[LoopAccesses] Create the analysis pass

[anemet]

Summary

This is a function pass that runs the analysis on demand. The analysis
can be initiated by querying the loop access info via LAA::getInfo. It
either returns the cached info or runs the analysis.

Symbolic stride information continues to reside outside of this analysis
pass. We may move it inside later but it's not a priority for me right
now. The idea is that Loop Distribution won't support run-time stride
checking at least initially.

This means that when querying the analysis, symbolic stride information
can be provided optionally. Whether stride information is used can
invalidate the cache entry and rerun the analysis. Note that if the
loop does not have any symbolic stride, the entry should be preserved
across Loop Distribution and LV.

Since currently the only user of the pass is LV, I just check that the
symbolic stride information didn't change when using a cached result.

On the LV side, LoopVectorizationLegality requests the info object
corresponding to the loop from the analysis pass. A large chunk of the
diff is due to LAI becoming a pointer from a reference.

A test will be added as part of the -analyze patch.

Also tested that with AVX, we generate identical assembly output for the
testsuite (including the external testsuite) before and after.

This is part of the patchset that converts LoopAccessAnalysis into an
actual analysis pass.

[hfinkel]

include/llvm/Analysis/LoopAccessAnalysis.h

200

We should be careful here; having an NDEBUG-dependent ABI is not necessarily desirable (and people complain about them). I believe there is currently a patch out for review to make our ABI non-NDEBUG-dependent. I'm not overly concerned about the size of this class (we won't have that many of them), so we may just want to always have this.

(may need to make it public, however, so that you don't get compiler warnings in -Asserts builds).

239

Returning a pointer seems odd here, who owns it? Should it be const?

lib/Analysis/LoopAccessAnalysis.cpp

1225

You can just grab DL, if available, from the Module. I think that's the "modern" way.

[anemet]

include/llvm/Analysis/LoopAccessAnalysis.h

239

It's owned by the pass using a unique_ptr. There is no transfer of ownership in getInfo. It simply gives out a pointer with unique_ptr::get(). I can extend the comment to explain the ownership situation.

Regarding const, absolutely but right now these interfaces don't use const so the pointer returned won't have access to most things. Would it be OK to fix this in a follow-up patch?

[hfinkel]

include/llvm/Analysis/LoopAccessAnalysis.h

239

Why not return a reference?

Fixing const in follow-up is okay.

[anemet]

include/llvm/Analysis/LoopAccessAnalysis.h

239

Makes sense. I am still bit confused when to use pointers vs. reference in LLVM...

Thanks.

[anemet]

Address Hal's comments:

• analyzeLoop is now called from the constructor
• Fix NDEBUG for NumSymbolicStrides
• Reference is returned from LAA::getInfo
• DL accessed from the module

[hfinkel]

LGTM (please fix the const-correctness in follow-up).

[anemet]

In D7684#125181, @hfinkel wrote:

LGTM (please fix the const-correctness in follow-up).

The cost-correctness fix is r229634.

[anemet]

r229893

include/llvm/Analysis/LoopAccessAnalysis.h

 
 #include "llvm/ADT/EquivalenceClasses.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/AliasSetTracker.h"
 #include "llvm/Analysis/ScalarEvolutionExpressions.h"
 #include "llvm/IR/ValueHandle.h"
+#include "llvm/Pass.h"
 #include "llvm/Support/raw_ostream.h"
 
 namespace llvm {
 
 class Value;
 class DataLayout;
 class AliasAnalysis;
 class ScalarEvolution;
struct RuntimePointerCheck {
     /// shared underlying object.
     SmallVector<unsigned, 2> DependencySetId;
     /// Holds the id of the disjoint alias set to which this pointer belongs.
     SmallVector<unsigned, 2> AliasSetId;
   };
 
   LoopAccessInfo(Loop *L, ScalarEvolution *SE, const DataLayout *DL,
                  const TargetLibraryInfo *TLI, AliasAnalysis *AA,
-                 DominatorTree *DT) :
-      TheLoop(L), SE(SE), DL(DL), TLI(TLI), AA(AA), DT(DT), NumLoads(0),
-      NumStores(0), MaxSafeDepDistBytes(-1U), CanVecMem(false) {}
-
-  /// \brief Analyze the loop.  Replaces symbolic strides using Strides.
-  void analyzeLoop(ValueToValueMap &Strides);
+                 DominatorTree *DT, ValueToValueMap &Strides);
 
