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Со стороны dqrun можно обратиться к инстансу коннектора, который работает на streaming стенде, и извлечь данные из облачного CH.

1 files changed, 650 insertions, 0 deletions

diff --git a/contrib/libs/llvm16/lib/Transforms/Scalar/LoopVersioningLICM.cpp b/contrib/libs/llvm16/lib/Transforms/Scalar/LoopVersioningLICM.cpp
new file mode 100644
index 0000000000..848be25a2f
--- /dev/null
+++ b/contrib/libs/llvm16/lib/Transforms/Scalar/LoopVersioningLICM.cpp
@@ -0,0 +1,650 @@
+//===- LoopVersioningLICM.cpp - LICM Loop Versioning ----------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// When alias analysis is uncertain about the aliasing between any two accesses,
+// it will return MayAlias. This uncertainty from alias analysis restricts LICM
+// from proceeding further. In cases where alias analysis is uncertain we might
+// use loop versioning as an alternative.
+//
+// Loop Versioning will create a version of the loop with aggressive aliasing
+// assumptions in addition to the original with conservative (default) aliasing
+// assumptions. The version of the loop making aggressive aliasing assumptions
+// will have all the memory accesses marked as no-alias. These two versions of
+// loop will be preceded by a memory runtime check. This runtime check consists
+// of bound checks for all unique memory accessed in loop, and it ensures the
+// lack of memory aliasing. The result of the runtime check determines which of
+// the loop versions is executed: If the runtime check detects any memory
+// aliasing, then the original loop is executed. Otherwise, the version with
+// aggressive aliasing assumptions is used.
+//
+// Following are the top level steps:
+//
+// a) Perform LoopVersioningLICM's feasibility check.
+// b) If loop is a candidate for versioning then create a memory bound check,
+//    by considering all the memory accesses in loop body.
+// c) Clone original loop and set all memory accesses as no-alias in new loop.
+// d) Set original loop & versioned loop as a branch target of the runtime check
+//    result.
+//
+// It transforms loop as shown below:
+//
+//                         +----------------+
+//                         |Runtime Memcheck|
+//                         +----------------+
+//                                 |
+//              +----------+----------------+----------+
+//              |                                      |
+//    +---------+----------+               +-----------+----------+
+//    |Orig Loop Preheader |               |Cloned Loop Preheader |
+//    +--------------------+               +----------------------+
+//              |                                      |
+//    +--------------------+               +----------------------+
+//    |Orig Loop Body      |               |Cloned Loop Body      |
+//    +--------------------+               +----------------------+
+//              |                                      |
+//    +--------------------+               +----------------------+
+//    |Orig Loop Exit Block|               |Cloned Loop Exit Block|
+//    +--------------------+               +-----------+----------+
+//              |                                      |
+//              +----------+--------------+-----------+
+//                                 |
+//                           +-----+----+
+//                           |Join Block|
+//                           +----------+
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Scalar/LoopVersioningLICM.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Analysis/AliasSetTracker.h"
+#include "llvm/Analysis/GlobalsModRef.h"
+#include "llvm/Analysis/LoopAccessAnalysis.h"
+#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/LoopPass.h"
+#include "llvm/Analysis/OptimizationRemarkEmitter.h"
+#include "llvm/Analysis/ScalarEvolution.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/MDBuilder.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/IR/Value.h"
+#include "llvm/InitializePasses.h"
+#include "llvm/Pass.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils.h"
+#include "llvm/Transforms/Utils/LoopUtils.h"
+#include "llvm/Transforms/Utils/LoopVersioning.h"
+#include <cassert>
+#include <memory>
+
+using namespace llvm;
+
+#define DEBUG_TYPE "loop-versioning-licm"
+
+static const char *LICMVersioningMetaData = "llvm.loop.licm_versioning.disable";
+
+/// Threshold minimum allowed percentage for possible
+/// invariant instructions in a loop.
