1 files changed, 0 insertions, 1250 deletions

diff --git a/contrib/llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp b/contrib/llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp
deleted file mode 100644
index 138f18e49c92..000000000000
--- a/contrib/llvm/lib/Transforms/Vectorize/LoopVectorizationLegality.cpp
+++ /dev/null
@@ -1,1250 +0,0 @@
-//===- LoopVectorizationLegality.cpp --------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This file provides loop vectorization legality analysis. Original code
-// resided in LoopVectorize.cpp for a long time.
-//
-// At this point, it is implemented as a utility class, not as an analysis
-// pass. It should be easy to create an analysis pass around it if there
-// is a need (but D45420 needs to happen first).
-//
-#include "llvm/Transforms/Vectorize/LoopVectorizationLegality.h"
-#include "llvm/Analysis/VectorUtils.h"
-#include "llvm/IR/IntrinsicInst.h"
-
-using namespace llvm;
-
-#define LV_NAME "loop-vectorize"
-#define DEBUG_TYPE LV_NAME
-
-extern cl::opt<bool> EnableVPlanPredication;
-
-static cl::opt<bool>
-    EnableIfConversion("enable-if-conversion", cl::init(true), cl::Hidden,
-                       cl::desc("Enable if-conversion during vectorization."));
-
-static cl::opt<unsigned> PragmaVectorizeMemoryCheckThreshold(
-    "pragma-vectorize-memory-check-threshold", cl::init(128), cl::Hidden,
-    cl::desc("The maximum allowed number of runtime memory checks with a "
-             "vectorize(enable) pragma."));
-
-static cl::opt<unsigned> VectorizeSCEVCheckThreshold(
-    "vectorize-scev-check-threshold", cl::init(16), cl::Hidden,
-    cl::desc("The maximum number of SCEV checks allowed."));
-
-static cl::opt<unsigned> PragmaVectorizeSCEVCheckThreshold(
-    "pragma-vectorize-scev-check-threshold", cl::init(128), cl::Hidden,
-    cl::desc("The maximum number of SCEV checks allowed with a "
-             "vectorize(enable) pragma"));
-
-/// Maximum vectorization interleave count.
-static const unsigned MaxInterleaveFactor = 16;
-
-namespace llvm {
-
-#ifndef NDEBUG
-static void debugVectorizationFailure(const StringRef DebugMsg,
-    Instruction *I) {
-  dbgs() << "LV: Not vectorizing: " << DebugMsg;
-  if (I != nullptr)
-    dbgs() << " " << *I;
-  else
-    dbgs() << '.';
-  dbgs() << '\n';
-}
-#endif
-
-OptimizationRemarkAnalysis createLVMissedAnalysis(const char *PassName,
-                                                  StringRef RemarkName,
-                                                  Loop *TheLoop,
-                                                  Instruction *I) {
-  Value *CodeRegion = TheLoop->getHeader();
-  DebugLoc DL = TheLoop->getStartLoc();
-
-  if (I) {
-    CodeRegion = I->getParent();
-    // If there is no debug location attached to the instruction, revert back to
-    // using the loop's.
-    if (I->getDebugLoc())
-      DL = I->getDebugLoc();
-  }
-
-  OptimizationRemarkAnalysis R(PassName, RemarkName, DL, CodeRegion);
-  R << "loop not vectorized: ";
-  return R;
-}
-
-bool LoopVectorizeHints::Hint::validate(unsigned Val) {
-  switch (Kind) {
-  case HK_WIDTH:
-    return isPowerOf2_32(Val) && Val <= VectorizerParams::MaxVectorWidth;
-  case HK_UNROLL:
-    return isPowerOf2_32(Val) && Val <= MaxInterleaveFactor;
-  case HK_FORCE:
-    return (Val <= 1);
-  case HK_ISVECTORIZED:
-    return (Val == 0 || Val == 1);
-  }
-  return false;
-}
-
-LoopVectorizeHints::LoopVectorizeHints(const Loop *L,
-                                       bool InterleaveOnlyWhenForced,
-                                       OptimizationRemarkEmitter &ORE)
-    : Width("vectorize.width", VectorizerParams::VectorizationFactor, HK_WIDTH),
-      Interleave("interleave.count", InterleaveOnlyWhenForced, HK_UNROLL),
-      Force("vectorize.enable", FK_Undefined, HK_FORCE),
-      IsVectorized("isvectorized", 0, HK_ISVECTORIZED), TheLoop(L), ORE(ORE) {
-  // Populate values with existing loop metadata.
-  getHintsFromMetadata();
-
-  // force-vector-interleave overrides DisableInterleaving.
-  if (VectorizerParams::isInterleaveForced())
-    Interleave.Value = VectorizerParams::VectorizationInterleave;
-
-  if (IsVectorized.Value != 1)
-    // If the vectorization width and interleaving count are both 1 then
-    // consider the loop to have been already vectorized because there's
-    // nothing more that we can do.
-    IsVectorized.Value = Width.Value == 1 && Interleave.Value == 1;
-  LLVM_DEBUG(if (InterleaveOnlyWhenForced && Interleave.Value == 1) dbgs()
-             << "LV: Interleaving disabled by the pass manager\n");
-}
-
-void LoopVectorizeHints::setAlreadyVectorized() {
-  LLVMContext &Context = TheLoop->getHeader()->getContext();
-
-  MDNode *IsVectorizedMD = MDNode::get(
-      Context,
-      {MDString::get(Context, "llvm.loop.isvectorized"),
-       ConstantAsMetadata::get(ConstantInt::get(Context, APInt(32, 1)))});
-  MDNode *LoopID = TheLoop->getLoopID();
-  MDNode *NewLoopID =
-      makePostTransformationMetadata(Context, LoopID,
-                                     {Twine(Prefix(), "vectorize.").str(),
-                                      Twine(Prefix(), "interleave.").str()},
-                                     {IsVectorizedMD});
-  TheLoop->setLoopID(NewLoopID);
-
-  // Update internal cache.