   /// Return true we can analyze the memory accesses in the loop and there are
   /// no memory dependence cycles.
   bool canVectorizeMemory() { return CanVecMem; }
 
   RuntimePointerCheck *getRuntimePointerCheck() { return &PtrRtCheck; }
 
   /// Return true if the block BB needs to be predicated in order for the loop
public:
   /// instruction generated in possibly a sequence of instructions and the
   /// second value is the final comparator value or NULL if no check is needed.
   std::pair<Instruction *, Instruction *> addRuntimeCheck(Instruction *Loc);
 
   /// \brief The diagnostics report generated for the analysis.  E.g. why we
   /// couldn't analyze the loop.
   Optional<VectorizationReport> &getReport() { return Report; }
 
+  /// \brief Used to ensure that if the analysis was run with speculating the
+  /// value of symbolic strides, the client queries it with the same assumption.
+  /// Only used in DEBUG build but we don't want NDEBUG-depedent ABI.
+  unsigned NumSymbolicStrides;
+
 private:
+  /// \brief Analyze the loop.  Substitute symbolic strides using Strides.
+  void analyzeLoop(ValueToValueMap &Strides);
+
   void emitAnalysis(VectorizationReport &Message);
 
   /// We need to check that all of the pointers in this list are disjoint
   /// at runtime.
   RuntimePointerCheck PtrRtCheck;
   Loop *TheLoop;
   ScalarEvolution *SE;
   const DataLayout *DL;
   const TargetLibraryInfo *TLI;
   AliasAnalysis *AA;
   DominatorTree *DT;
 
   unsigned NumLoads;
   unsigned NumStores;
 
   unsigned MaxSafeDepDistBytes;
 
   /// \brief Cache the result of analyzeLoop.
   bool CanVecMem;
 
   /// \brief The diagnostics report generated for the analysis.  E.g. why we
   /// couldn't analyze the loop.
   Optional<VectorizationReport> Report;
 };
 
 Value *stripIntegerCast(Value *V);
 
 ///\brief Return the SCEV corresponding to a pointer with the symbolic stride
 ///replaced with constant one.
 ///
 /// If \p OrigPtr is not null, use it to look up the stride value instead of \p
 /// Ptr.  \p PtrToStride provides the mapping between the pointer value and its
 /// stride as collected by LoopVectorizationLegality::collectStridedAccess.
 const SCEV *replaceSymbolicStrideSCEV(ScalarEvolution *SE,
                                       ValueToValueMap &PtrToStride,
                                       Value *Ptr, Value *OrigPtr = nullptr);
 
+/// \brief This analysis provides dependence information for the memory accesses
+/// of a loop.
+///
+/// It runs the analysis for a loop on demand.  This can be initiated by
+/// querying the loop access info via LAA::getInfo.  getInfo return a
+/// LoopAccessInfo object.  See this class for the specifics of what information
+/// is provided.
+class LoopAccessAnalysis : public FunctionPass {
+public:
+  static char ID;
+
+  LoopAccessAnalysis() : FunctionPass(ID) {
+    initializeLoopAccessAnalysisPass(*PassRegistry::getPassRegistry());
+  }
+
+  bool runOnFunction(Function &F) override;
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override;
+
+  /// \brief Query the result of the loop access information for the loop \p L.
+  ///
+  /// If the client speculates (and then issues run-time checks) for the values
+  /// of symbolic strides, \p Strides provides the mapping (see
+  /// replaceSymbolicStrideSCEV).  If there is no cached result available run
+  /// the analysis.
+  LoopAccessInfo &getInfo(Loop *L, ValueToValueMap &Strides);
+
+  void releaseMemory() override {
+    // Invalidate the cache when the pass is freed.
+    LoopAccessInfoMap.clear();
+  }
+
+private:
+  /// \brief The cache.
+  DenseMap<Loop *, std::unique_ptr<LoopAccessInfo>> LoopAccessInfoMap;
+
+  // The used analysis passes.
+  ScalarEvolution *SE;
+  const DataLayout *DL;
+  const TargetLibraryInfo *TLI;
+  AliasAnalysis *AA;
+  DominatorTree *DT;
+};
 } // End llvm namespace
 
