Remove LLVM 8.0.1 files.

1 files changed, 0 insertions, 1031 deletions

diff --git a/gnu/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp b/gnu/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
deleted file mode 100644
index 91e4f4254b3..00000000000
--- a/gnu/llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
+++ /dev/null
@@ -1,1031 +0,0 @@
-//===- PromoteMemoryToRegister.cpp - Convert allocas to registers ---------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file promotes memory references to be register references.  It promotes
-// alloca instructions which only have loads and stores as uses.  An alloca is
-// transformed by using iterated dominator frontiers to place PHI nodes, then
-// traversing the function in depth-first order to rewrite loads and stores as
-// appropriate.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/ADT/ArrayRef.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/ADT/TinyPtrVector.h"
-#include "llvm/ADT/Twine.h"
-#include "llvm/Analysis/AssumptionCache.h"
-#include "llvm/Analysis/InstructionSimplify.h"
-#include "llvm/Analysis/IteratedDominanceFrontier.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Analysis/ValueTracking.h"
-#include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CFG.h"
-#include "llvm/IR/Constant.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/DIBuilder.h"
-#include "llvm/IR/DerivedTypes.h"
-#include "llvm/IR/Dominators.h"
-#include "llvm/IR/Function.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/Module.h"
-#include "llvm/IR/Type.h"
-#include "llvm/IR/User.h"
-#include "llvm/Support/Casting.h"
-#include "llvm/Transforms/Utils/PromoteMemToReg.h"
-#include <algorithm>
-#include <cassert>
-#include <iterator>
-#include <utility>
-#include <vector>
-
-using namespace llvm;
-
-#define DEBUG_TYPE "mem2reg"
-
-STATISTIC(NumLocalPromoted, "Number of alloca's promoted within one block");
-STATISTIC(NumSingleStore,   "Number of alloca's promoted with a single store");
-STATISTIC(NumDeadAlloca,    "Number of dead alloca's removed");
-STATISTIC(NumPHIInsert,     "Number of PHI nodes inserted");
-
-bool llvm::isAllocaPromotable(const AllocaInst *AI) {
-  // FIXME: If the memory unit is of pointer or integer type, we can permit
-  // assignments to subsections of the memory unit.
-  unsigned AS = AI->getType()->getAddressSpace();
-
-  // Only allow direct and non-volatile loads and stores...
-  for (const User *U : AI->users()) {
-    if (const LoadInst *LI = dyn_cast<LoadInst>(U)) {
-      // Note that atomic loads can be transformed; atomic semantics do
-      // not have any meaning for a local alloca.
-      if (LI->isVolatile())
-        return false;
-    } else if (const StoreInst *SI = dyn_cast<StoreInst>(U)) {
-      if (SI->getOperand(0) == AI)
-        return false; // Don't allow a store OF the AI, only INTO the AI.
-      // Note that atomic stores can be transformed; atomic semantics do
-      // not have any meaning for a local alloca.
-      if (SI->isVolatile())
-        return false;
-    } else if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(U)) {
-      if (!II->isLifetimeStartOrEnd())
-        return false;
-    } else if (const BitCastInst *BCI = dyn_cast<BitCastInst>(U)) {
-      if (BCI->getType() != Type::getInt8PtrTy(U->getContext(), AS))
-        return false;
-      if (!onlyUsedByLifetimeMarkers(BCI))
-        return false;
-    } else if (const GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(U)) {
-      if (GEPI->getType() != Type::getInt8PtrTy(U->getContext(), AS))
-        return false;
-      if (!GEPI->hasAllZeroIndices())
-        return false;
-      if (!onlyUsedByLifetimeMarkers(GEPI))
-        return false;
-    } else {
-      return false;
-    }
-  }
-
-  return true;
-}
-
-namespace {
-
-struct AllocaInfo {
-  SmallVector<BasicBlock *, 32> DefiningBlocks;
-  SmallVector<BasicBlock *, 32> UsingBlocks;
-
-  StoreInst *OnlyStore;
-  BasicBlock *OnlyBlock;
-  bool OnlyUsedInOneBlock;
-
-  Value *AllocaPointerVal;
-  TinyPtrVector<DbgVariableIntrinsic *> DbgDeclares;
-
-  void clear() {
-    DefiningBlocks.clear();
-    UsingBlocks.clear();
-    OnlyStore = nullptr;
-    OnlyBlock = nullptr;
-    OnlyUsedInOneBlock = true;
-    AllocaPointerVal = nullptr;
-    DbgDeclares.clear();
-  }
-
-  /// Scan the uses of the specified alloca, filling in the AllocaInfo used
-  /// by the rest of the pass to reason about the uses of this alloca.
-  void AnalyzeAlloca(AllocaInst *AI) {
-    clear();
-
-    // As we scan the uses of the alloca instruction, keep track of stores,
-    // and decide whether all of the loads and stores to the alloca are within
-    // the same basic block.
-    for (auto UI = AI->user_begin(), E = AI->user_end(); UI != E;) {
-      Instruction *User = cast<Instruction>(*UI++);
-
-      if (StoreInst *SI = dyn_cast<StoreInst>(User)) {
-        // Remember the basic blocks which define new values for the alloca
-        DefiningBlocks.push_back(SI->getParent());
-        AllocaPointerVal = SI->getOperand(0);
-        OnlyStore = SI;
-      } else {
-        LoadInst *LI = cast<LoadInst>(User);
-        // Otherwise it must be a load instruction, keep track of variable
-        // reads.
