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diff --git a/llvm/lib/Transforms/Scalar/LoopUnrollAndJamPass.cpp b/llvm/lib/Transforms/Scalar/LoopUnrollAndJamPass.cpp
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--- a/llvm/lib/Transforms/Scalar/LoopUnrollAndJamPass.cpp
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-//===- LoopUnrollAndJam.cpp - Loop unroll and jam pass --------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This pass implements an unroll and jam pass. Most of the work is done by
-// Utils/UnrollLoopAndJam.cpp.
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Transforms/Scalar/LoopUnrollAndJamPass.h"
-#include "llvm/ADT/None.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/StringRef.h"
-#include "llvm/Analysis/AssumptionCache.h"
-#include "llvm/Analysis/CodeMetrics.h"
-#include "llvm/Analysis/DependenceAnalysis.h"
-#include "llvm/Analysis/LoopAnalysisManager.h"
-#include "llvm/Analysis/LoopInfo.h"
-#include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/OptimizationRemarkEmitter.h"
-#include "llvm/Analysis/ScalarEvolution.h"
-#include "llvm/Analysis/TargetTransformInfo.h"
-#include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CFG.h"
-#include "llvm/IR/Constant.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/Dominators.h"
-#include "llvm/IR/Function.h"
-#include "llvm/IR/Instruction.h"
-#include "llvm/IR/Instructions.h"
-#include "llvm/IR/IntrinsicInst.h"
-#include "llvm/IR/Metadata.h"
-#include "llvm/IR/PassManager.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/Casting.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/raw_ostream.h"
-#include "llvm/Transforms/Scalar.h"
-#include "llvm/Transforms/Scalar/LoopPassManager.h"
-#include "llvm/Transforms/Utils.h"
-#include "llvm/Transforms/Utils/LoopUtils.h"
-#include "llvm/Transforms/Utils/UnrollLoop.h"
-#include <algorithm>
-#include <cassert>
-#include <cstdint>
-#include <string>
-
-using namespace llvm;
-
-#define DEBUG_TYPE "loop-unroll-and-jam"
-
-static cl::opt<unsigned> UnrollAndJamCount(
- "unroll-and-jam-count", cl::Hidden,
- cl::desc("Use this unroll count for all loops including those with "
- "unroll_and_jam_count pragma values, for testing purposes"));
-
-static cl::opt<unsigned> UnrollAndJamThreshold(
- "unroll-and-jam-threshold", cl::init(60), cl::Hidden,
- cl::desc("Threshold to use for inner loop when doing unroll and jam."));
-
-static cl::opt<unsigned> PragmaUnrollAndJamThreshold(
- "pragma-unroll-and-jam-threshold", cl::init(1024), cl::Hidden,
- cl::desc("Unrolled size limit for loops with an unroll_and_jam(full) or "
- "unroll_count pragma."));
-
-// Returns the loop hint metadata node with the given name (for example,
-// "llvm.loop.unroll.count"). If no such metadata node exists, then nullptr is
-// returned.
-static MDNode *GetUnrollMetadataForLoop(const Loop *L, StringRef Name) {
- if (MDNode *LoopID = L->getLoopID())
- return GetUnrollMetadata(LoopID, Name);
- return nullptr;
-}
-
-// Returns true if the loop has any metadata starting with Prefix. For example a
-// Prefix of "llvm.loop.unroll." returns true if we have any unroll metadata.
-static bool HasAnyUnrollPragma(const Loop *L, StringRef Prefix) {
- if (MDNode *LoopID = L->getLoopID()) {
- // First operand should refer to the loop id itself.
- assert(LoopID->getNumOperands() > 0 && "requires at least one operand");
- assert(LoopID->getOperand(0) == LoopID && "invalid loop id");
-
- for (unsigned i = 1, e = LoopID->getNumOperands(); i < e; ++i) {
- MDNode *MD = dyn_cast<MDNode>(LoopID->getOperand(i));
- if (!MD)
- continue;
-
- MDString *S = dyn_cast<MDString>(MD->getOperand(0));
- if (!S)
- continue;
-
- if (S->getString().startswith(Prefix))
- return true;
- }
- }
- return false;
-}
-
-// Returns true if the loop has an unroll_and_jam(enable) pragma.