 #endif

include/llvm/InitializePasses.h

 void initializeUnreachableBlockElimPass(PassRegistry&);
 void initializeUnreachableMachineBlockElimPass(PassRegistry&);
 void initializeVerifierLegacyPassPass(PassRegistry&);
 void initializeVirtRegMapPass(PassRegistry&);
 void initializeVirtRegRewriterPass(PassRegistry&);
 void initializeInstSimplifierPass(PassRegistry&);
 void initializeUnpackMachineBundlesPass(PassRegistry&);
 void initializeFinalizeMachineBundlesPass(PassRegistry&);
+void initializeLoopAccessAnalysisPass(PassRegistry&);
 void initializeLoopVectorizePass(PassRegistry&);
 void initializeSLPVectorizerPass(PassRegistry&);
 void initializeBBVectorizePass(PassRegistry&);
 void initializeMachineFunctionPrinterPassPass(PassRegistry&);
 void initializeStackMapLivenessPass(PassRegistry&);
 void initializeMachineCombinerPass(PassRegistry &);
 void initializeLoadCombinePass(PassRegistry&);
 void initializeRewriteSymbolsPass(PassRegistry&);
 void initializeWinEHPreparePass(PassRegistry&);
 void initializePlaceBackedgeSafepointsImplPass(PassRegistry&);
 void initializePlaceSafepointsPass(PassRegistry&);
 }
 
 #endif

lib/Analysis/LoopAccessAnalysis.cpp

LoopAccessInfo::addRuntimeCheck(Instruction *Loc) {
   // constant expression in which case there is no Instruction anchored in a
   // the block.
   Instruction *Check = BinaryOperator::CreateAnd(MemoryRuntimeCheck,
                                                  ConstantInt::getTrue(Ctx));
   ChkBuilder.Insert(Check, "memcheck.conflict");
   FirstInst = getFirstInst(FirstInst, Check, Loc);
   return std::make_pair(FirstInst, Check);
 }
+
+LoopAccessInfo::LoopAccessInfo(Loop *L, ScalarEvolution *SE,
+                               const DataLayout *DL,
+                               const TargetLibraryInfo *TLI, AliasAnalysis *AA,
+                               DominatorTree *DT, ValueToValueMap &Strides)
+    : TheLoop(L), SE(SE), DL(DL), TLI(TLI), AA(AA), DT(DT), NumLoads(0),
+      NumStores(0), MaxSafeDepDistBytes(-1U), CanVecMem(false) {
+  analyzeLoop(Strides);
+}
+
+LoopAccessInfo &LoopAccessAnalysis::getInfo(Loop *L, ValueToValueMap &Strides) {
+  auto &LAI = LoopAccessInfoMap[L];
+
+#ifndef NDEBUG
+  assert((!LAI || LAI->NumSymbolicStrides == Strides.size()) &&
+         "Symbolic strides changed for loop");
+#endif
+
+  if (!LAI) {
+    LAI = make_unique<LoopAccessInfo>(L, SE, DL, TLI, AA, DT, Strides);
+#ifndef NDEBUG
+    LAI->NumSymbolicStrides = Strides.size();
+#endif
+  }
+  return *LAI.get();
+}
+
+bool LoopAccessAnalysis::runOnFunction(Function &F) {
+  SE = &getAnalysis<ScalarEvolution>();
+  DL = F.getParent()->getDataLayout();
+  auto *TLIP = getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>();
+  TLI = TLIP ? &TLIP->getTLI() : nullptr;
+  AA = &getAnalysis<AliasAnalysis>();
+  DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+
+  return false;
+}
+
+void LoopAccessAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
+    AU.addRequired<ScalarEvolution>();
+    AU.addRequired<AliasAnalysis>();
+    AU.addRequired<DominatorTreeWrapperPass>();
+
+    AU.setPreservesAll();
+}
+
+char LoopAccessAnalysis::ID = 0;
+static const char laa_name[] = "Loop Access Analysis";
+#define LAA_NAME "loop-accesses"
+
+INITIALIZE_PASS_BEGIN(LoopAccessAnalysis, LAA_NAME, laa_name, false, true)
+INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
+INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
+INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
+INITIALIZE_PASS_END(LoopAccessAnalysis, LAA_NAME, laa_name, false, true)
+
+namespace llvm {
+  Pass *createLAAPass() {
+    return new LoopAccessAnalysis();
+  }
+}