-  IsVectorized.Value = 1;
-}
-
-bool LoopVectorizeHints::allowVectorization(
-    Function *F, Loop *L, bool VectorizeOnlyWhenForced) const {
-  if (getForce() == LoopVectorizeHints::FK_Disabled) {
-    LLVM_DEBUG(dbgs() << "LV: Not vectorizing: #pragma vectorize disable.\n");
-    emitRemarkWithHints();
-    return false;
-  }
-
-  if (VectorizeOnlyWhenForced && getForce() != LoopVectorizeHints::FK_Enabled) {
-    LLVM_DEBUG(dbgs() << "LV: Not vectorizing: No #pragma vectorize enable.\n");
-    emitRemarkWithHints();
-    return false;
-  }
-
-  if (getIsVectorized() == 1) {
-    LLVM_DEBUG(dbgs() << "LV: Not vectorizing: Disabled/already vectorized.\n");
-    // FIXME: Add interleave.disable metadata. This will allow
-    // vectorize.disable to be used without disabling the pass and errors
-    // to differentiate between disabled vectorization and a width of 1.
-    ORE.emit([&]() {
-      return OptimizationRemarkAnalysis(vectorizeAnalysisPassName(),
-                                        "AllDisabled", L->getStartLoc(),
-                                        L->getHeader())
-             << "loop not vectorized: vectorization and interleaving are "
-                "explicitly disabled, or the loop has already been "
-                "vectorized";
-    });
-    return false;
-  }
-
-  return true;
-}
-
-void LoopVectorizeHints::emitRemarkWithHints() const {
-  using namespace ore;
-
-  ORE.emit([&]() {
-    if (Force.Value == LoopVectorizeHints::FK_Disabled)
-      return OptimizationRemarkMissed(LV_NAME, "MissedExplicitlyDisabled",
-                                      TheLoop->getStartLoc(),
-                                      TheLoop->getHeader())
-             << "loop not vectorized: vectorization is explicitly disabled";
-    else {
-      OptimizationRemarkMissed R(LV_NAME, "MissedDetails",
-                                 TheLoop->getStartLoc(), TheLoop->getHeader());
-      R << "loop not vectorized";
-      if (Force.Value == LoopVectorizeHints::FK_Enabled) {
-        R << " (Force=" << NV("Force", true);
-        if (Width.Value != 0)
-          R << ", Vector Width=" << NV("VectorWidth", Width.Value);
-        if (Interleave.Value != 0)
-          R << ", Interleave Count=" << NV("InterleaveCount", Interleave.Value);
-        R << ")";
-      }
-      return R;
-    }
-  });
-}
-
-const char *LoopVectorizeHints::vectorizeAnalysisPassName() const {
-  if (getWidth() == 1)
-    return LV_NAME;
-  if (getForce() == LoopVectorizeHints::FK_Disabled)
-    return LV_NAME;
-  if (getForce() == LoopVectorizeHints::FK_Undefined && getWidth() == 0)
-    return LV_NAME;
-  return OptimizationRemarkAnalysis::AlwaysPrint;
-}
-
-void LoopVectorizeHints::getHintsFromMetadata() {
-  MDNode *LoopID = TheLoop->getLoopID();
-  if (!LoopID)
-    return;
-
-  // First operand should refer to the loop id itself.
-  assert(LoopID->getNumOperands() > 0 && "requires at least one operand");
-  assert(LoopID->getOperand(0) == LoopID && "invalid loop id");
-
-  for (unsigned i = 1, ie = LoopID->getNumOperands(); i < ie; ++i) {
-    const MDString *S = nullptr;
-    SmallVector<Metadata *, 4> Args;
-
-    // The expected hint is either a MDString or a MDNode with the first
-    // operand a MDString.
-    if (const MDNode *MD = dyn_cast<MDNode>(LoopID->getOperand(i))) {
-      if (!MD || MD->getNumOperands() == 0)
-        continue;
-      S = dyn_cast<MDString>(MD->getOperand(0));
-      for (unsigned i = 1, ie = MD->getNumOperands(); i < ie; ++i)
-        Args.push_back(MD->getOperand(i));
-    } else {
-      S = dyn_cast<MDString>(LoopID->getOperand(i));
-      assert(Args.size() == 0 && "too many arguments for MDString");
-    }
-
-    if (!S)
-      continue;
-
-    // Check if the hint starts with the loop metadata prefix.
-    StringRef Name = S->getString();
-    if (Args.size() == 1)
-      setHint(Name, Args[0]);
-  }
-}
-
-void LoopVectorizeHints::setHint(StringRef Name, Metadata *Arg) {
-  if (!Name.startswith(Prefix()))
-    return;
-  Name = Name.substr(Prefix().size(), StringRef::npos);
-
-  const ConstantInt *C = mdconst::dyn_extract<ConstantInt>(Arg);
-  if (!C)
-    return;
-  unsigned Val = C->getZExtValue();
-
-  Hint *Hints[] = {&Width, &Interleave, &Force, &IsVectorized};
-  for (auto H : Hints) {
-    if (Name == H->Name) {
-      if (H->validate(Val))
-        H->Value = Val;
-      else
-        LLVM_DEBUG(dbgs() << "LV: ignoring invalid hint '" << Name << "'\n");
-      break;
-    }
-  }
-}
-
-bool LoopVectorizationRequirements::doesNotMeet(
-    Function *F, Loop *L, const LoopVectorizeHints &Hints) {
-  const char *PassName = Hints.vectorizeAnalysisPassName();
-  bool Failed = false;
-  if (UnsafeAlgebraInst && !Hints.allowReordering()) {
-    ORE.emit([&]() {
-      return OptimizationRemarkAnalysisFPCommute(
-                 PassName, "CantReorderFPOps", UnsafeAlgebraInst->getDebugLoc(),
-                 UnsafeAlgebraInst->getParent())
-             << "loop not vectorized: cannot prove it is safe to reorder "
-                "floating-point operations";
-    });
-    Failed = true;
-  }
-
-  // Test if runtime memcheck thresholds are exceeded.
-  bool PragmaThresholdReached =
-      NumRuntimePointerChecks > PragmaVectorizeMemoryCheckThreshold;
-  bool ThresholdReached =
-      NumRuntimePointerChecks > VectorizerParams::RuntimeMemoryCheckThreshold;
-  if ((ThresholdReached && !Hints.allowReordering()) ||
-      PragmaThresholdReached) {
-    ORE.emit([&]() {
-      return OptimizationRemarkAnalysisAliasing(PassName, "CantReorderMemOps",
-                                                L->getStartLoc(),
-                                                L->getHeader())
-             << "loop not vectorized: cannot prove it is safe to reorder "
-                "memory operations";
-    });
-    LLVM_DEBUG(dbgs() << "LV: Too many memory checks needed.\n");
-    Failed = true;
-  }
-
-  return Failed;
-}
-
-// Return true if the inner loop \p Lp is uniform with regard to the outer loop
-// \p OuterLp (i.e., if the outer loop is vectorized, all the vector lanes
-// executing the inner loop will execute the same iterations). This check is
-// very constrained for now but it will be relaxed in the future. \p Lp is
-// considered uniform if it meets all the following conditions:
-//   1) it has a canonical IV (starting from 0 and with stride 1),
-//   2) its latch terminator is a conditional branch and,
-//   3) its latch condition is a compare instruction whose operands are the
-//      canonical IV and an OuterLp invariant.