+static cl::opt<float>
+    LVInvarThreshold("licm-versioning-invariant-threshold",
+                     cl::desc("LoopVersioningLICM's minimum allowed percentage"
+                              "of possible invariant instructions per loop"),
+                     cl::init(25), cl::Hidden);
+
+/// Threshold for maximum allowed loop nest/depth
+static cl::opt<unsigned> LVLoopDepthThreshold(
+    "licm-versioning-max-depth-threshold",
+    cl::desc(
+        "LoopVersioningLICM's threshold for maximum allowed loop nest/depth"),
+    cl::init(2), cl::Hidden);
+
+namespace {
+
+struct LoopVersioningLICMLegacyPass : public LoopPass {
+  static char ID;
+
+  LoopVersioningLICMLegacyPass() : LoopPass(ID) {
+    initializeLoopVersioningLICMLegacyPassPass(
+        *PassRegistry::getPassRegistry());
+  }
+
+  bool runOnLoop(Loop *L, LPPassManager &LPM) override;
+
+  StringRef getPassName() const override { return "Loop Versioning for LICM"; }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesCFG();
+    AU.addRequired<AAResultsWrapperPass>();
+    AU.addRequired<DominatorTreeWrapperPass>();
+    AU.addRequiredID(LCSSAID);
+    AU.addRequired<LoopAccessLegacyAnalysis>();
+    AU.addRequired<LoopInfoWrapperPass>();
+    AU.addRequiredID(LoopSimplifyID);
+    AU.addRequired<ScalarEvolutionWrapperPass>();
+    AU.addPreserved<AAResultsWrapperPass>();
+    AU.addPreserved<GlobalsAAWrapperPass>();
+    AU.addRequired<OptimizationRemarkEmitterWrapperPass>();
+  }
+};
+
+struct LoopVersioningLICM {
+  // We don't explicitly pass in LoopAccessInfo to the constructor since the
+  // loop versioning might return early due to instructions that are not safe
+  // for versioning. By passing the proxy instead the construction of
+  // LoopAccessInfo will take place only when it's necessary.
+  LoopVersioningLICM(AliasAnalysis *AA, ScalarEvolution *SE,
+                     OptimizationRemarkEmitter *ORE,
+                     LoopAccessInfoManager &LAIs, LoopInfo &LI,
+                     Loop *CurLoop)
+      : AA(AA), SE(SE), LAIs(LAIs), LI(LI), CurLoop(CurLoop),
+        LoopDepthThreshold(LVLoopDepthThreshold),
+        InvariantThreshold(LVInvarThreshold), ORE(ORE) {}
+
+  bool run(DominatorTree *DT);
+
+private:
+  // Current AliasAnalysis information
+  AliasAnalysis *AA;
+
+  // Current ScalarEvolution
+  ScalarEvolution *SE;
+
+  // Current Loop's LoopAccessInfo
+  const LoopAccessInfo *LAI = nullptr;
+
+  // Proxy for retrieving LoopAccessInfo.
+  LoopAccessInfoManager &LAIs;
+
+  LoopInfo &LI;
+
+  // The current loop we are working on.
+  Loop *CurLoop;
+
+  // Maximum loop nest threshold
+  unsigned LoopDepthThreshold;
+
+  // Minimum invariant threshold
+  float InvariantThreshold;
+
+  // Counter to track num of load & store
+  unsigned LoadAndStoreCounter = 0;
+
+  // Counter to track num of invariant
+  unsigned InvariantCounter = 0;
+
+  // Read only loop marker.
+  bool IsReadOnlyLoop = true;
+
+  // OptimizationRemarkEmitter
+  OptimizationRemarkEmitter *ORE;
+
+  bool isLegalForVersioning();
+  bool legalLoopStructure();
+  bool legalLoopInstructions();
+  bool legalLoopMemoryAccesses();
+  bool isLoopAlreadyVisited();
+  void setNoAliasToLoop(Loop *VerLoop);
+  bool instructionSafeForVersioning(Instruction *I);
+};
+
+} // end anonymous namespace
+
+/// Check loop structure and confirms it's good for LoopVersioningLICM.
