Represents an analysis for computing liveness information from a given top-level operation. More...

#include "mlir/Analysis/Liveness.h"

Public Types
using	OperationListT = std::vector< Operation * >

using	BlockMapT = DenseMap< Block *, LivenessBlockInfo >

using	ValueSetT = SmallPtrSet< Value, 16 >

Public Member Functions
	Liveness (Operation *op)
	Creates a new Liveness analysis that computes liveness information for all associated regions. More...

Operation *	getOperation () const
	Returns the operation this analysis was constructed from. More...

OperationListT	resolveLiveness (Value value) const
	Gets liveness info (if any) for the given value. More...

const LivenessBlockInfo *	getLiveness (Block *block) const
	Gets liveness info (if any) for the block. More...

const ValueSetT &	getLiveIn (Block *block) const
	Returns a reference to a set containing live-in values (unordered). More...

const ValueSetT &	getLiveOut (Block *block) const
	Returns a reference to a set containing live-out values (unordered). More...

bool	isDeadAfter (Value value, Operation *operation) const
	Returns true if `value` is not live after `operation`. More...

void	dump () const
	Dumps the liveness information in a human readable format. More...

void	print (raw_ostream &os) const
	Dumps the liveness information to the given stream. More...

Detailed Description

Represents an analysis for computing liveness information from a given top-level operation.

The analysis iterates over all associated regions that are attached to the given top-level operation. It computes liveness information for every value and block that are included in the mentioned regions. It relies on a fixpoint iteration to compute all live-in and live-out values of all included blocks. Sample usage: Liveness liveness(topLevelOp); auto &allInValues = liveness.getLiveIn(block); auto &allOutValues = liveness.getLiveOut(block); auto allOperationsInWhichValueIsLive = liveness.resolveLiveness(value); bool isDeafAfter = liveness.isDeadAfter(value, operation);

Definition at line 47 of file Liveness.h.

Member Typedef Documentation

◆ BlockMapT

using mlir::Liveness::BlockMapT = DenseMap<Block *, LivenessBlockInfo>

Definition at line 50 of file Liveness.h.

◆ OperationListT

using mlir::Liveness::OperationListT = std::vector<Operation *>

Definition at line 49 of file Liveness.h.

◆ ValueSetT

using mlir::Liveness::ValueSetT = SmallPtrSet<Value, 16>

Definition at line 51 of file Liveness.h.

Constructor & Destructor Documentation

◆ Liveness()

Liveness::Liveness ( Operation * op )

Creates a new Liveness analysis that computes liveness information for all associated regions.

Definition at line 161 of file Liveness.cpp.

Member Function Documentation

◆ dump()

void Liveness::dump ( ) const

Dumps the liveness information in a human readable format.

Definition at line 261 of file Liveness.cpp.

References print().

◆ getLiveIn()

const Liveness::ValueSetT & Liveness::getLiveIn ( Block * block ) const

Returns a reference to a set containing live-in values (unordered).

Returns a reference to a set containing live-in values.

Definition at line 235 of file Liveness.cpp.

References getLiveness(), and mlir::LivenessBlockInfo::in().

Referenced by mlir::bufferization::DeallocationState::getLiveMemrefsIn(), and mlir::bufferization::DeallocationState::getMemrefsToRetain().

◆ getLiveness()

const LivenessBlockInfo * Liveness::getLiveness ( Block * block ) const

Gets liveness info (if any) for the block.

Definition at line 229 of file Liveness.cpp.

Referenced by getLiveIn(), getLiveOut(), mlir::bufferization::BufferPlacementAllocs::getStartOperation(), isDeadAfter(), and resolveLiveness().

◆ getLiveOut()

const Liveness::ValueSetT & Liveness::getLiveOut ( Block * block ) const

Returns a reference to a set containing live-out values (unordered).

Returns a reference to a set containing live-out values.

Definition at line 240 of file Liveness.cpp.

References getLiveness(), and mlir::LivenessBlockInfo::out().

Referenced by mlir::bufferization::DeallocationState::getMemrefsToRetain().

◆ getOperation()

Operation* mlir::Liveness::getOperation ( ) const

inline

Returns the operation this analysis was constructed from.

Definition at line 59 of file Liveness.h.

◆ isDeadAfter()

bool Liveness::isDeadAfter	(	Value	value,
		Operation *	operation
	)		const

Returns true if value is not live after operation.

Definition at line 245 of file Liveness.cpp.

References mlir::Operation::getBlock(), mlir::LivenessBlockInfo::getEndOperation(), getLiveness(), mlir::Operation::isBeforeInBlock(), and mlir::LivenessBlockInfo::isLiveOut().

◆ print()

void Liveness::print ( raw_ostream & os ) const

Dumps the liveness information to the given stream.

Definition at line 264 of file Liveness.cpp.

References mlir::Operation::getResults(), mlir::PreOrder, and mlir::Operation::walk().

Referenced by dump().

◆ resolveLiveness()

Liveness::OperationListT Liveness::resolveLiveness ( Value value ) const

Gets liveness info (if any) for the given value.

This includes all operations in which the given value is live. Note that the operations in this list are not ordered and the current implementation is computationally expensive (as it iterates over all blocks in which the given value is live).

Definition at line 181 of file Liveness.cpp.

References mlir::Value::getDefiningOp(), mlir::LivenessBlockInfo::getEndOperation(), getLiveness(), mlir::LivenessBlockInfo::getStartOperation(), mlir::Block::getSuccessors(), and mlir::Value::getUses().

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

include/mlir/Analysis/Liveness.h
lib/Analysis/Liveness.cpp

Public Types

Public Member Functions