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diff --git a/contrib/llvm-project/llvm/lib/Transforms/Scalar/LoopDataPrefetch.cpp b/contrib/llvm-project/llvm/lib/Transforms/Scalar/LoopDataPrefetch.cpp
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+++ b/contrib/llvm-project/llvm/lib/Transforms/Scalar/LoopDataPrefetch.cpp
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+//===-------- LoopDataPrefetch.cpp - Loop Data Prefetching Pass -----------===//
+//
+// 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 implements a Loop Data Prefetching Pass.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Scalar/LoopDataPrefetch.h"
+#include "llvm/InitializePasses.h"
+
+#define DEBUG_TYPE "loop-data-prefetch"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/AssumptionCache.h"
+#include "llvm/Analysis/CodeMetrics.h"
+#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/OptimizationRemarkEmitter.h"
+#include "llvm/Analysis/ScalarEvolution.h"
+#include "llvm/Analysis/ScalarEvolutionExpressions.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/IR/CFG.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/ScalarEvolutionExpander.h"
+#include "llvm/Transforms/Utils/ValueMapper.h"
+using namespace llvm;
+
+// By default, we limit this to creating 16 PHIs (which is a little over half
+// of the allocatable register set).
+static cl::opt<bool>
+PrefetchWrites("loop-prefetch-writes", cl::Hidden, cl::init(false),
+               cl::desc("Prefetch write addresses"));
+
+static cl::opt<unsigned>
+    PrefetchDistance("prefetch-distance",
+                     cl::desc("Number of instructions to prefetch ahead"),
+                     cl::Hidden);
+
+static cl::opt<unsigned>
+    MinPrefetchStride("min-prefetch-stride",
+                      cl::desc("Min stride to add prefetches"), cl::Hidden);
+
+static cl::opt<unsigned> MaxPrefetchIterationsAhead(
+    "max-prefetch-iters-ahead",
+    cl::desc("Max number of iterations to prefetch ahead"), cl::Hidden);
+
+STATISTIC(NumPrefetches, "Number of prefetches inserted");
+
+namespace {
+
+/// Loop prefetch implementation class.
+class LoopDataPrefetch {
+public:
+  LoopDataPrefetch(AssumptionCache *AC, DominatorTree *DT, LoopInfo *LI,
+                   ScalarEvolution *SE, const TargetTransformInfo *TTI,
+                   OptimizationRemarkEmitter *ORE)
+      : AC(AC), DT(DT), LI(LI), SE(SE), TTI(TTI), ORE(ORE) {}
+
+  bool run();
+
+private:
+  bool runOnLoop(Loop *L);
+
+  /// Check if the stride of the accesses is large enough to
+  /// warrant a prefetch.
+  bool isStrideLargeEnough(const SCEVAddRecExpr *AR, unsigned TargetMinStride);
+
+  unsigned getMinPrefetchStride(unsigned NumMemAccesses,
+                                unsigned NumStridedMemAccesses,
+                                unsigned NumPrefetches,
+                                bool HasCall) {
+    if (MinPrefetchStride.getNumOccurrences() > 0)
+      return MinPrefetchStride;
+    return TTI->getMinPrefetchStride(NumMemAccesses, NumStridedMemAccesses,
+                                     NumPrefetches, HasCall);
+  }
+
+  unsigned getPrefetchDistance() {
+    if (PrefetchDistance.getNumOccurrences() > 0)
+      return PrefetchDistance;
+    return TTI->getPrefetchDistance();
+  }
+
+  unsigned getMaxPrefetchIterationsAhead() {
+    if (MaxPrefetchIterationsAhead.getNumOccurrences() > 0)
+      return MaxPrefetchIterationsAhead;
+    return TTI->getMaxPrefetchIterationsAhead();
+  }
+
+  bool doPrefetchWrites() {
+    if (PrefetchWrites.getNumOccurrences() > 0)
+      return PrefetchWrites;
+    return TTI->enableWritePrefetching();
+  }
+
+  AssumptionCache *AC;
+  DominatorTree *DT;
+  LoopInfo *LI;
+  ScalarEvolution *SE;
+  const TargetTransformInfo *TTI;
+  OptimizationRemarkEmitter *ORE;
+};
+
+/// Legacy class for inserting loop data prefetches.
