),
-                                  SplatIntTy)),
-        "isplat");
-    return V;
-  }
-
-  /// Compute a vector splat for a given element value.
-  Value *getVectorSplat(Value *V, unsigned NumElements) {
-    V = IRB.CreateVectorSplat(NumElements, V, "vsplat");
-    LLVM_DEBUG(dbgs() << "       splat: " << *V << "\n");
-    return V;
-  }
-
-  bool visitMemSetInst(MemSetInst &II) {
-    LLVM_DEBUG(dbgs() << "    original: " << II << "\n");
-    assert(II.getRawDest() == OldPtr);
-
-    AAMDNodes AATags;
-    II.getAAMetadata(AATags);
-
-    // If the memset has a variable size, it cannot be split, just adjust the
-    // pointer to the new alloca.
-    if (!isa<Constant>(II.getLength())) {
-      assert(!IsSplit);
-      assert(NewBeginOffset == BeginOffset);
-      II.setDest(getNewAllocaSlicePtr(IRB, OldPtr->getType()));
-      II.setDestAlignment(getSliceAlign());
-
-      deleteIfTriviallyDead(OldPtr);
-      return false;
-    }
-
-    // Record this instruction for deletion.
-    Pass.DeadInsts.insert(&II);
-
-    Type *AllocaTy = NewAI.getAllocatedType();
-    Type *ScalarTy = AllocaTy->getScalarType();
-
-    // If this doesn't map cleanly onto the alloca type, and that type isn't
-    // a single value type, just emit a memset.
-    if (!VecTy && !IntTy &&
-        (BeginOffset > NewAllocaBeginOffset || EndOffset < NewAllocaEndOffset ||
-         SliceSize != DL.getTypeStoreSize(AllocaTy) ||
-         !AllocaTy->isSingleValueType() ||
-         !DL.isLegalInteger(DL.getTypeSizeInBits(ScalarTy)) ||
-         DL.getTypeSizeInBits(ScalarTy) % 8 != 0)) {
-      Type *SizeTy = II.getLength()->getType();
-      Constant *Size = ConstantInt::get(SizeTy, NewEndOffset - NewBeginOffset);
-      CallInst *New = IRB.CreateMemSet(
-          getNewAllocaSlicePtr(IRB, OldPtr->getType()), II.getValue(), Size,
-          getSliceAlign(), II.isVolatile());
-      if (AATags)
-        New->setAAMetadata(AATags);
-      LLVM_DEBUG(dbgs() << "          to: " << *New << "\n");
-      return false;
-    }
-
-    // If we can represent this as a simple value, we have to build the actual
-    // value to store, which requires expanding the byte present in memset to
-    // a sensible representation for the alloca type. This is essentially
-    // splatting the byte to a sufficiently wide integer, splatting it across
-    // any desired vector width, and bitcasting to the final type.
-    Value *V;
-
-    if (VecTy) {
-      // If this is a memset of a vectorized alloca, insert it.
-      assert(ElementTy == ScalarTy);
-
-      unsigned BeginIndex = getIndex(NewBeginOffset);
-      unsigned EndIndex = getIndex(NewEndOffset);
-      assert(EndIndex > BeginIndex && "Empty vector!");
-      unsigned NumElements = EndIndex - BeginIndex;
-      assert(NumElements <= VecTy->getNumElements() && "Too many elements!");
-
-      Value *Splat =
-          getIntegerSplat(II.getValue(), DL.getTypeSizeInBits(ElementTy) / 8);
-      Splat = convertValue(DL, IRB, Splat, ElementTy);
-      if (NumElements > 1)
-        Splat = getVectorSplat(Splat, NumElements);
-
-      Value *Old =
-          IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
-      V = insertVector(IRB, Old, Splat, BeginIndex, "vec");
-    } else if (IntTy) {
-      // If this is a memset on an alloca where we can widen stores, insert the
-      // set integer.
-      assert(!II.isVolatile());
-
-      uint64_t Size = NewEndOffset - NewBeginOffset;
-      V = getIntegerSplat(II.getValue(), Size);
-
-      if (IntTy && (BeginOffset != NewAllocaBeginOffset ||
-                    EndOffset != NewAllocaBeginOffset)) {
-        Value *Old =
-            IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
-        Old = convertValue(DL, IRB, Old, IntTy);
-        uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
-        V = insertInteger(DL, IRB, Old, V, Offset, "insert");
-      } else {
-        assert(V->getType() == IntTy &&
-               "Wrong type for an alloca wide integer!");
-      }
-      V = convertValue(DL, IRB, V, AllocaTy);
-    } else {
-      // Established these invariants above.
-      assert(NewBeginOffset == NewAllocaBeginOffset);
-      assert(NewEndOffset == NewAllocaEndOffset);
-
-      V = getIntegerSplat(II.getValue(), DL.getTypeSizeInBits(ScalarTy) / 8);
-      if (VectorType *AllocaVecTy = dyn_cast<VectorType>(AllocaTy))
-        V = getVectorSplat(V, AllocaVecTy->getNumElements());
-
-      V = convertValue(DL, IRB, V, AllocaTy);
-    }
-
-    StoreInst *New = IRB.CreateAlignedStore(V, &NewAI, NewAI.getAlignment(),
-                                            II.isVolatile());
-    if (AATags)
-      New->setAAMetadata(AATags);
-    LLVM_DEBUG(dbgs() << "          to: " << *New << "\n");
-    return !II.isVolatile();
-  }
-
-  bool visitMemTransferInst(MemTransferInst &II) {
-    // Rewriting of memory transfer instructions can be a bit tricky. We break
-    // them into two categories: split intrinsics and unsplit intrinsics.
-
-    LLVM_DEBUG(dbgs() << "    original: " << II << "\n");
-
-    AAMDNodes AATags;
-    II.getAAMetadata(AATags);
-
-    bool IsDest = &II.getRawDestUse() == OldUse;
-    assert((IsDest && II.getRawDest() == OldPtr) ||
-           (!IsDest && II.getRawSource() == OldPtr));
-
-    unsigned SliceAlign = getSliceAlign();
-
-    // For unsplit intrinsics, we simply modify the source and destination
-    // pointers in place. This isn't just an optimization, it is a matter of
-    // correctness. With unsplit intrinsics we may be dealing with transfers
-    // within a single alloca before SROA ran, or with transfers that have
-    // a variable length. We may also be dealing with memmove instead of
-    // memcpy, and so simply updating the pointers is the necessary for us to
-    // update both source and dest of a single call.
-    if (!IsSplittable) {
-      Value *AdjustedPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
-      if (IsDest) {
-        II.setDest(AdjustedPtr);
-        II.setDestAlignment(SliceAlign);
-      }
-      else {
-        II.setSource(AdjustedPtr);
-        II.setSourceAlignment(SliceAlign);
-      }
-
-      LLVM_DEBUG(dbgs() << "          to: " << II << "\n");
-      deleteIfTriviallyDead(OldPtr);
-      return false;
-    }
-    // For split transfer intrinsics we have an incredibly useful assurance:
-    // the source and destination do not reside within the same alloca, and at
-    // least one of them does not escape. This means that we can replace
-    // memmove with memcpy, and we don't need to worry about all manner of
-    // downsides to splitting and transforming the operations.
-
-    // If this doesn't map cleanly onto the alloca type, and that type isn't
-    // a single value type, just emit a memcpy.
-    bool EmitMemCpy =
-        !VecTy && !IntTy &&
-        (BeginOffset > NewAllocaBeginOffset || EndOffset < NewAllocaEndOffset ||
-         SliceSize != DL.getTypeStoreSize(NewAI.getAllocatedType()) ||
-         !NewAI.getAllocatedType()->isSingleValueType());
-
-    // If we're just going to emit a memcpy, the alloca hasn't changed, and the
-    // size hasn't been shrunk based on analysis of the viable range, this is
-    // a no-op.
-    if (EmitMemCpy && &OldAI == &NewAI) {
-      // Ensure the start lines up.
-      assert(NewBeginOffset == BeginOffset);
-
-      // Rewrite the size as needed.
-      if (NewEndOffset != EndOffset)
-        II.setLength(ConstantInt::get(II.getLength()->getType(),
-                                      NewEndOffset - NewBeginOffset));
-      return false;
-    }
-    // Record this instruction for deletion.
-    Pass.DeadInsts.insert(&II);
-
-    // Strip all inbounds GEPs and pointer casts to try to dig out any root
-    // alloca that should be re-examined after rewriting this instruction.
-    Value *OtherPtr = IsDest ? II.getRawSource() : II.getRawDest();
-    if (AllocaInst *AI =
-            dyn_cast<AllocaInst>(OtherPtr->stripInBoundsOffsets())) {
-      assert(AI != &OldAI && AI != &NewAI &&
-             "Splittable transfers cannot reach the same alloca on both ends.");
-      Pass.Worklist.insert(AI);
-    }
-
-    Type *OtherPtrTy = OtherPtr->getType();
-    unsigned OtherAS = OtherPtrTy->getPointerAddressSpace();
-
-    // Compute the relative offset for the other pointer within the transfer.
-    unsigned OffsetWidth = DL.getIndexSizeInBits(OtherAS);
-    APInt OtherOffset(OffsetWidth, NewBeginOffset - BeginOffset);
-    unsigned OtherAlign =
-      IsDest ? II.getSourceAlignment() : II.getDestAlignment();
-    OtherAlign =  MinAlign(OtherAlign ? OtherAlign : 1,
-                           OtherOffset.zextOrTrunc(64).getZExtValue());
-
-    if (EmitMemCpy) {
-      // Compute the other pointer, folding as much as possible to produce
-      // a single, simple GEP in most cases.