lib/Transforms/Scalar/Scalar.cpp

void llvm::initializeScalarOpts(PassRegistry &Registry) {
   initializeGVNPass(Registry);
   initializeEarlyCSELegacyPassPass(Registry);
   initializeFlattenCFGPassPass(Registry);
   initializeInductiveRangeCheckEliminationPass(Registry);
   initializeIndVarSimplifyPass(Registry);
   initializeJumpThreadingPass(Registry);
   initializeLICMPass(Registry);
   initializeLoopDeletionPass(Registry);
+  initializeLoopAccessAnalysisPass(Registry);
   initializeLoopInstSimplifyPass(Registry);
   initializeLoopRotatePass(Registry);
   initializeLoopStrengthReducePass(Registry);
   initializeLoopRerollPass(Registry);
   initializeLoopUnrollPass(Registry);
   initializeLoopUnswitchPass(Registry);
   initializeLoopIdiomRecognizePass(Registry);
   initializeLowerAtomicPass(Registry);

lib/Transforms/Vectorize/LoopVectorize.cpp

 /// etc. This code reflects the capabilities of InnerLoopVectorizer.
 /// This class is also used by InnerLoopVectorizer for identifying
 /// induction variable and the different reduction variables.
 class LoopVectorizationLegality {
 public:
   LoopVectorizationLegality(Loop *L, ScalarEvolution *SE, const DataLayout *DL,
                             DominatorTree *DT, TargetLibraryInfo *TLI,
                             AliasAnalysis *AA, Function *F,
-                            const TargetTransformInfo *TTI)
+                            const TargetTransformInfo *TTI,
+                            LoopAccessAnalysis *LAA)
       : NumPredStores(0), TheLoop(L), SE(SE), DL(DL),
-        TLI(TLI), TheFunction(F), TTI(TTI), DT(DT), Induction(nullptr),
-        WidestIndTy(nullptr),
-        LAI(L, SE, DL, TLI, AA, DT),
-        HasFunNoNaNAttr(false) {}
+        TLI(TLI), TheFunction(F), TTI(TTI), DT(DT), LAA(LAA), LAI(nullptr),
+        Induction(nullptr), WidestIndTy(nullptr), HasFunNoNaNAttr(false) {}
 
   /// This enum represents the kinds of reductions that we support.
   enum ReductionKind {
     RK_NoReduction, ///< Not a reduction.
     RK_IntegerAdd,  ///< Sum of integers.
     RK_IntegerMult, ///< Product of integers.
     RK_IntegerOr,   ///< Bitwise or logical OR of numbers.
     RK_IntegerAnd,  ///< Bitwise or logical AND of numbers.
public:
   /// Returns true if the value V is uniform within the loop.
   bool isUniform(Value *V);
 
   /// Returns true if this instruction will remain scalar after vectorization.
   bool isUniformAfterVectorization(Instruction* I) { return Uniforms.count(I); }
 
   /// Returns the information that we collected about runtime memory check.
   LoopAccessInfo::RuntimePointerCheck *getRuntimePointerCheck() {
-    return LAI.getRuntimePointerCheck();
+    return LAI->getRuntimePointerCheck();
   }
 
   LoopAccessInfo *getLAI() {
-    return &LAI;
+    return LAI;
   }
 
   /// This function returns the identity element (or neutral element) for
   /// the operation K.
   static Constant *getReductionIdentity(ReductionKind K, Type *Tp);
 
-  unsigned getMaxSafeDepDistBytes() { return LAI.getMaxSafeDepDistBytes(); }
+  unsigned getMaxSafeDepDistBytes() { return LAI->getMaxSafeDepDistBytes(); }
 
   bool hasStride(Value *V) { return StrideSet.count(V); }
   bool mustCheckStrides() { return !StrideSet.empty(); }
   SmallPtrSet<Value *, 8>::iterator strides_begin() {
     return StrideSet.begin();
   }
   SmallPtrSet<Value *, 8>::iterator strides_end() { return StrideSet.end(); }
 
