This lattice represents, for a given value, whether or not it is "live". More...

#include "mlir/Analysis/DataFlow/LivenessAnalysis.h"

Inheritance diagram for mlir::dataflow::Liveness:

Public Member Functions
void	print (raw_ostream &os) const override
	Print the contents of the analysis state. More...

ChangeResult	markLive ()

ChangeResult	meet (const AbstractSparseLattice &other) override
	Meet (intersect) the information in this lattice with 'rhs'. More...

	AbstractSparseLattice (Value value)
	Lattices can only be created for values. More...

Public Member Functions inherited from mlir::dataflow::AbstractSparseLattice
	AbstractSparseLattice (Value value)
	Lattices can only be created for values. More...

Value	getAnchor () const
	Return the value this lattice is located at. More...

virtual ChangeResult	join (const AbstractSparseLattice &rhs)
	Join the information contained in 'rhs' into this lattice. More...

void	onUpdate (DataFlowSolver *solver) const override
	When the lattice gets updated, propagate an update to users of the value using its use-def chain to subscribed analyses. More...

void	useDefSubscribe (DataFlowAnalysis *analysis)
	Subscribe an analysis to updates of the lattice. More...

Public Member Functions inherited from mlir::AnalysisState
virtual	~AnalysisState ()

	AnalysisState (LatticeAnchor anchor)
	Create the analysis state on the given lattice anchor. More...

LatticeAnchor	getAnchor () const
	Returns the lattice anchor this state is located at. More...

LLVM_DUMP_METHOD void	dump () const

void	addDependency (ProgramPoint point, DataFlowAnalysis analysis)
	Add a dependency to this analysis state on a lattice anchor and an analysis. More...

Public Attributes
bool	isLive = false

Additional Inherited Members
Protected Attributes inherited from mlir::AnalysisState
LatticeAnchor	anchor
	The lattice anchor to which the state belongs. More...

Detailed Description

This lattice represents, for a given value, whether or not it is "live".

A value is considered "live" iff it: (1) has memory effects OR (2) is returned by a public function OR (3) is used to compute a value of type (1) or (2). It is also to be noted that a value could be of multiple types (1/2/3) at the same time.

A value "has memory effects" iff it: (1.a) is an operand of an op with memory effects OR (1.b) is a non-forwarded branch operand and its branch op could take the control to a block that has an op with memory effects OR (1.c) is a non-forwarded call operand.

A value A is said to be "used to compute" value B iff B cannot be computed in the absence of A. Thus, in this implementation, we say that value A is used to compute value B iff: (3.a) B is a result of an op with operand A OR (3.b) A is used to compute some value C and C is used to compute B.

Definition at line 56 of file LivenessAnalysis.h.

Member Function Documentation

◆ AbstractSparseLattice()

mlir::dataflow::AbstractSparseLattice::AbstractSparseLattice

inline

Lattices can only be created for values.

Definition at line 37 of file SparseAnalysis.h.

◆ markLive()

ChangeResult Liveness::markLive ( )

Definition at line 34 of file LivenessAnalysis.cpp.

References mlir::Change, isLive, and mlir::NoChange.

Referenced by meet(), mlir::dataflow::LivenessAnalysis::setToExitState(), mlir::dataflow::LivenessAnalysis::visitBranchOperand(), and mlir::dataflow::LivenessAnalysis::visitCallOperand().

◆ meet()

ChangeResult Liveness::meet ( const AbstractSparseLattice & rhs )

overridevirtual

Meet (intersect) the information in this lattice with 'rhs'.

Returns if the value of the lattice changed.

Reimplemented from mlir::dataflow::AbstractSparseLattice.

Definition at line 40 of file LivenessAnalysis.cpp.

References isLive, markLive(), and mlir::NoChange.

◆ print()

void Liveness::print ( raw_ostream & os ) const

overridevirtual

Print the contents of the analysis state.

Implements mlir::AnalysisState.

Definition at line 30 of file LivenessAnalysis.cpp.

References isLive.

Member Data Documentation

◆ isLive

bool mlir::dataflow::Liveness::isLive = false

Definition at line 69 of file LivenessAnalysis.h.

Referenced by markLive(), meet(), and print().

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

include/mlir/Analysis/DataFlow/LivenessAnalysis.h
lib/Analysis/DataFlow/LivenessAnalysis.cpp

Public Member Functions

Public Attributes

Additional Inherited Members