llvm::LoopVectorizationPlanner Class Reference

Planner drives the vectorization process after having passed Legality checks. More...

#include "Transforms/Vectorize/LoopVectorizationPlanner.h"

Public Member Functions
	LoopVectorizationPlanner (Loop *L, LoopInfo *LI, DominatorTree *DT, const TargetLibraryInfo *TLI, const TargetTransformInfo &TTI, LoopVectorizationLegality *Legal, LoopVectorizationCostModel &CM, InterleavedAccessInfo &IAI, PredicatedScalarEvolution &PSE, const LoopVectorizeHints &Hints, OptimizationRemarkEmitter *ORE)
std::optional< VectorizationFactor >	plan (ElementCount UserVF, unsigned UserIC)
	Plan how to best vectorize, return the best VF and its cost, or std::nullopt if vectorization and interleaving should be avoided up front.
VectorizationFactor	planInVPlanNativePath (ElementCount UserVF)
	Use the VPlan-native path to plan how to best vectorize, return the best VF and its cost.
VPlan &	getPlanFor (ElementCount VF) const
	Return the VPlan for VF.
ElementCount	computeBestVF ()
	Compute and return the most profitable vectorization factor.
std::pair< DenseMap< const SCEV *, Value * >, DenseMap< const RecurrenceDescriptor *, Value * > >	executePlan (ElementCount VF, unsigned UF, VPlan &BestPlan, InnerLoopVectorizer &LB, DominatorTree *DT, bool IsEpilogueVectorization, const DenseMap< const SCEV *, Value * > *ExpandedSCEVs=nullptr)
	Generate the IR code for the vectorized loop captured in VPlan BestPlan according to the best selected VF and UF.
void	printPlans (raw_ostream &O)
bool	hasPlanWithVF (ElementCount VF) const
	Look through the existing plans and return true if we have one with vectorization factor VF.
VectorizationFactor	selectEpilogueVectorizationFactor (const ElementCount MaxVF, unsigned IC)
void	emitInvalidCostRemarks (OptimizationRemarkEmitter *ORE)
	Emit remarks for recipes with invalid costs in the available VPlans.

Static Public Member Functions
static bool	getDecisionAndClampRange (const std::function< bool(ElementCount)> &Predicate, VFRange &Range)
	Test a Predicate on a Range of VF's.

Protected Member Functions
void	buildVPlans (ElementCount MinVF, ElementCount MaxVF)
	Build VPlans for power-of-2 VF's between MinVF and MaxVF inclusive, according to the information gathered by Legal when it checked if it is legal to vectorize the loop.

Detailed Description

Planner drives the vectorization process after having passed Legality checks.

Definition at line 298 of file LoopVectorizationPlanner.h.

Constructor & Destructor Documentation

LoopVectorizationPlanner()

llvm::LoopVectorizationPlanner::LoopVectorizationPlanner ( Loop *  L, LoopInfo *  LI, DominatorTree *  DT, const TargetLibraryInfo *  TLI, const TargetTransformInfo &  TTI, LoopVectorizationLegality *  Legal, LoopVectorizationCostModel &  CM, InterleavedAccessInfo &  IAI, PredicatedScalarEvolution &  PSE, const LoopVectorizeHints &  Hints, OptimizationRemarkEmitter *  ORE  )

inline

Definition at line 348 of file LoopVectorizationPlanner.h.

References llvm::IRSimilarity::Legal.

Member Function Documentation

buildVPlans()

void LoopVectorizationPlanner::buildVPlans ( ElementCount  MinVF, ElementCount  MaxVF  )

protected

Build VPlans for power-of-2 VF's between MinVF and MaxVF inclusive, according to the information gathered by Legal when it checked if it is legal to vectorize the loop.

Build VPlans for the full range of feasible VF's = {MinVF, 2 * MinVF, 4 * MinVF, ..., MaxVF} by repeatedly building a VPlan for a sub-range of VF's starting at a given VF and extending it as much as possible.

Each vectorization decision can potentially shorten this sub-range during buildVPlan().

Definition at line 1671 of file VPlan.cpp.

References llvm::VFRange::End, llvm::details::FixedOrScalableQuantity< ElementCount, unsigned >::isKnownLT(), llvm::VPlanTransforms::optimize(), llvm::VPTransformState::Plan, and llvm::VPTransformState::VF.

Referenced by planInVPlanNativePath().

computeBestVF()

ElementCount LoopVectorizationPlanner::computeBestVF

(

)

Compute and return the most profitable vectorization factor.

Also collect all profitable VFs in ProfitableVFs.

