Holds information about the memory runtime legality checks to verify that a group of pointers do not overlap. More...

#include "llvm/Analysis/LoopAccessAnalysis.h"

Classes
struct	PointerInfo

Public Member Functions
	RuntimePointerChecking (MemoryDepChecker &DC, ScalarEvolution *SE, std::optional< ScalarEvolution::LoopGuards > &LoopGuards)
void	reset ()
	Reset the state of the pointer runtime information.
LLVM_ABI void	insert (Loop Lp, Value Ptr, const SCEV PtrExpr, Type AccessTy, bool WritePtr, unsigned DepSetId, unsigned ASId, PredicatedScalarEvolution &PSE, bool NeedsFreeze)
	Insert a pointer and calculate the start and end SCEVs.
bool	empty () const
	No run-time memory checking is necessary.
LLVM_ABI void	generateChecks (MemoryDepChecker::DepCandidates &DepCands, bool UseDependencies)
	Generate the checks and store it.
const SmallVectorImpl< RuntimePointerCheck > &	getChecks () const
	Returns the checks that generateChecks created.
std::optional< ArrayRef< PointerDiffInfo > >	getDiffChecks () const
LLVM_ABI bool	needsChecking (const RuntimeCheckingPtrGroup &M, const RuntimeCheckingPtrGroup &N) const
	Decide if we need to add a check between two groups of pointers, according to needsChecking.
unsigned	getNumberOfChecks () const
	Returns the number of run-time checks required according to needsChecking.
LLVM_ABI void	print (raw_ostream &OS, unsigned Depth=0) const
	Print the list run-time memory checks necessary.
LLVM_ABI void	printChecks (raw_ostream &OS, const SmallVectorImpl< RuntimePointerCheck > &Checks, unsigned Depth=0) const
	Print `Checks`.
LLVM_ABI bool	needsChecking (unsigned I, unsigned J) const
	Decide whether we need to issue a run-time check for pointer at index `I` and `J` to prove their independence.
const PointerInfo &	getPointerInfo (unsigned PtrIdx) const
	Return PointerInfo for pointer at index `PtrIdx`.
ScalarEvolution *	getSE () const

Static Public Member Functions
static LLVM_ABI bool	arePointersInSamePartition (const SmallVectorImpl< int > &PtrToPartition, unsigned PtrIdx1, unsigned PtrIdx2)
	Check if pointers are in the same partition.

Public Attributes
bool	Need = false
	This flag indicates if we need to add the runtime check.
SmallVector< PointerInfo, 2 >	Pointers
	Information about the pointers that may require checking.
SmallVector< RuntimeCheckingPtrGroup, 2 >	CheckingGroups
	Holds a partitioning of pointers into "check groups".

Friends
struct	RuntimeCheckingPtrGroup

Detailed Description

Holds information about the memory runtime legality checks to verify that a group of pointers do not overlap.

Definition at line 503 of file LoopAccessAnalysis.h.

Constructor & Destructor Documentation

◆ RuntimePointerChecking()

llvm::RuntimePointerChecking::RuntimePointerChecking	(	MemoryDepChecker &	DC,
		ScalarEvolution *	SE,
		std::optional< ScalarEvolution::LoopGuards > &	LoopGuards )

inline

Definition at line 536 of file LoopAccessAnalysis.h.

Member Function Documentation

◆ arePointersInSamePartition()

bool RuntimePointerChecking::arePointersInSamePartition	(	const SmallVectorImpl< int > &	PtrToPartition,
		unsigned	PtrIdx1,
		unsigned	PtrIdx2 )

static

Check if pointers are in the same partition.

PtrToPartition contains the partition number for pointers (-1 if the pointer belongs to multiple partitions).

Definition at line 717 of file LoopAccessAnalysis.cpp.

◆ empty()

bool llvm::RuntimePointerChecking::empty ( ) const

inline

No run-time memory checking is necessary.

Definition at line 561 of file LoopAccessAnalysis.h.

References Pointers.

◆ generateChecks()

void RuntimePointerChecking::generateChecks	(	MemoryDepChecker::DepCandidates &	DepCands,
		bool	UseDependencies )

Generate the checks and store it.

This also performs the grouping of pointers to reduce the number of memchecks necessary.

Definition at line 528 of file LoopAccessAnalysis.cpp.

References assert(), and generateChecks().

Referenced by generateChecks().

◆ getChecks()

const SmallVectorImpl< RuntimePointerCheck > & llvm::RuntimePointerChecking::getChecks ( ) const

inline

Returns the checks that generateChecks created.

They can be used to ensure no read/write accesses overlap across all loop iterations.

Definition at line 570 of file LoopAccessAnalysis.h.

◆ getDiffChecks()

std::optional< ArrayRef< PointerDiffInfo > > llvm::RuntimePointerChecking::getDiffChecks ( ) const

inline

Definition at line 579 of file LoopAccessAnalysis.h.

◆ getNumberOfChecks()

unsigned llvm::RuntimePointerChecking::getNumberOfChecks ( ) const

inline

Returns the number of run-time checks required according to needsChecking.

Definition at line 592 of file LoopAccessAnalysis.h.

◆ getPointerInfo()

const PointerInfo & llvm::RuntimePointerChecking::getPointerInfo ( unsigned PtrIdx ) const

inline

Return PointerInfo for pointer at index PtrIdx.

Definition at line 624 of file LoopAccessAnalysis.h.

References Pointers.

Referenced by llvm::LoopVersioning::prepareNoAliasMetadata().

◆ getSE()

ScalarEvolution * llvm::RuntimePointerChecking::getSE ( ) const

inline

Definition at line 628 of file LoopAccessAnalysis.h.

◆ insert()

void RuntimePointerChecking::insert	(	Loop *	Lp,
		Value *	Ptr,
		const SCEV *	PtrExpr,
		Type *	AccessTy,
		bool	WritePtr,
		unsigned	DepSetId,
		unsigned	ASId,
		PredicatedScalarEvolution &	PSE,
		bool	NeedsFreeze )

Insert a pointer and calculate the start and end SCEVs.

Calculate Start and End points of memory access using getStartAndEndForAccess.

We need PSE in order to compute the SCEV expression of the pointer according to the assumptions that we've made during the analysis. The method might also version the pointer stride according to Strides, and add new predicates to PSE.

Definition at line 389 of file LoopAccessAnalysis.cpp.

References assert(), llvm::PredicatedScalarEvolution::getBackedgeTakenCount(), llvm::PredicatedScalarEvolution::getSE(), llvm::getStartAndEndForAccess(), llvm::PredicatedScalarEvolution::getSymbolicMaxBackedgeTakenCount(), llvm::isa(), Pointers, and Ptr.