-        UsingBlocks.push_back(LI->getParent());
-        AllocaPointerVal = LI;
-      }
-
-      if (OnlyUsedInOneBlock) {
-        if (!OnlyBlock)
-          OnlyBlock = User->getParent();
-        else if (OnlyBlock != User->getParent())
-          OnlyUsedInOneBlock = false;
-      }
-    }
-
-    DbgDeclares = FindDbgAddrUses(AI);
-  }
-};
-
-/// Data package used by RenamePass().
-struct RenamePassData {
-  using ValVector = std::vector<Value *>;
-  using LocationVector = std::vector<DebugLoc>;
-
-  RenamePassData(BasicBlock *B, BasicBlock *P, ValVector V, LocationVector L)
-      : BB(B), Pred(P), Values(std::move(V)), Locations(std::move(L)) {}
-
-  BasicBlock *BB;
-  BasicBlock *Pred;
-  ValVector Values;
-  LocationVector Locations;
-};
-
-/// This assigns and keeps a per-bb relative ordering of load/store
-/// instructions in the block that directly load or store an alloca.
-///
-/// This functionality is important because it avoids scanning large basic
-/// blocks multiple times when promoting many allocas in the same block.
-class LargeBlockInfo {
-  /// For each instruction that we track, keep the index of the
-  /// instruction.
-  ///
-  /// The index starts out as the number of the instruction from the start of
-  /// the block.
-  DenseMap<const Instruction *, unsigned> InstNumbers;
-
-public:
-
-  /// This code only looks at accesses to allocas.
-  static bool isInterestingInstruction(const Instruction *I) {
-    return (isa<LoadInst>(I) && isa<AllocaInst>(I->getOperand(0))) ||
-           (isa<StoreInst>(I) && isa<AllocaInst>(I->getOperand(1)));
-  }
-
-  /// Get or calculate the index of the specified instruction.
-  unsigned getInstructionIndex(const Instruction *I) {
-    assert(isInterestingInstruction(I) &&
-           "Not a load/store to/from an alloca?");
-
-    // If we already have this instruction number, return it.
-    DenseMap<const Instruction *, unsigned>::iterator It = InstNumbers.find(I);
-    if (It != InstNumbers.end())
-      return It->second;
-
-    // Scan the whole block to get the instruction.  This accumulates
-    // information for every interesting instruction in the block, in order to
-    // avoid gratuitus rescans.
-    const BasicBlock *BB = I->getParent();
-    unsigned InstNo = 0;
-    for (const Instruction &BBI : *BB)
-      if (isInterestingInstruction(&BBI))
-        InstNumbers[&BBI] = InstNo++;
-    It = InstNumbers.find(I);
-
-    assert(It != InstNumbers.end() && "Didn't insert instruction?");
-    return It->second;
-  }
-
-  void deleteValue(const Instruction *I) { InstNumbers.erase(I); }
-
-  void clear() { InstNumbers.clear(); }
-};
-
-struct PromoteMem2Reg {
-  /// The alloca instructions being promoted.
-  std::vector<AllocaInst *> Allocas;
-
-  DominatorTree &DT;
-  DIBuilder DIB;
-
-  /// A cache of @llvm.assume intrinsics used by SimplifyInstruction.
-  AssumptionCache *AC;
-
-  const SimplifyQuery SQ;
-
-  /// Reverse mapping of Allocas.
-  DenseMap<AllocaInst *, unsigned> AllocaLookup;
-
-  /// The PhiNodes we're adding.
-  ///
-  /// That map is used to simplify some Phi nodes as we iterate over it, so
-  /// it should have deterministic iterators.  We could use a MapVector, but
-  /// since we already maintain a map from BasicBlock* to a stable numbering
-  /// (BBNumbers), the DenseMap is more efficient (also supports removal).
-  DenseMap<std::pair<unsigned, unsigned>, PHINode *> NewPhiNodes;
-
-  /// For each PHI node, keep track of which entry in Allocas it corresponds
-  /// to.
-  DenseMap<PHINode *, unsigned> PhiToAllocaMap;
-
-  /// If we are updating an AliasSetTracker, then for each alloca that is of
-  /// pointer type, we keep track of what to copyValue to the inserted PHI
-  /// nodes here.
-  std::vector<Value *> PointerAllocaValues;
-
-  /// For each alloca, we keep track of the dbg.declare intrinsic that
-  /// describes it, if any, so that we can convert it to a dbg.value
-  /// intrinsic if the alloca gets promoted.
-  SmallVector<TinyPtrVector<DbgVariableIntrinsic *>, 8> AllocaDbgDeclares;
-
-  /// The set of basic blocks the renamer has already visited.
-  SmallPtrSet<BasicBlock *, 16> Visited;
-
-  /// Contains a stable numbering of basic blocks to avoid non-determinstic
-  /// behavior.
-  DenseMap<BasicBlock *, unsigned> BBNumbers;
-
-  /// Lazily compute the number of predecessors a block has.