Definition at line 7258 of file LoopVectorize.cpp.

References assert(), llvm::VectorizationFactor::Cost, llvm::dbgs(), llvm::LoopVectorizationCostModel::expectedCost(), llvm::LoopVectorizeHints::FK_Enabled, llvm::ElementCount::getFixed(), llvm::LoopVectorizeHints::getForce(), llvm::InstructionCost::getMax(), hasPlanWithVF(), llvm::ElementCount::isScalar(), LLVM_DEBUG, P, llvm::size(), llvm::VPlan::vectorFactors(), llvm::VectorizationFactor::Width, and willGenerateVectors().

Referenced by llvm::LoopVectorizePass::processLoop().

emitInvalidCostRemarks()

void LoopVectorizationPlanner::emitInvalidCostRemarks

(

OptimizationRemarkEmitter *

ORE

)

Emit remarks for recipes with invalid costs in the available VPlans.

Definition at line 4346 of file LoopVectorize.cpp.

References A, assert(), B, llvm::TypeSwitch< T, ResultT >::Case(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::count(), llvm::SmallVectorImpl< T >::emplace_back(), llvm::SmallVectorBase< Size_T >::empty(), llvm::raw_ostream::flush(), llvm::BasicBlock::getContext(), llvm::LoopBase< BlockT, LoopT >::getHeader(), llvm::Value::getName(), llvm::Instruction::getOpcodeName(), llvm::LoopVectorizationLegality::getWidestInductionType(), I, if(), LHS, OS, llvm::reportVectorizationInfo(), RHS, llvm::sort(), llvm::CallingConv::Tail, llvm::LoopVectorizationCostModel::TLI, llvm::LoopVectorizationCostModel::TTI, and llvm::vp_depth_first_deep().

Referenced by llvm::LoopVectorizePass::processLoop().

executePlan()

std::pair< DenseMap< const SCEV *, Value * >, DenseMap< const RecurrenceDescriptor *, Value * > > LoopVectorizationPlanner::executePlan	(	ElementCount	VF,
		unsigned	UF,
		VPlan &	BestPlan,
		InnerLoopVectorizer &	LB,
		DominatorTree *	DT,
		bool	IsEpilogueVectorization,
		const DenseMap< const SCEV *, Value * > *	ExpandedSCEVs = nullptr
	)

Generate the IR code for the vectorized loop captured in VPlan BestPlan according to the best selected VF and UF.

TODO: IsEpilogueVectorization is needed to avoid issues due to epilogue vectorization re-using plans for both the main and epilogue vector loops. It should be removed once the re-use issue has been fixed. ExpandedSCEVs is passed during execution of the plan for epilogue loop to re-use expansion results generated during main plan execution.

Returns a mapping of SCEVs to their expanded IR values and a mapping for the reduction resume values. Note that this is a temporary workaround needed due to the current epilogue handling.

Definition at line 7409 of file LoopVectorize.cpp.

References AddRuntimeUnrollDisableMetaData(), assert(), llvm::InnerLoopVectorizer::Builder, llvm::VPTransformState::Builder, llvm::VPTransformState::CFG, createAndCollectMergePhiForReduction(), llvm::InnerLoopVectorizer::createVectorizedLoopSkeleton(), llvm::dbgs(), llvm::VPlan::dump(), llvm::SmallVectorBase< Size_T >::empty(), llvm::VPBasicBlock::empty(), llvm::VPlan::execute(), llvm::VPBasicBlock::execute(), llvm::VPTransformState::ExpandedSCEVs, llvm::InnerLoopVectorizer::fixVectorizedLoop(), llvm::VPTransformState::get(), llvm::RuntimePointerChecking::getChecks(), llvm::BasicBlock::getContext(), llvm::RuntimePointerChecking::getDiffChecks(), llvm::VPBlockBase::getEntryBasicBlock(), llvm::LoopBase< BlockT, LoopT >::getHeader(), llvm::details::FixedOrScalableQuantity< LeafTy, ValueTy >::getKnownMinValue(), llvm::LoopVectorizationLegality::getLAI(), llvm::LoopInfoBase< BlockT, LoopT >::getLoopFor(), llvm::Loop::getLoopID(), llvm::LoopBase< BlockT, LoopT >::getLoopLatch(), llvm::LoopBase< BlockT, LoopT >::getLoopPreheader(), llvm::InnerLoopVectorizer::getOrCreateVectorTripCount(), llvm::VPlan::getPreheader(), llvm::LoopAccessInfo::getRuntimePointerChecking(), llvm::PredicatedScalarEvolution::getSE(), llvm::VPBlockBase::getSingleSuccessor(), llvm::BasicBlock::getTerminator(), llvm::InnerLoopVectorizer::getTripCount(), llvm::VPlan::getTripCount(), llvm::TargetTransformInfo::getUnrollingPreferences(), llvm::VPlan::getVectorLoopRegion(), llvm::hasBranchWeightMD(), llvm::VPlan::hasUF(), llvm::VPlan::hasVF(), llvm::InnerLoopVectorizer::Legal, LLVM_DEBUG, LLVMLoopVectorizeFollowupAll, LLVMLoopVectorizeFollowupVectorized, llvm::VPTransformState::LVer, llvm::makeFollowupLoopID(), llvm::VPlanTransforms::optimizeForVFAndUF(), llvm::LoopVersioning::prepareNoAliasMetadata(), llvm::VPlan::prepareToExecute(), llvm::VPTransformState::CFGState::PrevBB, llvm::InnerLoopVectorizer::printDebugTracesAtEnd(), llvm::InnerLoopVectorizer::printDebugTracesAtStart(), llvm::LoopVectorizeHints::setAlreadyVectorized(), llvm::setBranchWeights(), llvm::IRBuilderBase::SetInsertPoint(), llvm::VPlan::setName(), llvm::InnerLoopVectorizer::setTripCount(), llvm::VPTransformState::UF, llvm::TargetTransformInfo::UnrollingPreferences::UnrollVectorizedLoop, llvm::DominatorTreeBase< NodeT, IsPostDom >::verify(), llvm::VPTransformState::VF, and llvm::VPTransformState::CFGState::VPBB2IRBB.

