This implementation of LoopSafetyInfo use ImplicitControlFlowTracking to give precise answers on "may throw" queries. More...

#include "llvm/Analysis/MustExecute.h"

Inheritance diagram for llvm::ICFLoopSafetyInfo:

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Collaboration diagram for llvm::ICFLoopSafetyInfo:

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Public Member Functions
virtual bool	blockMayThrow (const BasicBlock *BB) const
	Returns true iff the block `BB` potentially may throw exception. More...

virtual bool	anyBlockMayThrow () const
	Returns true iff any block of the loop for which this info is contains an instruction that may throw or otherwise exit abnormally. More...

virtual void	computeLoopSafetyInfo (const Loop *CurLoop)
	Computes safety information for a loop checks loop body & header for the possibility of may throw exception, it takes LoopSafetyInfo and loop as argument. More...

virtual bool	isGuaranteedToExecute (const Instruction &Inst, const DominatorTree DT, const Loop CurLoop) const
	Returns true if the instruction in a loop is guaranteed to execute at least once (under the assumption that the loop is entered). More...

bool	doesNotWriteMemoryBefore (const BasicBlock BB, const Loop CurLoop) const
	Returns true if we could not execute a memory-modifying instruction before we enter `BB` under assumption that `CurLoop` is entered. More...

bool	doesNotWriteMemoryBefore (const Instruction &I, const Loop *CurLoop) const
	Returns true if we could not execute a memory-modifying instruction before we execute `I` under assumption that `CurLoop` is entered. More...

void	insertInstructionTo (const Instruction Inst, const BasicBlock BB)
	Inform the safety info that we are planning to insert a new instruction `Inst` into the basic block `BB`. More...

void	removeInstruction (const Instruction *Inst)
	Inform safety info that we are planning to remove the instruction `Inst` from its block. More...

	ICFLoopSafetyInfo (DominatorTree *DT)

virtual	~ICFLoopSafetyInfo ()

Public Member Functions inherited from llvm::LoopSafetyInfo
const DenseMap< BasicBlock *, ColorVector > &	getBlockColors () const
	Returns block colors map that is used to update funclet operand bundles. More...

void	copyColors (BasicBlock New, BasicBlock Old)
	Copy colors of block `Old` into the block `New`. More...

bool	allLoopPathsLeadToBlock (const Loop CurLoop, const BasicBlock BB, const DominatorTree *DT) const
	Return true if we must reach the block `BB` under assumption that the loop `CurLoop` is entered. More...

	LoopSafetyInfo ()=default

virtual	~LoopSafetyInfo ()=default

Additional Inherited Members
Protected Member Functions inherited from llvm::LoopSafetyInfo
void	computeBlockColors (const Loop *CurLoop)
	Computes block colors. More...

Detailed Description

This implementation of LoopSafetyInfo use ImplicitControlFlowTracking to give precise answers on "may throw" queries.

This implementation uses cache that should be invalidated by calling the methods insertInstructionTo and removeInstruction whenever we modify a basic block's contents by adding or removing instructions.

Definition at line 124 of file MustExecute.h.

Constructor & Destructor Documentation

◆ ICFLoopSafetyInfo()

llvm::ICFLoopSafetyInfo::ICFLoopSafetyInfo ( DominatorTree * DT )

inline

Definition at line 163 of file MustExecute.h.

◆ ~ICFLoopSafetyInfo()

virtual llvm::ICFLoopSafetyInfo::~ICFLoopSafetyInfo ( )

inlinevirtual

Definition at line 165 of file MustExecute.h.

Member Function Documentation

◆ anyBlockMayThrow()

bool ICFLoopSafetyInfo::anyBlockMayThrow ( ) const

virtual

Returns true iff any block of the loop for which this info is contains an instruction that may throw or otherwise exit abnormally.

Implements llvm::LoopSafetyInfo.

Definition at line 68 of file MustExecute.cpp.

Referenced by llvm::promoteLoopAccessesToScalars().

◆ blockMayThrow()

bool ICFLoopSafetyInfo::blockMayThrow ( const BasicBlock * BB ) const

virtual

Returns true iff the block BB potentially may throw exception.

It can be false-positive in cases when we want to avoid complex analysis.