-      OtherPtr = getAdjustedPtr(IRB, DL, OtherPtr, OtherOffset, OtherPtrTy,
-                                OtherPtr->getName() + ".");
-
-      Value *OurPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
-      Type *SizeTy = II.getLength()->getType();
-      Constant *Size = ConstantInt::get(SizeTy, NewEndOffset - NewBeginOffset);
-
-      Value *DestPtr, *SrcPtr;
-      unsigned DestAlign, SrcAlign;
-      // Note: IsDest is true iff we're copying into the new alloca slice
-      if (IsDest) {
-        DestPtr = OurPtr;
-        DestAlign = SliceAlign;
-        SrcPtr = OtherPtr;
-        SrcAlign = OtherAlign;
-      } else {
-        DestPtr = OtherPtr;
-        DestAlign = OtherAlign;
-        SrcPtr = OurPtr;
-        SrcAlign = SliceAlign;
-      }
-      CallInst *New = IRB.CreateMemCpy(DestPtr, DestAlign, SrcPtr, SrcAlign,
-                                       Size, II.isVolatile());
-      if (AATags)
-        New->setAAMetadata(AATags);
-      LLVM_DEBUG(dbgs() << "          to: " << *New << "\n");
-      return false;
-    }
-
-    bool IsWholeAlloca = NewBeginOffset == NewAllocaBeginOffset &&
-                         NewEndOffset == NewAllocaEndOffset;
-    uint64_t Size = NewEndOffset - NewBeginOffset;
-    unsigned BeginIndex = VecTy ? getIndex(NewBeginOffset) : 0;
-    unsigned EndIndex = VecTy ? getIndex(NewEndOffset) : 0;
-    unsigned NumElements = EndIndex - BeginIndex;
-    IntegerType *SubIntTy =
-        IntTy ? Type::getIntNTy(IntTy->getContext(), Size * 8) : nullptr;
-
-    // Reset the other pointer type to match the register type we're going to
-    // use, but using the address space of the original other pointer.
-    if (VecTy && !IsWholeAlloca) {
-      if (NumElements == 1)
-        OtherPtrTy = VecTy->getElementType();
-      else
-        OtherPtrTy = VectorType::get(VecTy->getElementType(), NumElements);
-
-      OtherPtrTy = OtherPtrTy->getPointerTo(OtherAS);
-    } else if (IntTy && !IsWholeAlloca) {
-      OtherPtrTy = SubIntTy->getPointerTo(OtherAS);
-    } else {
-      OtherPtrTy = NewAllocaTy->getPointerTo(OtherAS);
-    }
-
-    Value *SrcPtr = getAdjustedPtr(IRB, DL, OtherPtr, OtherOffset, OtherPtrTy,
-                                   OtherPtr->getName() + ".");
-    unsigned SrcAlign = OtherAlign;
-    Value *DstPtr = &NewAI;
-    unsigned DstAlign = SliceAlign;
-    if (!IsDest) {
-      std::swap(SrcPtr, DstPtr);
-      std::swap(SrcAlign, DstAlign);
-    }
-
-    Value *Src;
-    if (VecTy && !IsWholeAlloca && !IsDest) {
-      Src = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
-      Src = extractVector(IRB, Src, BeginIndex, EndIndex, "vec");
-    } else if (IntTy && !IsWholeAlloca && !IsDest) {
-      Src = IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "load");
-      Src = convertValue(DL, IRB, Src, IntTy);
-      uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
-      Src = extractInteger(DL, IRB, Src, SubIntTy, Offset, "extract");
-    } else {
-      LoadInst *Load = IRB.CreateAlignedLoad(SrcPtr, SrcAlign, II.isVolatile(),
-                                             "copyload");
-      if (AATags)
-        Load->setAAMetadata(AATags);
-      Src = Load;
-    }
-
-    if (VecTy && !IsWholeAlloca && IsDest) {
-      Value *Old =
-          IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
-      Src = insertVector(IRB, Old, Src, BeginIndex, "vec");
-    } else if (IntTy && !IsWholeAlloca && IsDest) {
-      Value *Old =
-          IRB.CreateAlignedLoad(&NewAI, NewAI.getAlignment(), "oldload");
-      Old = convertValue(DL, IRB, Old, IntTy);
-      uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset;
-      Src = insertInteger(DL, IRB, Old, Src, Offset, "insert");
-      Src = convertValue(DL, IRB, Src, NewAllocaTy);
-    }
-
-    StoreInst *Store = cast<StoreInst>(
-        IRB.CreateAlignedStore(Src, DstPtr, DstAlign, II.isVolatile()));
-    if (AATags)
-      Store->setAAMetadata(AATags);
-    LLVM_DEBUG(dbgs() << "          to: " << *Store << "\n");
-    return !II.isVolatile();
-  }
-
-  bool visitIntrinsicInst(IntrinsicInst &II) {
-    assert(II.isLifetimeStartOrEnd());
-    LLVM_DEBUG(dbgs() << "    original: " << II << "\n");
-    assert(II.getArgOperand(1) == OldPtr);
-
-    // Record this instruction for deletion.
-    Pass.DeadInsts.insert(&II);
-
-    // Lifetime intrinsics are only promotable if they cover the whole alloca.
-    // Therefore, we drop lifetime intrinsics which don't cover the whole
-    // alloca.
-    // (In theory, intrinsics which partially cover an alloca could be
-    // promoted, but PromoteMemToReg doesn't handle that case.)
-    // FIXME: Check whether the alloca is promotable before dropping the
-    // lifetime intrinsics?
-    if (NewBeginOffset != NewAllocaBeginOffset ||
-        NewEndOffset != NewAllocaEndOffset)
-      return true;
-
-    ConstantInt *Size =
-        ConstantInt::get(cast<IntegerType>(II.getArgOperand(0)->getType()),
-                         NewEndOffset - NewBeginOffset);
-    // Lifetime intrinsics always expect an i8* so directly get such a pointer
-    // for the new alloca slice.
-    Type *PointerTy = IRB.getInt8PtrTy(OldPtr->getType()->getPointerAddressSpace());
-    Value *Ptr = getNewAllocaSlicePtr(IRB, PointerTy);
-    Value *New;
-    if (II.getIntrinsicID() == Intrinsic::lifetime_start)
-      New = IRB.CreateLifetimeStart(Ptr, Size);
-    else
-      New = IRB.CreateLifetimeEnd(Ptr, Size);
-
-    (void)New;
-    LLVM_DEBUG(dbgs() << "          to: " << *New << "\n");
-
-    return true;
-  }
-
-  void fixLoadStoreAlign(Instruction &Root) {
-    // This algorithm implements the same visitor loop as
-    // hasUnsafePHIOrSelectUse, and fixes the alignment of each load
-    // or store found.
-    SmallPtrSet<Instruction *, 4> Visited;
-    SmallVector<Instruction *, 4> Uses;
-    Visited.insert(&Root);
-    Uses.push_back(&Root);
-    do {
-      Instruction *I = Uses.pop_back_val();
-
-      if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
-        unsigned LoadAlign = LI->getAlignment();
-        if (!LoadAlign)
-          LoadAlign = DL.getABITypeAlignment(LI->getType());
-        LI->setAlignment(std::min(LoadAlign, getSliceAlign()));
-        continue;
-      }
-      if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
-        unsigned StoreAlign = SI->getAlignment();
-        if (!StoreAlign) {
-          Value *Op = SI->getOperand(0);
-          StoreAlign = DL.getABITypeAlignment(Op->getType());
-        }
-        SI->setAlignment(std::min(StoreAlign, getSliceAlign()));
-        continue;
-      }
-
-      assert(isa<BitCastInst>(I) || isa<PHINode>(I) ||
-             isa<SelectInst>(I) || isa<GetElementPtrInst>(I));
-      for (User *U : I->users())
-        if (Visited.insert(cast<Instruction>(U)).second)
-          Uses.push_back(cast<Instruction>(U));
-    } while (!Uses.empty());
-  }
-
-  bool visitPHINode(PHINode &PN) {
-    LLVM_DEBUG(dbgs() << "    original: " << PN << "\n");
-    assert(BeginOffset >= NewAllocaBeginOffset && "PHIs are unsplittable");
-    assert(EndOffset <= NewAllocaEndOffset && "PHIs are unsplittable");
-
-    // We would like to compute a new pointer in only one place, but have it be
-    // as local as possible to the PHI. To do that, we re-use the location of
-    // the old pointer, which necessarily must be in the right position to
-    // dominate the PHI.
-    IRBuilderTy PtrBuilder(IRB);
-    if (isa<PHINode>(OldPtr))
-      PtrBuilder.SetInsertPoint(&*OldPtr->getParent()->getFirstInsertionPt());
-    else
-      PtrBuilder.SetInsertPoint(OldPtr);
-    PtrBuilder.SetCurrentDebugLocation(OldPtr->getDebugLoc());
-
-    Value *NewPtr = getNewAllocaSlicePtr(PtrBuilder, OldPtr->getType());
-    // Replace the operands which were using the old pointer.
-    std::replace(PN.op_begin(), PN.op_end(), cast<Value>(OldPtr), NewPtr);
-
-    LLVM_DEBUG(dbgs() << "          to: " << PN << "\n");
-    deleteIfTriviallyDead(OldPtr);
-
-    // Fix the alignment of any loads or stores using this PHI node.
-    fixLoadStoreAlign(PN);
-
-    // PHIs can't be promoted on their own, but often can be speculated. We
-    // check the speculation outside of the rewriter so that we see the
-    // fully-rewritten alloca.
-    PHIUsers.insert(&PN);
-    return true;
-  }
-
-  bool visitSelectInst(SelectInst &SI) {
-    LLVM_DEBUG(dbgs() << "    original: " << SI << "\n");
-    assert((SI.getTrueValue() == OldPtr || SI.getFalseValue() == OldPtr) &&
-           "Pointer isn't an operand!");
-    assert(BeginOffset >= NewAllocaBeginOffset && "Selects are unsplittable");
-    assert(EndOffset <= NewAllocaEndOffset && "Selects are unsplittable");
-
-    Value *NewPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType());
-    // Replace the operands which were using the old pointer.
-    if (SI.getOperand(1) == OldPtr)
-      SI.setOperand(1, NewPtr);
-    if (SI.getOperand(2) == OldPtr)
-      SI.setOperand(2, NewPtr);
-
-    LLVM_DEBUG(dbgs() << "          to: " << SI << "\n");
-    deleteIfTriviallyDead(OldPtr);
-
-    // Fix the alignment of any loads or stores using this select.
-    fixLoadStoreAlign(SI);
-
-    // Selects can't be promoted on their own, but often can be speculated. We
-    // check the speculation outside of the rewriter so that we see the
-    // fully-rewritten alloca.
-    SelectUsers.insert(&SI);
-    return true;
-  }
-};
-
-namespace {
-
-/// Visitor to rewrite aggregate loads and stores as scalar.
-///
-/// This pass aggressively rewrites all aggregate loads and stores on
-/// a particular pointer (or any pointer derived from it which we can identify)
-/// with scalar loads and stores.