-// This check doesn't take into account the uniformity of other conditions not
-// related to the loop latch because they don't affect the loop uniformity.
-//
-// NOTE: We decided to keep all these checks and its associated documentation
-// together so that we can easily have a picture of the current supported loop
-// nests. However, some of the current checks don't depend on \p OuterLp and
-// would be redundantly executed for each \p Lp if we invoked this function for
-// different candidate outer loops. This is not the case for now because we
-// don't currently have the infrastructure to evaluate multiple candidate outer
-// loops and \p OuterLp will be a fixed parameter while we only support explicit
-// outer loop vectorization. It's also very likely that these checks go away
-// before introducing the aforementioned infrastructure. However, if this is not
-// the case, we should move the \p OuterLp independent checks to a separate
-// function that is only executed once for each \p Lp.
-static bool isUniformLoop(Loop *Lp, Loop *OuterLp) {
-  assert(Lp->getLoopLatch() && "Expected loop with a single latch.");
-
-  // If Lp is the outer loop, it's uniform by definition.
-  if (Lp == OuterLp)
-    return true;
-  assert(OuterLp->contains(Lp) && "OuterLp must contain Lp.");
-
-  // 1.
-  PHINode *IV = Lp->getCanonicalInductionVariable();
-  if (!IV) {
-    LLVM_DEBUG(dbgs() << "LV: Canonical IV not found.\n");
-    return false;
-  }
-
-  // 2.
-  BasicBlock *Latch = Lp->getLoopLatch();
-  auto *LatchBr = dyn_cast<BranchInst>(Latch->getTerminator());
-  if (!LatchBr || LatchBr->isUnconditional()) {
-    LLVM_DEBUG(dbgs() << "LV: Unsupported loop latch branch.\n");
-    return false;
-  }
-
-  // 3.
-  auto *LatchCmp = dyn_cast<CmpInst>(LatchBr->getCondition());
-  if (!LatchCmp) {
-    LLVM_DEBUG(
-        dbgs() << "LV: Loop latch condition is not a compare instruction.\n");
-    return false;
-  }
-
-  Value *CondOp0 = LatchCmp->getOperand(0);
-  Value *CondOp1 = LatchCmp->getOperand(1);
-  Value *IVUpdate = IV->getIncomingValueForBlock(Latch);
-  if (!(CondOp0 == IVUpdate && OuterLp->isLoopInvariant(CondOp1)) &&
-      !(CondOp1 == IVUpdate && OuterLp->isLoopInvariant(CondOp0))) {
-    LLVM_DEBUG(dbgs() << "LV: Loop latch condition is not uniform.\n");
-    return false;
-  }
-
-  return true;
-}
-
-// Return true if \p Lp and all its nested loops are uniform with regard to \p
-// OuterLp.
-static bool isUniformLoopNest(Loop *Lp, Loop *OuterLp) {
-  if (!isUniformLoop(Lp, OuterLp))
-    return false;
-
-  // Check if nested loops are uniform.
-  for (Loop *SubLp : *Lp)
-    if (!isUniformLoopNest(SubLp, OuterLp))
-      return false;
-
-  return true;
-}
-
-/// Check whether it is safe to if-convert this phi node.
-///
-/// Phi nodes with constant expressions that can trap are not safe to if
-/// convert.
-static bool canIfConvertPHINodes(BasicBlock *BB) {
-  for (PHINode &Phi : BB->phis()) {
-    for (Value *V : Phi.incoming_values())
-      if (auto *C = dyn_cast<Constant>(V))
-        if (C->canTrap())
-          return false;
-  }
-  return true;
-}
-
-static Type *convertPointerToIntegerType(const DataLayout &DL, Type *Ty) {
-  if (Ty->isPointerTy())
-    return DL.getIntPtrType(Ty);
-
-  // It is possible that char's or short's overflow when we ask for the loop's
-  // trip count, work around this by changing the type size.
-  if (Ty->getScalarSizeInBits() < 32)
-    return Type::getInt32Ty(Ty->getContext());
-
-  return Ty;
-}
-
-static Type *getWiderType(const DataLayout &DL, Type *Ty0, Type *Ty1) {
-  Ty0 = convertPointerToIntegerType(DL, Ty0);
-  Ty1 = convertPointerToIntegerType(DL, Ty1);
-  if (Ty0->getScalarSizeInBits() > Ty1->getScalarSizeInBits())
-    return Ty0;
-  return Ty1;
-}
-
-/// Check that the instruction has outside loop users and is not an
-/// identified reduction variable.
-static bool hasOutsideLoopUser(const Loop *TheLoop, Instruction *Inst,
-                               SmallPtrSetImpl<Value *> &AllowedExit) {
-  // Reductions, Inductions and non-header phis are allowed to have exit users. All
-  // other instructions must not have external users.
-  if (!AllowedExit.count(Inst))
-    // Check that all of the users of the loop are inside the BB.
-    for (User *U : Inst->users()) {
-      Instruction *UI = cast<Instruction>(U);
-      // This user may be a reduction exit value.
-      if (!TheLoop->contains(UI)) {
-        LLVM_DEBUG(dbgs() << "LV: Found an outside user for : " << *UI << '\n');
-        return true;
-      }
-    }
-  return false;
-}
-
-int LoopVectorizationLegality::isConsecutivePtr(Value *Ptr) {
-  const ValueToValueMap &Strides =
-      getSymbolicStrides() ? *getSymbolicStrides() : ValueToValueMap();
-
-  int Stride = getPtrStride(PSE, Ptr, TheLoop, Strides, true, false);
-  if (Stride == 1 || Stride == -1)
-    return Stride;
-  return 0;
-}
-
-bool LoopVectorizationLegality::isUniform(Value *V) {
-  return LAI->isUniform(V);
-}
-
-void LoopVectorizationLegality::reportVectorizationFailure(
-    const StringRef DebugMsg, const StringRef OREMsg,
-    const StringRef ORETag, Instruction *I) const {
-  LLVM_DEBUG(debugVectorizationFailure(DebugMsg, I));
-  ORE->emit(createLVMissedAnalysis(Hints->vectorizeAnalysisPassName(),
-      ORETag, TheLoop, I) << OREMsg);
-}
-
-bool LoopVectorizationLegality::canVectorizeOuterLoop() {
-  assert(!TheLoop->empty() && "We are not vectorizing an outer loop.");
-  // Store the result and return it at the end instead of exiting early, in case
-  // allowExtraAnalysis is used to report multiple reasons for not vectorizing.