-  DenseMap<const BasicBlock *, unsigned> BBNumPreds;
-
-public:
-  PromoteMem2Reg(ArrayRef<AllocaInst *> Allocas, DominatorTree &DT,
-                 AssumptionCache *AC)
-      : Allocas(Allocas.begin(), Allocas.end()), DT(DT),
-        DIB(*DT.getRoot()->getParent()->getParent(), /*AllowUnresolved*/ false),
-        AC(AC), SQ(DT.getRoot()->getParent()->getParent()->getDataLayout(),
-                   nullptr, &DT, AC) {}
-
-  void run();
-
-private:
-  void RemoveFromAllocasList(unsigned &AllocaIdx) {
-    Allocas[AllocaIdx] = Allocas.back();
-    Allocas.pop_back();
-    --AllocaIdx;
-  }
-
-  unsigned getNumPreds(const BasicBlock *BB) {
-    unsigned &NP = BBNumPreds[BB];
-    if (NP == 0)
-      NP = pred_size(BB) + 1;
-    return NP - 1;
-  }
-
-  void ComputeLiveInBlocks(AllocaInst *AI, AllocaInfo &Info,
-                           const SmallPtrSetImpl<BasicBlock *> &DefBlocks,
-                           SmallPtrSetImpl<BasicBlock *> &LiveInBlocks);
-  void RenamePass(BasicBlock *BB, BasicBlock *Pred,
-                  RenamePassData::ValVector &IncVals,
-                  RenamePassData::LocationVector &IncLocs,
-                  std::vector<RenamePassData> &Worklist);
-  bool QueuePhiNode(BasicBlock *BB, unsigned AllocaIdx, unsigned &Version);
-};
-
-} // end anonymous namespace
-
-/// Given a LoadInst LI this adds assume(LI != null) after it.
-static void addAssumeNonNull(AssumptionCache *AC, LoadInst *LI) {
-  Function *AssumeIntrinsic =
-      Intrinsic::getDeclaration(LI->getModule(), Intrinsic::assume);
-  ICmpInst *LoadNotNull = new ICmpInst(ICmpInst::ICMP_NE, LI,
-                                       Constant::getNullValue(LI->getType()));
-  LoadNotNull->insertAfter(LI);
-  CallInst *CI = CallInst::Create(AssumeIntrinsic, {LoadNotNull});
-  CI->insertAfter(LoadNotNull);
-  AC->registerAssumption(CI);
-}
-
-static void removeLifetimeIntrinsicUsers(AllocaInst *AI) {
-  // Knowing that this alloca is promotable, we know that it's safe to kill all
-  // instructions except for load and store.
-
-  for (auto UI = AI->user_begin(), UE = AI->user_end(); UI != UE;) {
-    Instruction *I = cast<Instruction>(*UI);
-    ++UI;
-    if (isa<LoadInst>(I) || isa<StoreInst>(I))
-      continue;
-
-    if (!I->getType()->isVoidTy()) {
-      // The only users of this bitcast/GEP instruction are lifetime intrinsics.
-      // Follow the use/def chain to erase them now instead of leaving it for
-      // dead code elimination later.
-      for (auto UUI = I->user_begin(), UUE = I->user_end(); UUI != UUE;) {
-        Instruction *Inst = cast<Instruction>(*UUI);
-        ++UUI;
-        Inst->eraseFromParent();
-      }
-    }
-    I->eraseFromParent();
-  }
-}
-
-/// Rewrite as many loads as possible given a single store.
-///
-/// When there is only a single store, we can use the domtree to trivially
-/// replace all of the dominated loads with the stored value. Do so, and return
-/// true if this has successfully promoted the alloca entirely. If this returns
-/// false there were some loads which were not dominated by the single store
-/// and thus must be phi-ed with undef. We fall back to the standard alloca
-/// promotion algorithm in that case.
-static bool rewriteSingleStoreAlloca(AllocaInst *AI, AllocaInfo &Info,
-                                     LargeBlockInfo &LBI, const DataLayout &DL,
-                                     DominatorTree &DT, AssumptionCache *AC) {
-  StoreInst *OnlyStore = Info.OnlyStore;
-  bool StoringGlobalVal = !isa<Instruction>(OnlyStore->getOperand(0));
-  BasicBlock *StoreBB = OnlyStore->getParent();
-  int StoreIndex = -1;
-
-  // Clear out UsingBlocks.  We will reconstruct it here if needed.
-  Info.UsingBlocks.clear();
-
-  for (auto UI = AI->user_begin(), E = AI->user_end(); UI != E;) {
-    Instruction *UserInst = cast<Instruction>(*UI++);
-    if (!isa<LoadInst>(UserInst)) {
-      assert(UserInst == OnlyStore && "Should only have load/stores");
-      continue;
-    }
-    LoadInst *LI = cast<LoadInst>(UserInst);
-
-    // Okay, if we have a load from the alloca, we want to replace it with the
-    // only value stored to the alloca.  We can do this if the value is
-    // dominated by the store.  If not, we use the rest of the mem2reg machinery
-    // to insert the phi nodes as needed.
-    if (!StoringGlobalVal) { // Non-instructions are always dominated.
-      if (LI->getParent() == StoreBB) {
-        // If we have a use that is in the same block as the store, compare the
-        // indices of the two instructions to see which one came first.  If the
-        // load came before the store, we can't handle it.
-        if (StoreIndex == -1)
-          StoreIndex = LBI.getInstructionIndex(OnlyStore);
-
-        if (unsigned(StoreIndex) > LBI.getInstructionIndex(LI)) {
-          // Can't handle this load, bail out.
-          Info.UsingBlocks.push_back(StoreBB);
-          continue;
-        }
-      } else if (LI->getParent() != StoreBB &&
-                 !DT.dominates(StoreBB, LI->getParent())) {
-        // If the load and store are in different blocks, use BB dominance to
-        // check their relationships.  If the store doesn't dom the use, bail
-        // out.