-class AggLoadStoreRewriter : public InstVisitor<AggLoadStoreRewriter, bool> {
-  // Befriend the base class so it can delegate to private visit methods.
-  friend class InstVisitor<AggLoadStoreRewriter, bool>;
-
-  /// Queue of pointer uses to analyze and potentially rewrite.
-  SmallVector<Use *, 8> Queue;
-
-  /// Set to prevent us from cycling with phi nodes and loops.
-  SmallPtrSet<User *, 8> Visited;
-
-  /// The current pointer use being rewritten. This is used to dig up the used
-  /// value (as opposed to the user).
-  Use *U;
-
-  /// Used to calculate offsets, and hence alignment, of subobjects.
-  const DataLayout &DL;
-
-public:
-  AggLoadStoreRewriter(const DataLayout &DL) : DL(DL) {}
-
-  /// Rewrite loads and stores through a pointer and all pointers derived from
-  /// it.
-  bool rewrite(Instruction &I) {
-    LLVM_DEBUG(dbgs() << "  Rewriting FCA loads and stores...\n");
-    enqueueUsers(I);
-    bool Changed = false;
-    while (!Queue.empty()) {
-      U = Queue.pop_back_val();
-      Changed |= visit(cast<Instruction>(U->getUser()));
-    }
-    return Changed;
-  }
-
-private:
-  /// Enqueue all the users of the given instruction for further processing.
-  /// This uses a set to de-duplicate users.
-  void enqueueUsers(Instruction &I) {
-    for (Use &U : I.uses())
-      if (Visited.insert(U.getUser()).second)
-        Queue.push_back(&U);
-  }
-
-  // Conservative default is to not rewrite anything.
-  bool visitInstruction(Instruction &I) { return false; }
-
-  /// Generic recursive split emission class.
-  template <typename Derived> class OpSplitter {
-  protected:
-    /// The builder used to form new instructions.
-    IRBuilderTy IRB;
-
-    /// The indices which to be used with insert- or extractvalue to select the
-    /// appropriate value within the aggregate.
-    SmallVector<unsigned, 4> Indices;
-
-    /// The indices to a GEP instruction which will move Ptr to the correct slot
-    /// within the aggregate.
-    SmallVector<Value *, 4> GEPIndices;
-
-    /// The base pointer of the original op, used as a base for GEPing the
-    /// split operations.
-    Value *Ptr;
-
-    /// The base pointee type being GEPed into.
-    Type *BaseTy;
-
-    /// Known alignment of the base pointer.
-    unsigned BaseAlign;
-
-    /// To calculate offset of each component so we can correctly deduce
-    /// alignments.
-    const DataLayout &DL;
-
-    /// Initialize the splitter with an insertion point, Ptr and start with a
-    /// single zero GEP index.
-    OpSplitter(Instruction *InsertionPoint, Value *Ptr, Type *BaseTy,
-               unsigned BaseAlign, const DataLayout &DL)
-        : IRB(InsertionPoint), GEPIndices(1, IRB.getInt32(0)), Ptr(Ptr),
-          BaseTy(BaseTy), BaseAlign(BaseAlign), DL(DL) {}
-
-  public:
-    /// Generic recursive split emission routine.
-    ///
-    /// This method recursively splits an aggregate op (load or store) into
-    /// scalar or vector ops. It splits recursively until it hits a single value
-    /// and emits that single value operation via the template argument.
-    ///
-    /// The logic of this routine relies on GEPs and insertvalue and
-    /// extractvalue all operating with the same fundamental index list, merely
-    /// formatted differently (GEPs need actual values).
-    ///
-    /// \param Ty  The type being split recursively into smaller ops.
-    /// \param Agg The aggregate value being built up or stored, depending on
-    /// whether this is splitting a load or a store respectively.
-    void emitSplitOps(Type *Ty, Value *&Agg, const Twine &Name) {
-      if (Ty->isSingleValueType()) {
-        unsigned Offset = DL.getIndexedOffsetInType(BaseTy, GEPIndices);
-        return static_cast<Derived *>(this)->emitFunc(
-            Ty, Agg, MinAlign(BaseAlign, Offset), Name);
-      }
-
-      if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
-        unsigned OldSize = Indices.size();
-        (void)OldSize;
-        for (unsigned Idx = 0, Size = ATy->getNumElements(); Idx != Size;
-             ++Idx) {
-          assert(Indices.size() == OldSize && "Did not return to the old size");
-          Indices.push_back(Idx);
-          GEPIndices.push_back(IRB.getInt32(Idx));
-          emitSplitOps(ATy->getElementType(), Agg, Name + "." + Twine(Idx));
-          GEPIndices.pop_back();
-          Indices.pop_back();
-        }
-        return;
-      }
-
-      if (StructType *STy = dyn_cast<StructType>(Ty)) {
-        unsigned OldSize = Indices.size();
-        (void)OldSize;
-        for (unsigned Idx = 0, Size = STy->getNumElements(); Idx != Size;
-             ++Idx) {
-          assert(Indices.size() == OldSize && "Did not return to the old size");
-          Indices.push_back(Idx);
-          GEPIndices.push_back(IRB.getInt32(Idx));
-          emitSplitOps(STy->getElementType(Idx), Agg, Name + "." + Twine(Idx));
-          GEPIndices.pop_back();
-          Indices.pop_back();
-        }
-        return;
-      }
-
-      llvm_unreachable("Only arrays and structs are aggregate loadable types");
-    }
-  };
-
-  struct LoadOpSplitter : public OpSplitter<LoadOpSplitter> {
-    AAMDNodes AATags;
-
-    LoadOpSplitter(Instruction *InsertionPoint, Value *Ptr, Type *BaseTy,
-                   AAMDNodes AATags, unsigned BaseAlign, const DataLayout &DL)
-        : OpSplitter<LoadOpSplitter>(InsertionPoint, Ptr, BaseTy, BaseAlign,
-                                     DL), AATags(AATags) {}
-
-    /// Emit a leaf load of a single value. This is called at the leaves of the
-    /// recursive emission to actually load values.
-    void emitFunc(Type *Ty, Value *&Agg, unsigned Align, const Twine &Name) {
-      assert(Ty->isSingleValueType());
-      // Load the single value and insert it using the indices.
-      Value *GEP =
-          IRB.CreateInBoundsGEP(nullptr, Ptr, GEPIndices, Name + ".gep");
-      LoadInst *Load = IRB.CreateAlignedLoad(GEP, Align, Name + ".load");
-      if (AATags)
-        Load->setAAMetadata(AATags);
-      Agg = IRB.CreateInsertValue(Agg, Load, Indices, Name + ".insert");
-      LLVM_DEBUG(dbgs() << "          to: " << *Load << "\n");
-    }
-  };
-
-  bool visitLoadInst(LoadInst &LI) {
-    assert(LI.getPointerOperand() == *U);
-    if (!LI.isSimple() || LI.getType()->isSingleValueType())
-      return false;
-
-    // We have an aggregate being loaded, split it apart.
-    LLVM_DEBUG(dbgs() << "    original: " << LI << "\n");
-    AAMDNodes AATags;
-    LI.getAAMetadata(AATags);
-    LoadOpSplitter Splitter(&LI, *U, LI.getType(), AATags,
-                            getAdjustedAlignment(&LI, 0, DL), DL);
-    Value *V = UndefValue::get(LI.getType());
-    Splitter.emitSplitOps(LI.getType(), V, LI.getName() + ".fca");
-    LI.replaceAllUsesWith(V);
-    LI.eraseFromParent();
-    return true;
-  }
-
-  struct StoreOpSplitter : public OpSplitter<StoreOpSplitter> {
-    StoreOpSplitter(Instruction *InsertionPoint, Value *Ptr, Type *BaseTy,
-                    AAMDNodes AATags, unsigned BaseAlign, const DataLayout &DL)
-        : OpSplitter<StoreOpSplitter>(InsertionPoint, Ptr, BaseTy, BaseAlign,
-                                      DL),
-          AATags(AATags) {}
-    AAMDNodes AATags;
-    /// Emit a leaf store of a single value. This is called at the leaves of the
-    /// recursive emission to actually produce stores.
-    void emitFunc(Type *Ty, Value *&Agg, unsigned Align, const Twine &Name) {
-      assert(Ty->isSingleValueType());
-      // Extract the single value and store it using the indices.
-      //
-      // The gep and extractvalue values are factored out of the CreateStore
-      // call to make the output independent of the argument evaluation order.
-      Value *ExtractValue =
-          IRB.CreateExtractValue(Agg, Indices, Name + ".extract");
-      Value *InBoundsGEP =
-          IRB.CreateInBoundsGEP(nullptr, Ptr, GEPIndices, Name + ".gep");
-      StoreInst *Store =
-          IRB.CreateAlignedStore(ExtractValue, InBoundsGEP, Align);
-      if (AATags)
-        Store->setAAMetadata(AATags);
-      LLVM_DEBUG(dbgs() << "          to: " << *Store << "\n");
-    }
-  };
-
-  bool visitStoreInst(StoreInst &SI) {
-    if (!SI.isSimple() || SI.getPointerOperand() != *U)
-      return false;
-    Value *V = SI.getValueOperand();
-    if (V->getType()->isSingleValueType())
-      return false;
-
-    // We have an aggregate being stored, split it apart.
-    LLVM_DEBUG(dbgs() << "    original: " << SI << "\n");
-    AAMDNodes AATags;
-    SI.getAAMetadata(AATags);
-    StoreOpSplitter Splitter(&SI, *U, V->getType(), AATags,
-                             getAdjustedAlignment(&SI, 0, DL), DL);
-    Splitter.emitSplitOps(V->getType(), V, V->getName() + ".fca");
-    SI.eraseFromParent();
-    return true;
-  }
-
-  bool visitBitCastInst(BitCastInst &BC) {
-    enqueueUsers(BC);
-    return false;
-  }
-
-  bool visitGetElementPtrInst(GetElementPtrInst &GEPI) {
-    enqueueUsers(GEPI);
-    return false;
-  }
-
-  bool visitPHINode(PHINode &PN) {
-    enqueueUsers(PN);
-    return false;
-  }
-
-  bool visitSelectInst(SelectInst &SI) {
-    enqueueUsers(SI);
-    return false;
-  }
-};
-
-} // end anonymous namespace
-
-/// Strip aggregate type wrapping.
