Encapsulates MemorySSA, including all data associated with memory accesses. More...

#include "llvm/Analysis/MemorySSA.h"

Classes
class	OptimizeUses
	This class is a batch walker of all MemoryUse's in the program, and points their defining access at the thing that actually clobbers them. More...

Public Types
enum	VerificationLevel { VerificationLevel::Fast, VerificationLevel::Full }

enum	InsertionPlace { Beginning, End, BeforeTerminator }
	Used in various insertion functions to specify whether we are talking about the beginning or end of a block. More...

using	AccessList = iplist< MemoryAccess, ilist_tag< MSSAHelpers::AllAccessTag > >

using	DefsList = simple_ilist< MemoryAccess, ilist_tag< MSSAHelpers::DefsOnlyTag > >

Public Member Functions
	MemorySSA (Function &, AliasAnalysis , DominatorTree )

	MemorySSA (MemorySSA &&)=delete

	~MemorySSA ()

MemorySSAWalker *	getWalker ()

MemorySSAWalker *	getSkipSelfWalker ()

MemoryUseOrDef *	getMemoryAccess (const Instruction *I) const
	Given a memory Mod/Ref'ing instruction, get the MemorySSA access associated with it. More...

MemoryPhi *	getMemoryAccess (const BasicBlock *BB) const

DominatorTree &	getDomTree () const

void	dump () const

void	print (raw_ostream &) const

bool	isLiveOnEntryDef (const MemoryAccess *MA) const
	Return true if `MA` represents the live on entry value. More...

MemoryAccess *	getLiveOnEntryDef () const

const AccessList *	getBlockAccesses (const BasicBlock *BB) const
	Return the list of MemoryAccess's for a given basic block. More...

const DefsList *	getBlockDefs (const BasicBlock *BB) const
	Return the list of MemoryDef's and MemoryPhi's for a given basic block. More...

bool	locallyDominates (const MemoryAccess A, const MemoryAccess B) const
	Given two memory accesses in the same basic block, determine whether MemoryAccess `A` dominates MemoryAccess `B`. More...

bool	dominates (const MemoryAccess A, const MemoryAccess B) const
	Given two memory accesses in potentially different blocks, determine whether MemoryAccess `A` dominates MemoryAccess `B`. More...

bool	dominates (const MemoryAccess *A, const Use &B) const
	Given a MemoryAccess and a Use, determine whether MemoryAccess `A` dominates Use `B`. More...

void	verifyMemorySSA (VerificationLevel=VerificationLevel::Fast) const
	Verify that MemorySSA is self consistent (IE definitions dominate all uses, uses appear in the right places). More...

void	ensureOptimizedUses ()
	By default, uses are not optimized during MemorySSA construction. More...

Protected Member Functions
void	verifyOrderingDominationAndDefUses (Function &F, VerificationLevel=VerificationLevel::Fast) const
	Verify ordering: the order and existence of MemoryAccesses matches the order and existence of memory affecting instructions. More...

void	verifyDominationNumbers (const Function &F) const
	Verify that all of the blocks we believe to have valid domination numbers actually have valid domination numbers. More...

void	verifyPrevDefInPhis (Function &F) const

AccessList *	getWritableBlockAccesses (const BasicBlock *BB) const

DefsList *	getWritableBlockDefs (const BasicBlock *BB) const

void	moveTo (MemoryUseOrDef What, BasicBlock BB, AccessList::iterator Where)

void	moveTo (MemoryAccess What, BasicBlock BB, InsertionPlace Point)

void	renamePass (BasicBlock BB, MemoryAccess IncomingVal, SmallPtrSetImpl< BasicBlock * > &Visited)

void	removeFromLookups (MemoryAccess *)
	Properly remove `MA` from all of MemorySSA's lookup tables. More...

void	removeFromLists (MemoryAccess *, bool ShouldDelete=true)
	Properly remove `MA` from all of MemorySSA's lists. More...

void	insertIntoListsForBlock (MemoryAccess , const BasicBlock , InsertionPlace)

void	insertIntoListsBefore (MemoryAccess , const BasicBlock , AccessList::iterator)

MemoryUseOrDef *	createDefinedAccess (Instruction , MemoryAccess , const MemoryUseOrDef *Template=nullptr, bool CreationMustSucceed=true)

Friends
class	MemorySSAPrinterLegacyPass

class	MemorySSAUpdater

Detailed Description

Encapsulates MemorySSA, including all data associated with memory accesses.