Implements llvm::LoopSafetyInfo.

Definition at line 64 of file MustExecute.cpp.

◆ computeLoopSafetyInfo()

void ICFLoopSafetyInfo::computeLoopSafetyInfo ( const Loop * CurLoop )

virtual

Computes safety information for a loop checks loop body & header for the possibility of may throw exception, it takes LoopSafetyInfo and loop as argument.

Updates safety information in LoopSafetyInfo argument. Note: This is defined to clear and reinitialize an already initialized LoopSafetyInfo. Some callers rely on this fact.

Implements llvm::LoopSafetyInfo.

Definition at line 72 of file MustExecute.cpp.

References assert(), llvm::LoopBase< BlockT, LoopT >::blocks(), and llvm::LoopSafetyInfo::computeBlockColors().

Referenced by llvm::createLICMPass().

◆ doesNotWriteMemoryBefore() [1/2]

bool ICFLoopSafetyInfo::doesNotWriteMemoryBefore	(	const BasicBlock *	BB,
		const Loop *	CurLoop
	)		const

Returns true if we could not execute a memory-modifying instruction before we enter BB under assumption that CurLoop is entered.

Definition at line 261 of file MustExecute.cpp.

References assert(), collectTransitivePredecessors(), llvm::LoopBase< BlockT, LoopT >::contains(), and llvm::LoopBase< BlockT, LoopT >::getHeader().

Referenced by llvm::hoistRegion().

◆ doesNotWriteMemoryBefore() [2/2]

bool ICFLoopSafetyInfo::doesNotWriteMemoryBefore	(	const Instruction &	I,
		const Loop *	CurLoop
	)		const

Returns true if we could not execute a memory-modifying instruction before we execute I under assumption that CurLoop is entered.

Definition at line 281 of file MustExecute.cpp.

References llvm::AnalysisUsage::addRequired(), assert(), llvm::LoopBase< BlockT, LoopT >::contains(), F(), llvm::Instruction::getParent(), llvm::PassRegistry::getPassRegistry(), INITIALIZE_PASS_BEGIN(), INITIALIZE_PASS_DEPENDENCY, llvm::initializeMustExecutePrinterPass(), runOnFunction(), and llvm::AnalysisUsage::setPreservesAll().

◆ insertInstructionTo()

void ICFLoopSafetyInfo::insertInstructionTo	(	const Instruction *	Inst,
		const BasicBlock *	BB
	)

Inform the safety info that we are planning to insert a new instruction Inst into the basic block BB.

It will make all cache updates to keep it correct after this insertion.

Definition at line 86 of file MustExecute.cpp.

Referenced by llvm::hoistRegion(), and moveInstructionBefore().

◆ isGuaranteedToExecute()

bool ICFLoopSafetyInfo::isGuaranteedToExecute	(	const Instruction &	Inst,
		const DominatorTree *	DT,
		const Loop *	CurLoop
	)		const

virtual

Returns true if the instruction in a loop is guaranteed to execute at least once (under the assumption that the loop is entered).

Implements llvm::LoopSafetyInfo.

Definition at line 254 of file MustExecute.cpp.

References llvm::LoopSafetyInfo::allLoopPathsLeadToBlock(), and llvm::Instruction::getParent().

Referenced by hoist(), llvm::hoistRegion(), and llvm::promoteLoopAccessesToScalars().

◆ removeInstruction()

void ICFLoopSafetyInfo::removeInstruction ( const Instruction * Inst )

Inform safety info that we are planning to remove the instruction Inst from its block.

It will make all cache updates to keep it correct after this removal.

Definition at line 92 of file MustExecute.cpp.

Referenced by eraseInstruction(), isSafeToExecuteUnconditionally(), and moveInstructionBefore().

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

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

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ ICFLoopSafetyInfo()

◆ ~ICFLoopSafetyInfo()

Member Function Documentation

◆ anyBlockMayThrow()

◆ blockMayThrow()

◆ computeLoopSafetyInfo()

◆ doesNotWriteMemoryBefore() [1/2]

◆ doesNotWriteMemoryBefore() [2/2]

◆ insertInstructionTo()

◆ isGuaranteedToExecute()

◆ removeInstruction()