-///
-/// This removes no-op aggregate types wrapping an underlying type. It will
-/// strip as many layers of types as it can without changing either the type
-/// size or the allocated size.
-static Type *stripAggregateTypeWrapping(const DataLayout &DL, Type *Ty) {
-  if (Ty->isSingleValueType())
-    return Ty;
-
-  uint64_t AllocSize = DL.getTypeAllocSize(Ty);
-  uint64_t TypeSize = DL.getTypeSizeInBits(Ty);
-
-  Type *InnerTy;
-  if (ArrayType *ArrTy = dyn_cast<ArrayType>(Ty)) {
-    InnerTy = ArrTy->getElementType();
-  } else if (StructType *STy = dyn_cast<StructType>(Ty)) {
-    const StructLayout *SL = DL.getStructLayout(STy);
-    unsigned Index = SL->getElementContainingOffset(0);
-    InnerTy = STy->getElementType(Index);
-  } else {
-    return Ty;
-  }
-
-  if (AllocSize > DL.getTypeAllocSize(InnerTy) ||
-      TypeSize > DL.getTypeSizeInBits(InnerTy))
-    return Ty;
-
-  return stripAggregateTypeWrapping(DL, InnerTy);
-}
-
-/// Try to find a partition of the aggregate type passed in for a given
-/// offset and size.
-///
-/// This recurses through the aggregate type and tries to compute a subtype
-/// based on the offset and size. When the offset and size span a sub-section
-/// of an array, it will even compute a new array type for that sub-section,
-/// and the same for structs.
-///
-/// Note that this routine is very strict and tries to find a partition of the
-/// type which produces the *exact* right offset and size. It is not forgiving
-/// when the size or offset cause either end of type-based partition to be off.
-/// Also, this is a best-effort routine. It is reasonable to give up and not
-/// return a type if necessary.
-static Type *getTypePartition(const DataLayout &DL, Type *Ty, uint64_t Offset,
-                              uint64_t Size) {
-  if (Offset == 0 && DL.getTypeAllocSize(Ty) == Size)
-    return stripAggregateTypeWrapping(DL, Ty);
-  if (Offset > DL.getTypeAllocSize(Ty) ||
-      (DL.getTypeAllocSize(Ty) - Offset) < Size)
-    return nullptr;
-
-  if (SequentialType *SeqTy = dyn_cast<SequentialType>(Ty)) {
-    Type *ElementTy = SeqTy->getElementType();
-    uint64_t ElementSize = DL.getTypeAllocSize(ElementTy);
-    uint64_t NumSkippedElements = Offset / ElementSize;
-    if (NumSkippedElements >= SeqTy->getNumElements())
-      return nullptr;
-    Offset -= NumSkippedElements * ElementSize;
-
-    // First check if we need to recurse.
-    if (Offset > 0 || Size < ElementSize) {
-      // Bail if the partition ends in a different array element.
-      if ((Offset + Size) > ElementSize)
-        return nullptr;
-      // Recurse through the element type trying to peel off offset bytes.
-      return getTypePartition(DL, ElementTy, Offset, Size);
-    }
-    assert(Offset == 0);
-
-    if (Size == ElementSize)
-      return stripAggregateTypeWrapping(DL, ElementTy);
-    assert(Size > ElementSize);
-    uint64_t NumElements = Size / ElementSize;
-    if (NumElements * ElementSize != Size)
-      return nullptr;
-    return ArrayType::get(ElementTy, NumElements);
-  }
-
-  StructType *STy = dyn_cast<StructType>(Ty);
-  if (!STy)
-    return nullptr;
-
-  const StructLayout *SL = DL.getStructLayout(STy);
-  if (Offset >= SL->getSizeInBytes())
-    return nullptr;
-  uint64_t EndOffset = Offset + Size;
-  if (EndOffset > SL->getSizeInBytes())
-    return nullptr;
-
-  unsigned Index = SL->getElementContainingOffset(Offset);
-  Offset -= SL->getElementOffset(Index);
-
-  Type *ElementTy = STy->getElementType(Index);
-  uint64_t ElementSize = DL.getTypeAllocSize(ElementTy);
-  if (Offset >= ElementSize)
-    return nullptr; // The offset points into alignment padding.
-
-  // See if any partition must be contained by the element.
-  if (Offset > 0 || Size < ElementSize) {
-    if ((Offset + Size) > ElementSize)
-      return nullptr;
-    return getTypePartition(DL, ElementTy, Offset, Size);
-  }
-  assert(Offset == 0);
-
-  if (Size == ElementSize)
-    return stripAggregateTypeWrapping(DL, ElementTy);
-
-  StructType::element_iterator EI = STy->element_begin() + Index,
-                               EE = STy->element_end();
-  if (EndOffset < SL->getSizeInBytes()) {
-    unsigned EndIndex = SL->getElementContainingOffset(EndOffset);
-    if (Index == EndIndex)
-      return nullptr; // Within a single element and its padding.
-
-    // Don't try to form "natural" types if the elements don't line up with the
-    // expected size.
-    // FIXME: We could potentially recurse down through the last element in the
-    // sub-struct to find a natural end point.
-    if (SL->getElementOffset(EndIndex) != EndOffset)
-      return nullptr;
-
-    assert(Index < EndIndex);
-    EE = STy->element_begin() + EndIndex;
-  }
-
-  // Try to build up a sub-structure.
-  StructType *SubTy =
-      StructType::get(STy->getContext(), makeArrayRef(EI, EE), STy->isPacked());
-  const StructLayout *SubSL = DL.getStructLayout(SubTy);
-  if (Size != SubSL->getSizeInBytes())
-    return nullptr; // The sub-struct doesn't have quite the size needed.
-
-  return SubTy;
-}
-
-/// Pre-split loads and stores to simplify rewriting.
-///
-/// We want to break up the splittable load+store pairs as much as
-/// possible. This is important to do as a preprocessing step, as once we
-/// start rewriting the accesses to partitions of the alloca we lose the
-/// necessary information to correctly split apart paired loads and stores
-/// which both point into this alloca. The case to consider is something like
-/// the following:
-///
-///   %a = alloca [12 x i8]
-///   %gep1 = getelementptr [12 x i8]* %a, i32 0, i32 0
-///   %gep2 = getelementptr [12 x i8]* %a, i32 0, i32 4
-///   %gep3 = getelementptr [12 x i8]* %a, i32 0, i32 8
-///   %iptr1 = bitcast i8* %gep1 to i64*
-///   %iptr2 = bitcast i8* %gep2 to i64*
-///   %fptr1 = bitcast i8* %gep1 to float*
-///   %fptr2 = bitcast i8* %gep2 to float*
-///   %fptr3 = bitcast i8* %gep3 to float*
-///   store float 0.0, float* %fptr1
-///   store float 1.0, float* %fptr2
-///   %v = load i64* %iptr1
-///   store i64 %v, i64* %iptr2
-///   %f1 = load float* %fptr2
-///   %f2 = load float* %fptr3
-///
-/// Here we want to form 3 partitions of the alloca, each 4 bytes large, and
-/// promote everything so we recover the 2 SSA values that should have been
-/// there all along.
-///
-/// \returns true if any changes are made.
-bool SROA::presplitLoadsAndStores(AllocaInst &AI, AllocaSlices &AS) {
-  LLVM_DEBUG(dbgs() << "Pre-splitting loads and stores\n");
-
-  // Track the loads and stores which are candidates for pre-splitting here, in
-  // the order they first appear during the partition scan. These give stable
-  // iteration order and a basis for tracking which loads and stores we
-  // actually split.
-  SmallVector<LoadInst *, 4> Loads;
-  SmallVector<StoreInst *, 4> Stores;
-
-  // We need to accumulate the splits required of each load or store where we
-  // can find them via a direct lookup. This is important to cross-check loads
-  // and stores against each other. We also track the slice so that we can kill
-  // all the slices that end up split.
-  struct SplitOffsets {
-    Slice *S;
-    std::vector<uint64_t> Splits;
-  };
-  SmallDenseMap<Instruction *, SplitOffsets, 8> SplitOffsetsMap;
-
-  // Track loads out of this alloca which cannot, for any reason, be pre-split.
-  // This is important as we also cannot pre-split stores of those loads!
-  // FIXME: This is all pretty gross. It means that we can be more aggressive
-  // in pre-splitting when the load feeding the store happens to come from
-  // a separate alloca. Put another way, the effectiveness of SROA would be
-  // decreased by a frontend which just concatenated all of its local allocas
-  // into one big flat alloca. But defeating such patterns is exactly the job
-  // SROA is tasked with! Sadly, to not have this discrepancy we would have
-  // change store pre-splitting to actually force pre-splitting of the load
-  // that feeds it *and all stores*. That makes pre-splitting much harder, but
-  // maybe it would make it more principled?
-  SmallPtrSet<LoadInst *, 8> UnsplittableLoads;
-
-  LLVM_DEBUG(dbgs() << "  Searching for candidate loads and stores\n");
-  for (auto &P : AS.partitions()) {
-    for (Slice &S : P) {
-      Instruction *I = cast<Instruction>(S.getUse()->getUser());
-      if (!S.isSplittable() || S.endOffset() <= P.endOffset()) {
-        // If this is a load we have to track that it can't participate in any
-        // pre-splitting. If this is a store of a load we have to track that
-        // that load also can't participate in any pre-splitting.
-        if (auto *LI = dyn_cast<LoadInst>(I))
-          UnsplittableLoads.insert(LI);
-        else if (auto *SI = dyn_cast<StoreInst>(I))
-          if (auto *LI = dyn_cast<LoadInst>(SI->getValueOperand()))
-            UnsplittableLoads.insert(LI);
-        continue;
-      }
-      assert(P.endOffset() > S.beginOffset() &&
-             "Empty or backwards partition!");
-
-      // Determine if this is a pre-splittable slice.
-      if (auto *LI = dyn_cast<LoadInst>(I)) {
-        assert(!LI->isVolatile() && "Cannot split volatile loads!");
-
-        // The load must be used exclusively to store into other pointers for
-        // us to be able to arbitrarily pre-split it. The stores must also be
-        // simple to avoid changing semantics.