Referenced by llvm::LoopVectorizePass::processLoop(), and processLoopInVPlanNativePath().

getDecisionAndClampRange()

bool LoopVectorizationPlanner::getDecisionAndClampRange ( const std::function< bool(ElementCount)> &  Predicate, VFRange &  Range  )

static

Test a Predicate on a Range of VF's.

Return the value of applying Predicate on Range.Start, possibly decreasing Range.End such that the returned value holds for the entire Range.

Definition at line 1652 of file VPlan.cpp.

References assert(), and Range.

Referenced by llvm::VPRecipeBuilder::handleReplication(), and llvm::VPRecipeBuilder::tryToCreateWidenRecipe().

getPlanFor()

VPlan & LoopVectorizationPlanner::getPlanFor

(

ElementCount

VF

)

const

Return the VPlan for VF.

At the moment, there is always a single VPlan for each VF.

Definition at line 1683 of file VPlan.cpp.

References assert(), llvm::count_if(), llvm::VPlan::hasVF(), llvm_unreachable, llvm::VPTransformState::Plan, and llvm::VPTransformState::VF.

Referenced by llvm::LoopVectorizePass::processLoop(), and processLoopInVPlanNativePath().

hasPlanWithVF()

bool llvm::LoopVectorizationPlanner::hasPlanWithVF ( ElementCount  VF ) const

inline

Look through the existing plans and return true if we have one with vectorization factor VF.

Definition at line 398 of file LoopVectorizationPlanner.h.

References llvm::any_of().

Referenced by computeBestVF(), plan(), and selectEpilogueVectorizationFactor().

plan()

std::optional< VectorizationFactor > LoopVectorizationPlanner::plan	(	ElementCount	UserVF,
		unsigned	UserIC
	)

Plan how to best vectorize, return the best VF and its cost, or std::nullopt if vectorization and interleaving should be avoided up front.

Definition at line 6989 of file LoopVectorize.cpp.

References llvm::all_of(), assert(), llvm::LoopVectorizationCostModel::blockNeedsPredicationForAnyReason(), llvm::LoopVectorizationCostModel::collectElementTypesForWidening(), llvm::LoopVectorizationCostModel::collectInLoopReductions(), llvm::LoopVectorizationCostModel::collectInstsToScalarize(), llvm::LoopVectorizationCostModel::collectUniformsAndScalars(), llvm::LoopVectorizationCostModel::collectValuesToIgnore(), llvm::LoopVectorizationCostModel::computeMaxVF(), llvm::dbgs(), llvm::VectorizationFactor::Disabled(), llvm::FixedScalableVFPair::FixedVF, llvm::LoopVectorizationCostModel::foldTailByMasking(), llvm::ElementCount::getFixed(), llvm::LoopBase< BlockT, LoopT >::getHeader(), llvm::details::FixedOrScalableQuantity< LeafTy, ValueTy >::getKnownMinValue(), llvm::ElementCount::getScalable(), hasPlanWithVF(), llvm::LoopVectorizationCostModel::InterleaveInfo, llvm::LoopVectorizationCostModel::invalidateCostModelingDecisions(), llvm::InterleavedAccessInfo::invalidateGroups(), llvm::LoopBase< BlockT, LoopT >::isInnermost(), llvm::details::FixedOrScalableQuantity< ElementCount, unsigned >::isKnownLE(), llvm::isPowerOf2_32(), llvm::details::FixedOrScalableQuantity< LeafTy, ValueTy >::isScalable(), llvm::ElementCount::isScalar(), llvm::ElementCount::isVector(), LLVM_DEBUG, P, llvm::LoopVectorizationLegality::prepareToFoldTailByMasking(), printPlans(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::reportVectorizationInfo(), llvm::FixedScalableVFPair::ScalableVF, llvm::VectorizationFactor::ScalarCost, llvm::LoopVectorizationCostModel::selectUserVectorizationFactor(), useMaskedInterleavedAccesses(), and llvm::VectorizationFactor::Width.