+class LoopDataPrefetchLegacyPass : public FunctionPass {
+public:
+  static char ID; // Pass ID, replacement for typeid
+  LoopDataPrefetchLegacyPass() : FunctionPass(ID) {
+    initializeLoopDataPrefetchLegacyPassPass(*PassRegistry::getPassRegistry());
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.addRequired<AssumptionCacheTracker>();
+    AU.addRequired<DominatorTreeWrapperPass>();
+    AU.addPreserved<DominatorTreeWrapperPass>();
+    AU.addRequired<LoopInfoWrapperPass>();
+    AU.addPreserved<LoopInfoWrapperPass>();
+    AU.addRequired<OptimizationRemarkEmitterWrapperPass>();
+    AU.addRequired<ScalarEvolutionWrapperPass>();
+    AU.addPreserved<ScalarEvolutionWrapperPass>();
+    AU.addRequired<TargetTransformInfoWrapperPass>();
+  }
+
+  bool runOnFunction(Function &F) override;
+  };
+}
+
+char LoopDataPrefetchLegacyPass::ID = 0;
+INITIALIZE_PASS_BEGIN(LoopDataPrefetchLegacyPass, "loop-data-prefetch",
+                      "Loop Data Prefetch", false, false)
+INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
+INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(OptimizationRemarkEmitterWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
+INITIALIZE_PASS_END(LoopDataPrefetchLegacyPass, "loop-data-prefetch",
+                    "Loop Data Prefetch", false, false)
+
+FunctionPass *llvm::createLoopDataPrefetchPass() {
+  return new LoopDataPrefetchLegacyPass();
+}
+
+bool LoopDataPrefetch::isStrideLargeEnough(const SCEVAddRecExpr *AR,
+                                           unsigned TargetMinStride) {
+  // No need to check if any stride goes.
+  if (TargetMinStride <= 1)
+    return true;
+
+  const auto *ConstStride = dyn_cast<SCEVConstant>(AR->getStepRecurrence(*SE));
+  // If MinStride is set, don't prefetch unless we can ensure that stride is
+  // larger.
+  if (!ConstStride)
+    return false;
+
+  unsigned AbsStride = std::abs(ConstStride->getAPInt().getSExtValue());
+  return TargetMinStride <= AbsStride;
+}
+
+PreservedAnalyses LoopDataPrefetchPass::run(Function &F,
+                                            FunctionAnalysisManager &AM) {
+  DominatorTree *DT = &AM.getResult<DominatorTreeAnalysis>(F);
+  LoopInfo *LI = &AM.getResult<LoopAnalysis>(F);
+  ScalarEvolution *SE = &AM.getResult<ScalarEvolutionAnalysis>(F);
+  AssumptionCache *AC = &AM.getResult<AssumptionAnalysis>(F);
+  OptimizationRemarkEmitter *ORE =
+      &AM.getResult<OptimizationRemarkEmitterAnalysis>(F);
+  const TargetTransformInfo *TTI = &AM.getResult<TargetIRAnalysis>(F);
+
+  LoopDataPrefetch LDP(AC, DT, LI, SE, TTI, ORE);
+  bool Changed = LDP.run();
+
+  if (Changed) {
+    PreservedAnalyses PA;
+    PA.preserve<DominatorTreeAnalysis>();
+    PA.preserve<LoopAnalysis>();
+    return PA;
+  }
+
+  return PreservedAnalyses::all();
+}
+
+bool LoopDataPrefetchLegacyPass::runOnFunction(Function &F) {
+  if (skipFunction(F))
+    return false;
+
+  DominatorTree *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+  LoopInfo *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+  ScalarEvolution *SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
+  AssumptionCache *AC =
+      &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
+  OptimizationRemarkEmitter *ORE =
+      &getAnalysis<OptimizationRemarkEmitterWrapperPass>().getORE();
+  const TargetTransformInfo *TTI =
+      &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
+
+  LoopDataPrefetch LDP(AC, DT, LI, SE, TTI, ORE);
+  return LDP.run();
+}
+
+bool LoopDataPrefetch::run() {
+  // If PrefetchDistance is not set, don't run the pass.  This gives an
+  // opportunity for targets to run this pass for selected subtargets only
+  // (whose TTI sets PrefetchDistance).
+  if (getPrefetchDistance() == 0)
+    return false;
+  assert(TTI->getCacheLineSize() && "Cache line size is not set for target");
+
+  bool MadeChange = false;
+
+  for (Loop *I : *LI)
+    for (auto L = df_begin(I), LE = df_end(I); L != LE; ++L)
+      MadeChange |= runOnLoop(*L);
+
+  return MadeChange;
+}
+
+/// A record for a potential prefetch made during the initial scan of the
+/// loop. This is used to let a single prefetch target multiple memory accesses.