-static bool HasUnrollAndJamEnablePragma(const Loop *L) {
- return GetUnrollMetadataForLoop(L, "llvm.loop.unroll_and_jam.enable");
-}
-
-// Returns true if the loop has an unroll_and_jam(disable) pragma.
-static bool HasUnrollAndJamDisablePragma(const Loop *L) {
- return GetUnrollMetadataForLoop(L, "llvm.loop.unroll_and_jam.disable");
-}
-
-// If loop has an unroll_and_jam_count pragma return the (necessarily
-// positive) value from the pragma. Otherwise return 0.
-static unsigned UnrollAndJamCountPragmaValue(const Loop *L) {
- MDNode *MD = GetUnrollMetadataForLoop(L, "llvm.loop.unroll_and_jam.count");
- if (MD) {
- assert(MD->getNumOperands() == 2 &&
- "Unroll count hint metadata should have two operands.");
- unsigned Count =
- mdconst::extract<ConstantInt>(MD->getOperand(1))->getZExtValue();
- assert(Count >= 1 && "Unroll count must be positive.");
- return Count;
- }
- return 0;
-}
-
-// Returns loop size estimation for unrolled loop.
-static uint64_t
-getUnrollAndJammedLoopSize(unsigned LoopSize,
- TargetTransformInfo::UnrollingPreferences &UP) {
- assert(LoopSize >= UP.BEInsns && "LoopSize should not be less than BEInsns!");
- return static_cast<uint64_t>(LoopSize - UP.BEInsns) * UP.Count + UP.BEInsns;
-}
-
-// Calculates unroll and jam count and writes it to UP.Count. Returns true if
-// unroll count was set explicitly.
-static bool computeUnrollAndJamCount(
- Loop *L, Loop *SubLoop, const TargetTransformInfo &TTI, DominatorTree &DT,
- LoopInfo *LI, ScalarEvolution &SE,
- const SmallPtrSetImpl<const Value *> &EphValues,
- OptimizationRemarkEmitter *ORE, unsigned OuterTripCount,
- unsigned OuterTripMultiple, unsigned OuterLoopSize, unsigned InnerTripCount,
- unsigned InnerLoopSize, TargetTransformInfo::UnrollingPreferences &UP) {
- // Check for explicit Count from the "unroll-and-jam-count" option.
- bool UserUnrollCount = UnrollAndJamCount.getNumOccurrences() > 0;
- if (UserUnrollCount) {
- UP.Count = UnrollAndJamCount;
- UP.Force = true;
- if (UP.AllowRemainder &&
- getUnrollAndJammedLoopSize(OuterLoopSize, UP) < UP.Threshold &&
- getUnrollAndJammedLoopSize(InnerLoopSize, UP) <
- UP.UnrollAndJamInnerLoopThreshold)
- return true;
- }
-
- // Check for unroll_and_jam pragmas
- unsigned PragmaCount = UnrollAndJamCountPragmaValue(L);
- if (PragmaCount > 0) {
- UP.Count = PragmaCount;
- UP.Runtime = true;
- UP.Force = true;
- if ((UP.AllowRemainder || (OuterTripMultiple % PragmaCount == 0)) &&
- getUnrollAndJammedLoopSize(OuterLoopSize, UP) < UP.Threshold &&
- getUnrollAndJammedLoopSize(InnerLoopSize, UP) <
- UP.UnrollAndJamInnerLoopThreshold)
- return true;
- }
-
- // Use computeUnrollCount from the loop unroller to get a sensible count
- // for the unrolling the outer loop. This uses UP.Threshold /
- // UP.PartialThreshold / UP.MaxCount to come up with sensible loop values.
- // We have already checked that the loop has no unroll.* pragmas.
