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 | getPoint () const |
| Return the program point 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 (ProgramPoint point) | |
| Create the analysis state at the given program point. More... | |
| ProgramPoint | getPoint () const |
| Returns the program point this state is located at. More... | |
| LLVM_DUMP_METHOD void | dump () const |
| void | addDependency (ProgramPoint dependent, DataFlowAnalysis *analysis) |
| Add a dependency to this analysis state on a program point and an analysis. More... | |
Public Attributes | |
| bool | isLive = false |
Additional Inherited Members | |
| Protected Attributes inherited from mlir::AnalysisState | |
| ProgramPoint | point |
| The program point 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()
|
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(), and mlir::dataflow::LivenessAnalysis::visitCallOperand().
◆ meet()
|
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()
|
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