+bool LoopVersioningLICM::legalLoopStructure() {
+  // Loop must be in loop simplify form.
+  if (!CurLoop->isLoopSimplifyForm()) {
+    LLVM_DEBUG(dbgs() << "    loop is not in loop-simplify form.\n");
+    return false;
+  }
+  // Loop should be innermost loop, if not return false.
+  if (!CurLoop->getSubLoops().empty()) {
+    LLVM_DEBUG(dbgs() << "    loop is not innermost\n");
+    return false;
+  }
+  // Loop should have a single backedge, if not return false.
+  if (CurLoop->getNumBackEdges() != 1) {
+    LLVM_DEBUG(dbgs() << "    loop has multiple backedges\n");
+    return false;
+  }
+  // Loop must have a single exiting block, if not return false.
+  if (!CurLoop->getExitingBlock()) {
+    LLVM_DEBUG(dbgs() << "    loop has multiple exiting block\n");
+    return false;
+  }
+  // We only handle bottom-tested loop, 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 (CurLoop->getExitingBlock() != CurLoop->getLoopLatch()) {
+    LLVM_DEBUG(dbgs() << "    loop is not bottom tested\n");
+    return false;
+  }
+  // Parallel loops must not have aliasing loop-invariant memory accesses.
+  // Hence we don't need to version anything in this case.
+  if (CurLoop->isAnnotatedParallel()) {
+    LLVM_DEBUG(dbgs() << "    Parallel loop is not worth versioning\n");
+    return false;
+  }
+  // Loop depth more then LoopDepthThreshold are not allowed
+  if (CurLoop->getLoopDepth() > LoopDepthThreshold) {
+    LLVM_DEBUG(dbgs() << "    loop depth is more then threshold\n");
+    return false;
+  }
+  // We need to be able to compute the loop trip count in order
+  // to generate the bound checks.
+  const SCEV *ExitCount = SE->getBackedgeTakenCount(CurLoop);
+  if (isa<SCEVCouldNotCompute>(ExitCount)) {
+    LLVM_DEBUG(dbgs() << "    loop does not has trip count\n");
+    return false;
+  }
+  return true;
+}
+
+/// Check memory accesses in loop and confirms it's good for
+/// LoopVersioningLICM.
+bool LoopVersioningLICM::legalLoopMemoryAccesses() {
+  // Loop over the body of this loop, construct AST.
+  BatchAAResults BAA(*AA);
+  AliasSetTracker AST(BAA);
+  for (auto *Block : CurLoop->getBlocks()) {
+    // Ignore blocks in subloops.
+    if (LI.getLoopFor(Block) == CurLoop)
+      AST.add(*Block);
+  }
+
+  // Memory check:
+  // Transform phase will generate a versioned loop and also a runtime check to
+  // ensure the pointers are independent and they don’t alias.
+  // In version variant of loop, alias meta data asserts that all access are
+  // mutually independent.
+  //
+  // Pointers aliasing in alias domain are avoided because with multiple
+  // aliasing domains we may not be able to hoist potential loop invariant
+  // access out of the loop.
+  //
+  // Iterate over alias tracker sets, and confirm AliasSets doesn't have any
+  // must alias set.
+  bool HasMayAlias = false;
+  bool TypeSafety = false;
+  bool HasMod = false;
+  for (const auto &I : AST) {
+    const AliasSet &AS = I;
+    // Skip Forward Alias Sets, as this should be ignored as part of
+    // the AliasSetTracker object.
+    if (AS.isForwardingAliasSet())
+      continue;
+    // With MustAlias its not worth adding runtime bound check.
+    if (AS.isMustAlias())
+      return false;
+    Value *SomePtr = AS.begin()->getValue();
+    bool TypeCheck = true;
+    // Check for Mod & MayAlias
+    HasMayAlias |= AS.isMayAlias();
+    HasMod |= AS.isMod();
+    for (const auto &A : AS) {
+      Value *Ptr = A.getValue();
+      // Alias tracker should have pointers of same data type.