   /// Returns true if the target machine supports masked store operation
   /// for the given \p DataType and kind of access to \p Ptr.
   bool isLegalMaskedStore(Type *DataType, Value *Ptr) {
     return TTI->isLegalMaskedStore(DataType, isConsecutivePtr(Ptr));
   }
   /// Returns true if the target machine supports masked load operation
   /// for the given \p DataType and kind of access to \p Ptr.
   bool isLegalMaskedLoad(Type *DataType, Value *Ptr) {
     return TTI->isLegalMaskedLoad(DataType, isConsecutivePtr(Ptr));
   }
   /// Returns true if vector representation of the instruction \p I
   /// requires mask.
   bool isMaskRequired(const Instruction* I) {
     return (MaskedOp.count(I) != 0);
   }
   unsigned getNumStores() const {
-    return LAI.getNumStores();
+    return LAI->getNumStores();
   }
   unsigned getNumLoads() const {
-    return LAI.getNumLoads();
+    return LAI->getNumLoads();
   }
   unsigned getNumPredStores() const {
     return NumPredStores;
   }
 private:
   /// Check if a single basic block loop is vectorizable.
   /// At this point we know that this is a loop with a constant trip count
   /// and we only need to check individual instructions.
private:
   /// Target Library Info.
   TargetLibraryInfo *TLI;
   /// Parent function
   Function *TheFunction;
   /// Target Transform Info
   const TargetTransformInfo *TTI;
   /// Dominator Tree.
   DominatorTree *DT;
+  // LoopAccess analysis.
+  LoopAccessAnalysis *LAA;
+  // And the loop-accesses info corresponding to this loop.  This pointer is
+  // null until canVectorizeMemory sets it up.
+  LoopAccessInfo *LAI;
 
   //  ---  vectorization state --- //
 
   /// Holds the integer induction variable. This is the counter of the
   /// loop.
   PHINode *Induction;
   /// Holds the reduction variables.
   ReductionList Reductions;
   /// Holds all of the induction variables that we found in the loop.
   /// Notice that inductions don't need to start at zero and that induction
   /// variables can be pointers.
   InductionList Inductions;
   /// Holds the widest induction type encountered.
   Type *WidestIndTy;
 
   /// Allowed outside users. This holds the reduction
   /// vars which can be accessed from outside the loop.
   SmallPtrSet<Value*, 4> AllowedExit;
   /// This set holds the variables which are known to be uniform after
   /// vectorization.
   SmallPtrSet<Instruction*, 4> Uniforms;
-  LoopAccessInfo LAI;
+
   /// Can we assume the absence of NaNs.
   bool HasFunNoNaNAttr;
 
   ValueToValueMap Strides;
   SmallPtrSet<Value *, 8> StrideSet;
   
   /// While vectorizing these instructions we have to generate a
   /// call to the appropriate masked intrinsic
struct LoopVectorize : public FunctionPass {
   const DataLayout *DL;
   LoopInfo *LI;
   TargetTransformInfo *TTI;
   DominatorTree *DT;
   BlockFrequencyInfo *BFI;
   TargetLibraryInfo *TLI;
   AliasAnalysis *AA;
   AssumptionCache *AC;
+  LoopAccessAnalysis *LAA;
   bool DisableUnrolling;
   bool AlwaysVectorize;
 
   BlockFrequency ColdEntryFreq;
 
   bool runOnFunction(Function &F) override {
     SE = &getAnalysis<ScalarEvolution>();
     DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
     DL = DLP ? &DLP->getDataLayout() : nullptr;
     LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
     TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
     DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
     BFI = &getAnalysis<BlockFrequencyInfo>();
     auto *TLIP = getAnalysisIfAvailable<TargetLibraryInfoWrapperPass>();
     TLI = TLIP ? &TLIP->getTLI() : nullptr;
     AA = &getAnalysis<AliasAnalysis>();
     AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
+    LAA = &getAnalysis<LoopAccessAnalysis>();
 
     // Compute some weights outside of the loop over the loops. Compute this
     // using a BranchProbability to re-use its scaling math.
     const BranchProbability ColdProb(1, 5); // 20%
     ColdEntryFreq = BlockFrequency(BFI->getEntryFreq()) * ColdProb;
 
     // If the target claims to have no vector registers don't attempt
     // vectorization.
if (TC > 0u && TC < TinyTripCountVectorThreshold) {
         emitOptimizationRemarkAnalysis(
             F->getContext(), DEBUG_TYPE, *F, L->getStartLoc(),
             "vectorization is not beneficial and is not explicitly forced");
         return false;
       }
     }
 