-  bool Result = true;
-  bool DoExtraAnalysis = ORE->allowExtraAnalysis(DEBUG_TYPE);
-
-  for (BasicBlock *BB : TheLoop->blocks()) {
-    // Check whether the BB terminator is a BranchInst. Any other terminator is
-    // not supported yet.
-    auto *Br = dyn_cast<BranchInst>(BB->getTerminator());
-    if (!Br) {
-      reportVectorizationFailure("Unsupported basic block terminator",
-          "loop control flow is not understood by vectorizer",
-          "CFGNotUnderstood");
-      if (DoExtraAnalysis)
-        Result = false;
-      else
-        return false;
-    }
-
-    // Check whether the BranchInst is a supported one. Only unconditional
-    // branches, conditional branches with an outer loop invariant condition or
-    // backedges are supported.
-    // FIXME: We skip these checks when VPlan predication is enabled as we
-    // want to allow divergent branches. This whole check will be removed
-    // once VPlan predication is on by default.
-    if (!EnableVPlanPredication && Br && Br->isConditional() &&
-        !TheLoop->isLoopInvariant(Br->getCondition()) &&
-        !LI->isLoopHeader(Br->getSuccessor(0)) &&
-        !LI->isLoopHeader(Br->getSuccessor(1))) {
-      reportVectorizationFailure("Unsupported conditional branch",
-          "loop control flow is not understood by vectorizer",
-          "CFGNotUnderstood");
-      if (DoExtraAnalysis)
-        Result = false;
-      else
-        return false;
-    }
-  }
-
-  // Check whether inner loops are uniform. At this point, we only support
-  // simple outer loops scenarios with uniform nested loops.
-  if (!isUniformLoopNest(TheLoop /*loop nest*/,
-                         TheLoop /*context outer loop*/)) {
-    reportVectorizationFailure("Outer loop contains divergent loops",
-        "loop control flow is not understood by vectorizer",
-        "CFGNotUnderstood");
-    if (DoExtraAnalysis)
-      Result = false;
-    else
-      return false;
-  }
-
-  // Check whether we are able to set up outer loop induction.
-  if (!setupOuterLoopInductions()) {
-    reportVectorizationFailure("Unsupported outer loop Phi(s)",
-                               "Unsupported outer loop Phi(s)",
-                               "UnsupportedPhi");
-    if (DoExtraAnalysis)
-      Result = false;
-    else
-      return false;
-  }
-
-  return Result;
-}
-
-void LoopVectorizationLegality::addInductionPhi(
-    PHINode *Phi, const InductionDescriptor &ID,
-    SmallPtrSetImpl<Value *> &AllowedExit) {
-  Inductions[Phi] = ID;
-
-  // In case this induction also comes with casts that we know we can ignore
-  // in the vectorized loop body, record them here. All casts could be recorded
-  // here for ignoring, but suffices to record only the first (as it is the
-  // only one that may bw used outside the cast sequence).
-  const SmallVectorImpl<Instruction *> &Casts = ID.getCastInsts();
-  if (!Casts.empty())
-    InductionCastsToIgnore.insert(*Casts.begin());
-
-  Type *PhiTy = Phi->getType();
-  const DataLayout &DL = Phi->getModule()->getDataLayout();
-
-  // Get the widest type.
-  if (!PhiTy->isFloatingPointTy()) {
-    if (!WidestIndTy)
-      WidestIndTy = convertPointerToIntegerType(DL, PhiTy);
-    else
-      WidestIndTy = getWiderType(DL, PhiTy, WidestIndTy);
-  }
-
-  // Int inductions are special because we only allow one IV.
-  if (ID.getKind() == InductionDescriptor::IK_IntInduction &&
-      ID.getConstIntStepValue() && ID.getConstIntStepValue()->isOne() &&
-      isa<Constant>(ID.getStartValue()) &&
-      cast<Constant>(ID.getStartValue())->isNullValue()) {
-
-    // Use the phi node with the widest type as induction. Use the last
-    // one if there are multiple (no good reason for doing this other
-    // than it is expedient). We've checked that it begins at zero and
-    // steps by one, so this is a canonical induction variable.
-    if (!PrimaryInduction || PhiTy == WidestIndTy)
-      PrimaryInduction = Phi;
-  }
-
-  // Both the PHI node itself, and the "post-increment" value feeding
-  // back into the PHI node may have external users.
-  // We can allow those uses, except if the SCEVs we have for them rely
-  // on predicates that only hold within the loop, since allowing the exit
-  // currently means re-using this SCEV outside the loop (see PR33706 for more
-  // details).
-  if (PSE.getUnionPredicate().isAlwaysTrue()) {
-    AllowedExit.insert(Phi);
-    AllowedExit.insert(Phi->getIncomingValueForBlock(TheLoop->getLoopLatch()));
-  }
-
-  LLVM_DEBUG(dbgs() << "LV: Found an induction variable.\n");
-}
-
-bool LoopVectorizationLegality::setupOuterLoopInductions() {
-  BasicBlock *Header = TheLoop->getHeader();
-
-  // Returns true if a given Phi is a supported induction.
-  auto isSupportedPhi = [&](PHINode &Phi) -> bool {
-    InductionDescriptor ID;
-    if (InductionDescriptor::isInductionPHI(&Phi, TheLoop, PSE, ID) &&
-        ID.getKind() == InductionDescriptor::IK_IntInduction) {
-      addInductionPhi(&Phi, ID, AllowedExit);
-      return true;
-    } else {
-      // Bail out for any Phi in the outer loop header that is not a supported
-      // induction.
-      LLVM_DEBUG(
-          dbgs()
-          << "LV: Found unsupported PHI for outer loop vectorization.\n");
-      return false;
-    }
-  };
-
-  if (llvm::all_of(Header->phis(), isSupportedPhi))
-    return true;
-  else
-    return false;
-}
-
-bool LoopVectorizationLegality::canVectorizeInstrs() {
-  BasicBlock *Header = TheLoop->getHeader();
-
-  // Look for the attribute signaling the absence of NaNs.
-  Function &F = *Header->getParent();
-  HasFunNoNaNAttr =
-      F.getFnAttribute("no-nans-fp-math").getValueAsString() == "true";
-
-  // For each block in the loop.
