BasicAliasAnalysis.cpp File Reference

#include "llvm/Analysis/BasicAliasAnalysis.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/CFG.h"
#include "llvm/Analysis/CaptureTracking.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/Analysis/MemoryLocation.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/Argument.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/Operator.h"
#include "llvm/IR/PatternMatch.h"
#include "llvm/IR/Type.h"
#include "llvm/IR/User.h"
#include "llvm/IR/Value.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/KnownBits.h"
#include "llvm/Support/SaveAndRestore.h"
#include <cassert>
#include <cstdint>
#include <cstdlib>
#include <optional>
#include <utility>

Go to the source code of this file.

Classes
struct	llvm::BasicAAResult::DecomposedGEP

Macros
#define	DEBUG_TYPE   "basicaa"

Functions
	STATISTIC (SearchLimitReached, "Number of times the limit to " "decompose GEPs is reached")
	SearchLimitReached / SearchTimes shows how often the limit of to decompose GEPs is reached.
	STATISTIC (SearchTimes, "Number of times a GEP is decomposed")
static std::optional< TypeSize >	getObjectSize (const Value *V, const DataLayout &DL, const TargetLibraryInfo &TLI, bool NullIsValidLoc, bool RoundToAlign=false)
	Returns the size of the object specified by V or UnknownSize if unknown.
static bool	isObjectSmallerThan (const Value *V, TypeSize Size, const DataLayout &DL, const TargetLibraryInfo &TLI, bool NullIsValidLoc)
	Returns true if we can prove that the object specified by V is smaller than Size.
static TypeSize	getMinimalExtentFrom (const Value &V, const LocationSize &LocSize, const DataLayout &DL, bool NullIsValidLoc)
	Return the minimal extent from V to the end of the underlying object, assuming the result is used in an aliasing query.
static bool	isObjectSize (const Value *V, TypeSize Size, const DataLayout &DL, const TargetLibraryInfo &TLI, bool NullIsValidLoc)
	Returns true if we can prove that the object specified by V has size Size.
static bool	areBothVScale (const Value *V1, const Value *V2)
	Return true if both V1 and V2 are VScale.
static bool	isNotInCycle (const Instruction *I, const DominatorTree *DT, const LoopInfo *LI)
static LinearExpression	GetLinearExpression (const CastedValue &Val, const DataLayout &DL, unsigned Depth, AssumptionCache *AC, DominatorTree *DT)
	Analyzes the specified value as a linear expression: "A*V + B", where A and B are constant integers.
static bool	isIntrinsicCall (const CallBase *Call, Intrinsic::ID IID)
static const Function *	getParent (const Value *V)
static bool	notDifferentParent (const Value *O1, const Value *O2)
static AliasResult	MergeAliasResults (AliasResult A, AliasResult B)
static bool	isArgumentOrArgumentLike (const Value *V)
	INITIALIZE_PASS_BEGIN (BasicAAWrapperPass, "basic-aa", "Basic Alias Analysis (stateless AA impl)", true, true) INITIALIZE_PASS_END(BasicAAWrapperPass
basic Basic Alias	Analysis (stateless AA impl)"

Variables
static cl::opt< bool >	EnableRecPhiAnalysis ("basic-aa-recphi", cl::Hidden, cl::init(true))
	Enable analysis of recursive PHI nodes.
static cl::opt< bool >	EnableSeparateStorageAnalysis ("basic-aa-separate-storage", cl::Hidden, cl::init(true))
basic	aa
basic Basic Alias	true

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "basicaa"

Definition at line 64 of file BasicAliasAnalysis.cpp.

Function Documentation

Analysis()

basic Basic Alias Analysis

(

stateless AA

impl

)

areBothVScale()

bool areBothVScale ( const Value * V1, const Value * V2 )

static

Return true if both V1 and V2 are VScale.

Definition at line 187 of file BasicAliasAnalysis.cpp.

References llvm::PatternMatch::m_VScale(), and llvm::PatternMatch::match().

GetLinearExpression()

LinearExpression GetLinearExpression ( const CastedValue & Val, const DataLayout & DL, unsigned Depth, AssumptionCache * AC, DominatorTree * DT )

static

Analyzes the specified value as a linear expression: "A*V + B", where A and B are constant integers.

Definition at line 419 of file BasicAliasAnalysis.cpp.

References llvm::cast(), llvm::Depth, DL, llvm::dyn_cast(), E(), GetLinearExpression(), llvm::isa(), and RHS.

Referenced by GetLinearExpression().

getMinimalExtentFrom()

TypeSize getMinimalExtentFrom ( const Value & V, const LocationSize & LocSize, const DataLayout & DL, bool NullIsValidLoc )

static

Return the minimal extent from V to the end of the underlying object, assuming the result is used in an aliasing query.

