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

#include "llvm/Analysis/LoopAccessAnalysis.h"

Collaboration diagram for llvm::RuntimePointerChecking:

[legend]

Classes
struct	CheckingPtrGroup
	A grouping of pointers. More...

struct	PointerInfo

Public Types
typedef std::pair< const CheckingPtrGroup , const CheckingPtrGroup >	PointerCheck
	A memcheck which made up of a pair of grouped pointers. More...

Public Member Functions
	RuntimePointerChecking (ScalarEvolution *SE)

void	reset ()
	Reset the state of the pointer runtime information. More...

void	insert (Loop Lp, Value Ptr, bool WritePtr, unsigned DepSetId, unsigned ASId, const ValueToValueMap &Strides, PredicatedScalarEvolution &PSE)
	Insert a pointer and calculate the start and end SCEVs. More...

bool	empty () const
	No run-time memory checking is necessary. More...

void	generateChecks (MemoryDepChecker::DepCandidates &DepCands, bool UseDependencies)
	Generate the checks and store it. More...

const SmallVector< PointerCheck, 4 > &	getChecks () const
	Returns the checks that generateChecks created. More...

bool	needsChecking (const CheckingPtrGroup &M, const CheckingPtrGroup &N) const
	Decide if we need to add a check between two groups of pointers, according to needsChecking. More...

unsigned	getNumberOfChecks () const
	Returns the number of run-time checks required according to needsChecking. More...

void	print (raw_ostream &OS, unsigned Depth=0) const
	Print the list run-time memory checks necessary. More...

void	printChecks (raw_ostream &OS, const SmallVectorImpl< PointerCheck > &Checks, unsigned Depth=0) const
	Print `Checks`. More...

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. More...

const PointerInfo &	getPointerInfo (unsigned PtrIdx) const
	Return PointerInfo for pointer at index `PtrIdx`. More...

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

Public Attributes
bool	Need
	This flag indicates if we need to add the runtime check. More...

SmallVector< PointerInfo, 2 >	Pointers
	Information about the pointers that may require checking. More...

SmallVector< CheckingPtrGroup, 2 >	CheckingGroups
	Holds a partitioning of pointers into "check groups". More...

Detailed Description

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

Definition at line 335 of file LoopAccessAnalysis.h.

Member Typedef Documentation

◆ PointerCheck

typedef std::pair<const CheckingPtrGroup *, const CheckingPtrGroup *> llvm::RuntimePointerChecking::PointerCheck

A memcheck which made up of a pair of grouped pointers.

These have to be const for now, since checks are generated from CheckingPtrGroups in LAI::addRuntimeChecks which is a const member function. FIXME: once check-generation is moved inside this class (after the PtrPartition hack is removed), we could drop const.

Definition at line 424 of file LoopAccessAnalysis.h.

Constructor & Destructor Documentation

◆ RuntimePointerChecking()

llvm::RuntimePointerChecking::RuntimePointerChecking ( ScalarEvolution * SE )

inline

Definition at line 364 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 427 of file LoopAccessAnalysis.cpp.

◆ empty()

bool llvm::RuntimePointerChecking::empty ( ) const

inline

No run-time memory checking is necessary.

Definition at line 383 of file LoopAccessAnalysis.h.

◆ 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 250 of file LoopAccessAnalysis.cpp.

References assert().

Referenced by isNoWrap().

◆ getChecks()

const SmallVector<PointerCheck, 4>& llvm::RuntimePointerChecking::getChecks ( ) const

inline

Returns the checks that generateChecks created.

Definition at line 432 of file LoopAccessAnalysis.h.

References N.

Referenced by isLoadConditional(), and llvm::LoopVersioning::LoopVersioning().

◆ getNumberOfChecks()

unsigned llvm::RuntimePointerChecking::getNumberOfChecks ( ) const

inline

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

Definition at line 441 of file LoopAccessAnalysis.h.

References llvm::Depth, and print().

Referenced by isNoWrap().

◆ getPointerInfo()

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

inline

Return PointerInfo for pointer at index PtrIdx.

Definition at line 472 of file LoopAccessAnalysis.h.

Referenced by isLoadConditional(), and llvm::LoopVersioning::prepareNoAliasMetadata().

◆ insert()

void RuntimePointerChecking::insert	(	Loop *	Lp,
		Value *	Ptr,
		bool	WritePtr,
		unsigned	DepSetId,
		unsigned	ASId,
		const ValueToValueMap &	Strides,
		PredicatedScalarEvolution &	PSE
	)

Insert a pointer and calculate the start and end SCEVs.

Calculate Start and End points of memory access.

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.

