forked from OSchip/llvm-project
125 lines
4.6 KiB
C++
125 lines
4.6 KiB
C++
//===- LoopRotation.cpp - Loop Rotation Pass ------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements Loop Rotation Pass.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Transforms/Scalar/LoopRotation.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/Analysis/InstructionSimplify.h"
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#include "llvm/Analysis/LoopPass.h"
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#include "llvm/Analysis/MemorySSA.h"
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#include "llvm/Analysis/MemorySSAUpdater.h"
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#include "llvm/Analysis/ScalarEvolution.h"
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#include "llvm/Analysis/TargetTransformInfo.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Transforms/Scalar.h"
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#include "llvm/Transforms/Scalar/LoopPassManager.h"
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#include "llvm/Transforms/Utils/LoopRotationUtils.h"
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#include "llvm/Transforms/Utils/LoopUtils.h"
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using namespace llvm;
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#define DEBUG_TYPE "loop-rotate"
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static cl::opt<unsigned> DefaultRotationThreshold(
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"rotation-max-header-size", cl::init(16), cl::Hidden,
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cl::desc("The default maximum header size for automatic loop rotation"));
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LoopRotatePass::LoopRotatePass(bool EnableHeaderDuplication)
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: EnableHeaderDuplication(EnableHeaderDuplication) {}
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PreservedAnalyses LoopRotatePass::run(Loop &L, LoopAnalysisManager &AM,
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LoopStandardAnalysisResults &AR,
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LPMUpdater &) {
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int Threshold = EnableHeaderDuplication ? DefaultRotationThreshold : 0;
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const DataLayout &DL = L.getHeader()->getModule()->getDataLayout();
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const SimplifyQuery SQ = getBestSimplifyQuery(AR, DL);
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Optional<MemorySSAUpdater> MSSAU;
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if (AR.MSSA)
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MSSAU = MemorySSAUpdater(AR.MSSA);
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bool Changed = LoopRotation(&L, &AR.LI, &AR.TTI, &AR.AC, &AR.DT, &AR.SE,
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MSSAU.hasValue() ? MSSAU.getPointer() : nullptr,
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SQ, false, Threshold, false);
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if (!Changed)
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return PreservedAnalyses::all();
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if (AR.MSSA && VerifyMemorySSA)
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AR.MSSA->verifyMemorySSA();
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return getLoopPassPreservedAnalyses();
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}
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namespace {
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class LoopRotateLegacyPass : public LoopPass {
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unsigned MaxHeaderSize;
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public:
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static char ID; // Pass ID, replacement for typeid
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LoopRotateLegacyPass(int SpecifiedMaxHeaderSize = -1) : LoopPass(ID) {
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initializeLoopRotateLegacyPassPass(*PassRegistry::getPassRegistry());
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if (SpecifiedMaxHeaderSize == -1)
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MaxHeaderSize = DefaultRotationThreshold;
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else
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MaxHeaderSize = unsigned(SpecifiedMaxHeaderSize);
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}
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// LCSSA form makes instruction renaming easier.
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void getAnalysisUsage(AnalysisUsage &AU) const override {
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AU.addRequired<AssumptionCacheTracker>();
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AU.addRequired<TargetTransformInfoWrapperPass>();
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if (EnableMSSALoopDependency) {
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AU.addRequired<MemorySSAWrapperPass>();
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AU.addPreserved<MemorySSAWrapperPass>();
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}
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getLoopAnalysisUsage(AU);
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}
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bool runOnLoop(Loop *L, LPPassManager &LPM) override {
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if (skipLoop(L))
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return false;
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Function &F = *L->getHeader()->getParent();
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auto *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
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const auto *TTI = &getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
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auto *AC = &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
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auto *DTWP = getAnalysisIfAvailable<DominatorTreeWrapperPass>();
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auto *DT = DTWP ? &DTWP->getDomTree() : nullptr;
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auto *SEWP = getAnalysisIfAvailable<ScalarEvolutionWrapperPass>();
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auto *SE = SEWP ? &SEWP->getSE() : nullptr;
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const SimplifyQuery SQ = getBestSimplifyQuery(*this, F);
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Optional<MemorySSAUpdater> MSSAU;
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if (EnableMSSALoopDependency) {
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MemorySSA *MSSA = &getAnalysis<MemorySSAWrapperPass>().getMSSA();
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MSSAU = MemorySSAUpdater(MSSA);
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}
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return LoopRotation(L, LI, TTI, AC, DT, SE,
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MSSAU.hasValue() ? MSSAU.getPointer() : nullptr, SQ,
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false, MaxHeaderSize, false);
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}
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};
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}
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char LoopRotateLegacyPass::ID = 0;
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INITIALIZE_PASS_BEGIN(LoopRotateLegacyPass, "loop-rotate", "Rotate Loops",
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false, false)
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INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
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INITIALIZE_PASS_DEPENDENCY(LoopPass)
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INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
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INITIALIZE_PASS_DEPENDENCY(MemorySSAWrapperPass)
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INITIALIZE_PASS_END(LoopRotateLegacyPass, "loop-rotate", "Rotate Loops", false,
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false)
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Pass *llvm::createLoopRotatePass(int MaxHeaderSize) {
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return new LoopRotateLegacyPass(MaxHeaderSize);
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}
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