-        Info.UsingBlocks.push_back(LI->getParent());
-        continue;
-      }
-    }
-
-    // Otherwise, we *can* safely rewrite this load.
-    Value *ReplVal = OnlyStore->getOperand(0);
-    // If the replacement value is the load, this must occur in unreachable
-    // code.
-    if (ReplVal == LI)
-      ReplVal = UndefValue::get(LI->getType());
-
-    // If the load was marked as nonnull we don't want to lose
-    // that information when we erase this Load. So we preserve
-    // it with an assume.
-    if (AC && LI->getMetadata(LLVMContext::MD_nonnull) &&
-        !isKnownNonZero(ReplVal, DL, 0, AC, LI, &DT))
-      addAssumeNonNull(AC, LI);
-
-    LI->replaceAllUsesWith(ReplVal);
-    LI->eraseFromParent();
-    LBI.deleteValue(LI);
-  }
-
-  // Finally, after the scan, check to see if the store is all that is left.
-  if (!Info.UsingBlocks.empty())
-    return false; // If not, we'll have to fall back for the remainder.
-
-  // Record debuginfo for the store and remove the declaration's
-  // debuginfo.
-  for (DbgVariableIntrinsic *DII : Info.DbgDeclares) {
-    DIBuilder DIB(*AI->getModule(), /*AllowUnresolved*/ false);
-    ConvertDebugDeclareToDebugValue(DII, Info.OnlyStore, DIB);
-    DII->eraseFromParent();
-    LBI.deleteValue(DII);
-  }
-  // Remove the (now dead) store and alloca.
-  Info.OnlyStore->eraseFromParent();
-  LBI.deleteValue(Info.OnlyStore);
-
-  AI->eraseFromParent();
-  LBI.deleteValue(AI);
-  return true;
-}
-
-/// Many allocas are only used within a single basic block.  If this is the
-/// case, avoid traversing the CFG and inserting a lot of potentially useless
-/// PHI nodes by just performing a single linear pass over the basic block
-/// using the Alloca.
-///
-/// If we cannot promote this alloca (because it is read before it is written),
-/// return false.  This is necessary in cases where, due to control flow, the
-/// alloca is undefined only on some control flow paths.  e.g. code like
-/// this is correct in LLVM IR:
-///  // A is an alloca with no stores so far
-///  for (...) {
-///    int t = *A;
-///    if (!first_iteration)
-///      use(t);
-///    *A = 42;
-///  }
-static bool promoteSingleBlockAlloca(AllocaInst *AI, const AllocaInfo &Info,
-                                     LargeBlockInfo &LBI,
-                                     const DataLayout &DL,
-                                     DominatorTree &DT,
-                                     AssumptionCache *AC) {
-  // The trickiest case to handle is when we have large blocks. Because of this,
-  // this code is optimized assuming that large blocks happen.  This does not
-  // significantly pessimize the small block case.  This uses LargeBlockInfo to
-  // make it efficient to get the index of various operations in the block.
-
-  // Walk the use-def list of the alloca, getting the locations of all stores.
-  using StoresByIndexTy = SmallVector<std::pair<unsigned, StoreInst *>, 64>;
-  StoresByIndexTy StoresByIndex;
-
-  for (User *U : AI->users())
-    if (StoreInst *SI = dyn_cast<StoreInst>(U))
-      StoresByIndex.push_back(std::make_pair(LBI.getInstructionIndex(SI), SI));
-
-  // Sort the stores by their index, making it efficient to do a lookup with a
-  // binary search.
-  llvm::sort(StoresByIndex, less_first());
-
-  // Walk all of the loads from this alloca, replacing them with the nearest
-  // store above them, if any.
-  for (auto UI = AI->user_begin(), E = AI->user_end(); UI != E;) {
-    LoadInst *LI = dyn_cast<LoadInst>(*UI++);
-    if (!LI)
-      continue;
-
-    unsigned LoadIdx = LBI.getInstructionIndex(LI);
-
-    // Find the nearest store that has a lower index than this load.
-    StoresByIndexTy::iterator I =
-        std::lower_bound(StoresByIndex.begin(), StoresByIndex.end(),
-                         std::make_pair(LoadIdx,
-                                        static_cast<StoreInst *>(nullptr)),
-                         less_first());
-    if (I == StoresByIndex.begin()) {
-      if (StoresByIndex.empty())
-        // If there are no stores, the load takes the undef value.
-        LI->replaceAllUsesWith(UndefValue::get(LI->getType()));
-      else
-        // There is no store before this load, bail out (load may be affected
-        // by the following stores - see main comment).
-        return false;
-    } else {
-      // Otherwise, there was a store before this load, the load takes its value.
-      // Note, if the load was marked as nonnull we don't want to lose that
-      // information when we erase it. So we preserve it with an assume.
-      Value *ReplVal = std::prev(I)->second->getOperand(0);
-      if (AC && LI->getMetadata(LLVMContext::MD_nonnull) &&
-          !isKnownNonZero(ReplVal, DL, 0, AC, LI, &DT))
-        addAssumeNonNull(AC, LI);
-
-      // If the replacement value is the load, this must occur in unreachable
-      // code.
-      if (ReplVal == LI)
-        ReplVal = UndefValue::get(LI->getType());
-
-      LI->replaceAllUsesWith(ReplVal);
-    }
-
-    LI->eraseFromParent();
-    LBI.deleteValue(LI);
-  }
-
-  // Remove the (now dead) stores and alloca.