Definition at line 714 of file MemorySSA.h.

Member Typedef Documentation

◆ AccessList

using llvm::MemorySSA::AccessList = iplist<MemoryAccess, ilist_tag<MSSAHelpers::AllAccessTag> >

Definition at line 764 of file MemorySSA.h.

◆ DefsList

using llvm::MemorySSA::DefsList = simple_ilist<MemoryAccess, ilist_tag<MSSAHelpers::DefsOnlyTag> >

Definition at line 766 of file MemorySSA.h.

Member Enumeration Documentation

◆ InsertionPlace

enum llvm::MemorySSA::InsertionPlace

Used in various insertion functions to specify whether we are talking about the beginning or end of a block.

Enumerator
Beginning
End
BeforeTerminator

Definition at line 802 of file MemorySSA.h.

◆ VerificationLevel

enum llvm::MemorySSA::VerificationLevel

strong

Enumerator
Fast
Full

Definition at line 795 of file MemorySSA.h.

Constructor & Destructor Documentation

◆ MemorySSA() [1/2]

MemorySSA::MemorySSA	(	Function &	Func,
		AliasAnalysis *	AA,
		DominatorTree *	DT
	)

Definition at line 1273 of file MemorySSA.cpp.

References assert(), and getWalker().

◆ MemorySSA() [2/2]

llvm::MemorySSA::MemorySSA ( MemorySSA && )

delete

◆ ~MemorySSA()

MemorySSA::~MemorySSA ( )

Definition at line 1291 of file MemorySSA.cpp.

References llvm::User::dropAllReferences().

Member Function Documentation

◆ createDefinedAccess()

MemoryUseOrDef * MemorySSA::createDefinedAccess	(	Instruction *	I,
		MemoryAccess *	Definition,
		const MemoryUseOrDef *	Template = `nullptr`,
		bool	CreationMustSucceed = `true`
	)

protected

Definition at line 1743 of file MemorySSA.cpp.

References assert(), I, llvm::MemoryUseOrDef::setDefiningAccess(), and Template.

Referenced by llvm::MemorySSAUpdater::createMemoryAccessAfter(), llvm::MemorySSAUpdater::createMemoryAccessBefore(), and llvm::MemorySSAUpdater::createMemoryAccessInBB().

◆ dominates() [1/2]

bool MemorySSA::dominates	(	const MemoryAccess *	A,
		const MemoryAccess *	B
	)		const

Given two memory accesses in potentially different blocks, determine whether MemoryAccess A dominates MemoryAccess B.

Definition at line 2159 of file MemorySSA.cpp.

References llvm::DominatorTree::dominates(), llvm::MemoryAccess::getBlock(), isLiveOnEntryDef(), and locallyDominates().

Referenced by llvm::canSinkOrHoistInst(), checkClobberSanity(), dominates(), and verifyOrderingDominationAndDefUses().

◆ dominates() [2/2]

bool MemorySSA::dominates	(	const MemoryAccess *	A,
		const Use &	B
	)		const

Given a MemoryAccess and a Use, determine whether MemoryAccess A dominates Use B.

Definition at line 2172 of file MemorySSA.cpp.

References llvm::DominatorTree::dominates(), dominates(), llvm::MemoryAccess::getBlock(), llvm::Use::getUser(), and locallyDominates().