Let's assume A is the first access and B is a memory access on N-th loop iteration. Then B is calculated as: B = A + Step*N . Step value may be positive or negative. N is a calculated back-edge taken count: N = (TripCount > 0) ? RoundDown(TripCount -1 , VF) : 0 Start and End points are calculated in the following way: Start = UMIN(A, B) ; End = UMAX(A, B) + SizeOfElt, where SizeOfElt is the size of single memory access in bytes.

There is no conflict when the intervals are disjoint: NoConflict = (P2.Start >= P1.End) || (P1.Start >= P2.End)

Definition at line 190 of file LoopAccessAnalysis.cpp.

References assert(), llvm::dyn_cast(), llvm::SCEVAddRecExpr::evaluateAtIteration(), llvm::ScalarEvolution::getAddExpr(), llvm::PredicatedScalarEvolution::getBackedgeTakenCount(), llvm::ScalarEvolution::getConstant(), llvm::Type::getPointerElementType(), llvm::Type::getScalarSizeInBits(), llvm::PredicatedScalarEvolution::getSE(), llvm::SCEVAddRecExpr::getStart(), llvm::SCEVAddRecExpr::getStepRecurrence(), llvm::SCEV::getType(), llvm::Value::getType(), llvm::ScalarEvolution::getUMaxExpr(), llvm::ScalarEvolution::getUMinExpr(), I, llvm::ScalarEvolution::isLoopInvariant(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::replaceSymbolicStrideSCEV(), and std::swap().

Referenced by isNoWrap().

◆ needsChecking() [1/2]

bool RuntimePointerChecking::needsChecking	(	const CheckingPtrGroup &	M,
		const CheckingPtrGroup &	N
	)		const

Decide if we need to add a check between two groups of pointers, according to needsChecking.

Definition at line 257 of file LoopAccessAnalysis.cpp.

References I, llvm::RuntimePointerChecking::CheckingPtrGroup::Members, and llvm::SmallVectorBase::size().

◆ needsChecking() [2/2]

bool RuntimePointerChecking::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.

Definition at line 434 of file LoopAccessAnalysis.cpp.

References llvm::RuntimePointerChecking::PointerInfo::AliasSetId, llvm::RuntimePointerChecking::PointerInfo::DependencySetId, I, and llvm::RuntimePointerChecking::PointerInfo::IsWritePtr.

◆ print()

void RuntimePointerChecking::print	(	raw_ostream &	OS,
		unsigned	Depth = `0`
	)		const

Print the list run-time memory checks necessary.

Definition at line 472 of file LoopAccessAnalysis.cpp.

References llvm::MemoryLocation::AATags, llvm::MemoryDepChecker::clearDependences(), I, llvm::raw_ostream::indent(), llvm::MemoryLocation::Ptr, and llvm::LocationSize::unknown().

◆ printChecks()

void RuntimePointerChecking::printChecks	(	raw_ostream &	OS,
		const SmallVectorImpl< PointerCheck > &	Checks,
		unsigned	Depth = `0`
	)		const

Print Checks.

Definition at line 453 of file LoopAccessAnalysis.cpp.

References Check(), llvm::raw_ostream::indent(), and N.

Referenced by isLoadConditional().

◆ reset()

void llvm::RuntimePointerChecking::reset ( )

inline

Reset the state of the pointer runtime information.

Definition at line 367 of file LoopAccessAnalysis.h.

Referenced by isNoWrap().

Member Data Documentation

◆ CheckingGroups

SmallVector<CheckingPtrGroup, 2> llvm::RuntimePointerChecking::CheckingGroups

Holds a partitioning of pointers into "check groups".

Definition at line 457 of file LoopAccessAnalysis.h.

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

◆ Need

bool llvm::RuntimePointerChecking::Need

This flag indicates if we need to add the runtime check.

Definition at line 451 of file LoopAccessAnalysis.h.

Referenced by llvm::LoopVectorizationCostModel::computeMaxVF(), isNoWrap(), and llvm::LoopVectorizationCostModel::selectInterleaveCount().

◆ Pointers

SmallVector<PointerInfo, 2> llvm::RuntimePointerChecking::Pointers

Information about the pointers that may require checking.

Definition at line 454 of file LoopAccessAnalysis.h.

Referenced by expandBounds(), and isNoWrap().

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

include/llvm/Analysis/LoopAccessAnalysis.h
lib/Analysis/LoopAccessAnalysis.cpp

Classes

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Detailed Description

Member Typedef Documentation

◆ PointerCheck

Constructor & Destructor Documentation

◆ RuntimePointerChecking()

Member Function Documentation

◆ arePointersInSamePartition()

◆ empty()

◆ generateChecks()

◆ getChecks()

◆ getNumberOfChecks()

◆ getPointerInfo()

◆ insert()

◆ needsChecking() [1/2]

◆ needsChecking() [2/2]

◆ print()

◆ printChecks()

◆ reset()

Member Data Documentation

◆ CheckingGroups

◆ Need

◆ Pointers