-  for (BasicBlock *BB : TheLoop->blocks()) {
-    // Scan the instructions in the block and look for hazards.
-    for (Instruction &I : *BB) {
-      if (auto *Phi = dyn_cast<PHINode>(&I)) {
-        Type *PhiTy = Phi->getType();
-        // Check that this PHI type is allowed.
-        if (!PhiTy->isIntegerTy() && !PhiTy->isFloatingPointTy() &&
-            !PhiTy->isPointerTy()) {
-          reportVectorizationFailure("Found a non-int non-pointer PHI",
-                                     "loop control flow is not understood by vectorizer",
-                                     "CFGNotUnderstood");
-          return false;
-        }
-
-        // If this PHINode is not in the header block, then we know that we
-        // can convert it to select during if-conversion. No need to check if
-        // the PHIs in this block are induction or reduction variables.
-        if (BB != Header) {
-          // Non-header phi nodes that have outside uses can be vectorized. Add
-          // them to the list of allowed exits.
-          // Unsafe cyclic dependencies with header phis are identified during
-          // legalization for reduction, induction and first order
-          // recurrences.
-          AllowedExit.insert(&I);
-          continue;
-        }
-
-        // We only allow if-converted PHIs with exactly two incoming values.
-        if (Phi->getNumIncomingValues() != 2) {
-          reportVectorizationFailure("Found an invalid PHI",
-              "loop control flow is not understood by vectorizer",
-              "CFGNotUnderstood", Phi);
-          return false;
-        }
-
-        RecurrenceDescriptor RedDes;
-        if (RecurrenceDescriptor::isReductionPHI(Phi, TheLoop, RedDes, DB, AC,
-                                                 DT)) {
-          if (RedDes.hasUnsafeAlgebra())
-            Requirements->addUnsafeAlgebraInst(RedDes.getUnsafeAlgebraInst());
-          AllowedExit.insert(RedDes.getLoopExitInstr());
-          Reductions[Phi] = RedDes;
-          continue;
-        }
-
-        // TODO: Instead of recording the AllowedExit, it would be good to record the
-        // complementary set: NotAllowedExit. These include (but may not be
-        // limited to):
-        // 1. Reduction phis as they represent the one-before-last value, which
-        // is not available when vectorized 
-        // 2. Induction phis and increment when SCEV predicates cannot be used
-        // outside the loop - see addInductionPhi
-        // 3. Non-Phis with outside uses when SCEV predicates cannot be used
-        // outside the loop - see call to hasOutsideLoopUser in the non-phi
-        // handling below
-        // 4. FirstOrderRecurrence phis that can possibly be handled by
-        // extraction.
-        // By recording these, we can then reason about ways to vectorize each
-        // of these NotAllowedExit. 
-        InductionDescriptor ID;
-        if (InductionDescriptor::isInductionPHI(Phi, TheLoop, PSE, ID)) {
-          addInductionPhi(Phi, ID, AllowedExit);
-          if (ID.hasUnsafeAlgebra() && !HasFunNoNaNAttr)
-            Requirements->addUnsafeAlgebraInst(ID.getUnsafeAlgebraInst());
-          continue;
-        }
-
-        if (RecurrenceDescriptor::isFirstOrderRecurrence(Phi, TheLoop,
-                                                         SinkAfter, DT)) {
-          FirstOrderRecurrences.insert(Phi);
-          continue;
-        }
-
-        // As a last resort, coerce the PHI to a AddRec expression
-        // and re-try classifying it a an induction PHI.
-        if (InductionDescriptor::isInductionPHI(Phi, TheLoop, PSE, ID, true)) {
-          addInductionPhi(Phi, ID, AllowedExit);
-          continue;
-        }
-
-        reportVectorizationFailure("Found an unidentified PHI",
-            "value that could not be identified as "
-            "reduction is used outside the loop",
-            "NonReductionValueUsedOutsideLoop", Phi);
-        return false;
-      } // end of PHI handling
-
-      // We handle calls that:
-      //   * Are debug info intrinsics.
-      //   * Have a mapping to an IR intrinsic.
-      //   * Have a vector version available.
-      auto *CI = dyn_cast<CallInst>(&I);
-      if (CI && !getVectorIntrinsicIDForCall(CI, TLI) &&
-          !isa<DbgInfoIntrinsic>(CI) &&
-          !(CI->getCalledFunction() && TLI &&
-            TLI->isFunctionVectorizable(CI->getCalledFunction()->getName()))) {
-        // If the call is a recognized math libary call, it is likely that
-        // we can vectorize it given loosened floating-point constraints.
-        LibFunc Func;
-        bool IsMathLibCall =
-            TLI && CI->getCalledFunction() &&
-            CI->getType()->isFloatingPointTy() &&
-            TLI->getLibFunc(CI->getCalledFunction()->getName(), Func) &&
-            TLI->hasOptimizedCodeGen(Func);
-
-        if (IsMathLibCall) {
-          // TODO: Ideally, we should not use clang-specific language here,
-          // but it's hard to provide meaningful yet generic advice.
-          // Also, should this be guarded by allowExtraAnalysis() and/or be part
-          // of the returned info from isFunctionVectorizable()?
-          reportVectorizationFailure("Found a non-intrinsic callsite",
-              "library call cannot be vectorized. "
-              "Try compiling with -fno-math-errno, -ffast-math, "
-              "or similar flags",
-              "CantVectorizeLibcall", CI);
-        } else {
-          reportVectorizationFailure("Found a non-intrinsic callsite",
-                                     "call instruction cannot be vectorized",
-                                     "CantVectorizeLibcall", CI);
-        }
-        return false;
-      }
-
-      // Some intrinsics have scalar arguments and should be same in order for
-      // them to be vectorized (i.e. loop invariant).
-      if (CI) {
-        auto *SE = PSE.getSE();
-        Intrinsic::ID IntrinID = getVectorIntrinsicIDForCall(CI, TLI);
-        for (unsigned i = 0, e = CI->getNumArgOperands(); i != e; ++i)
-          if (hasVectorInstrinsicScalarOpd(IntrinID, i)) {
-            if (!SE->isLoopInvariant(PSE.getSCEV(CI->getOperand(i)), TheLoop)) {
-              reportVectorizationFailure("Found unvectorizable intrinsic",
-                  "intrinsic instruction cannot be vectorized",
-                  "CantVectorizeIntrinsic", CI);
-              return false;
-            }
-          }
-      }
-
-      // Check that the instruction return type is vectorizable.