◆ dump()

LLVM_DUMP_METHOD void MemorySSA::dump ( ) const

Definition at line 1903 of file MemorySSA.cpp.

References llvm::dbgs(), and print().

◆ ensureOptimizedUses()

void MemorySSA::ensureOptimizedUses ( )

By default, uses are not optimized during MemorySSA construction.

Calling this method will attempt to optimize all MemoryUses, if this has not happened yet for this MemorySSA instance. This should be done if you plan to query the clobbering access for most uses, or if you walk the def-use chain of uses.

Definition at line 2186 of file MemorySSA.cpp.

References llvm::MemorySSA::OptimizeUses::optimizeUses().

Referenced by llvm::GVNHoist::GVNHoist(), llvm::MemorySSAPrinterPass::run(), and llvm::MemorySSAPrinterLegacyPass::runOnFunction().

◆ getBlockAccesses()

const AccessList* llvm::MemorySSA::getBlockAccesses ( const BasicBlock * BB ) const

inline

Return the list of MemoryAccess's for a given basic block.

This list is not modifiable by the user.

Definition at line 771 of file MemorySSA.h.

References BB.

Referenced by llvm::canSinkOrHoistInst(), foreachMemoryAccess(), llvm::MemorySSAUpdater::moveAllAfterSpliceBlocks(), llvm::SinkAndHoistLICMFlags::SinkAndHoistLICMFlags(), verifyDominationNumbers(), and verifyOrderingDominationAndDefUses().

◆ getBlockDefs()

const DefsList* llvm::MemorySSA::getBlockDefs ( const BasicBlock * BB ) const

inline

Return the list of MemoryDef's and MemoryPhi's for a given basic block.

This list is not modifiable by the user.

Definition at line 779 of file MemorySSA.h.

References BB.

Referenced by getNewDefiningAccessForClone(), llvm::MemorySSAUpdater::insertUse(), pointerInvalidatedByBlock(), unswitchAllTrivialConditions(), verifyOrderingDominationAndDefUses(), and verifyPrevDefInPhis().

◆ getDomTree()

DominatorTree& llvm::MemorySSA::getDomTree ( ) const

inline

Definition at line 739 of file MemorySSA.h.

Referenced by checkClobberSanity().

◆ getLiveOnEntryDef()

MemoryAccess* llvm::MemorySSA::getLiveOnEntryDef ( ) const

inline

Definition at line 755 of file MemorySSA.h.

Referenced by llvm::MemorySSAUpdater::insertDef(), and llvm::MemorySSA::OptimizeUses::optimizeUses().

◆ getMemoryAccess() [1/2]

MemoryPhi* llvm::MemorySSA::getMemoryAccess ( const BasicBlock * BB ) const

inline

Definition at line 735 of file MemorySSA.h.

References BB.

◆ getMemoryAccess() [2/2]

MemoryUseOrDef* llvm::MemorySSA::getMemoryAccess ( const Instruction * I ) const

inline

Given a memory Mod/Ref'ing instruction, get the MemorySSA access associated with it.

If passed a basic block gets the memory phi node that exists for that block, if there is one. Otherwise, this will get a MemoryUseOrDef.

Definition at line 731 of file MemorySSA.h.

References I.

◆ getSkipSelfWalker()

MemorySSAWalker * MemorySSA::getSkipSelfWalker ( )

Definition at line 1619 of file MemorySSA.cpp.

Referenced by llvm::canSinkOrHoistInst(), and pointerInvalidatedByLoop().

◆ getWalker()

MemorySSAWalker * MemorySSA::getWalker ( )

Definition at line 1604 of file MemorySSA.cpp.

Referenced by llvm::AMDGPU::isClobberedInFunction(), MemorySSA(), and removeFromLookups().

◆ getWritableBlockAccesses()

AccessList* llvm::MemorySSA::getWritableBlockAccesses ( const BasicBlock * BB ) const

inlineprotected

Definition at line 822 of file MemorySSA.h.