-  while (!AI->use_empty()) {
-    StoreInst *SI = cast<StoreInst>(AI->user_back());
-    // Record debuginfo for the store before removing it.
-    for (DbgVariableIntrinsic *DII : Info.DbgDeclares) {
-      DIBuilder DIB(*AI->getModule(), /*AllowUnresolved*/ false);
-      ConvertDebugDeclareToDebugValue(DII, SI, DIB);
-    }
-    SI->eraseFromParent();
-    LBI.deleteValue(SI);
-  }
-
-  AI->eraseFromParent();
-  LBI.deleteValue(AI);
-
-  // The alloca's debuginfo can be removed as well.
-  for (DbgVariableIntrinsic *DII : Info.DbgDeclares) {
-    DII->eraseFromParent();
-    LBI.deleteValue(DII);
-  }
-
-  ++NumLocalPromoted;
-  return true;
-}
-
-void PromoteMem2Reg::run() {
-  Function &F = *DT.getRoot()->getParent();
-
-  AllocaDbgDeclares.resize(Allocas.size());
-
-  AllocaInfo Info;
-  LargeBlockInfo LBI;
-  ForwardIDFCalculator IDF(DT);
-
-  for (unsigned AllocaNum = 0; AllocaNum != Allocas.size(); ++AllocaNum) {
-    AllocaInst *AI = Allocas[AllocaNum];
-
-    assert(isAllocaPromotable(AI) && "Cannot promote non-promotable alloca!");
-    assert(AI->getParent()->getParent() == &F &&
-           "All allocas should be in the same function, which is same as DF!");
-
-    removeLifetimeIntrinsicUsers(AI);
-
-    if (AI->use_empty()) {
-      // If there are no uses of the alloca, just delete it now.
-      AI->eraseFromParent();
-
-      // Remove the alloca from the Allocas list, since it has been processed
-      RemoveFromAllocasList(AllocaNum);
-      ++NumDeadAlloca;
-      continue;
-    }
-
-    // Calculate the set of read and write-locations for each alloca.  This is
-    // analogous to finding the 'uses' and 'definitions' of each variable.
-    Info.AnalyzeAlloca(AI);
-
-    // If there is only a single store to this value, replace any loads of
-    // it that are directly dominated by the definition with the value stored.
-    if (Info.DefiningBlocks.size() == 1) {
-      if (rewriteSingleStoreAlloca(AI, Info, LBI, SQ.DL, DT, AC)) {
-        // The alloca has been processed, move on.
-        RemoveFromAllocasList(AllocaNum);
-        ++NumSingleStore;
-        continue;
-      }
-    }
-
-    // If the alloca is only read and written in one basic block, just perform a
-    // linear sweep over the block to eliminate it.
-    if (Info.OnlyUsedInOneBlock &&
-        promoteSingleBlockAlloca(AI, Info, LBI, SQ.DL, DT, AC)) {
-      // The alloca has been processed, move on.
-      RemoveFromAllocasList(AllocaNum);
-      continue;
-    }
-
-    // If we haven't computed a numbering for the BB's in the function, do so
-    // now.
-    if (BBNumbers.empty()) {
-      unsigned ID = 0;
-      for (auto &BB : F)
-        BBNumbers[&BB] = ID++;
-    }
-
-    // Remember the dbg.declare intrinsic describing this alloca, if any.
-    if (!Info.DbgDeclares.empty())
-      AllocaDbgDeclares[AllocaNum] = Info.DbgDeclares;
-
-    // Keep the reverse mapping of the 'Allocas' array for the rename pass.
-    AllocaLookup[Allocas[AllocaNum]] = AllocaNum;
-
-    // At this point, we're committed to promoting the alloca using IDF's, and
-    // the standard SSA construction algorithm.  Determine which blocks need PHI
-    // nodes and see if we can optimize out some work by avoiding insertion of
-    // dead phi nodes.
-
-    // Unique the set of defining blocks for efficient lookup.
-    SmallPtrSet<BasicBlock *, 32> DefBlocks;
-    DefBlocks.insert(Info.DefiningBlocks.begin(), Info.DefiningBlocks.end());
-
-    // Determine which blocks the value is live in.  These are blocks which lead
-    // to uses.
-    SmallPtrSet<BasicBlock *, 32> LiveInBlocks;
-    ComputeLiveInBlocks(AI, Info, DefBlocks, LiveInBlocks);
-
-    // At this point, we're committed to promoting the alloca using IDF's, and
-    // the standard SSA construction algorithm.  Determine which blocks need phi
-    // nodes and see if we can optimize out some work by avoiding insertion of
-    // dead phi nodes.
-    IDF.setLiveInBlocks(LiveInBlocks);
-    IDF.setDefiningBlocks(DefBlocks);
-    SmallVector<BasicBlock *, 32> PHIBlocks;
-    IDF.calculate(PHIBlocks);
-    if (PHIBlocks.size() > 1)
-      llvm::sort(PHIBlocks, [this](BasicBlock *A, BasicBlock *B) {
-        return BBNumbers.lookup(A) < BBNumbers.lookup(B);
-      });
-
-    unsigned CurrentVersion = 0;
-    for (BasicBlock *BB : PHIBlocks)
-      QueuePhiNode(BB, AllocaNum, CurrentVersion);
-  }
-
-  if (Allocas.empty())
-    return; // All of the allocas must have been trivial!
-
-  LBI.clear();
-
-  // Set the incoming values for the basic block to be null values for all of
-  // the alloca's.  We do this in case there is a load of a value that has not
-  // been stored yet.  In this case, it will get this null value.