-        auto IsLoadSimplyStored = [](LoadInst *LI) {
-          for (User *LU : LI->users()) {
-            auto *SI = dyn_cast<StoreInst>(LU);
-            if (!SI || !SI->isSimple())
-              return false;
-          }
-          return true;
-        };
-        if (!IsLoadSimplyStored(LI)) {
-          UnsplittableLoads.insert(LI);
-          continue;
-        }
-
-        Loads.push_back(LI);
-      } else if (auto *SI = dyn_cast<StoreInst>(I)) {
-        if (S.getUse() != &SI->getOperandUse(SI->getPointerOperandIndex()))
-          // Skip stores *of* pointers. FIXME: This shouldn't even be possible!
-          continue;
-        auto *StoredLoad = dyn_cast<LoadInst>(SI->getValueOperand());
-        if (!StoredLoad || !StoredLoad->isSimple())
-          continue;
-        assert(!SI->isVolatile() && "Cannot split volatile stores!");
-
-        Stores.push_back(SI);
-      } else {
-        // Other uses cannot be pre-split.
-        continue;
-      }
-
-      // Record the initial split.
-      LLVM_DEBUG(dbgs() << "    Candidate: " << *I << "\n");
-      auto &Offsets = SplitOffsetsMap[I];
-      assert(Offsets.Splits.empty() &&
-             "Should not have splits the first time we see an instruction!");
-      Offsets.S = &S;
-      Offsets.Splits.push_back(P.endOffset() - S.beginOffset());
-    }
-
-    // Now scan the already split slices, and add a split for any of them which
-    // we're going to pre-split.
-    for (Slice *S : P.splitSliceTails()) {
-      auto SplitOffsetsMapI =
-          SplitOffsetsMap.find(cast<Instruction>(S->getUse()->getUser()));
-      if (SplitOffsetsMapI == SplitOffsetsMap.end())
-        continue;
-      auto &Offsets = SplitOffsetsMapI->second;
-
-      assert(Offsets.S == S && "Found a mismatched slice!");
-      assert(!Offsets.Splits.empty() &&
-             "Cannot have an empty set of splits on the second partition!");
-      assert(Offsets.Splits.back() ==
-                 P.beginOffset() - Offsets.S->beginOffset() &&
-             "Previous split does not end where this one begins!");
-
-      // Record each split. The last partition's end isn't needed as the size
-      // of the slice dictates that.
-      if (S->endOffset() > P.endOffset())
-        Offsets.Splits.push_back(P.endOffset() - Offsets.S->beginOffset());
-    }
-  }
-
-  // We may have split loads where some of their stores are split stores. For
-  // such loads and stores, we can only pre-split them if their splits exactly
-  // match relative to their starting offset. We have to verify this prior to
-  // any rewriting.
-  Stores.erase(
-      llvm::remove_if(Stores,
-                      [&UnsplittableLoads, &SplitOffsetsMap](StoreInst *SI) {
-                        // Lookup the load we are storing in our map of split
-                        // offsets.
-                        auto *LI = cast<LoadInst>(SI->getValueOperand());
-                        // If it was completely unsplittable, then we're done,
-                        // and this store can't be pre-split.
-                        if (UnsplittableLoads.count(LI))
-                          return true;
-
-                        auto LoadOffsetsI = SplitOffsetsMap.find(LI);
-                        if (LoadOffsetsI == SplitOffsetsMap.end())
-                          return false; // Unrelated loads are definitely safe.
-                        auto &LoadOffsets = LoadOffsetsI->second;
-
-                        // Now lookup the store's offsets.
-                        auto &StoreOffsets = SplitOffsetsMap[SI];
-
-                        // If the relative offsets of each split in the load and
-                        // store match exactly, then we can split them and we
-                        // don't need to remove them here.
-                        if (LoadOffsets.Splits == StoreOffsets.Splits)
-                          return false;
-
-                        LLVM_DEBUG(
-                            dbgs()
-                            << "    Mismatched splits for load and store:\n"
-                            << "      " << *LI << "\n"
-                            << "      " << *SI << "\n");
-
-                        // We've found a store and load that we need to split
-                        // with mismatched relative splits. Just give up on them
-                        // and remove both instructions from our list of
-                        // candidates.
-                        UnsplittableLoads.insert(LI);
-                        return true;
-                      }),
-      Stores.end());
-  // Now we have to go *back* through all the stores, because a later store may
-  // have caused an earlier store's load to become unsplittable and if it is
-  // unsplittable for the later store, then we can't rely on it being split in
-  // the earlier store either.
-  Stores.erase(llvm::remove_if(Stores,
-                               [&UnsplittableLoads](StoreInst *SI) {
-                                 auto *LI =
-                                     cast<LoadInst>(SI->getValueOperand());
-                                 return UnsplittableLoads.count(LI);
-                               }),
-               Stores.end());
-  // Once we've established all the loads that can't be split for some reason,
-  // filter any that made it into our list out.
-  Loads.erase(llvm::remove_if(Loads,
-                              [&UnsplittableLoads](LoadInst *LI) {
-                                return UnsplittableLoads.count(LI);
-                              }),
-              Loads.end());
-
-  // If no loads or stores are left, there is no pre-splitting to be done for
-  // this alloca.
-  if (Loads.empty() && Stores.empty())
-    return false;
-
-  // From here on, we can't fail and will be building new accesses, so rig up
-  // an IR builder.
-  IRBuilderTy IRB(&AI);
-
-  // Collect the new slices which we will merge into the alloca slices.
-  SmallVector<Slice, 4> NewSlices;
-
-  // Track any allocas we end up splitting loads and stores for so we iterate
-  // on them.
-  SmallPtrSet<AllocaInst *, 4> ResplitPromotableAllocas;
-
-  // At this point, we have collected all of the loads and stores we can
-  // pre-split, and the specific splits needed for them. We actually do the
-  // splitting in a specific order in order to handle when one of the loads in
-  // the value operand to one of the stores.
-  //
-  // First, we rewrite all of the split loads, and just accumulate each split
-  // load in a parallel structure. We also build the slices for them and append
-  // them to the alloca slices.
-  SmallDenseMap<LoadInst *, std::vector<LoadInst *>, 1> SplitLoadsMap;
-  std::vector<LoadInst *> SplitLoads;
-  const DataLayout &DL = AI.getModule()->getDataLayout();
-  for (LoadInst *LI : Loads) {
-    SplitLoads.clear();
-
-    IntegerType *Ty = cast<IntegerType>(LI->getType());
-    uint64_t LoadSize = Ty->getBitWidth() / 8;
-    assert(LoadSize > 0 && "Cannot have a zero-sized integer load!");
-
-    auto &Offsets = SplitOffsetsMap[LI];
-    assert(LoadSize == Offsets.S->endOffset() - Offsets.S->beginOffset() &&
-           "Slice size should always match load size exactly!");
-    uint64_t BaseOffset = Offsets.S->beginOffset();
-    assert(BaseOffset + LoadSize > BaseOffset &&
-           "Cannot represent alloca access size using 64-bit integers!");
-
-    Instruction *BasePtr = cast<Instruction>(LI->getPointerOperand());
-    IRB.SetInsertPoint(LI);
-
-    LLVM_DEBUG(dbgs() << "  Splitting load: " << *LI << "\n");
-
-    uint64_t PartOffset = 0, PartSize = Offsets.Splits.front();
-    int Idx = 0, Size = Offsets.Splits.size();
-    for (;;) {
-      auto *PartTy = Type::getIntNTy(Ty->getContext(), PartSize * 8);
-      auto AS = LI->getPointerAddressSpace();
-      auto *PartPtrTy = PartTy->getPointerTo(AS);
-      LoadInst *PLoad = IRB.CreateAlignedLoad(
-          getAdjustedPtr(IRB, DL, BasePtr,
-                         APInt(DL.getIndexSizeInBits(AS), PartOffset),
-                         PartPtrTy, BasePtr->getName() + "."),
-          getAdjustedAlignment(LI, PartOffset, DL), /*IsVolatile*/ false,
-          LI->getName());
-      PLoad->copyMetadata(*LI, {LLVMContext::MD_mem_parallel_loop_access,
-                                LLVMContext::MD_access_group});
-
-      // Append this load onto the list of split loads so we can find it later
-      // to rewrite the stores.
-      SplitLoads.push_back(PLoad);
-
-      // Now build a new slice for the alloca.
-      NewSlices.push_back(
-          Slice(BaseOffset + PartOffset, BaseOffset + PartOffset + PartSize,
-                &PLoad->getOperandUse(PLoad->getPointerOperandIndex()),
-                /*IsSplittable*/ false));
-      LLVM_DEBUG(dbgs() << "    new slice [" << NewSlices.back().beginOffset()
-                        << ", " << NewSlices.back().endOffset()
-                        << "): " << *PLoad << "\n");
-
-      // See if we've handled all the splits.
-      if (Idx >= Size)
-        break;
-
-      // Setup the next partition.
-      PartOffset = Offsets.Splits[Idx];
-      ++Idx;
-      PartSize = (Idx < Size ? Offsets.Splits[Idx] : LoadSize) - PartOffset;
-    }
-
-    // Now that we have the split loads, do the slow walk over all uses of the
-    // load and rewrite them as split stores, or save the split loads to use
-    // below if the store is going to be split there anyways.
-    bool DeferredStores = false;
-    for (User *LU : LI->users()) {
-      StoreInst *SI = cast<StoreInst>(LU);
-      if (!Stores.empty() && SplitOffsetsMap.count(SI)) {
-        DeferredStores = true;
-        LLVM_DEBUG(dbgs() << "    Deferred splitting of store: " << *SI
-                          << "\n");
-        continue;
-      }
-
-      Value *StoreBasePtr = SI->getPointerOperand();
-      IRB.SetInsertPoint(SI);
-
-      LLVM_DEBUG(dbgs() << "    Splitting store of load: " << *SI << "\n");
-
-      for (int Idx = 0, Size = SplitLoads.size(); Idx < Size; ++Idx) {
-        LoadInst *PLoad = SplitLoads[Idx];
-        uint64_t PartOffset = Idx == 0 ? 0 : Offsets.Splits[Idx - 1];
-        auto *PartPtrTy =
-            PLoad->getType()->getPointerTo(SI->getPointerAddressSpace());
-
-        auto AS = SI->getPointerAddressSpace();
-        StoreInst *PStore = IRB.CreateAlignedStore(
-            PLoad,
-            getAdjustedPtr(IRB, DL, StoreBasePtr,
-                           APInt(DL.getIndexSizeInBits(AS), PartOffset),
-                           PartPtrTy, StoreBasePtr->getName() + "."),
-            getAdjustedAlignment(SI, PartOffset, DL), /*IsVolatile*/ false);
-        PStore->copyMetadata(*LI, {LLVMContext::MD_mem_parallel_loop_access,
-                                   LLVMContext::MD_access_group});
-        LLVM_DEBUG(dbgs() << "      +" << PartOffset << ":" << *PStore << "\n");
-      }
-
-      // We want to immediately iterate on any allocas impacted by splitting
-      // this store, and we have to track any promotable alloca (indicated by
-      // a direct store) as needing to be resplit because it is no longer
-      // promotable.