References BB.

Referenced by insertIntoListsBefore(), llvm::MemorySSAUpdater::removeBlocks(), llvm::MemorySSAUpdater::updateForClonedLoop(), and llvm::MemorySSAUpdater::wireOldPredecessorsToNewImmediatePredecessor().

◆ getWritableBlockDefs()

DefsList* llvm::MemorySSA::getWritableBlockDefs ( const BasicBlock * BB ) const

inlineprotected

Definition at line 828 of file MemorySSA.h.

References BB, and llvm::simple_ilist< T, Options >::end().

Referenced by llvm::MemorySSAUpdater::insertDef(), and llvm::MemorySSAUpdater::insertUse().

◆ insertIntoListsBefore()

void MemorySSA::insertIntoListsBefore	(	MemoryAccess *	What,
		const BasicBlock *	BB,
		AccessList::iterator	InsertPt
	)

protected

Definition at line 1668 of file MemorySSA.cpp.

References BB, and getWritableBlockAccesses().

Referenced by llvm::MemorySSAUpdater::createMemoryAccessAfter(), llvm::MemorySSAUpdater::createMemoryAccessBefore(), and moveTo().

◆ insertIntoListsForBlock()

void MemorySSA::insertIntoListsForBlock	(	MemoryAccess *	NewAccess,
		const BasicBlock *	BB,
		InsertionPlace	Point
	)

protected

Definition at line 1636 of file MemorySSA.cpp.

References BB, Beginning, and llvm::find_if_not().

Referenced by llvm::MemorySSAUpdater::createMemoryAccessInBB(), and moveTo().

◆ isLiveOnEntryDef()

bool llvm::MemorySSA::isLiveOnEntryDef ( const MemoryAccess * MA ) const

inline

Return true if MA represents the live on entry value.

Loads and stores from pointer arguments and other global values may be defined by memory operations that do not occur in the current function, so they may be live on entry to the function. MemorySSA represents such memory state by the live on entry definition, which is guaranteed to occur before any other memory access in the function.

Definition at line 751 of file MemorySSA.h.

Referenced by llvm::canSinkOrHoistInst(), checkClobberSanity(), dominates(), getNewDefiningAccessForClone(), hasUndefContents(), llvm::AMDGPU::isClobberedInFunction(), locallyDominates(), pointerInvalidatedByLoop(), llvm::MemorySSAUpdater::removeMemoryAccess(), and llvm::MemorySSAUpdater::updateForClonedLoop().

◆ locallyDominates()

bool MemorySSA::locallyDominates	(	const MemoryAccess *	Dominator,
		const MemoryAccess *	Dominatee
	)		const

Given two memory accesses in the same basic block, determine whether MemoryAccess A dominates MemoryAccess B.

Determine, for two memory accesses in the same block, whether Dominator dominates Dominatee.

Returns: True if Dominator dominates Dominatee.

Definition at line 2128 of file MemorySSA.cpp.

References assert(), llvm::MemoryAccess::getBlock(), and isLiveOnEntryDef().

Referenced by dominates(), and pointerInvalidatedByBlock().

◆ moveTo() [1/2]

void MemorySSA::moveTo	(	MemoryAccess *	What,
		BasicBlock *	BB,
		InsertionPlace	Point
	)

protected

Definition at line 1718 of file MemorySSA.cpp.

References assert(), BB, Beginning, llvm::MemoryAccess::getBlock(), and insertIntoListsForBlock().

◆ moveTo() [2/2]

void MemorySSA::moveTo	(	MemoryUseOrDef *	What,
		BasicBlock *	BB,
		AccessList::iterator	Where
	)

protected

Definition at line 1712 of file MemorySSA.cpp.

References BB, and insertIntoListsBefore().

Referenced by llvm::MemorySSAUpdater::wireOldPredecessorsToNewImmediatePredecessor().