+      TypeCheck = (TypeCheck && (SomePtr->getType() == Ptr->getType()));
+    }
+    // At least one alias tracker should have pointers of same data type.
+    TypeSafety |= TypeCheck;
+  }
+  // Ensure types should be of same type.
+  if (!TypeSafety) {
+    LLVM_DEBUG(dbgs() << "    Alias tracker type safety failed!\n");
+    return false;
+  }
+  // Ensure loop body shouldn't be read only.
+  if (!HasMod) {
+    LLVM_DEBUG(dbgs() << "    No memory modified in loop body\n");
+    return false;
+  }
+  // Make sure alias set has may alias case.
+  // If there no alias memory ambiguity, return false.
+  if (!HasMayAlias) {
+    LLVM_DEBUG(dbgs() << "    No ambiguity in memory access.\n");
+    return false;
+  }
+  return true;
+}
+
+/// Check loop instructions safe for Loop versioning.
+/// It returns true if it's safe else returns false.
+/// Consider following:
+/// 1) Check all load store in loop body are non atomic & non volatile.
+/// 2) Check function call safety, by ensuring its not accessing memory.
+/// 3) Loop body shouldn't have any may throw instruction.
+/// 4) Loop body shouldn't have any convergent or noduplicate instructions.
+bool LoopVersioningLICM::instructionSafeForVersioning(Instruction *I) {
+  assert(I != nullptr && "Null instruction found!");
+  // Check function call safety
+  if (auto *Call = dyn_cast<CallBase>(I)) {
+    if (Call->isConvergent() || Call->cannotDuplicate()) {
+      LLVM_DEBUG(dbgs() << "    Convergent call site found.\n");
+      return false;
+    }
+
+    if (!AA->doesNotAccessMemory(Call)) {
+      LLVM_DEBUG(dbgs() << "    Unsafe call site found.\n");
+      return false;
+    }
+  }
+
+  // Avoid loops with possiblity of throw
+  if (I->mayThrow()) {
+    LLVM_DEBUG(dbgs() << "    May throw instruction found in loop body\n");
+    return false;
+  }
+  // If current instruction is load instructions
+  // make sure it's a simple load (non atomic & non volatile)
+  if (I->mayReadFromMemory()) {
+    LoadInst *Ld = dyn_cast<LoadInst>(I);
+    if (!Ld || !Ld->isSimple()) {
+      LLVM_DEBUG(dbgs() << "    Found a non-simple load.\n");
+      return false;
+    }
+    LoadAndStoreCounter++;
+    Value *Ptr = Ld->getPointerOperand();
+    // Check loop invariant.
+    if (SE->isLoopInvariant(SE->getSCEV(Ptr), CurLoop))
+      InvariantCounter++;
+  }
+  // If current instruction is store instruction
+  // make sure it's a simple store (non atomic & non volatile)
+  else if (I->mayWriteToMemory()) {
+    StoreInst *St = dyn_cast<StoreInst>(I);
+    if (!St || !St->isSimple()) {
+      LLVM_DEBUG(dbgs() << "    Found a non-simple store.\n");
+      return false;
+    }
+    LoadAndStoreCounter++;
+    Value *Ptr = St->getPointerOperand();
+    // Check loop invariant.
+    if (SE->isLoopInvariant(SE->getSCEV(Ptr), CurLoop))
+      InvariantCounter++;
+
+    IsReadOnlyLoop = false;
+  }
+  return true;
+}
+
+/// Check loop instructions and confirms it's good for
+/// LoopVersioningLICM.
+bool LoopVersioningLICM::legalLoopInstructions() {
+  // Resetting counters.
+  LoadAndStoreCounter = 0;
+  InvariantCounter = 0;
+  IsReadOnlyLoop = true;
+  using namespace ore;
+  // Iterate over loop blocks and instructions of each block and check
+  // instruction safety.
