f92109dc01
This patch applies only to the new pass manager. Currently, when MSSA Analysis is available, and pass to each loop pass, it will be preserved by that loop pass. Hence, mark the analysis preserved based on that condition, vs the current `EnableMSSALoopDependency`. This leaves the global flag to affect only the entry point in the loop pass manager (in FunctionToLoopPassAdaptor). llvm-svn: 369181
127 lines
4.7 KiB
C++
127 lines
4.7 KiB
C++
//===- LoopRotation.cpp - Loop Rotation Pass ------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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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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auto PA = getLoopPassPreservedAnalyses();
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if (AR.MSSA)
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PA.preserve<MemorySSAAnalysis>();
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return PA;
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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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