◆ print()

void MemorySSA::print ( raw_ostream & OS ) const

Definition at line 1897 of file MemorySSA.cpp.

References F.

Referenced by llvm::MemoryAccess::dump(), dump(), llvm::MemoryAccess::print(), llvm::MemorySSAWrapperPass::print(), llvm::MemorySSAPrinterPass::run(), and llvm::MemorySSAPrinterLegacyPass::runOnFunction().

◆ removeFromLists()

void MemorySSA::removeFromLists	(	MemoryAccess *	MA,
		bool	ShouldDelete = `true`
	)

protected

Properly remove MA from all of MemorySSA's lists.

Because of the way the intrusive list and use lists work, it is important to do removal in the right order. ShouldDelete defaults to true, and will cause the memory access to also be deleted, not just removed.

Definition at line 1870 of file MemorySSA.cpp.

References BB, llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::erase(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::find(), and llvm::MemoryAccess::getBlock().

Referenced by llvm::MemorySSAUpdater::removeBlocks(), and llvm::MemorySSAUpdater::removeMemoryAccess().

◆ removeFromLookups()

void MemorySSA::removeFromLookups ( MemoryAccess * MA )

protected

Properly remove MA from all of MemorySSA's lookup tables.

Definition at line 1843 of file MemorySSA.cpp.

References assert(), llvm::MemoryAccess::getBlock(), llvm::MemoryUseOrDef::getMemoryInst(), getWalker(), llvm::MemorySSAWalker::invalidateInfo(), llvm::MemoryUseOrDef::setDefiningAccess(), and llvm::Value::use_empty().

Referenced by llvm::MemorySSAUpdater::removeBlocks(), and llvm::MemorySSAUpdater::removeMemoryAccess().

◆ renamePass()

void llvm::MemorySSA::renamePass	(	BasicBlock *	BB,
		MemoryAccess *	IncomingVal,
		SmallPtrSetImpl< BasicBlock * > &	Visited
	)

inlineprotected

Definition at line 841 of file MemorySSA.h.

References BB.

Referenced by llvm::MemorySSAUpdater::insertDef(), and llvm::MemorySSAUpdater::insertUse().

◆ verifyDominationNumbers()

void MemorySSA::verifyDominationNumbers ( const Function & F ) const

protected

Verify that all of the blocks we believe to have valid domination numbers actually have valid domination numbers.

Definition at line 1965 of file MemorySSA.cpp.

References assert(), BB, llvm::SmallPtrSetImpl< PtrType >::count(), llvm::SmallPtrSetImplBase::empty(), llvm::SmallPtrSetImpl< PtrType >::erase(), F, and getBlockAccesses().

Referenced by verifyMemorySSA().

◆ verifyMemorySSA()

void MemorySSA::verifyMemorySSA ( VerificationLevel VL = VerificationLevel::Fast ) const

Verify that MemorySSA is self consistent (IE definitions dominate all uses, uses appear in the right places).

This is used by unit tests.

Definition at line 1906 of file MemorySSA.cpp.

References F, Full, verifyDominationNumbers(), verifyOrderingDominationAndDefUses(), and verifyPrevDefInPhis().

Referenced by llvm::deleteDeadLoop(), llvm::hoistRegion(), mergeBlocksIntoPredecessors(), llvm::LoopFlattenPass::run(), llvm::LoopInstSimplifyPass::run(), llvm::LoopRotatePass::run(), llvm::SimpleLoopUnswitchPass::run(), llvm::FunctionToLoopPassAdaptor::run(), llvm::MemCpyOptPass::runImpl(), llvm::MemorySSAPrinterLegacyPass::runOnFunction(), simplifyLoopInst(), simplifyOneLoop(), llvm::sinkRegion(), llvm::splitBlockBefore(), turnGuardIntoBranch(), unswitchNontrivialInvariants(), unswitchTrivialBranch(), unswitchTrivialSwitch(), and llvm::MemorySSAWrapperPass::verifyAnalysis().