- unsigned MaxTripCount = 0;
- bool UseUpperBound = false;
- bool ExplicitUnroll = computeUnrollCount(
- L, TTI, DT, LI, SE, EphValues, ORE, OuterTripCount, MaxTripCount,
- OuterTripMultiple, OuterLoopSize, UP, UseUpperBound);
- if (ExplicitUnroll || UseUpperBound) {
- // If the user explicitly set the loop as unrolled, dont UnJ it. Leave it
- // for the unroller instead.
- UP.Count = 0;
- return false;
- }
-
- bool PragmaEnableUnroll = HasUnrollAndJamEnablePragma(L);
- ExplicitUnroll = PragmaCount > 0 || PragmaEnableUnroll || UserUnrollCount;
-
- // If the loop has an unrolling pragma, we want to be more aggressive with
- // unrolling limits.
- if (ExplicitUnroll && OuterTripCount != 0)
- UP.UnrollAndJamInnerLoopThreshold = PragmaUnrollAndJamThreshold;
-
- if (!UP.AllowRemainder && getUnrollAndJammedLoopSize(InnerLoopSize, UP) >=
- UP.UnrollAndJamInnerLoopThreshold) {
- UP.Count = 0;
- return false;
- }
-
- // If the inner loop count is known and small, leave the entire loop nest to
- // be the unroller
- if (!ExplicitUnroll && InnerTripCount &&
- InnerLoopSize * InnerTripCount < UP.Threshold) {
- UP.Count = 0;
- return false;
- }
-
- // We have a sensible limit for the outer loop, now adjust it for the inner
- // loop and UP.UnrollAndJamInnerLoopThreshold.
- while (UP.Count != 0 && UP.AllowRemainder &&
- getUnrollAndJammedLoopSize(InnerLoopSize, UP) >=
- UP.UnrollAndJamInnerLoopThreshold)
- UP.Count--;
-
- if (!ExplicitUnroll) {
- // Check for situations where UnJ is likely to be unprofitable. Including
- // subloops with more than 1 block.
- if (SubLoop->getBlocks().size() != 1) {
- UP.Count = 0;
- return false;
- }
-
- // Limit to loops where there is something to gain from unrolling and
- // jamming the loop. In this case, look for loads that are invariant in the
- // outer loop and can become shared.
- unsigned NumInvariant = 0;
- for (BasicBlock *BB : SubLoop->getBlocks()) {
- for (Instruction &I : *BB) {
- if (auto *Ld = dyn_cast<LoadInst>(&I)) {
- Value *V = Ld->getPointerOperand();
- const SCEV *LSCEV = SE.getSCEVAtScope(V, L);
- if (SE.isLoopInvariant(LSCEV, L))
- NumInvariant++;
- }
- }
- }
- if (NumInvariant == 0) {
- UP.Count = 0;
- return false;
- }
- }
-
- return ExplicitUnroll;
-}
-
-static LoopUnrollResult
-tryToUnrollAndJamLoop(Loop *L, DominatorTree &DT, LoopInfo *LI,
- ScalarEvolution &SE, const TargetTransformInfo &TTI,
- AssumptionCache &AC, DependenceInfo &DI,
- OptimizationRemarkEmitter &ORE, int OptLevel) {
- // Quick checks of the correct loop form
- if (!L->isLoopSimplifyForm() || L->getSubLoops().size() != 1)
- return LoopUnrollResult::Unmodified;
- Loop *SubLoop = L->getSubLoops()[0];
- if (!SubLoop->isLoopSimplifyForm())
- return LoopUnrollResult::Unmodified;
-
- BasicBlock *Latch = L->getLoopLatch();
- BasicBlock *Exit = L->getExitingBlock();
- BasicBlock *SubLoopLatch = SubLoop->getLoopLatch();
- BasicBlock *SubLoopExit = SubLoop->getExitingBlock();
-
- if (Latch != Exit || SubLoopLatch != SubLoopExit)
- return LoopUnrollResult::Unmodified;
-
- TargetTransformInfo::UnrollingPreferences UP = gatherUnrollingPreferences(
- L, SE, TTI, OptLevel, None, None, None, None, None, None);
- if (UnrollAndJamThreshold.getNumOccurrences() > 0)
- UP.UnrollAndJamInnerLoopThreshold = UnrollAndJamThreshold;
- // Exit early if unrolling is disabled.
