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diff --git a/lib/Target/PowerPC/PPCLoopDataPrefetch.cpp b/lib/Target/PowerPC/PPCLoopDataPrefetch.cpp
new file mode 100644
index 0000000..efd2d92
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+++ b/lib/Target/PowerPC/PPCLoopDataPrefetch.cpp
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+//===-------- PPCLoopDataPrefetch.cpp - Loop Data Prefetching Pass --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements a Loop Data Prefetching Pass.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "ppc-loop-data-prefetch"
+#include "PPC.h"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/AssumptionCache.h"
+#include "llvm/Analysis/CodeMetrics.h"
+#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/ScalarEvolution.h"
+#include "llvm/Analysis/ScalarEvolutionExpander.h"
+#include "llvm/Analysis/ScalarEvolutionExpressions.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/IR/CFG.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Transforms/Utils/BasicBlockUtils.h"
+#include "llvm/Transforms/Utils/Local.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("ppc-loop-prefetch-writes", cl::Hidden, cl::init(false),
+               cl::desc("Prefetch write addresses"));
+
+// This seems like a reasonable default for the BG/Q (this pass is enabled, by
+// default, only on the BG/Q).
+static cl::opt<unsigned>
+PrefDist("ppc-loop-prefetch-distance", cl::Hidden, cl::init(300),
+         cl::desc("The loop prefetch distance"));
+
+static cl::opt<unsigned>
+CacheLineSize("ppc-loop-prefetch-cache-line", cl::Hidden, cl::init(64),
+              cl::desc("The loop prefetch cache line size"));
+
+namespace llvm {
+  void initializePPCLoopDataPrefetchPass(PassRegistry&);
+}
+
+namespace {
+
+  class PPCLoopDataPrefetch : public FunctionPass {
+  public:
+    static char ID; // Pass ID, replacement for typeid
+    PPCLoopDataPrefetch() : FunctionPass(ID) {
+      initializePPCLoopDataPrefetchPass(*PassRegistry::getPassRegistry());
+    }
+
+    void getAnalysisUsage(AnalysisUsage &AU) const override {
+      AU.addRequired<AssumptionCacheTracker>();
+      AU.addPreserved<DominatorTreeWrapperPass>();
+      AU.addRequired<LoopInfoWrapperPass>();
+      AU.addPreserved<LoopInfoWrapperPass>();
+      AU.addRequired<ScalarEvolution>();
+      // FIXME: For some reason, preserving SE here breaks LSR (even if
+      // this pass changes nothing).
+      // AU.addPreserved<ScalarEvolution>();
+      AU.addRequired<TargetTransformInfoWrapperPass>();
+    }
+
+    bool runOnFunction(Function &F) override;
+    bool runOnLoop(Loop *L);
+
+  private:
+    AssumptionCache *AC;
+    LoopInfo *LI;
+    ScalarEvolution *SE;
+    const TargetTransformInfo *TTI;
+    const DataLayout *DL;
+  };
+}
+
+char PPCLoopDataPrefetch::ID = 0;
+INITIALIZE_PASS_BEGIN(PPCLoopDataPrefetch, "ppc-loop-data-prefetch",
+                      "PPC Loop Data Prefetch", false, false)
+INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
+INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
+INITIALIZE_PASS_END(PPCLoopDataPrefetch, "ppc-loop-data-prefetch",
+                    "PPC Loop Data Prefetch", false, false)
+
+FunctionPass *llvm::createPPCLoopDataPrefetchPass() { return new PPCLoopDataPrefetch(); }
+
+bool PPCLoopDataPrefetch::runOnFunction(Function &F) {
+  LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
+  SE = &getAnalysis<ScalarEvolution>();
+  DL = F.getParent()->getDataLayout();
+  AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
+  TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
+
+  bool MadeChange = false;
+
+  for (LoopInfo::iterator I = LI->begin(), E = LI->end();
+       I != E; ++I) {
+    Loop *L = *I;
+    MadeChange |= runOnLoop(L);
+  }
+
+  return MadeChange;
+}
+
+bool PPCLoopDataPrefetch::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;
+  for (Loop::block_iterator I = L->block_begin(), IE = L->block_end();
+       I != IE; ++I) {
+
+    // If the loop already has prefetches, then assume that the user knows
+    // what he or she is doing and don't add any more.