+  for (auto *Block : CurLoop->getBlocks())
+    for (auto &Inst : *Block) {
+      // If instruction is unsafe just return false.
+      if (!instructionSafeForVersioning(&Inst)) {
+        ORE->emit([&]() {
+          return OptimizationRemarkMissed(DEBUG_TYPE, "IllegalLoopInst", &Inst)
+                 << " Unsafe Loop Instruction";
+        });
+        return false;
+      }
+    }
+  // Get LoopAccessInfo from current loop via the proxy.
+  LAI = &LAIs.getInfo(*CurLoop);
+  // Check LoopAccessInfo for need of runtime check.
+  if (LAI->getRuntimePointerChecking()->getChecks().empty()) {
+    LLVM_DEBUG(dbgs() << "    LAA: Runtime check not found !!\n");
+    return false;
+  }
+  // Number of runtime-checks should be less then RuntimeMemoryCheckThreshold
+  if (LAI->getNumRuntimePointerChecks() >
+      VectorizerParams::RuntimeMemoryCheckThreshold) {
+    LLVM_DEBUG(
+        dbgs() << "    LAA: Runtime checks are more than threshold !!\n");
+    ORE->emit([&]() {
+      return OptimizationRemarkMissed(DEBUG_TYPE, "RuntimeCheck",
+                                      CurLoop->getStartLoc(),
+                                      CurLoop->getHeader())
+             << "Number of runtime checks "
+             << NV("RuntimeChecks", LAI->getNumRuntimePointerChecks())
+             << " exceeds threshold "
+             << NV("Threshold", VectorizerParams::RuntimeMemoryCheckThreshold);
+    });
+    return false;
+  }
+  // Loop should have at least one invariant load or store instruction.
+  if (!InvariantCounter) {
+    LLVM_DEBUG(dbgs() << "    Invariant not found !!\n");
+    return false;
+  }
+  // Read only loop not allowed.
+  if (IsReadOnlyLoop) {
+    LLVM_DEBUG(dbgs() << "    Found a read-only loop!\n");
+    return false;
+  }
+  // Profitablity check:
+  // Check invariant threshold, should be in limit.
+  if (InvariantCounter * 100 < InvariantThreshold * LoadAndStoreCounter) {
+    LLVM_DEBUG(
+        dbgs()
+        << "    Invariant load & store are less then defined threshold\n");
+    LLVM_DEBUG(dbgs() << "    Invariant loads & stores: "
+                      << ((InvariantCounter * 100) / LoadAndStoreCounter)
+                      << "%\n");
+    LLVM_DEBUG(dbgs() << "    Invariant loads & store threshold: "
+                      << InvariantThreshold << "%\n");
+    ORE->emit([&]() {
+      return OptimizationRemarkMissed(DEBUG_TYPE, "InvariantThreshold",
+                                      CurLoop->getStartLoc(),
+                                      CurLoop->getHeader())
+             << "Invariant load & store "
+             << NV("LoadAndStoreCounter",
+                   ((InvariantCounter * 100) / LoadAndStoreCounter))
+             << " are less then defined threshold "
+             << NV("Threshold", InvariantThreshold);
+    });
+    return false;
+  }
+  return true;
+}
+
+/// It checks loop is already visited or not.
+/// check loop meta data, if loop revisited return true
+/// else false.
+bool LoopVersioningLICM::isLoopAlreadyVisited() {
+  // Check LoopVersioningLICM metadata into loop
+  if (findStringMetadataForLoop(CurLoop, LICMVersioningMetaData)) {
+    return true;
+  }
+  return false;
+}
+
+/// Checks legality for LoopVersioningLICM by considering following:
+/// a) loop structure legality   b) loop instruction legality
+/// c) loop memory access legality.
+/// Return true if legal else returns false.
+bool LoopVersioningLICM::isLegalForVersioning() {
+  using namespace ore;
+  LLVM_DEBUG(dbgs() << "Loop: " << *CurLoop);
+  // Make sure not re-visiting same loop again.