- if (!UP.UnrollAndJam || UP.UnrollAndJamInnerLoopThreshold == 0)
- return LoopUnrollResult::Unmodified;
-
- LLVM_DEBUG(dbgs() << "Loop Unroll and Jam: F["
- << L->getHeader()->getParent()->getName() << "] Loop %"
- << L->getHeader()->getName() << "\n");
-
- // A loop with any unroll pragma (enabling/disabling/count/etc) is left for
- // the unroller, so long as it does not explicitly have unroll_and_jam
- // metadata. This means #pragma nounroll will disable unroll and jam as well
- // as unrolling
- if (HasUnrollAndJamDisablePragma(L) ||
- (HasAnyUnrollPragma(L, "llvm.loop.unroll.") &&
- !HasAnyUnrollPragma(L, "llvm.loop.unroll_and_jam."))) {
- LLVM_DEBUG(dbgs() << " Disabled due to pragma.\n");
- return LoopUnrollResult::Unmodified;
- }
-
- if (!isSafeToUnrollAndJam(L, SE, DT, DI)) {
- LLVM_DEBUG(dbgs() << " Disabled due to not being safe.\n");
- return LoopUnrollResult::Unmodified;
- }
-
- // Approximate the loop size and collect useful info
- unsigned NumInlineCandidates;
- bool NotDuplicatable;
- bool Convergent;
- SmallPtrSet<const Value *, 32> EphValues;
- CodeMetrics::collectEphemeralValues(L, &AC, EphValues);
- unsigned InnerLoopSize =
- ApproximateLoopSize(SubLoop, NumInlineCandidates, NotDuplicatable,
- Convergent, TTI, EphValues, UP.BEInsns);
- unsigned OuterLoopSize =
- ApproximateLoopSize(L, NumInlineCandidates, NotDuplicatable, Convergent,
- TTI, EphValues, UP.BEInsns);
- LLVM_DEBUG(dbgs() << " Outer Loop Size: " << OuterLoopSize << "\n");
- LLVM_DEBUG(dbgs() << " Inner Loop Size: " << InnerLoopSize << "\n");
- if (NotDuplicatable) {
- LLVM_DEBUG(dbgs() << " Not unrolling loop which contains non-duplicatable "
- "instructions.\n");
- return LoopUnrollResult::Unmodified;
- }
- if (NumInlineCandidates != 0) {
- LLVM_DEBUG(dbgs() << " Not unrolling loop with inlinable calls.\n");
- return LoopUnrollResult::Unmodified;
- }
- if (Convergent) {
- LLVM_DEBUG(
- dbgs() << " Not unrolling loop with convergent instructions.\n");
- return LoopUnrollResult::Unmodified;
- }
-
- // Find trip count and trip multiple
- unsigned OuterTripCount = SE.getSmallConstantTripCount(L, Latch);
- unsigned OuterTripMultiple = SE.getSmallConstantTripMultiple(L, Latch);
- unsigned InnerTripCount = SE.getSmallConstantTripCount(SubLoop, SubLoopLatch);
-
- // Decide if, and by how much, to unroll
- bool IsCountSetExplicitly = computeUnrollAndJamCount(
- L, SubLoop, TTI, DT, LI, SE, EphValues, &ORE, OuterTripCount,
- OuterTripMultiple, OuterLoopSize, InnerTripCount, InnerLoopSize, UP);
- if (UP.Count <= 1)
- return LoopUnrollResult::Unmodified;
- // Unroll factor (Count) must be less or equal to TripCount.
- if (OuterTripCount && UP.Count > OuterTripCount)
- UP.Count = OuterTripCount;
-
- LoopUnrollResult UnrollResult =
- UnrollAndJamLoop(L, UP.Count, OuterTripCount, OuterTripMultiple,
- UP.UnrollRemainder, LI, &SE, &DT, &AC, &ORE);
-
- // If loop has an unroll count pragma or unrolled by explicitly set count
- // mark loop as unrolled to prevent unrolling beyond that requested.