Referenced by llvm::LoopVectorizePass::processLoop().

planInVPlanNativePath()

VectorizationFactor LoopVectorizationPlanner::planInVPlanNativePath

(

ElementCount

UserVF

)

Use the VPlan-native path to plan how to best vectorize, return the best VF and its cost.

Definition at line 6937 of file LoopVectorize.cpp.

References assert(), buildVPlans(), llvm::dbgs(), determineVPlanVF(), llvm::VectorizationFactor::Disabled(), llvm::EnableVPlanNativePath, ForceTargetSupportsScalableVectors, llvm::ElementCount::getFixed(), llvm::details::FixedOrScalableQuantity< LeafTy, ValueTy >::getKnownMinValue(), llvm::LoopBase< BlockT, LoopT >::isInnermost(), llvm::isPowerOf2_32(), llvm::details::FixedOrScalableQuantity< LeafTy, ValueTy >::isScalable(), llvm::ElementCount::isScalar(), llvm::details::FixedOrScalableQuantity< LeafTy, ValueTy >::isZero(), LLVM_DEBUG, llvm::reportVectorizationFailure(), llvm::TargetTransformInfo::supportsScalableVectors(), and VPlanBuildStressTest.

Referenced by processLoopInVPlanNativePath().

printPlans()

void LoopVectorizationPlanner::printPlans

(

raw_ostream &

O

)

Definition at line 1697 of file VPlan.cpp.

References llvm::VPTransformState::Plan, llvm::VPlan::print(), llvm::VPlan::printDOT(), and PrintVPlansInDotFormat.

Referenced by plan().

selectEpilogueVectorizationFactor()

VectorizationFactor LoopVectorizationPlanner::selectEpilogueVectorizationFactor	(	const ElementCount	MaxVF,
		unsigned	IC
	)

Returns

The most profitable vectorization factor and the cost of that VF for vectorizing the epilogue. Returns VectorizationFactor::Disabled if epilogue vectorization is not supported for the loop.

Definition at line 4681 of file LoopVectorize.cpp.

References llvm::createTripCountSCEV(), llvm::dbgs(), llvm::VectorizationFactor::Disabled(), EnableEpilogueVectorization, EpilogueVectorizationForceVF, llvm::ScalarEvolution::getConstant(), llvm::ElementCount::getFixed(), llvm::LoopBase< BlockT, LoopT >::getHeader(), llvm::details::FixedOrScalableQuantity< LeafTy, ValueTy >::getKnownMinValue(), llvm::BasicBlock::getParent(), llvm::PredicatedScalarEvolution::getSE(), llvm::ScalarEvolution::getURemExpr(), getVScaleForTuning(), llvm::LoopVectorizationLegality::getWidestInductionType(), llvm::Function::hasMinSize(), llvm::Function::hasOptSize(), hasPlanWithVF(), llvm::CmpInst::ICMP_UGT, llvm::LoopVectorizationCostModel::isEpilogueVectorizationProfitable(), llvm::details::FixedOrScalableQuantity< ElementCount, unsigned >::isKnownGE(), llvm::ScalarEvolution::isKnownPredicate(), llvm::details::FixedOrScalableQuantity< LeafTy, ValueTy >::isScalable(), llvm::LoopVectorizationCostModel::isScalarEpilogueAllowed(), and LLVM_DEBUG.

Referenced by llvm::LoopVectorizePass::processLoop().

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The documentation for this class was generated from the following files:

• lib/Transforms/Vectorize/LoopVectorizationPlanner.h
• lib/Transforms/Vectorize/LoopVectorize.cpp
• lib/Transforms/Vectorize/VPlan.cpp