Simple and conservative implementation of LoopSafetyInfo that can give false-positive answers to its queries in order to avoid complicated analysis. More...

#include "llvm/Analysis/MustExecute.h"

Inheritance diagram for llvm::SimpleLoopSafetyInfo:

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

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

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

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

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.

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

virtual bool	blockMayThrow (const BasicBlock *BB) const =0
	Returns true iff the block `BB` potentially may throw exception.

virtual bool	anyBlockMayThrow () const =0
	Returns true iff any block of the loop for which this info is contains an instruction that may throw or otherwise exit abnormally.

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.

virtual void	computeLoopSafetyInfo (const Loop *CurLoop)=0
	Computes safety information for a loop checks loop body & header for the possibility of may throw exception, it takes LoopSafetyInfo and loop as argument.

virtual bool	isGuaranteedToExecute (const Instruction &Inst, const DominatorTree DT, const Loop CurLoop) const =0
	Returns true if the instruction in a loop is guaranteed to execute at least once (under the assumption that the loop is entered).

	LoopSafetyInfo ()=default

virtual	~LoopSafetyInfo ()=default

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

Detailed Description

Simple and conservative implementation of LoopSafetyInfo that can give false-positive answers to its queries in order to avoid complicated analysis.

Definition at line 109 of file MustExecute.h.

Member Function Documentation

◆ anyBlockMayThrow()

bool SimpleLoopSafetyInfo::anyBlockMayThrow ( ) const

overridevirtual

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 47 of file MustExecute.cpp.

Referenced by blockMayThrow(), and llvm::isSafeToUnrollAndJam().

◆ blockMayThrow()

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

overridevirtual

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 42 of file MustExecute.cpp.

References anyBlockMayThrow().

◆ computeLoopSafetyInfo()

void SimpleLoopSafetyInfo::computeLoopSafetyInfo ( const Loop * CurLoop )

overridevirtual

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 51 of file MustExecute.cpp.

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

Referenced by isMustExecuteIn(), and llvm::isSafeToUnrollAndJam().