-      // Also, we can't vectorize extractelement instructions.
-      if ((!VectorType::isValidElementType(I.getType()) &&
-           !I.getType()->isVoidTy()) ||
-          isa<ExtractElementInst>(I)) {
-        reportVectorizationFailure("Found unvectorizable type",
-            "instruction return type cannot be vectorized",
-            "CantVectorizeInstructionReturnType", &I);
-        return false;
-      }
-
-      // Check that the stored type is vectorizable.
-      if (auto *ST = dyn_cast<StoreInst>(&I)) {
-        Type *T = ST->getValueOperand()->getType();
-        if (!VectorType::isValidElementType(T)) {
-          reportVectorizationFailure("Store instruction cannot be vectorized",
-                                     "store instruction cannot be vectorized",
-                                     "CantVectorizeStore", ST);
-          return false;
-        }
-
-        // For nontemporal stores, check that a nontemporal vector version is
-        // supported on the target.
-        if (ST->getMetadata(LLVMContext::MD_nontemporal)) {
-          // Arbitrarily try a vector of 2 elements.
-          Type *VecTy = VectorType::get(T, /*NumElements=*/2);
-          assert(VecTy && "did not find vectorized version of stored type");
-          unsigned Alignment = getLoadStoreAlignment(ST);
-          if (!TTI->isLegalNTStore(VecTy, Alignment)) {
-            reportVectorizationFailure(
-                "nontemporal store instruction cannot be vectorized",
-                "nontemporal store instruction cannot be vectorized",
-                "CantVectorizeNontemporalStore", ST);
-            return false;
-          }
-        }
-
-      } else if (auto *LD = dyn_cast<LoadInst>(&I)) {
-        if (LD->getMetadata(LLVMContext::MD_nontemporal)) {
-          // For nontemporal loads, check that a nontemporal vector version is
-          // supported on the target (arbitrarily try a vector of 2 elements).
-          Type *VecTy = VectorType::get(I.getType(), /*NumElements=*/2);
-          assert(VecTy && "did not find vectorized version of load type");
-          unsigned Alignment = getLoadStoreAlignment(LD);
-          if (!TTI->isLegalNTLoad(VecTy, Alignment)) {
-            reportVectorizationFailure(
-                "nontemporal load instruction cannot be vectorized",
-                "nontemporal load instruction cannot be vectorized",
-                "CantVectorizeNontemporalLoad", LD);
-            return false;
-          }
-        }
-
-        // FP instructions can allow unsafe algebra, thus vectorizable by
-        // non-IEEE-754 compliant SIMD units.
-        // This applies to floating-point math operations and calls, not memory
-        // operations, shuffles, or casts, as they don't change precision or
-        // semantics.
-      } else if (I.getType()->isFloatingPointTy() && (CI || I.isBinaryOp()) &&
-                 !I.isFast()) {
-        LLVM_DEBUG(dbgs() << "LV: Found FP op with unsafe algebra.\n");
-        Hints->setPotentiallyUnsafe();
-      }
-
-      // Reduction instructions are allowed to have exit users.
-      // All other instructions must not have external users.
-      if (hasOutsideLoopUser(TheLoop, &I, AllowedExit)) {
-        // We can safely vectorize loops where instructions within the loop are
-        // used outside the loop only if the SCEV predicates within the loop is
-        // same as outside the loop. Allowing the exit means reusing the SCEV
-        // outside the loop.
-        if (PSE.getUnionPredicate().isAlwaysTrue()) {
-          AllowedExit.insert(&I);
-          continue;
-        }
-        reportVectorizationFailure("Value cannot be used outside the loop",
-                                   "value cannot be used outside the loop",
-                                   "ValueUsedOutsideLoop", &I);
-        return false;
-      }
-    } // next instr.
-  }
-
-  if (!PrimaryInduction) {
-    if (Inductions.empty()) {
-      reportVectorizationFailure("Did not find one integer induction var",
-          "loop induction variable could not be identified",
-          "NoInductionVariable");
-      return false;
-    } else if (!WidestIndTy) {
-      reportVectorizationFailure("Did not find one integer induction var",
-          "integer loop induction variable could not be identified",
-          "NoIntegerInductionVariable");
-      return false;
-    } else {
-      LLVM_DEBUG(dbgs() << "LV: Did not find one integer induction var.\n");
-    }
-  }
-
-  // Now we know the widest induction type, check if our found induction
-  // is the same size. If it's not, unset it here and InnerLoopVectorizer
-  // will create another.
-  if (PrimaryInduction && WidestIndTy != PrimaryInduction->getType())
-    PrimaryInduction = nullptr;
-
-  return true;
-}
-
-bool LoopVectorizationLegality::canVectorizeMemory() {
-  LAI = &(*GetLAA)(*TheLoop);
-  const OptimizationRemarkAnalysis *LAR = LAI->getReport();
-  if (LAR) {
-    ORE->emit([&]() {
-      return OptimizationRemarkAnalysis(Hints->vectorizeAnalysisPassName(),
-                                        "loop not vectorized: ", *LAR);
-    });
-  }
-  if (!LAI->canVectorizeMemory())
-    return false;
-
-  if (LAI->hasDependenceInvolvingLoopInvariantAddress()) {
-    reportVectorizationFailure("Stores to a uniform address",
-        "write to a loop invariant address could not be vectorized",
-        "CantVectorizeStoreToLoopInvariantAddress");
-    return false;
-  }
-  Requirements->addRuntimePointerChecks(LAI->getNumRuntimePointerChecks());
-  PSE.addPredicate(LAI->getPSE().getUnionPredicate());
-
-  return true;
-}
-
-bool LoopVectorizationLegality::isInductionPhi(const Value *V) {
-  Value *In0 = const_cast<Value *>(V);
-  PHINode *PN = dyn_cast_or_null<PHINode>(In0);
-  if (!PN)
-    return false;
-
-  return Inductions.count(PN);
-}
-
-bool LoopVectorizationLegality::isCastedInductionVariable(const Value *V) {
-  auto *Inst = dyn_cast<Instruction>(V);
-  return (Inst && InductionCastsToIgnore.count(Inst));
-}
-
-bool LoopVectorizationLegality::isInductionVariable(const Value *V) {
-  return isInductionPhi(V) || isCastedInductionVariable(V);
-}
-
-bool LoopVectorizationLegality::isFirstOrderRecurrence(const PHINode *Phi) {
-  return FirstOrderRecurrences.count(Phi);
-}
-
-bool LoopVectorizationLegality::blockNeedsPredication(BasicBlock *BB) {
-  return LoopAccessInfo::blockNeedsPredication(BB, TheLoop, DT);
-}
-
-bool LoopVectorizationLegality::blockCanBePredicated(
-    BasicBlock *BB, SmallPtrSetImpl<Value *> &SafePtrs) {
-  const bool IsAnnotatedParallel = TheLoop->isAnnotatedParallel();
-
-  for (Instruction &I : *BB) {
-    // Check that we don't have a constant expression that can trap as operand.