-  RenamePassData::ValVector Values(Allocas.size());
-  for (unsigned i = 0, e = Allocas.size(); i != e; ++i)
-    Values[i] = UndefValue::get(Allocas[i]->getAllocatedType());
-
-  // When handling debug info, treat all incoming values as if they have unknown
-  // locations until proven otherwise.
-  RenamePassData::LocationVector Locations(Allocas.size());
-
-  // Walks all basic blocks in the function performing the SSA rename algorithm
-  // and inserting the phi nodes we marked as necessary
-  std::vector<RenamePassData> RenamePassWorkList;
-  RenamePassWorkList.emplace_back(&F.front(), nullptr, std::move(Values),
-                                  std::move(Locations));
-  do {
-    RenamePassData RPD = std::move(RenamePassWorkList.back());
-    RenamePassWorkList.pop_back();
-    // RenamePass may add new worklist entries.
-    RenamePass(RPD.BB, RPD.Pred, RPD.Values, RPD.Locations, RenamePassWorkList);
-  } while (!RenamePassWorkList.empty());
-
-  // The renamer uses the Visited set to avoid infinite loops.  Clear it now.
-  Visited.clear();
-
-  // Remove the allocas themselves from the function.
-  for (Instruction *A : Allocas) {
-    // If there are any uses of the alloca instructions left, they must be in
-    // unreachable basic blocks that were not processed by walking the dominator
-    // tree. Just delete the users now.
-    if (!A->use_empty())
-      A->replaceAllUsesWith(UndefValue::get(A->getType()));
-    A->eraseFromParent();
-  }
-
-  // Remove alloca's dbg.declare instrinsics from the function.
-  for (auto &Declares : AllocaDbgDeclares)
-    for (auto *DII : Declares)
-      DII->eraseFromParent();
-
-  // Loop over all of the PHI nodes and see if there are any that we can get
-  // rid of because they merge all of the same incoming values.  This can
-  // happen due to undef values coming into the PHI nodes.  This process is
-  // iterative, because eliminating one PHI node can cause others to be removed.
-  bool EliminatedAPHI = true;
-  while (EliminatedAPHI) {
-    EliminatedAPHI = false;
-
-    // Iterating over NewPhiNodes is deterministic, so it is safe to try to
-    // simplify and RAUW them as we go.  If it was not, we could add uses to
-    // the values we replace with in a non-deterministic order, thus creating
-    // non-deterministic def->use chains.
-    for (DenseMap<std::pair<unsigned, unsigned>, PHINode *>::iterator
-             I = NewPhiNodes.begin(),
-             E = NewPhiNodes.end();
-         I != E;) {
-      PHINode *PN = I->second;
-
-      // If this PHI node merges one value and/or undefs, get the value.
-      if (Value *V = SimplifyInstruction(PN, SQ)) {
-        PN->replaceAllUsesWith(V);
-        PN->eraseFromParent();
-        NewPhiNodes.erase(I++);
-        EliminatedAPHI = true;
-        continue;
-      }
-      ++I;
-    }
-  }
-
-  // At this point, the renamer has added entries to PHI nodes for all reachable
-  // code.  Unfortunately, there may be unreachable blocks which the renamer
-  // hasn't traversed.  If this is the case, the PHI nodes may not
-  // have incoming values for all predecessors.  Loop over all PHI nodes we have
-  // created, inserting undef values if they are missing any incoming values.
-  for (DenseMap<std::pair<unsigned, unsigned>, PHINode *>::iterator
-           I = NewPhiNodes.begin(),
-           E = NewPhiNodes.end();
-       I != E; ++I) {
-    // We want to do this once per basic block.  As such, only process a block
-    // when we find the PHI that is the first entry in the block.
-    PHINode *SomePHI = I->second;
-    BasicBlock *BB = SomePHI->getParent();
-    if (&BB->front() != SomePHI)
-      continue;
-
-    // Only do work here if there the PHI nodes are missing incoming values.  We
-    // know that all PHI nodes that were inserted in a block will have the same
-    // number of incoming values, so we can just check any of them.
-    if (SomePHI->getNumIncomingValues() == getNumPreds(BB))
-      continue;
-
-    // Get the preds for BB.
-    SmallVector<BasicBlock *, 16> Preds(pred_begin(BB), pred_end(BB));
-
-    // Ok, now we know that all of the PHI nodes are missing entries for some
-    // basic blocks.  Start by sorting the incoming predecessors for efficient
-    // access.
-    auto CompareBBNumbers = [this](BasicBlock *A, BasicBlock *B) {
-      return BBNumbers.lookup(A) < BBNumbers.lookup(B);
-    };
-    llvm::sort(Preds, CompareBBNumbers);
-
-    // Now we loop through all BB's which have entries in SomePHI and remove
-    // them from the Preds list.
-    for (unsigned i = 0, e = SomePHI->getNumIncomingValues(); i != e; ++i) {
-      // Do a log(n) search of the Preds list for the entry we want.
-      SmallVectorImpl<BasicBlock *>::iterator EntIt = std::lower_bound(
-          Preds.begin(), Preds.end(), SomePHI->getIncomingBlock(i),
-          CompareBBNumbers);
-      assert(EntIt != Preds.end() && *EntIt == SomePHI->getIncomingBlock(i) &&
-             "PHI node has entry for a block which is not a predecessor!");
-
-      // Remove the entry
-      Preds.erase(EntIt);
-    }
-
-    // At this point, the blocks left in the preds list must have dummy
-    // entries inserted into every PHI nodes for the block.  Update all the phi
-    // nodes in this block that we are inserting (there could be phis before
-    // mem2reg runs).