-      if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(StoreBasePtr)) {
-        ResplitPromotableAllocas.insert(OtherAI);
-        Worklist.insert(OtherAI);
-      } else if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(
-                     StoreBasePtr->stripInBoundsOffsets())) {
-        Worklist.insert(OtherAI);
-      }
-
-      // Mark the original store as dead.
-      DeadInsts.insert(SI);
-    }
-
-    // Save the split loads if there are deferred stores among the users.
-    if (DeferredStores)
-      SplitLoadsMap.insert(std::make_pair(LI, std::move(SplitLoads)));
-
-    // Mark the original load as dead and kill the original slice.
-    DeadInsts.insert(LI);
-    Offsets.S->kill();
-  }
-
-  // Second, we rewrite all of the split stores. At this point, we know that
-  // all loads from this alloca have been split already. For stores of such
-  // loads, we can simply look up the pre-existing split loads. For stores of
-  // other loads, we split those loads first and then write split stores of
-  // them.
-  for (StoreInst *SI : Stores) {
-    auto *LI = cast<LoadInst>(SI->getValueOperand());
-    IntegerType *Ty = cast<IntegerType>(LI->getType());
-    uint64_t StoreSize = Ty->getBitWidth() / 8;
-    assert(StoreSize > 0 && "Cannot have a zero-sized integer store!");
-
-    auto &Offsets = SplitOffsetsMap[SI];
-    assert(StoreSize == Offsets.S->endOffset() - Offsets.S->beginOffset() &&
-           "Slice size should always match load size exactly!");
-    uint64_t BaseOffset = Offsets.S->beginOffset();
-    assert(BaseOffset + StoreSize > BaseOffset &&
-           "Cannot represent alloca access size using 64-bit integers!");
-
-    Value *LoadBasePtr = LI->getPointerOperand();
-    Instruction *StoreBasePtr = cast<Instruction>(SI->getPointerOperand());
-
-    LLVM_DEBUG(dbgs() << "  Splitting store: " << *SI << "\n");
-
-    // Check whether we have an already split load.
-    auto SplitLoadsMapI = SplitLoadsMap.find(LI);
-    std::vector<LoadInst *> *SplitLoads = nullptr;
-    if (SplitLoadsMapI != SplitLoadsMap.end()) {
-      SplitLoads = &SplitLoadsMapI->second;
-      assert(SplitLoads->size() == Offsets.Splits.size() + 1 &&
-             "Too few split loads for the number of splits in the store!");
-    } else {
-      LLVM_DEBUG(dbgs() << "          of load: " << *LI << "\n");
-    }
-
-    uint64_t PartOffset = 0, PartSize = Offsets.Splits.front();
-    int Idx = 0, Size = Offsets.Splits.size();
-    for (;;) {
-      auto *PartTy = Type::getIntNTy(Ty->getContext(), PartSize * 8);
-      auto *LoadPartPtrTy = PartTy->getPointerTo(LI->getPointerAddressSpace());
-      auto *StorePartPtrTy = PartTy->getPointerTo(SI->getPointerAddressSpace());
-
-      // Either lookup a split load or create one.
-      LoadInst *PLoad;
-      if (SplitLoads) {
-        PLoad = (*SplitLoads)[Idx];
-      } else {
-        IRB.SetInsertPoint(LI);
-        auto AS = LI->getPointerAddressSpace();
-        PLoad = IRB.CreateAlignedLoad(
-            getAdjustedPtr(IRB, DL, LoadBasePtr,
-                           APInt(DL.getIndexSizeInBits(AS), PartOffset),
-                           LoadPartPtrTy, LoadBasePtr->getName() + "."),
-            getAdjustedAlignment(LI, PartOffset, DL), /*IsVolatile*/ false,
-            LI->getName());
-      }
-
-      // And store this partition.
-      IRB.SetInsertPoint(SI);
-      auto AS = SI->getPointerAddressSpace();
-      StoreInst *PStore = IRB.CreateAlignedStore(
-          PLoad,
-          getAdjustedPtr(IRB, DL, StoreBasePtr,
-                         APInt(DL.getIndexSizeInBits(AS), PartOffset),
-                         StorePartPtrTy, StoreBasePtr->getName() + "."),
-          getAdjustedAlignment(SI, PartOffset, DL), /*IsVolatile*/ false);
-
-      // Now build a new slice for the alloca.
-      NewSlices.push_back(
-          Slice(BaseOffset + PartOffset, BaseOffset + PartOffset + PartSize,
-                &PStore->getOperandUse(PStore->getPointerOperandIndex()),
-                /*IsSplittable*/ false));
-      LLVM_DEBUG(dbgs() << "    new slice [" << NewSlices.back().beginOffset()
-                        << ", " << NewSlices.back().endOffset()
-                        << "): " << *PStore << "\n");
-      if (!SplitLoads) {
-        LLVM_DEBUG(dbgs() << "      of split load: " << *PLoad << "\n");
-      }
-
-      // See if we've finished all the splits.
-      if (Idx >= Size)
-        break;
-
-      // Setup the next partition.
-      PartOffset = Offsets.Splits[Idx];
-      ++Idx;
-      PartSize = (Idx < Size ? Offsets.Splits[Idx] : StoreSize) - PartOffset;
-    }
-
-    // We want to immediately iterate on any allocas impacted by splitting
-    // this load, which is only relevant if it isn't a load of this alloca and
-    // thus we didn't already split the loads above. We also have to keep track
-    // of any promotable allocas we split loads on as they can no longer be
-    // promoted.
-    if (!SplitLoads) {
-      if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(LoadBasePtr)) {
-        assert(OtherAI != &AI && "We can't re-split our own alloca!");
-        ResplitPromotableAllocas.insert(OtherAI);
-        Worklist.insert(OtherAI);
-      } else if (AllocaInst *OtherAI = dyn_cast<AllocaInst>(
-                     LoadBasePtr->stripInBoundsOffsets())) {
-        assert(OtherAI != &AI && "We can't re-split our own alloca!");
-        Worklist.insert(OtherAI);
-      }
-    }
-
-    // Mark the original store as dead now that we've split it up and kill its
-    // slice. Note that we leave the original load in place unless this store
-    // was its only use. It may in turn be split up if it is an alloca load
-    // for some other alloca, but it may be a normal load. This may introduce
-    // redundant loads, but where those can be merged the rest of the optimizer
-    // should handle the merging, and this uncovers SSA splits which is more
-    // important. In practice, the original loads will almost always be fully
-    // split and removed eventually, and the splits will be merged by any
-    // trivial CSE, including instcombine.
-    if (LI->hasOneUse()) {
-      assert(*LI->user_begin() == SI && "Single use isn't this store!");
-      DeadInsts.insert(LI);
-    }
-    DeadInsts.insert(SI);
-    Offsets.S->kill();
-  }
-
-  // Remove the killed slices that have ben pre-split.
-  AS.erase(llvm::remove_if(AS, [](const Slice &S) { return S.isDead(); }),
-           AS.end());
-
-  // Insert our new slices. This will sort and merge them into the sorted
-  // sequence.
-  AS.insert(NewSlices);
-
-  LLVM_DEBUG(dbgs() << "  Pre-split slices:\n");
-#ifndef NDEBUG
-  for (auto I = AS.begin(), E = AS.end(); I != E; ++I)
-    LLVM_DEBUG(AS.print(dbgs(), I, "    "));
-#endif
-
-  // Finally, don't try to promote any allocas that new require re-splitting.
-  // They have already been added to the worklist above.
-  PromotableAllocas.erase(
-      llvm::remove_if(
-          PromotableAllocas,
-          [&](AllocaInst *AI) { return ResplitPromotableAllocas.count(AI); }),
-      PromotableAllocas.end());
-
-  return true;
-}
-
-/// Rewrite an alloca partition's users.
-///
-/// This routine drives both of the rewriting goals of the SROA pass. It tries
-/// to rewrite uses of an alloca partition to be conducive for SSA value
-/// promotion. If the partition needs a new, more refined alloca, this will
-/// build that new alloca, preserving as much type information as possible, and
-/// rewrite the uses of the old alloca to point at the new one and have the
-/// appropriate new offsets. It also evaluates how successful the rewrite was
-/// at enabling promotion and if it was successful queues the alloca to be
-/// promoted.
-AllocaInst *SROA::rewritePartition(AllocaInst &AI, AllocaSlices &AS,
-                                   Partition &P) {
-  // Try to compute a friendly type for this partition of the alloca. This
-  // won't always succeed, in which case we fall back to a legal integer type
-  // or an i8 array of an appropriate size.
-  Type *SliceTy = nullptr;
-  const DataLayout &DL = AI.getModule()->getDataLayout();
-  if (Type *CommonUseTy = findCommonType(P.begin(), P.end(), P.endOffset()))
-    if (DL.getTypeAllocSize(CommonUseTy) >= P.size())
-      SliceTy = CommonUseTy;
-  if (!SliceTy)
-    if (Type *TypePartitionTy = getTypePartition(DL, AI.getAllocatedType(),
-                                                 P.beginOffset(), P.size()))
-      SliceTy = TypePartitionTy;
-  if ((!SliceTy || (SliceTy->isArrayTy() &&
-                    SliceTy->getArrayElementType()->isIntegerTy())) &&
-      DL.isLegalInteger(P.size() * 8))
-    SliceTy = Type::getIntNTy(*C, P.size() * 8);
-  if (!SliceTy)
-    SliceTy = ArrayType::get(Type::getInt8Ty(*C), P.size());
-  assert(DL.getTypeAllocSize(SliceTy) >= P.size());
-
-  bool IsIntegerPromotable = isIntegerWideningViable(P, SliceTy, DL);
-
-  VectorType *VecTy =
-      IsIntegerPromotable ? nullptr : isVectorPromotionViable(P, DL);
-  if (VecTy)
-    SliceTy = VecTy;
-
-  // Check for the case where we're going to rewrite to a new alloca of the
-  // exact same type as the original, and with the same access offsets. In that
-  // case, re-use the existing alloca, but still run through the rewriter to
-  // perform phi and select speculation.