-    for (Value *Operand : I.operands()) {
-      if (auto *C = dyn_cast<Constant>(Operand))
-        if (C->canTrap())
-          return false;
-    }
-    // We might be able to hoist the load.
-    if (I.mayReadFromMemory()) {
-      auto *LI = dyn_cast<LoadInst>(&I);
-      if (!LI)
-        return false;
-      if (!SafePtrs.count(LI->getPointerOperand())) {
-        // !llvm.mem.parallel_loop_access implies if-conversion safety.
-        // Otherwise, record that the load needs (real or emulated) masking
-        // and let the cost model decide.
-        if (!IsAnnotatedParallel)
-          MaskedOp.insert(LI);
-        continue;
-      }
-    }
-
-    if (I.mayWriteToMemory()) {
-      auto *SI = dyn_cast<StoreInst>(&I);
-      if (!SI)
-        return false;
-      // Predicated store requires some form of masking:
-      // 1) masked store HW instruction,
-      // 2) emulation via load-blend-store (only if safe and legal to do so,
-      //    be aware on the race conditions), or
-      // 3) element-by-element predicate check and scalar store.
-      MaskedOp.insert(SI);
-      continue;
-    }
-    if (I.mayThrow())
-      return false;
-  }
-
-  return true;
-}
-
-bool LoopVectorizationLegality::canVectorizeWithIfConvert() {
-  if (!EnableIfConversion) {
-    reportVectorizationFailure("If-conversion is disabled",
-                               "if-conversion is disabled",
-                               "IfConversionDisabled");
-    return false;
-  }
-
-  assert(TheLoop->getNumBlocks() > 1 && "Single block loops are vectorizable");
-
-  // A list of pointers that we can safely read and write to.
-  SmallPtrSet<Value *, 8> SafePointes;
-
-  // Collect safe addresses.
-  for (BasicBlock *BB : TheLoop->blocks()) {
-    if (blockNeedsPredication(BB))
-      continue;
-
-    for (Instruction &I : *BB)
-      if (auto *Ptr = getLoadStorePointerOperand(&I))
-        SafePointes.insert(Ptr);
-  }
-
-  // Collect the blocks that need predication.
-  BasicBlock *Header = TheLoop->getHeader();
-  for (BasicBlock *BB : TheLoop->blocks()) {
-    // We don't support switch statements inside loops.
-    if (!isa<BranchInst>(BB->getTerminator())) {
-      reportVectorizationFailure("Loop contains a switch statement",
-                                 "loop contains a switch statement",
-                                 "LoopContainsSwitch", BB->getTerminator());
-      return false;
-    }
-
-    // We must be able to predicate all blocks that need to be predicated.
-    if (blockNeedsPredication(BB)) {
-      if (!blockCanBePredicated(BB, SafePointes)) {
-        reportVectorizationFailure(
-            "Control flow cannot be substituted for a select",
-            "control flow cannot be substituted for a select",
-            "NoCFGForSelect", BB->getTerminator());
-        return false;
-      }
-    } else if (BB != Header && !canIfConvertPHINodes(BB)) {
-      reportVectorizationFailure(
-          "Control flow cannot be substituted for a select",
-          "control flow cannot be substituted for a select",
-          "NoCFGForSelect", BB->getTerminator());
-      return false;
-    }
-  }
-
-  // We can if-convert this loop.
-  return true;
-}
-
-// Helper function to canVectorizeLoopNestCFG.
-bool LoopVectorizationLegality::canVectorizeLoopCFG(Loop *Lp,
-                                                    bool UseVPlanNativePath) {
-  assert((UseVPlanNativePath || Lp->empty()) &&
-         "VPlan-native path is not enabled.");
-
-  // TODO: ORE should be improved to show more accurate information when an
-  // outer loop can't be vectorized because a nested loop is not understood or
-  // legal. Something like: "outer_loop_location: loop not vectorized:
-  // (inner_loop_location) loop control flow is not understood by vectorizer".
-
-  // Store the result and return it at the end instead of exiting early, in case
-  // allowExtraAnalysis is used to report multiple reasons for not vectorizing.
-  bool Result = true;
-  bool DoExtraAnalysis = ORE->allowExtraAnalysis(DEBUG_TYPE);
-
-  // We must have a loop in canonical form. Loops with indirectbr in them cannot
-  // be canonicalized.
-  if (!Lp->getLoopPreheader()) {
-    reportVectorizationFailure("Loop doesn't have a legal pre-header",
-        "loop control flow is not understood by vectorizer",
-        "CFGNotUnderstood");
-    if (DoExtraAnalysis)
-      Result = false;
-    else
-      return false;
-  }
-
-  // We must have a single backedge.
-  if (Lp->getNumBackEdges() != 1) {
-    reportVectorizationFailure("The loop must have a single backedge",
-        "loop control flow is not understood by vectorizer",
-        "CFGNotUnderstood");
-    if (DoExtraAnalysis)
-      Result = false;
-    else
-      return false;
-  }
-
-  // We must have a single exiting block.
-  if (!Lp->getExitingBlock()) {
-    reportVectorizationFailure("The loop must have an exiting block",
-        "loop control flow is not understood by vectorizer",
-        "CFGNotUnderstood");
-    if (DoExtraAnalysis)
-      Result = false;
-    else
-      return false;
-  }
-
-  // We only handle bottom-tested loops, i.e. loop in which the condition is
-  // checked at the end of each iteration. With that we can assume that all
-  // instructions in the loop are executed the same number of times.
-  if (Lp->getExitingBlock() != Lp->getLoopLatch()) {
-    reportVectorizationFailure("The exiting block is not the loop latch",
-        "loop control flow is not understood by vectorizer",
-        "CFGNotUnderstood");
-    if (DoExtraAnalysis)
-      Result = false;
-    else
-      return false;
-  }
-
-  return Result;
-}
-
-bool LoopVectorizationLegality::canVectorizeLoopNestCFG(
-    Loop *Lp, bool UseVPlanNativePath) {
-  // Store the result and return it at the end instead of exiting early, in case
-  // allowExtraAnalysis is used to report multiple reasons for not vectorizing.