-    unsigned NumBadPreds = SomePHI->getNumIncomingValues();
-    BasicBlock::iterator BBI = BB->begin();
-    while ((SomePHI = dyn_cast<PHINode>(BBI++)) &&
-           SomePHI->getNumIncomingValues() == NumBadPreds) {
-      Value *UndefVal = UndefValue::get(SomePHI->getType());
-      for (BasicBlock *Pred : Preds)
-        SomePHI->addIncoming(UndefVal, Pred);
-    }
-  }
-
-  NewPhiNodes.clear();
-}
-
-/// Determine which blocks the value is live in.
-///
-/// These are blocks which lead to uses.  Knowing this allows us to avoid
-/// inserting PHI nodes into blocks which don't lead to uses (thus, the
-/// inserted phi nodes would be dead).
-void PromoteMem2Reg::ComputeLiveInBlocks(
-    AllocaInst *AI, AllocaInfo &Info,
-    const SmallPtrSetImpl<BasicBlock *> &DefBlocks,
-    SmallPtrSetImpl<BasicBlock *> &LiveInBlocks) {
-  // To determine liveness, we must iterate through the predecessors of blocks
-  // where the def is live.  Blocks are added to the worklist if we need to
-  // check their predecessors.  Start with all the using blocks.
-  SmallVector<BasicBlock *, 64> LiveInBlockWorklist(Info.UsingBlocks.begin(),
-                                                    Info.UsingBlocks.end());
-
-  // If any of the using blocks is also a definition block, check to see if the
-  // definition occurs before or after the use.  If it happens before the use,
-  // the value isn't really live-in.
-  for (unsigned i = 0, e = LiveInBlockWorklist.size(); i != e; ++i) {
-    BasicBlock *BB = LiveInBlockWorklist[i];
-    if (!DefBlocks.count(BB))
-      continue;
-
-    // Okay, this is a block that both uses and defines the value.  If the first
-    // reference to the alloca is a def (store), then we know it isn't live-in.
-    for (BasicBlock::iterator I = BB->begin();; ++I) {
-      if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
-        if (SI->getOperand(1) != AI)
-          continue;
-
-        // We found a store to the alloca before a load.  The alloca is not
-        // actually live-in here.
-        LiveInBlockWorklist[i] = LiveInBlockWorklist.back();
-        LiveInBlockWorklist.pop_back();
-        --i;
-        --e;
-        break;
-      }
-
-      if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
-        if (LI->getOperand(0) != AI)
-          continue;
-
-        // Okay, we found a load before a store to the alloca.  It is actually
-        // live into this block.
-        break;
-      }
-    }
-  }
-
-  // Now that we have a set of blocks where the phi is live-in, recursively add
-  // their predecessors until we find the full region the value is live.
-  while (!LiveInBlockWorklist.empty()) {
-    BasicBlock *BB = LiveInBlockWorklist.pop_back_val();
-
-    // The block really is live in here, insert it into the set.  If already in
-    // the set, then it has already been processed.
-    if (!LiveInBlocks.insert(BB).second)
-      continue;
-
-    // Since the value is live into BB, it is either defined in a predecessor or
-    // live into it to.  Add the preds to the worklist unless they are a
-    // defining block.
-    for (BasicBlock *P : predecessors(BB)) {
-      // The value is not live into a predecessor if it defines the value.
-      if (DefBlocks.count(P))
-        continue;
-
-      // Otherwise it is, add to the worklist.
-      LiveInBlockWorklist.push_back(P);
-    }
-  }
-}
-
-/// Queue a phi-node to be added to a basic-block for a specific Alloca.
-///
-/// Returns true if there wasn't already a phi-node for that variable
-bool PromoteMem2Reg::QueuePhiNode(BasicBlock *BB, unsigned AllocaNo,
-                                  unsigned &Version) {
-  // Look up the basic-block in question.
-  PHINode *&PN = NewPhiNodes[std::make_pair(BBNumbers[BB], AllocaNo)];
-
-  // If the BB already has a phi node added for the i'th alloca then we're done!
-  if (PN)
-    return false;
-
-  // Create a PhiNode using the dereferenced type... and add the phi-node to the
-  // BasicBlock.
-  PN = PHINode::Create(Allocas[AllocaNo]->getAllocatedType(), getNumPreds(BB),
-                       Allocas[AllocaNo]->getName() + "." + Twine(Version++),
-                       &BB->front());
-  ++NumPHIInsert;
-  PhiToAllocaMap[PN] = AllocaNo;
-  return true;
-}
-
-/// Update the debug location of a phi. \p ApplyMergedLoc indicates whether to
-/// create a merged location incorporating \p DL, or to set \p DL directly.
-static void updateForIncomingValueLocation(PHINode *PN, DebugLoc DL,
-                                           bool ApplyMergedLoc) {
-  if (ApplyMergedLoc)
-    PN->applyMergedLocation(PN->getDebugLoc(), DL);
-  else
-    PN->setDebugLoc(DL);
-}
-
-/// Recursively traverse the CFG of the function, renaming loads and
-/// stores to the allocas which we are promoting.
-///
-/// IncomingVals indicates what value each Alloca contains on exit from the
-/// predecessor block Pred.