-  // P.beginOffset() can be non-zero even with the same type in a case with
-  // out-of-bounds access (e.g. @PR35657 function in SROA/basictest.ll).
-  AllocaInst *NewAI;
-  if (SliceTy == AI.getAllocatedType() && P.beginOffset() == 0) {
-    NewAI = &AI;
-    // FIXME: We should be able to bail at this point with "nothing changed".
-    // FIXME: We might want to defer PHI speculation until after here.
-    // FIXME: return nullptr;
-  } else {
-    unsigned Alignment = AI.getAlignment();
-    if (!Alignment) {
-      // The minimum alignment which users can rely on when the explicit
-      // alignment is omitted or zero is that required by the ABI for this
-      // type.
-      Alignment = DL.getABITypeAlignment(AI.getAllocatedType());
-    }
-    Alignment = MinAlign(Alignment, P.beginOffset());
-    // If we will get at least this much alignment from the type alone, leave
-    // the alloca's alignment unconstrained.
-    if (Alignment <= DL.getABITypeAlignment(SliceTy))
-      Alignment = 0;
-    NewAI = new AllocaInst(
-      SliceTy, AI.getType()->getAddressSpace(), nullptr, Alignment,
-        AI.getName() + ".sroa." + Twine(P.begin() - AS.begin()), &AI);
-    // Copy the old AI debug location over to the new one.
-    NewAI->setDebugLoc(AI.getDebugLoc());
-    ++NumNewAllocas;
-  }
-
-  LLVM_DEBUG(dbgs() << "Rewriting alloca partition "
-                    << "[" << P.beginOffset() << "," << P.endOffset()
-                    << ") to: " << *NewAI << "\n");
-
-  // Track the high watermark on the worklist as it is only relevant for
-  // promoted allocas. We will reset it to this point if the alloca is not in
-  // fact scheduled for promotion.
-  unsigned PPWOldSize = PostPromotionWorklist.size();
-  unsigned NumUses = 0;
-  SmallSetVector<PHINode *, 8> PHIUsers;
-  SmallSetVector<SelectInst *, 8> SelectUsers;
-
-  AllocaSliceRewriter Rewriter(DL, AS, *this, AI, *NewAI, P.beginOffset(),
-                               P.endOffset(), IsIntegerPromotable, VecTy,
-                               PHIUsers, SelectUsers);
-  bool Promotable = true;
-  for (Slice *S : P.splitSliceTails()) {
-    Promotable &= Rewriter.visit(S);
-    ++NumUses;
-  }
-  for (Slice &S : P) {
-    Promotable &= Rewriter.visit(&S);
-    ++NumUses;
-  }
-
-  NumAllocaPartitionUses += NumUses;
-  MaxUsesPerAllocaPartition.updateMax(NumUses);
-
-  // Now that we've processed all the slices in the new partition, check if any
-  // PHIs or Selects would block promotion.
-  for (PHINode *PHI : PHIUsers)
-    if (!isSafePHIToSpeculate(*PHI)) {
-      Promotable = false;
-      PHIUsers.clear();
-      SelectUsers.clear();
-      break;
-    }
-
-  for (SelectInst *Sel : SelectUsers)
-    if (!isSafeSelectToSpeculate(*Sel)) {
-      Promotable = false;
-      PHIUsers.clear();
-      SelectUsers.clear();
-      break;
-    }
-
-  if (Promotable) {
-    if (PHIUsers.empty() && SelectUsers.empty()) {
-      // Promote the alloca.
-      PromotableAllocas.push_back(NewAI);
-    } else {
-      // If we have either PHIs or Selects to speculate, add them to those
-      // worklists and re-queue the new alloca so that we promote in on the
-      // next iteration.
-      for (PHINode *PHIUser : PHIUsers)
-        SpeculatablePHIs.insert(PHIUser);
-      for (SelectInst *SelectUser : SelectUsers)
-        SpeculatableSelects.insert(SelectUser);
-      Worklist.insert(NewAI);
-    }
-  } else {
-    // Drop any post-promotion work items if promotion didn't happen.
-    while (PostPromotionWorklist.size() > PPWOldSize)
-      PostPromotionWorklist.pop_back();
-
-    // We couldn't promote and we didn't create a new partition, nothing
-    // happened.
-    if (NewAI == &AI)
-      return nullptr;
-
-    // If we can't promote the alloca, iterate on it to check for new
-    // refinements exposed by splitting the current alloca. Don't iterate on an
-    // alloca which didn't actually change and didn't get promoted.
-    Worklist.insert(NewAI);
-  }
-
-  return NewAI;
-}
-
-/// Walks the slices of an alloca and form partitions based on them,
-/// rewriting each of their uses.
-bool SROA::splitAlloca(AllocaInst &AI, AllocaSlices &AS) {
-  if (AS.begin() == AS.end())
-    return false;
-
-  unsigned NumPartitions = 0;
-  bool Changed = false;
-  const DataLayout &DL = AI.getModule()->getDataLayout();
-
-  // First try to pre-split loads and stores.
-  Changed |= presplitLoadsAndStores(AI, AS);
-
-  // Now that we have identified any pre-splitting opportunities,
-  // mark loads and stores unsplittable except for the following case.
-  // We leave a slice splittable if all other slices are disjoint or fully
-  // included in the slice, such as whole-alloca loads and stores.
-  // If we fail to split these during pre-splitting, we want to force them
-  // to be rewritten into a partition.
-  bool IsSorted = true;
-
-  uint64_t AllocaSize = DL.getTypeAllocSize(AI.getAllocatedType());
-  const uint64_t MaxBitVectorSize = 1024;
-  if (AllocaSize <= MaxBitVectorSize) {
-    // If a byte boundary is included in any load or store, a slice starting or
-    // ending at the boundary is not splittable.
-    SmallBitVector SplittableOffset(AllocaSize + 1, true);
-    for (Slice &S : AS)
-      for (unsigned O = S.beginOffset() + 1;
-           O < S.endOffset() && O < AllocaSize; O++)
-        SplittableOffset.reset(O);
-
-    for (Slice &S : AS) {
-      if (!S.isSplittable())
-        continue;
-
-      if ((S.beginOffset() > AllocaSize || SplittableOffset[S.beginOffset()]) &&
-          (S.endOffset() > AllocaSize || SplittableOffset[S.endOffset()]))
-        continue;
-
-      if (isa<LoadInst>(S.getUse()->getUser()) ||
-          isa<StoreInst>(S.getUse()->getUser())) {
-        S.makeUnsplittable();
-        IsSorted = false;
-      }
-    }
-  }
-  else {
-    // We only allow whole-alloca splittable loads and stores
-    // for a large alloca to avoid creating too large BitVector.
-    for (Slice &S : AS) {
-      if (!S.isSplittable())
-        continue;
-
-      if (S.beginOffset() == 0 && S.endOffset() >= AllocaSize)
-        continue;
-
-      if (isa<LoadInst>(S.getUse()->getUser()) ||
-          isa<StoreInst>(S.getUse()->getUser())) {
-        S.makeUnsplittable();
-        IsSorted = false;
-      }
-    }
-  }
-
-  if (!IsSorted)
-    llvm::sort(AS);
-
-  /// Describes the allocas introduced by rewritePartition in order to migrate
-  /// the debug info.
-  struct Fragment {
-    AllocaInst *Alloca;
-    uint64_t Offset;
-    uint64_t Size;
-    Fragment(AllocaInst *AI, uint64_t O, uint64_t S)
-      : Alloca(AI), Offset(O), Size(S) {}
-  };
-  SmallVector<Fragment, 4> Fragments;
-
-  // Rewrite each partition.
-  for (auto &P : AS.partitions()) {
-    if (AllocaInst *NewAI = rewritePartition(AI, AS, P)) {
-      Changed = true;
-      if (NewAI != &AI) {
-        uint64_t SizeOfByte = 8;
-        uint64_t AllocaSize = DL.getTypeSizeInBits(NewAI->getAllocatedType());
-        // Don't include any padding.
-        uint64_t Size = std::min(AllocaSize, P.size() * SizeOfByte);
-        Fragments.push_back(Fragment(NewAI, P.beginOffset() * SizeOfByte, Size));
-      }
-    }
-    ++NumPartitions;
-  }
-
-  NumAllocaPartitions += NumPartitions;
-  MaxPartitionsPerAlloca.updateMax(NumPartitions);
-
-  // Migrate debug information from the old alloca to the new alloca(s)
-  // and the individual partitions.
-  TinyPtrVector<DbgVariableIntrinsic *> DbgDeclares = FindDbgAddrUses(&AI);
-  if (!DbgDeclares.empty()) {
-    auto *Var = DbgDeclares.front()->getVariable();
-    auto *Expr = DbgDeclares.front()->getExpression();
-    auto VarSize = Var->getSizeInBits();
-    DIBuilder DIB(*AI.getModule(), /*AllowUnresolved*/ false);
-    uint64_t AllocaSize = DL.getTypeSizeInBits(AI.getAllocatedType());
-    for (auto Fragment : Fragments) {
-      // Create a fragment expression describing the new partition or reuse AI's
-      // expression if there is only one partition.
-      auto *FragmentExpr = Expr;
-      if (Fragment.Size < AllocaSize || Expr->isFragment()) {
-        // If this alloca is already a scalar replacement of a larger aggregate,
-        // Fragment.Offset describes the offset inside the scalar.
-        auto ExprFragment = Expr->getFragmentInfo();
-        uint64_t Offset = ExprFragment ? ExprFragment->OffsetInBits : 0;
-        uint64_t Start = Offset + Fragment.Offset;
-        uint64_t Size = Fragment.Size;
-        if (ExprFragment) {
-          uint64_t AbsEnd =
-              ExprFragment->OffsetInBits + ExprFragment->SizeInBits;
-          if (Start >= AbsEnd)
-            // No need to describe a SROAed padding.
-            continue;
-          Size = std::min(Size, AbsEnd - Start);
-        }
-        // The new, smaller fragment is stenciled out from the old fragment.
-        if (auto OrigFragment = FragmentExpr->getFragmentInfo()) {
-          assert(Start >= OrigFragment->OffsetInBits &&
-                 "new fragment is outside of original fragment");
-          Start -= OrigFragment->OffsetInBits;
-        }
-
-        // The alloca may be larger than the variable.