E.g., we do use the query location size and the fact that null pointers cannot alias here.

Definition at line 159 of file BasicAliasAnalysis.cpp.

References DL, llvm::TypeSize::getFixed(), llvm::details::FixedOrScalableQuantity< LeafTy, ValueTy >::getKnownMinValue(), llvm::LocationSize::getValue(), and llvm::LocationSize::isPrecise().

getObjectSize()

std::optional< TypeSize > getObjectSize ( const Value * V, const DataLayout & DL, const TargetLibraryInfo & TLI, bool NullIsValidLoc, bool RoundToAlign = false )

static

Returns the size of the object specified by V or UnknownSize if unknown.

Definition at line 101 of file BasicAliasAnalysis.cpp.

References DL, llvm::getBaseObjectSize(), llvm::ObjectSizeOpts::NullIsUnknownSize, llvm::ObjectSizeOpts::RoundToAlign, and Size.

getParent()

const Function * getParent ( const Value * V )

static

Definition at line 885 of file BasicAliasAnalysis.cpp.

References llvm::dyn_cast(), and llvm::GlobalValue::getParent().

Referenced by llvm::slpvectorizer::BoUpSLP::canVectorizeLoads(), llvm::CFIInstBuilder::CFIInstBuilder(), llvm::CloneAndPruneIntoFromInst(), llvm::LoopVectorizationCostModel::collectValuesToIgnore(), llvm::JumpThreadingPass::computeValueKnownInPredecessorsImpl(), llvm::DataDependenceGraph::DataDependenceGraph(), detectPopcountIdiom(), llvm::DiagnosticInfoMIROptimization::DiagnosticInfoMIROptimization(), llvm::DiagnosticInfoMisExpect::DiagnosticInfoMisExpect(), llvm::DiagnosticInfoOptimizationFailure::DiagnosticInfoOptimizationFailure(), ensureValueAvailableInSuccessor(), llvm::InstCombinerImpl::foldOpIntoPhi(), foldURemOfLoopIncrement(), llvm::FunctionPropertiesUpdater::FunctionPropertiesUpdater(), llvm::RegionBase< Tr >::getDepth(), getLocalFunctionMetadata(), llvm::LoopBase< BasicBlock, Loop >::getLoopLatch(), llvm::TargetLoweringObjectFileGOFF::getModuleMetadata(), llvm::LazyValueInfo::getPredicateAt(), llvm::slpvectorizer::BoUpSLP::getReorderingData(), llvm::MCSectionGOFF::getTextStyle(), llvm::InlineAdvice::InlineAdvice(), ARMInstructionSelector::InsertInfo::InsertInfo(), llvm::InstrEmitter::InstrEmitter(), isBlockValidForExtraction(), llvm::VPWidenIntOrFpInductionRecipe::isCanonical(), llvm::PHINode::isComplete(), isOnlyUsedInEntryBlock(), isUsedOutsideOfDefiningBlock(), LLVMGetBasicBlockParent(), LLVMGetGlobalParent(), LLVMGetInstructionParent(), LLVMGetParamParent(), llvm::LoopConstrainer::LoopConstrainer(), llvm::MachineIRBuilder::MachineIRBuilder(), llvm::MachineModuleSlotTracker::MachineModuleSlotTracker(), llvm::MachineOptimizationRemarkAnalysis::MachineOptimizationRemarkAnalysis(), llvm::VPlanTransforms::materializeBroadcasts(), llvm::MIBundleBuilder::MIBundleBuilder(), notDifferentParent(), llvm::OptimizationRemark::OptimizationRemark(), llvm::OptimizationRemark::OptimizationRemark(), llvm::OptimizationRemarkAnalysis::OptimizationRemarkAnalysis(), llvm::OptimizationRemarkAnalysis::OptimizationRemarkAnalysis(), llvm::OptimizationRemarkAnalysis::OptimizationRemarkAnalysis(), llvm::OptimizationRemarkMissed::OptimizationRemarkMissed(), llvm::OptimizationRemarkMissed::OptimizationRemarkMissed(), llvm::BasicBlock::print(), llvm::DbgMarker::print(), llvm::Function::print(), llvm::MachineFunction::print(), llvm::NamedMDNode::print(), llvm::NamedMDNode::print(), llvm::PrologEpilogSGPRSpillBuilder::PrologEpilogSGPRSpillBuilder(), redirectValuesFromPredecessorsToPhi(), llvm::AssumptionCache::registerAssumption(), llvm::VerifyInstrumentation::registerCallbacks(), RemarkInfo::RemarkInfo(), llvm::LoopRotatePass::run(), llvm::ScheduleDAGMI::schedule(), llvm::ScheduleDAGMILive::schedule(), llvm::SIScheduleDAGMI::schedule(), llvm::VLIWMachineScheduler::schedule(), llvm::SGPRSpillBuilder::SGPRSpillBuilder(), llvm::SlotTracker::SlotTracker(), splitCallSite(), llvm::GenericCycle< ContextT >::verifyCycle(), and llvm::slpvectorizer::BoUpSLP::VLOperands::VLOperands().