+struct Prefetch {
+  /// The address formula for this prefetch as returned by ScalarEvolution.
+  const SCEVAddRecExpr *LSCEVAddRec;
+  /// The point of insertion for the prefetch instruction.
+  Instruction *InsertPt;
+  /// True if targeting a write memory access.
+  bool Writes;
+  /// The (first seen) prefetched instruction.
+  Instruction *MemI;
+
+  /// Constructor to create a new Prefetch for \p I.
+  Prefetch(const SCEVAddRecExpr *L, Instruction *I)
+      : LSCEVAddRec(L), InsertPt(nullptr), Writes(false), MemI(nullptr) {
+    addInstruction(I);
+  };
+
+  /// Add the instruction \param I to this prefetch. If it's not the first
+  /// one, 'InsertPt' and 'Writes' will be updated as required.
+  /// \param PtrDiff the known constant address difference to the first added
+  /// instruction.
+  void addInstruction(Instruction *I, DominatorTree *DT = nullptr,
+                      int64_t PtrDiff = 0) {
+    if (!InsertPt) {
+      MemI = I;
+      InsertPt = I;
+      Writes = isa<StoreInst>(I);
+    } else {
+      BasicBlock *PrefBB = InsertPt->getParent();
+      BasicBlock *InsBB = I->getParent();
+      if (PrefBB != InsBB) {
+        BasicBlock *DomBB = DT->findNearestCommonDominator(PrefBB, InsBB);
+        if (DomBB != PrefBB)
+          InsertPt = DomBB->getTerminator();
+      }
+
+      if (isa<StoreInst>(I) && PtrDiff == 0)
+        Writes = true;
+    }
+  }
+};
+
+bool LoopDataPrefetch::runOnLoop(Loop *L) {
+  bool MadeChange = false;
+
+  // Only prefetch in the inner-most loop
+  if (!L->empty())
+    return MadeChange;
+
+  SmallPtrSet<const Value *, 32> EphValues;
+  CodeMetrics::collectEphemeralValues(L, AC, EphValues);
+
+  // Calculate the number of iterations ahead to prefetch
+  CodeMetrics Metrics;
+  bool HasCall = false;
+  for (const auto BB : L->blocks()) {
+    // If the loop already has prefetches, then assume that the user knows
+    // what they are doing and don't add any more.
+    for (auto &I : *BB) {
+      if (isa<CallInst>(&I) || isa<InvokeInst>(&I)) {
+        if (const Function *F = cast<CallBase>(I).getCalledFunction()) {
+          if (F->getIntrinsicID() == Intrinsic::prefetch)
+            return MadeChange;
+          if (TTI->isLoweredToCall(F))
+            HasCall = true;
+        } else { // indirect call.
+          HasCall = true;
+        }
+      }
+    }
+    Metrics.analyzeBasicBlock(BB, *TTI, EphValues);
+  }
+  unsigned LoopSize = Metrics.NumInsts;
+  if (!LoopSize)
+    LoopSize = 1;
+
+  unsigned ItersAhead = getPrefetchDistance() / LoopSize;
+  if (!ItersAhead)
+    ItersAhead = 1;
+
+  if (ItersAhead > getMaxPrefetchIterationsAhead())
+    return MadeChange;
+
+  unsigned ConstantMaxTripCount = SE->getSmallConstantMaxTripCount(L);
+  if (ConstantMaxTripCount && ConstantMaxTripCount < ItersAhead + 1)
+    return MadeChange;
+
+  unsigned NumMemAccesses = 0;
+  unsigned NumStridedMemAccesses = 0;
+  SmallVector<Prefetch, 16> Prefetches;
+  for (const auto BB : L->blocks())
+    for (auto &I : *BB) {
+      Value *PtrValue;
+      Instruction *MemI;
+
+      if (LoadInst *LMemI = dyn_cast<LoadInst>(&I)) {
+        MemI = LMemI;
+        PtrValue = LMemI->getPointerOperand();
+      } else if (StoreInst *SMemI = dyn_cast<StoreInst>(&I)) {
+        if (!doPrefetchWrites()) continue;
+        MemI = SMemI;
+        PtrValue = SMemI->getPointerOperand();
+      } else continue;
+
+      unsigned PtrAddrSpace = PtrValue->getType()->getPointerAddressSpace();
+      if (PtrAddrSpace)
+        continue;
+      NumMemAccesses++;
+      if (L->isLoopInvariant(PtrValue))
+        continue;
+
+      const SCEV *LSCEV = SE->getSCEV(PtrValue);
+      const SCEVAddRecExpr *LSCEVAddRec = dyn_cast<SCEVAddRecExpr>(LSCEV);
+      if (!LSCEVAddRec)
+        continue;
+      NumStridedMemAccesses++;
+
+      // We don't want to double prefetch individual cache lines. If this
+      // access is known to be within one cache line of some other one that
+      // has already been prefetched, then don't prefetch this one as well.