+    for (BasicBlock::iterator J = (*I)->begin(), JE = (*I)->end();
+         J != JE; ++J)
+      if (CallInst *CI = dyn_cast<CallInst>(J))
+        if (Function *F = CI->getCalledFunction())
+          if (F->getIntrinsicID() == Intrinsic::prefetch)
+            return MadeChange;
+
+    Metrics.analyzeBasicBlock(*I, *TTI, EphValues);
+  }
+  unsigned LoopSize = Metrics.NumInsts;
+  if (!LoopSize)
+    LoopSize = 1;
+
+  unsigned ItersAhead = PrefDist/LoopSize;
+  if (!ItersAhead)
+    ItersAhead = 1;
+
+  SmallVector<std::pair<Instruction *, const SCEVAddRecExpr *>, 16> PrefLoads;
+  for (Loop::block_iterator I = L->block_begin(), IE = L->block_end();
+       I != IE; ++I) {
+    for (BasicBlock::iterator J = (*I)->begin(), JE = (*I)->end();
+        J != JE; ++J) {
+      Value *PtrValue;
+      Instruction *MemI;
+
+      if (LoadInst *LMemI = dyn_cast<LoadInst>(J)) {
+        MemI = LMemI;
+        PtrValue = LMemI->getPointerOperand();
+      } else if (StoreInst *SMemI = dyn_cast<StoreInst>(J)) {
+        if (!PrefetchWrites) continue;
+        MemI = SMemI;
+        PtrValue = SMemI->getPointerOperand();
+      } else continue;
+
+      unsigned PtrAddrSpace = PtrValue->getType()->getPointerAddressSpace();
+      if (PtrAddrSpace)
+        continue;
+
+      if (L->isLoopInvariant(PtrValue))
+        continue;
+
+      const SCEV *LSCEV = SE->getSCEV(PtrValue);
+      const SCEVAddRecExpr *LSCEVAddRec = dyn_cast<SCEVAddRecExpr>(LSCEV);
+      if (!LSCEVAddRec)
+        continue;
+
+      // We don't want to double prefetch individual cache lines. If this load
+      // is known to be within one cache line of some other load that has
+      // already been prefetched, then don't prefetch this one as well.
+      bool DupPref = false;
+      for (SmallVector<std::pair<Instruction *, const SCEVAddRecExpr *>,
+             16>::iterator K = PrefLoads.begin(), KE = PrefLoads.end();
+           K != KE; ++K) {
+        const SCEV *PtrDiff = SE->getMinusSCEV(LSCEVAddRec, K->second);
+        if (const SCEVConstant *ConstPtrDiff =
+            dyn_cast<SCEVConstant>(PtrDiff)) {
+          int64_t PD = abs64(ConstPtrDiff->getValue()->getSExtValue());
+          if (PD < (int64_t) CacheLineSize) {
+            DupPref = true;
+            break;
+          }
+        }
+      }
+      if (DupPref)
+        continue;
+
+      const SCEV *NextLSCEV = SE->getAddExpr(LSCEVAddRec, SE->getMulExpr(
+        SE->getConstant(LSCEVAddRec->getType(), ItersAhead),
+        LSCEVAddRec->getStepRecurrence(*SE)));
+      if (!isSafeToExpand(NextLSCEV, *SE))
+        continue;
+
+      PrefLoads.push_back(std::make_pair(MemI, LSCEVAddRec));
+
+      Type *I8Ptr = Type::getInt8PtrTy((*I)->getContext(), PtrAddrSpace);
+      SCEVExpander SCEVE(*SE, "prefaddr");
+      Value *PrefPtrValue = SCEVE.expandCodeFor(NextLSCEV, I8Ptr, MemI);
+
+      IRBuilder<> Builder(MemI);
+      Module *M = (*I)->getParent()->getParent();
+      Type *I32 = Type::getInt32Ty((*I)->getContext());
+      Value *PrefetchFunc = Intrinsic::getDeclaration(M, Intrinsic::prefetch);
+      Builder.CreateCall4(PrefetchFunc, PrefPtrValue,
+        ConstantInt::get(I32, MemI->mayReadFromMemory() ? 0 : 1),
+        ConstantInt::get(I32, 3), ConstantInt::get(I32, 1));
+
+      MadeChange = true;
+    }
+  }
+
+  return MadeChange;
+}
+