◆ verifyOrderingDominationAndDefUses()

void MemorySSA::verifyOrderingDominationAndDefUses	(	Function &	F,
		VerificationLevel	VL = `VerificationLevel::Fast`
	)		const

protected

Verify ordering: the order and existence of MemoryAccesses matches the order and existence of memory affecting instructions.

Verify domination: each definition dominates all of its uses. Verify def-uses: the immediate use information - walk all the memory accesses and verifying that, for each use, it appears in the appropriate def's use list

Definition at line 2006 of file MemorySSA.cpp.

References llvm::AArch64CC::AL, assert(), B, llvm::MachineBasicBlock::begin(), llvm::SmallVectorImpl< T >::clear(), DL, dominates(), E, llvm::MachineBasicBlock::end(), F, Full, getBlockAccesses(), getBlockDefs(), llvm::MemoryUseOrDef::getDefiningAccess(), llvm::MemoryPhi::getIncomingBlock(), llvm::MemoryPhi::getIncomingValue(), getMemoryAccess(), llvm::MemoryPhi::getNumIncomingValues(), llvm::User::getNumOperands(), I, llvm::is_contained(), llvm::pred_begin(), llvm::pred_end(), llvm::predecessors(), llvm::MachineBasicBlock::size(), and llvm::Value::uses().

Referenced by verifyMemorySSA().

◆ verifyPrevDefInPhis()

void MemorySSA::verifyPrevDefInPhis ( Function & F ) const

protected

Definition at line 1929 of file MemorySSA.cpp.

References assert(), BB, E, F, getBlockDefs(), llvm::MemoryPhi::getIncomingBlock(), llvm::MemoryPhi::getIncomingValue(), getMemoryAccess(), llvm::DominatorTreeBase< NodeT, IsPostDom >::getNode(), llvm::MemoryPhi::getNumIncomingValues(), and I.

Referenced by verifyMemorySSA().

Friends And Related Function Documentation

◆ MemorySSAPrinterLegacyPass

friend class MemorySSAPrinterLegacyPass

friend

Definition at line 813 of file MemorySSA.h.

◆ MemorySSAUpdater

friend class MemorySSAUpdater

friend

Definition at line 814 of file MemorySSA.h.

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

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

Classes

Public Types

Public Member Functions

Protected Member Functions

Friends

Detailed Description

Member Typedef Documentation

◆ AccessList

◆ DefsList

Member Enumeration Documentation

◆ InsertionPlace

◆ VerificationLevel

Constructor & Destructor Documentation

◆ MemorySSA() [1/2]

◆ MemorySSA() [2/2]

◆ ~MemorySSA()

Member Function Documentation

◆ createDefinedAccess()

◆ dominates() [1/2]

◆ dominates() [2/2]

◆ dump()

◆ ensureOptimizedUses()

◆ getBlockAccesses()

◆ getBlockDefs()

◆ getDomTree()

◆ getLiveOnEntryDef()

◆ getMemoryAccess() [1/2]

◆ getMemoryAccess() [2/2]

◆ getSkipSelfWalker()

◆ getWalker()

◆ getWritableBlockAccesses()

◆ getWritableBlockDefs()

◆ insertIntoListsBefore()

◆ insertIntoListsForBlock()

◆ isLiveOnEntryDef()

◆ locallyDominates()

◆ moveTo() [1/2]

◆ moveTo() [2/2]

◆ print()

◆ removeFromLists()

◆ removeFromLookups()

◆ renamePass()

◆ verifyDominationNumbers()

◆ verifyMemorySSA()

◆ verifyOrderingDominationAndDefUses()

◆ verifyPrevDefInPhis()

Friends And Related Function Documentation

◆ MemorySSAPrinterLegacyPass

◆ MemorySSAUpdater