-  bool Result = true;
-  bool DoExtraAnalysis = ORE->allowExtraAnalysis(DEBUG_TYPE);
-  if (!canVectorizeLoopCFG(Lp, UseVPlanNativePath)) {
-    if (DoExtraAnalysis)
-      Result = false;
-    else
-      return false;
-  }
-
-  // Recursively check whether the loop control flow of nested loops is
-  // understood.
-  for (Loop *SubLp : *Lp)
-    if (!canVectorizeLoopNestCFG(SubLp, UseVPlanNativePath)) {
-      if (DoExtraAnalysis)
-        Result = false;
-      else
-        return false;
-    }
-
-  return Result;
-}
-
-bool LoopVectorizationLegality::canVectorize(bool UseVPlanNativePath) {
-  // Store the result and return it at the end instead of exiting early, in case
-  // allowExtraAnalysis is used to report multiple reasons for not vectorizing.
-  bool Result = true;
-
-  bool DoExtraAnalysis = ORE->allowExtraAnalysis(DEBUG_TYPE);
-  // Check whether the loop-related control flow in the loop nest is expected by
-  // vectorizer.
-  if (!canVectorizeLoopNestCFG(TheLoop, UseVPlanNativePath)) {
-    if (DoExtraAnalysis)
-      Result = false;
-    else
-      return false;
-  }
-
-  // We need to have a loop header.
-  LLVM_DEBUG(dbgs() << "LV: Found a loop: " << TheLoop->getHeader()->getName()
-                    << '\n');
-
-  // Specific checks for outer loops. We skip the remaining legal checks at this
-  // point because they don't support outer loops.
-  if (!TheLoop->empty()) {
-    assert(UseVPlanNativePath && "VPlan-native path is not enabled.");
-
-    if (!canVectorizeOuterLoop()) {
-      reportVectorizationFailure("Unsupported outer loop",
-                                 "unsupported outer loop",
-                                 "UnsupportedOuterLoop");
-      // TODO: Implement DoExtraAnalysis when subsequent legal checks support
-      // outer loops.
-      return false;
-    }
-
-    LLVM_DEBUG(dbgs() << "LV: We can vectorize this outer loop!\n");
-    return Result;
-  }
-
-  assert(TheLoop->empty() && "Inner loop expected.");
-  // Check if we can if-convert non-single-bb loops.
-  unsigned NumBlocks = TheLoop->getNumBlocks();
-  if (NumBlocks != 1 && !canVectorizeWithIfConvert()) {
-    LLVM_DEBUG(dbgs() << "LV: Can't if-convert the loop.\n");
-    if (DoExtraAnalysis)
-      Result = false;
-    else
-      return false;
-  }
-
-  // Check if we can vectorize the instructions and CFG in this loop.
-  if (!canVectorizeInstrs()) {
-    LLVM_DEBUG(dbgs() << "LV: Can't vectorize the instructions or CFG\n");
-    if (DoExtraAnalysis)
-      Result = false;
-    else
-      return false;
-  }
-
-  // Go over each instruction and look at memory deps.
-  if (!canVectorizeMemory()) {
-    LLVM_DEBUG(dbgs() << "LV: Can't vectorize due to memory conflicts\n");
-    if (DoExtraAnalysis)
-      Result = false;
-    else
-      return false;
-  }
-
-  LLVM_DEBUG(dbgs() << "LV: We can vectorize this loop"
-                    << (LAI->getRuntimePointerChecking()->Need
-                            ? " (with a runtime bound check)"
-                            : "")
-                    << "!\n");
-
-  unsigned SCEVThreshold = VectorizeSCEVCheckThreshold;
-  if (Hints->getForce() == LoopVectorizeHints::FK_Enabled)
-    SCEVThreshold = PragmaVectorizeSCEVCheckThreshold;
-
-  if (PSE.getUnionPredicate().getComplexity() > SCEVThreshold) {
-    reportVectorizationFailure("Too many SCEV checks needed",
-        "Too many SCEV assumptions need to be made and checked at runtime",
-        "TooManySCEVRunTimeChecks");
-    if (DoExtraAnalysis)
-      Result = false;
-    else
-      return false;
-  }
-
-  // Okay! We've done all the tests. If any have failed, return false. Otherwise
-  // we can vectorize, and 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 Result;
-}
-
-bool LoopVectorizationLegality::canFoldTailByMasking() {
-
-  LLVM_DEBUG(dbgs() << "LV: checking if tail can be folded by masking.\n");
-
-  if (!PrimaryInduction) {
-    reportVectorizationFailure(
-        "No primary induction, cannot fold tail by masking",
-        "Missing a primary induction variable in the loop, which is "
-        "needed in order to fold tail by masking as required.",
-        "NoPrimaryInduction");
-    return false;
-  }
-
-  // TODO: handle reductions when tail is folded by masking.
-  if (!Reductions.empty()) {
-    reportVectorizationFailure(
-        "Loop has reductions, cannot fold tail by masking",
-        "Cannot fold tail by masking in the presence of reductions.",
-        "ReductionFoldingTailByMasking");
-    return false;
-  }
-
-  // TODO: handle outside users when tail is folded by masking.
-  for (auto *AE : AllowedExit) {
-    // Check that all users of allowed exit values are inside the loop.
-    for (User *U : AE->users()) {
-      Instruction *UI = cast<Instruction>(U);
-      if (TheLoop->contains(UI))
-        continue;
-      reportVectorizationFailure(
-          "Cannot fold tail by masking, loop has an outside user for",
-          "Cannot fold tail by masking in the presence of live outs.",
-          "LiveOutFoldingTailByMasking", UI);
-      return false;
-    }
-  }
-
-  // The list of pointers that we can safely read and write to remains empty.
-  SmallPtrSet<Value *, 8> SafePointers;
-
-  // Check and mark all blocks for predication, including those that ordinarily
-  // do not need predication such as the header block.
-  for (BasicBlock *BB : TheLoop->blocks()) {
-    if (!blockCanBePredicated(BB, SafePointers)) {
-      reportVectorizationFailure(
-          "Cannot fold tail by masking as required",
-          "control flow cannot be substituted for a select",
-          "NoCFGForSelect", BB->getTerminator());
-      return false;
-    }
-  }
-
-  LLVM_DEBUG(dbgs() << "LV: can fold tail by masking.\n");
-  return true;
-}
-
-} // namespace llvm