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to reflect the new license. We understand that people may be surprised that we're moving the header entirely to discuss the new license. We checked this carefully with the Foundation's lawyer and we believe this is the correct approach. Essentially, all code in the project is now made available by the LLVM project under our new license, so you will see that the license headers include that license only. Some of our contributors have contributed code under our old license, and accordingly, we have retained a copy of our old license notice in the top-level files in each project and repository. llvm-svn: 351636
124 lines
4.6 KiB
C++
124 lines
4.6 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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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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