-        if (VarSize) {
-          if (Size > *VarSize)
-            Size = *VarSize;
-          if (Size == 0 || Start + Size > *VarSize)
-            continue;
-        }
-
-        // Avoid creating a fragment expression that covers the entire variable.
-        if (!VarSize || *VarSize != Size) {
-          if (auto E =
-                  DIExpression::createFragmentExpression(Expr, Start, Size))
-            FragmentExpr = *E;
-          else
-            continue;
-        }
-      }
-
-      // Remove any existing intrinsics describing the same alloca.
-      for (DbgVariableIntrinsic *OldDII : FindDbgAddrUses(Fragment.Alloca))
-        OldDII->eraseFromParent();
-
-      DIB.insertDeclare(Fragment.Alloca, Var, FragmentExpr,
-                        DbgDeclares.front()->getDebugLoc(), &AI);
-    }
-  }
-  return Changed;
-}
-
-/// Clobber a use with undef, deleting the used value if it becomes dead.
-void SROA::clobberUse(Use &U) {
-  Value *OldV = U;
-  // Replace the use with an undef value.
-  U = UndefValue::get(OldV->getType());
-
-  // Check for this making an instruction dead. We have to garbage collect
-  // all the dead instructions to ensure the uses of any alloca end up being
-  // minimal.
-  if (Instruction *OldI = dyn_cast<Instruction>(OldV))
-    if (isInstructionTriviallyDead(OldI)) {
-      DeadInsts.insert(OldI);
-    }
-}
-
-/// Analyze an alloca for SROA.
-///
-/// This analyzes the alloca to ensure we can reason about it, builds
-/// the slices of the alloca, and then hands it off to be split and
-/// rewritten as needed.
-bool SROA::runOnAlloca(AllocaInst &AI) {
-  LLVM_DEBUG(dbgs() << "SROA alloca: " << AI << "\n");
-  ++NumAllocasAnalyzed;
-
-  // Special case dead allocas, as they're trivial.
-  if (AI.use_empty()) {
-    AI.eraseFromParent();
-    return true;
-  }
-  const DataLayout &DL = AI.getModule()->getDataLayout();
-
-  // Skip alloca forms that this analysis can't handle.
-  if (AI.isArrayAllocation() || !AI.getAllocatedType()->isSized() ||
-      DL.getTypeAllocSize(AI.getAllocatedType()) == 0)
-    return false;
-
-  bool Changed = false;
-
-  // First, split any FCA loads and stores touching this alloca to promote
-  // better splitting and promotion opportunities.
-  AggLoadStoreRewriter AggRewriter(DL);
-  Changed |= AggRewriter.rewrite(AI);
-
-  // Build the slices using a recursive instruction-visiting builder.
-  AllocaSlices AS(DL, AI);
-  LLVM_DEBUG(AS.print(dbgs()));
-  if (AS.isEscaped())
-    return Changed;
-
-  // Delete all the dead users of this alloca before splitting and rewriting it.
-  for (Instruction *DeadUser : AS.getDeadUsers()) {
-    // Free up everything used by this instruction.
-    for (Use &DeadOp : DeadUser->operands())
-      clobberUse(DeadOp);
-
-    // Now replace the uses of this instruction.
-    DeadUser->replaceAllUsesWith(UndefValue::get(DeadUser->getType()));
-
-    // And mark it for deletion.
-    DeadInsts.insert(DeadUser);
-    Changed = true;
-  }
-  for (Use *DeadOp : AS.getDeadOperands()) {
-    clobberUse(*DeadOp);
-    Changed = true;
-  }
-
-  // No slices to split. Leave the dead alloca for a later pass to clean up.
-  if (AS.begin() == AS.end())
-    return Changed;
-
-  Changed |= splitAlloca(AI, AS);
-
-  LLVM_DEBUG(dbgs() << "  Speculating PHIs\n");
-  while (!SpeculatablePHIs.empty())
-    speculatePHINodeLoads(*SpeculatablePHIs.pop_back_val());
-
-  LLVM_DEBUG(dbgs() << "  Speculating Selects\n");
-  while (!SpeculatableSelects.empty())
-    speculateSelectInstLoads(*SpeculatableSelects.pop_back_val());
-
-  return Changed;
-}
-
-/// Delete the dead instructions accumulated in this run.
-///
-/// Recursively deletes the dead instructions we've accumulated. This is done
-/// at the very end to maximize locality of the recursive delete and to
-/// minimize the problems of invalidated instruction pointers as such pointers
-/// are used heavily in the intermediate stages of the algorithm.
-///
-/// We also record the alloca instructions deleted here so that they aren't
-/// subsequently handed to mem2reg to promote.
-bool SROA::deleteDeadInstructions(
-    SmallPtrSetImpl<AllocaInst *> &DeletedAllocas) {
-  bool Changed = false;
-  while (!DeadInsts.empty()) {
-    Instruction *I = DeadInsts.pop_back_val();
-    LLVM_DEBUG(dbgs() << "Deleting dead instruction: " << *I << "\n");
-
-    // If the instruction is an alloca, find the possible dbg.declare connected
-    // to it, and remove it too. We must do this before calling RAUW or we will
-    // not be able to find it.
-    if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
-      DeletedAllocas.insert(AI);
-      for (DbgVariableIntrinsic *OldDII : FindDbgAddrUses(AI))
-        OldDII->eraseFromParent();
-    }
-
-    I->replaceAllUsesWith(UndefValue::get(I->getType()));
-
-    for (Use &Operand : I->operands())
-      if (Instruction *U = dyn_cast<Instruction>(Operand)) {
-        // Zero out the operand and see if it becomes trivially dead.
-        Operand = nullptr;
-        if (isInstructionTriviallyDead(U))
-          DeadInsts.insert(U);
-      }
-
-    ++NumDeleted;
-    I->eraseFromParent();
-    Changed = true;
-  }
-  return Changed;
-}
-
-/// Promote the allocas, using the best available technique.
-///
-/// This attempts to promote whatever allocas have been identified as viable in
-/// the PromotableAllocas list. If that list is empty, there is nothing to do.
-/// This function returns whether any promotion occurred.
-bool SROA::promoteAllocas(Function &F) {
-  if (PromotableAllocas.empty())
-    return false;
-
-  NumPromoted += PromotableAllocas.size();
-
-  LLVM_DEBUG(dbgs() << "Promoting allocas with mem2reg...\n");
-  PromoteMemToReg(PromotableAllocas, *DT, AC);
-  PromotableAllocas.clear();
-  return true;
-}
-
-PreservedAnalyses SROA::runImpl(Function &F, DominatorTree &RunDT,
-                                AssumptionCache &RunAC) {
-  LLVM_DEBUG(dbgs() << "SROA function: " << F.getName() << "\n");
-  C = &F.getContext();
-  DT = &RunDT;
-  AC = &RunAC;
-
-  BasicBlock &EntryBB = F.getEntryBlock();
-  for (BasicBlock::iterator I = EntryBB.begin(), E = std::prev(EntryBB.end());
-       I != E; ++I) {
-    if (AllocaInst *AI = dyn_cast<AllocaInst>(I))
-      Worklist.insert(AI);
-  }
-
-  bool Changed = false;
-  // A set of deleted alloca instruction pointers which should be removed from
-  // the list of promotable allocas.
-  SmallPtrSet<AllocaInst *, 4> DeletedAllocas;
-
-  do {
-    while (!Worklist.empty()) {
-      Changed |= runOnAlloca(*Worklist.pop_back_val());
-      Changed |= deleteDeadInstructions(DeletedAllocas);
-
-      // Remove the deleted allocas from various lists so that we don't try to
-      // continue processing them.
-      if (!DeletedAllocas.empty()) {
-        auto IsInSet = [&](AllocaInst *AI) { return DeletedAllocas.count(AI); };
-        Worklist.remove_if(IsInSet);
-        PostPromotionWorklist.remove_if(IsInSet);
-        PromotableAllocas.erase(llvm::remove_if(PromotableAllocas, IsInSet),
-                                PromotableAllocas.end());
-        DeletedAllocas.clear();
-      }
-    }
-
-    Changed |= promoteAllocas(F);
-
-    Worklist = PostPromotionWorklist;
-    PostPromotionWorklist.clear();
-  } while (!Worklist.empty());
-
-  if (!Changed)
-    return PreservedAnalyses::all();
-
-  PreservedAnalyses PA;
-  PA.preserveSet<CFGAnalyses>();
-  PA.preserve<GlobalsAA>();
-  return PA;
-}
-
-PreservedAnalyses SROA::run(Function &F, FunctionAnalysisManager &AM) {
-  return runImpl(F, AM.getResult<DominatorTreeAnalysis>(F),
-                 AM.getResult<AssumptionAnalysis>(F));
-}
-
-/// A legacy pass for the legacy pass manager that wraps the \c SROA pass.
-///
-/// This is in the llvm namespace purely to allow it to be a friend of the \c
-/// SROA pass.
-class llvm::sroa::SROALegacyPass : public FunctionPass {
-  /// The SROA implementation.
-  SROA Impl;
-
-public:
-  static char ID;
-
-  SROALegacyPass() : FunctionPass(ID) {
-    initializeSROALegacyPassPass(*PassRegistry::getPassRegistry());
-  }
-
-  bool runOnFunction(Function &F) override {
-    if (skipFunction(F))
-      return false;
-
-    auto PA = Impl.runImpl(
-        F, getAnalysis<DominatorTreeWrapperPass>().getDomTree(),
-        getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F));
-    return !PA.areAllPreserved();
-  }
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.addRequired<AssumptionCacheTracker>();
-    AU.addRequired<DominatorTreeWrapperPass>();
-    AU.addPreserved<GlobalsAAWrapperPass>();
-    AU.setPreservesCFG();
-  }
-
-  StringRef getPassName() const override { return "SROA"; }
-};
-
-char SROALegacyPass::ID = 0;
-
-FunctionPass *llvm::createSROAPass() { return new SROALegacyPass(); }
-
-INITIALIZE_PASS_BEGIN(SROALegacyPass, "sroa",
-                      "Scalar Replacement Of Aggregates", false, false)
-INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
-INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
-INITIALIZE_PASS_END(SROALegacyPass, "sroa", "Scalar Replacement Of Aggregates",
-                    false, false)