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-rw-r--r--contrib/llvm/lib/Target/PowerPC/PPCLoopDataPrefetch.cpp233
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diff --git a/contrib/llvm/lib/Target/PowerPC/PPCLoopDataPrefetch.cpp b/contrib/llvm/lib/Target/PowerPC/PPCLoopDataPrefetch.cpp
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--- a/contrib/llvm/lib/Target/PowerPC/PPCLoopDataPrefetch.cpp
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@@ -1,233 +0,0 @@
-//===-------- 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/DepthFirstIterator.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/ScalarEvolutionAliasAnalysis.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<ScalarEvolutionWrapperPass>();
- // FIXME: For some reason, preserving SE here breaks LSR (even if
- // this pass changes nothing).
- // AU.addPreserved<ScalarEvolutionWrapperPass>();
- 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(ScalarEvolutionWrapperPass)
-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<ScalarEvolutionWrapperPass>().getSE();
- DL = &F.getParent()->getDataLayout();
- AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
- TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
-
- bool MadeChange = false;
-
- for (auto I = LI->begin(), IE = LI->end(); I != IE; ++I)
- for (auto L = df_begin(*I), LE = df_end(*I); L != LE; ++L)
- 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 = std::abs(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, J->getModule()->getDataLayout(), "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.CreateCall(
- PrefetchFunc,
- {PrefPtrValue,
- ConstantInt::get(I32, MemI->mayReadFromMemory() ? 0 : 1),
- ConstantInt::get(I32, 3), ConstantInt::get(I32, 1)});
-
- MadeChange = true;
- }
- }
-
- return MadeChange;
-}
-
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