- if (UnrollResult != LoopUnrollResult::FullyUnrolled && IsCountSetExplicitly)
- L->setLoopAlreadyUnrolled();
-
- return UnrollResult;
-}
-
-namespace {
-
-class LoopUnrollAndJam : public LoopPass {
-public:
- static char ID; // Pass ID, replacement for typeid
- unsigned OptLevel;
-
- LoopUnrollAndJam(int OptLevel = 2) : LoopPass(ID), OptLevel(OptLevel) {
- initializeLoopUnrollAndJamPass(*PassRegistry::getPassRegistry());
- }
-
- bool runOnLoop(Loop *L, LPPassManager &LPM) override {
- if (skipLoop(L))
- return false;
-
- Function &F = *L->getHeader()->getParent();
-
- auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
- LoopInfo *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
- ScalarEvolution &SE = getAnalysis<ScalarEvolutionWrapperPass>().getSE();
- const TargetTransformInfo &TTI =
- getAnalysis<TargetTransformInfoWrapperPass>().getTTI(F);
- auto &AC = getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
- auto &DI = getAnalysis<DependenceAnalysisWrapperPass>().getDI();
- // For the old PM, we can't use OptimizationRemarkEmitter as an analysis
- // pass. Function analyses need to be preserved across loop transformations
- // but ORE cannot be preserved (see comment before the pass definition).
- OptimizationRemarkEmitter ORE(&F);
-
- LoopUnrollResult Result =
- tryToUnrollAndJamLoop(L, DT, LI, SE, TTI, AC, DI, ORE, OptLevel);
-
- if (Result == LoopUnrollResult::FullyUnrolled)
- LPM.markLoopAsDeleted(*L);
-
- return Result != LoopUnrollResult::Unmodified;
- }
-
- /// This transformation requires natural loop information & requires that
- /// loop preheaders be inserted into the CFG...
- void getAnalysisUsage(AnalysisUsage &AU) const override {
- AU.addRequired<AssumptionCacheTracker>();
- AU.addRequired<TargetTransformInfoWrapperPass>();
- AU.addRequired<DependenceAnalysisWrapperPass>();
- getLoopAnalysisUsage(AU);
- }
-};
-
-} // end anonymous namespace
-
-char LoopUnrollAndJam::ID = 0;
-
-INITIALIZE_PASS_BEGIN(LoopUnrollAndJam, "loop-unroll-and-jam",
- "Unroll and Jam loops", false, false)
-INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
-INITIALIZE_PASS_DEPENDENCY(LoopPass)
-INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(DependenceAnalysisWrapperPass)
-INITIALIZE_PASS_END(LoopUnrollAndJam, "loop-unroll-and-jam",
- "Unroll and Jam loops", false, false)
-
-Pass *llvm::createLoopUnrollAndJamPass(int OptLevel) {
- return new LoopUnrollAndJam(OptLevel);
-}
-
-PreservedAnalyses LoopUnrollAndJamPass::run(Loop &L, LoopAnalysisManager &AM,
- LoopStandardAnalysisResults &AR,
- LPMUpdater &) {
- const auto &FAM =
- AM.getResult<FunctionAnalysisManagerLoopProxy>(L, AR).getManager();
- Function *F = L.getHeader()->getParent();
-
- auto *ORE = FAM.getCachedResult<OptimizationRemarkEmitterAnalysis>(*F);
- // FIXME: This should probably be optional rather than required.
- if (!ORE)
- report_fatal_error(
- "LoopUnrollAndJamPass: OptimizationRemarkEmitterAnalysis not cached at "
- "a higher level");
-
- DependenceInfo DI(F, &AR.AA, &AR.SE, &AR.LI);
-
- LoopUnrollResult Result = tryToUnrollAndJamLoop(
- &L, AR.DT, &AR.LI, AR.SE, AR.TTI, AR.AC, DI, *ORE, OptLevel);
-
- if (Result == LoopUnrollResult::Unmodified)
- return PreservedAnalyses::all();
-
- return getLoopPassPreservedAnalyses();
-}
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