+  if (isLoopAlreadyVisited()) {
+    LLVM_DEBUG(
+        dbgs() << "    Revisiting loop in LoopVersioningLICM not allowed.\n\n");
+    return false;
+  }
+  // Check loop structure leagality.
+  if (!legalLoopStructure()) {
+    LLVM_DEBUG(
+        dbgs() << "    Loop structure not suitable for LoopVersioningLICM\n\n");
+    ORE->emit([&]() {
+      return OptimizationRemarkMissed(DEBUG_TYPE, "IllegalLoopStruct",
+                                      CurLoop->getStartLoc(),
+                                      CurLoop->getHeader())
+             << " Unsafe Loop structure";
+    });
+    return false;
+  }
+  // Check loop instruction leagality.
+  if (!legalLoopInstructions()) {
+    LLVM_DEBUG(
+        dbgs()
+        << "    Loop instructions not suitable for LoopVersioningLICM\n\n");
+    return false;
+  }
+  // Check loop memory access leagality.
+  if (!legalLoopMemoryAccesses()) {
+    LLVM_DEBUG(
+        dbgs()
+        << "    Loop memory access not suitable for LoopVersioningLICM\n\n");
+    ORE->emit([&]() {
+      return OptimizationRemarkMissed(DEBUG_TYPE, "IllegalLoopMemoryAccess",
+                                      CurLoop->getStartLoc(),
+                                      CurLoop->getHeader())
+             << " Unsafe Loop memory access";
+    });
+    return false;
+  }
+  // Loop versioning is feasible, return true.
+  LLVM_DEBUG(dbgs() << "    Loop Versioning found to be beneficial\n\n");
+  ORE->emit([&]() {
+    return OptimizationRemark(DEBUG_TYPE, "IsLegalForVersioning",
+                              CurLoop->getStartLoc(), CurLoop->getHeader())
+           << " Versioned loop for LICM."
+           << " Number of runtime checks we had to insert "
+           << NV("RuntimeChecks", LAI->getNumRuntimePointerChecks());
+  });
+  return true;
+}
+
+/// Update loop with aggressive aliasing assumptions.
+/// It marks no-alias to any pairs of memory operations by assuming
+/// loop should not have any must-alias memory accesses pairs.
+/// During LoopVersioningLICM legality we ignore loops having must
+/// aliasing memory accesses.
+void LoopVersioningLICM::setNoAliasToLoop(Loop *VerLoop) {
+  // Get latch terminator instruction.
+  Instruction *I = VerLoop->getLoopLatch()->getTerminator();
+  // Create alias scope domain.
+  MDBuilder MDB(I->getContext());
+  MDNode *NewDomain = MDB.createAnonymousAliasScopeDomain("LVDomain");
+  StringRef Name = "LVAliasScope";
+  MDNode *NewScope = MDB.createAnonymousAliasScope(NewDomain, Name);
+  SmallVector<Metadata *, 4> Scopes{NewScope}, NoAliases{NewScope};
+  // Iterate over each instruction of loop.
+  // set no-alias for all load & store instructions.
+  for (auto *Block : CurLoop->getBlocks()) {
+    for (auto &Inst : *Block) {
+      // Only interested in instruction that may modify or read memory.
+      if (!Inst.mayReadFromMemory() && !Inst.mayWriteToMemory())
+        continue;
+      // Set no-alias for current instruction.
+      Inst.setMetadata(
+          LLVMContext::MD_noalias,
+          MDNode::concatenate(Inst.getMetadata(LLVMContext::MD_noalias),
+                              MDNode::get(Inst.getContext(), NoAliases)));
+      // set alias-scope for current instruction.