-void PromoteMem2Reg::RenamePass(BasicBlock *BB, BasicBlock *Pred,
-                                RenamePassData::ValVector &IncomingVals,
-                                RenamePassData::LocationVector &IncomingLocs,
-                                std::vector<RenamePassData> &Worklist) {
-NextIteration:
-  // If we are inserting any phi nodes into this BB, they will already be in the
-  // block.
-  if (PHINode *APN = dyn_cast<PHINode>(BB->begin())) {
-    // If we have PHI nodes to update, compute the number of edges from Pred to
-    // BB.
-    if (PhiToAllocaMap.count(APN)) {
-      // We want to be able to distinguish between PHI nodes being inserted by
-      // this invocation of mem2reg from those phi nodes that already existed in
-      // the IR before mem2reg was run.  We determine that APN is being inserted
-      // because it is missing incoming edges.  All other PHI nodes being
-      // inserted by this pass of mem2reg will have the same number of incoming
-      // operands so far.  Remember this count.
-      unsigned NewPHINumOperands = APN->getNumOperands();
-
-      unsigned NumEdges = std::count(succ_begin(Pred), succ_end(Pred), BB);
-      assert(NumEdges && "Must be at least one edge from Pred to BB!");
-
-      // Add entries for all the phis.
-      BasicBlock::iterator PNI = BB->begin();
-      do {
-        unsigned AllocaNo = PhiToAllocaMap[APN];
-
-        // Update the location of the phi node.
-        updateForIncomingValueLocation(APN, IncomingLocs[AllocaNo],
-                                       APN->getNumIncomingValues() > 0);
-
-        // Add N incoming values to the PHI node.
-        for (unsigned i = 0; i != NumEdges; ++i)
-          APN->addIncoming(IncomingVals[AllocaNo], Pred);
-
-        // The currently active variable for this block is now the PHI.
-        IncomingVals[AllocaNo] = APN;
-        for (DbgVariableIntrinsic *DII : AllocaDbgDeclares[AllocaNo])
-          ConvertDebugDeclareToDebugValue(DII, APN, DIB);
-
-        // Get the next phi node.
-        ++PNI;
-        APN = dyn_cast<PHINode>(PNI);
-        if (!APN)
-          break;
-
-        // Verify that it is missing entries.  If not, it is not being inserted
-        // by this mem2reg invocation so we want to ignore it.
-      } while (APN->getNumOperands() == NewPHINumOperands);
-    }
-  }
-
-  // Don't revisit blocks.
-  if (!Visited.insert(BB).second)
-    return;
-
-  for (BasicBlock::iterator II = BB->begin(); !II->isTerminator();) {
-    Instruction *I = &*II++; // get the instruction, increment iterator
-
-    if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
-      AllocaInst *Src = dyn_cast<AllocaInst>(LI->getPointerOperand());
-      if (!Src)
-        continue;
-
-      DenseMap<AllocaInst *, unsigned>::iterator AI = AllocaLookup.find(Src);
-      if (AI == AllocaLookup.end())
-        continue;
-
-      Value *V = IncomingVals[AI->second];
-
-      // If the load was marked as nonnull we don't want to lose
-      // that information when we erase this Load. So we preserve
-      // it with an assume.
-      if (AC && LI->getMetadata(LLVMContext::MD_nonnull) &&
-          !isKnownNonZero(V, SQ.DL, 0, AC, LI, &DT))
-        addAssumeNonNull(AC, LI);
-
-      // Anything using the load now uses the current value.
-      LI->replaceAllUsesWith(V);
-      BB->getInstList().erase(LI);
-    } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
-      // Delete this instruction and mark the name as the current holder of the
-      // value
-      AllocaInst *Dest = dyn_cast<AllocaInst>(SI->getPointerOperand());
-      if (!Dest)
-        continue;
-
-      DenseMap<AllocaInst *, unsigned>::iterator ai = AllocaLookup.find(Dest);
-      if (ai == AllocaLookup.end())
-        continue;
-
-      // what value were we writing?
-      unsigned AllocaNo = ai->second;
-      IncomingVals[AllocaNo] = SI->getOperand(0);
-
-      // Record debuginfo for the store before removing it.
-      IncomingLocs[AllocaNo] = SI->getDebugLoc();
-      for (DbgVariableIntrinsic *DII : AllocaDbgDeclares[ai->second])
-        ConvertDebugDeclareToDebugValue(DII, SI, DIB);
-      BB->getInstList().erase(SI);
-    }
-  }
-
-  // 'Recurse' to our successors.
-  succ_iterator I = succ_begin(BB), E = succ_end(BB);
-  if (I == E)
-    return;
-
-  // Keep track of the successors so we don't visit the same successor twice
-  SmallPtrSet<BasicBlock *, 8> VisitedSuccs;
-
-  // Handle the first successor without using the worklist.
-  VisitedSuccs.insert(*I);
-  Pred = BB;
-  BB = *I;
-  ++I;
-
-  for (; I != E; ++I)
-    if (VisitedSuccs.insert(*I).second)
-      Worklist.emplace_back(*I, Pred, IncomingVals, IncomingLocs);
-
-  goto NextIteration;
-}
-
-void llvm::PromoteMemToReg(ArrayRef<AllocaInst *> Allocas, DominatorTree &DT,
-                           AssumptionCache *AC) {
-  // If there is nothing to do, bail out...
-  if (Allocas.empty())
-    return;
-
-  PromoteMem2Reg(Allocas, DT, AC).run();
-}