INITIALIZE_PASS_BEGIN()

INITIALIZE_PASS_BEGIN	(	BasicAAWrapperPass	,
		"basic-aa"	,
		"Basic Alias Analysis (stateless AA impl)"	,
		true	,
		true	)

References INITIALIZE_PASS_DEPENDENCY.

isArgumentOrArgumentLike()

bool isArgumentOrArgumentLike ( const Value * V )

static

Definition at line 1579 of file BasicAliasAnalysis.cpp.

References llvm::dyn_cast(), E(), and llvm::isa().

isIntrinsicCall()

bool isIntrinsicCall ( const CallBase * Call, Intrinsic::ID IID )

static

Definition at line 827 of file BasicAliasAnalysis.cpp.

References Call, llvm::dyn_cast(), and II.

Referenced by llvm::BasicAAResult::getModRefInfo(), llvm::BasicAAResult::getModRefInfo(), isPreserveArrayIndex(), isPreserveStructIndex(), and isPreserveUnionIndex().

isNotInCycle()

bool isNotInCycle ( const Instruction * I, const DominatorTree * DT, const LoopInfo * LI )

static

Definition at line 216 of file BasicAliasAnalysis.cpp.

References llvm::SmallVectorTemplateCommon< T, typename >::empty(), I, llvm::isPotentiallyReachableFromMany(), and llvm::successors().

Referenced by llvm::EarliestEscapeAnalysis::getCapturesBefore().

isObjectSize()

bool isObjectSize ( const Value * V, TypeSize Size, const DataLayout & DL, const TargetLibraryInfo & TLI, bool NullIsValidLoc )

static

Returns true if we can prove that the object specified by V has size Size.

Definition at line 179 of file BasicAliasAnalysis.cpp.

References DL, llvm::getObjectSize(), and Size.

isObjectSmallerThan()

bool isObjectSmallerThan ( const Value * V, TypeSize Size, const DataLayout & DL, const TargetLibraryInfo & TLI, bool NullIsValidLoc )

static

Returns true if we can prove that the object specified by V is smaller than Size.

Bails out early unless the root object is passed as the first parameter.

Definition at line 121 of file BasicAliasAnalysis.cpp.

References DL, llvm::getObjectSize(), llvm::isIdentifiedObject(), llvm::details::FixedOrScalableQuantity< TypeSize, uint64_t >::isKnownLT(), and Size.

MergeAliasResults()

AliasResult MergeAliasResults ( AliasResult A, AliasResult B )

static

Definition at line 1410 of file BasicAliasAnalysis.cpp.

References A(), B(), llvm::AliasResult::MayAlias, llvm::AliasResult::MustAlias, and llvm::AliasResult::PartialAlias.

notDifferentParent()

bool notDifferentParent ( const Value * O1, const Value * O2 )

static

Definition at line 898 of file BasicAliasAnalysis.cpp.

References getParent().

Referenced by llvm::BasicAAResult::alias(), and llvm::BasicAAResult::getModRefInfo().

STATISTIC() [1/2]

STATISTIC	(	SearchLimitReached	,
		"Number of times the limit to " "decompose GEPs is reached"	)

SearchLimitReached / SearchTimes shows how often the limit of to decompose GEPs is reached.

It will affect the precision of basic alias analysis.

STATISTIC() [2/2]

STATISTIC	(	SearchTimes	,
		"Number of times a GEP is decomposed"	)

Variable Documentation

aa

basic aa

Definition at line 2035 of file BasicAliasAnalysis.cpp.

EnableRecPhiAnalysis

cl::opt< bool > EnableRecPhiAnalysis("basic-aa-recphi", cl::Hidden, cl::init(true)) ( "basic-aa-recphi" , cl::Hidden , cl::init(true)  )

static

Enable analysis of recursive PHI nodes.

EnableSeparateStorageAnalysis

cl::opt< bool > EnableSeparateStorageAnalysis("basic-aa-separate-storage", cl::Hidden, cl::init(true)) ( "basic-aa-separate-storage" , cl::Hidden , cl::init(true)  )

static

true

print machine Print Machine Cycle Info true

Definition at line 2036 of file BasicAliasAnalysis.cpp.