+      Inst.setMetadata(
+          LLVMContext::MD_alias_scope,
+          MDNode::concatenate(Inst.getMetadata(LLVMContext::MD_alias_scope),
+                              MDNode::get(Inst.getContext(), Scopes)));
+    }
+  }
+}
+
+bool LoopVersioningLICMLegacyPass::runOnLoop(Loop *L, LPPassManager &LPM) {
+  if (skipLoop(L))
+    return false;
+
+  AliasAnalysis *AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
+  ScalarEvolution *SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
+  OptimizationRemarkEmitter *ORE =
+      &getAnalysis<OptimizationRemarkEmitterWrapperPass>().getORE();
+  LoopInfo &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+  DominatorTree *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+  auto &LAIs = getAnalysis<LoopAccessLegacyAnalysis>().getLAIs();
+
+  return LoopVersioningLICM(AA, SE, ORE, LAIs, LI, L).run(DT);
+}
+
+bool LoopVersioningLICM::run(DominatorTree *DT) {
+  // Do not do the transformation if disabled by metadata.
+  if (hasLICMVersioningTransformation(CurLoop) & TM_Disable)
+    return false;
+
+  bool Changed = false;
+
+  // Check feasiblity of LoopVersioningLICM.
+  // If versioning found to be feasible and beneficial then proceed
+  // else simply return, by cleaning up memory.
+  if (isLegalForVersioning()) {
+    // Do loop versioning.
+    // Create memcheck for memory accessed inside loop.
+    // Clone original loop, and set blocks properly.
+    LoopVersioning LVer(*LAI, LAI->getRuntimePointerChecking()->getChecks(),
+                        CurLoop, &LI, DT, SE);
+    LVer.versionLoop();
+    // Set Loop Versioning metaData for original loop.
+    addStringMetadataToLoop(LVer.getNonVersionedLoop(), LICMVersioningMetaData);
+    // Set Loop Versioning metaData for version loop.
+    addStringMetadataToLoop(LVer.getVersionedLoop(), LICMVersioningMetaData);
+    // Set "llvm.mem.parallel_loop_access" metaData to versioned loop.
+    // FIXME: "llvm.mem.parallel_loop_access" annotates memory access
+    // instructions, not loops.
+    addStringMetadataToLoop(LVer.getVersionedLoop(),
+                            "llvm.mem.parallel_loop_access");
+    // Update version loop with aggressive aliasing assumption.
+    setNoAliasToLoop(LVer.getVersionedLoop());
+    Changed = true;
+  }
+  return Changed;
+}
+
+char LoopVersioningLICMLegacyPass::ID = 0;
+
+INITIALIZE_PASS_BEGIN(LoopVersioningLICMLegacyPass, "loop-versioning-licm",
+                      "Loop Versioning For LICM", false, false)
+INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(GlobalsAAWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(LCSSAWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(LoopAccessLegacyAnalysis)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(LoopSimplify)
+INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(OptimizationRemarkEmitterWrapperPass)
+INITIALIZE_PASS_END(LoopVersioningLICMLegacyPass, "loop-versioning-licm",
+                    "Loop Versioning For LICM", false, false)
+
+Pass *llvm::createLoopVersioningLICMPass() {
+  return new LoopVersioningLICMLegacyPass();
+}
+
+namespace llvm {
+
+PreservedAnalyses LoopVersioningLICMPass::run(Loop &L, LoopAnalysisManager &AM,
+                                              LoopStandardAnalysisResults &LAR,
+                                              LPMUpdater &U) {
+  AliasAnalysis *AA = &LAR.AA;
+  ScalarEvolution *SE = &LAR.SE;
+  DominatorTree *DT = &LAR.DT;
+  const Function *F = L.getHeader()->getParent();
+  OptimizationRemarkEmitter ORE(F);
+
+  LoopAccessInfoManager LAIs(*SE, *AA, *DT, LAR.LI, nullptr);
+  if (!LoopVersioningLICM(AA, SE, &ORE, LAIs, LAR.LI, &L).run(DT))
+    return PreservedAnalyses::all();
+  return getLoopPassPreservedAnalyses();
+}
+} // namespace llvm