     // Check if it is legal to vectorize the loop.
-    LoopVectorizationLegality LVL(L, SE, DL, DT, TLI, AA, F, TTI);
+    LoopVectorizationLegality LVL(L, SE, DL, DT, TLI, AA, F, TTI, LAA);
     if (!LVL.canVectorize()) {
       DEBUG(dbgs() << "LV: Not vectorizing: Cannot prove legality.\n");
       emitMissedWarning(F, L, Hints);
       return false;
     }
 
     // Use the cost model.
     LoopVectorizationCostModel CM(L, SE, LI, &LVL, *TTI, DL, TLI, AC, F,
void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.addRequiredID(LoopSimplifyID);
     AU.addRequiredID(LCSSAID);
     AU.addRequired<BlockFrequencyInfo>();
     AU.addRequired<DominatorTreeWrapperPass>();
     AU.addRequired<LoopInfoWrapperPass>();
     AU.addRequired<ScalarEvolution>();
     AU.addRequired<TargetTransformInfoWrapperPass>();
     AU.addRequired<AliasAnalysis>();
+    AU.addRequired<LoopAccessAnalysis>();
     AU.addPreserved<LoopInfoWrapperPass>();
     AU.addPreserved<DominatorTreeWrapperPass>();
     AU.addPreserved<AliasAnalysis>();
   }
 
 };
 
 } // end anonymous namespace
if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(Last)) {
     if (Step->isAllOnesValue())
       return -1;
   }
 
   return 0;
 }
 
 bool LoopVectorizationLegality::isUniform(Value *V) {
-  return LAI.isUniform(V);
+  return LAI->isUniform(V);
 }
 
 InnerLoopVectorizer::VectorParts&
 InnerLoopVectorizer::getVectorValue(Value *V) {
   assert(V != Induction && "The new induction variable should not be used.");
   assert(!V->getType()->isVectorTy() && "Can't widen a vector");
 
   // If we have a stride that is replaced by one, do it here.
if (!canVectorizeMemory()) {
     DEBUG(dbgs() << "LV: Can't vectorize due to memory conflicts\n");
     return false;
   }
 
   // Collect all of the variables that remain uniform after vectorization.
   collectLoopUniforms();
 
   DEBUG(dbgs() << "LV: We can vectorize this loop" <<
-        (LAI.getRuntimePointerCheck()->Need ? " (with a runtime bound check)" :
+        (LAI->getRuntimePointerCheck()->Need ? " (with a runtime bound check)" :
          "")
         <<"!\n");
 
   // Okay! We can vectorize. At this point we don't have any other mem analysis
   // which may limit our maximum vectorization factor, so just return true with
   // no restrictions.
   return true;
 }
while (!Worklist.empty()) {
     Uniforms.insert(I);
 
     // Insert all operands.
     Worklist.insert(Worklist.end(), I->op_begin(), I->op_end());
   }
 }
 
 bool LoopVectorizationLegality::canVectorizeMemory() {
-  LAI.analyzeLoop(Strides);
-  auto &OptionalReport = LAI.getReport();
+  LAI = &LAA->getInfo(TheLoop, Strides);
+  auto &OptionalReport = LAI->getReport();
   if (OptionalReport)
     emitAnalysis(*OptionalReport);
-  return LAI.canVectorizeMemory();
+  return LAI->canVectorizeMemory();
 }
 
 static bool hasMultipleUsesOf(Instruction *I,
                               SmallPtrSetImpl<Instruction *> &Insts) {
   unsigned NumUses = 0;
   for(User::op_iterator Use = I->op_begin(), E = I->op_end(); Use != E; ++Use) {
     if (Insts.count(dyn_cast<Instruction>(*Use)))
       ++NumUses;

 INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
 INITIALIZE_PASS_DEPENDENCY(BlockFrequencyInfo)
 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
 INITIALIZE_PASS_DEPENDENCY(LCSSA)
 INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
+INITIALIZE_PASS_DEPENDENCY(LoopAccessAnalysis)
 INITIALIZE_PASS_END(LoopVectorize, LV_NAME, lv_name, false, false)
 
 namespace llvm {
   Pass *createLoopVectorizePass(bool NoUnrolling, bool AlwaysVectorize) {
     return new LoopVectorize(NoUnrolling, AlwaysVectorize);
   }
 }