+      bool DupPref = false;
+      for (auto &Pref : Prefetches) {
+        const SCEV *PtrDiff = SE->getMinusSCEV(LSCEVAddRec, Pref.LSCEVAddRec);
+        if (const SCEVConstant *ConstPtrDiff =
+            dyn_cast<SCEVConstant>(PtrDiff)) {
+          int64_t PD = std::abs(ConstPtrDiff->getValue()->getSExtValue());
+          if (PD < (int64_t) TTI->getCacheLineSize()) {
+            Pref.addInstruction(MemI, DT, PD);
+            DupPref = true;
+            break;
+          }
+        }
+      }
+      if (!DupPref)
+        Prefetches.push_back(Prefetch(LSCEVAddRec, MemI));
+    }
+
+  unsigned TargetMinStride =
+    getMinPrefetchStride(NumMemAccesses, NumStridedMemAccesses,
+                         Prefetches.size(), HasCall);
+
+  LLVM_DEBUG(dbgs() << "Prefetching " << ItersAhead
+             << " iterations ahead (loop size: " << LoopSize << ") in "
+             << L->getHeader()->getParent()->getName() << ": " << *L);
+  LLVM_DEBUG(dbgs() << "Loop has: "
+             << NumMemAccesses << " memory accesses, "
+             << NumStridedMemAccesses << " strided memory accesses, "
+             << Prefetches.size() << " potential prefetch(es), "
+             << "a minimum stride of " << TargetMinStride << ", "
+             << (HasCall ? "calls" : "no calls") << ".\n");
+
+  for (auto &P : Prefetches) {
+    // Check if the stride of the accesses is large enough to warrant a
+    // prefetch.
+    if (!isStrideLargeEnough(P.LSCEVAddRec, TargetMinStride))
+      continue;
+
+    const SCEV *NextLSCEV = SE->getAddExpr(P.LSCEVAddRec, SE->getMulExpr(
+      SE->getConstant(P.LSCEVAddRec->getType(), ItersAhead),
+      P.LSCEVAddRec->getStepRecurrence(*SE)));
+    if (!isSafeToExpand(NextLSCEV, *SE))
+      continue;
+
+    BasicBlock *BB = P.InsertPt->getParent();
+    Type *I8Ptr = Type::getInt8PtrTy(BB->getContext(), 0/*PtrAddrSpace*/);
+    SCEVExpander SCEVE(*SE, BB->getModule()->getDataLayout(), "prefaddr");
+    Value *PrefPtrValue = SCEVE.expandCodeFor(NextLSCEV, I8Ptr, P.InsertPt);
+
+    IRBuilder<> Builder(P.InsertPt);
+    Module *M = BB->getParent()->getParent();
+    Type *I32 = Type::getInt32Ty(BB->getContext());
+    Function *PrefetchFunc = Intrinsic::getDeclaration(
+        M, Intrinsic::prefetch, PrefPtrValue->getType());
+    Builder.CreateCall(
+        PrefetchFunc,
+        {PrefPtrValue,
+         ConstantInt::get(I32, P.Writes),
+         ConstantInt::get(I32, 3), ConstantInt::get(I32, 1)});
+    ++NumPrefetches;
+    LLVM_DEBUG(dbgs() << "  Access: "
+               << *P.MemI->getOperand(isa<LoadInst>(P.MemI) ? 0 : 1)
+               << ", SCEV: " << *P.LSCEVAddRec << "\n");
+    ORE->emit([&]() {
+        return OptimizationRemark(DEBUG_TYPE, "Prefetched", P.MemI)
+          << "prefetched memory access";
+      });
+
+    MadeChange = true;
+  }
+
+  return MadeChange;
+}