soot.jimple.toolkits.scalar.pre
Class DelayabilityAnalysis

java.lang.Object
  |
  +--soot.toolkits.scalar.FlowAnalysis
        |
        +--soot.toolkits.scalar.ForwardFlowAnalysis
              |
              +--soot.jimple.toolkits.scalar.pre.DelayabilityAnalysis

public class DelayabilityAnalysis
extends ForwardFlowAnalysis

Performs a Delayability-analysis on the given graph. This analysis is the third analysis in the PRE (lazy code motion) and has little (no?) sense if used alone. Basicly it tries to push the computations we would insert in the Busy Code Motion as far down as possible, to decrease life-time ranges (clearly this is not true, if the computation "uses" two variables and produces only one temporary).


Field Summary
 
Fields inherited from class soot.toolkits.scalar.FlowAnalysis
graph, unitToAfterFlow, unitToBeforeFlow
 
Constructor Summary
DelayabilityAnalysis(DirectedGraph dg)
          this constructor should not be used, and will throw a runtime-exception!
DelayabilityAnalysis(DirectedGraph dg, EarliestnessComputation earliest, java.util.Map equivRhsMap)
          automaticly performs the Delayability-analysis on the graph dg and the Earliest-computation earliest.
the equivRhsMap is only here to avoid doing these things again...
DelayabilityAnalysis(DirectedGraph dg, EarliestnessComputation earliest, java.util.Map equivRhsMap, BoundedFlowSet set)
          automaticly performs the Delayability-analysis on the graph dg and the Earliest-computation earliest.
the equivRhsMap is only here to avoid doing these things again...
as set-operations are usually more efficient, if the sets come from one source, sets should be shared around analyses, if the analyses are to be combined.
 
Method Summary
protected  void copy(java.lang.Object source, java.lang.Object dest)
          Creates a copy of the source flow object in dest.
protected  void customizeInitialFlowGraph()
          Customize the initial flow graph.
protected  void flowThrough(java.lang.Object inValue, java.lang.Object unit, java.lang.Object outValue)
          Given the merge of the out sets, compute the in set for s.
protected  void merge(java.lang.Object in1, java.lang.Object in2, java.lang.Object out)
          Compute the merge of the in1 and in2 sets, putting the result into out.
protected  java.lang.Object newInitialFlow()
          Returns the flow object corresponding to the initial values for each graph node.
 
Methods inherited from class soot.toolkits.scalar.ForwardFlowAnalysis
doAnalysis, isForward
 
Methods inherited from class soot.toolkits.scalar.FlowAnalysis
entryInitialFlow, getFlowAfter, getFlowBefore
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

DelayabilityAnalysis

public DelayabilityAnalysis(DirectedGraph dg)
this constructor should not be used, and will throw a runtime-exception!


DelayabilityAnalysis

public DelayabilityAnalysis(DirectedGraph dg,
                            EarliestnessComputation earliest,
                            java.util.Map equivRhsMap)
automaticly performs the Delayability-analysis on the graph dg and the Earliest-computation earliest.
the equivRhsMap is only here to avoid doing these things again...

Parameters:
dg - a CompleteUnitGraph
earliest - the earliest-computation of the same graph.
equivRhsMap - the rhs of each unit (if assignment-stmt).

DelayabilityAnalysis

public DelayabilityAnalysis(DirectedGraph dg,
                            EarliestnessComputation earliest,
                            java.util.Map equivRhsMap,
                            BoundedFlowSet set)
automaticly performs the Delayability-analysis on the graph dg and the Earliest-computation earliest.
the equivRhsMap is only here to avoid doing these things again...
as set-operations are usually more efficient, if the sets come from one source, sets should be shared around analyses, if the analyses are to be combined.

Parameters:
dg - a CompleteUnitGraph
earliest - the earliest-computation of the same graph.
equivRhsMap - the rhs of each unit (if assignment-stmt).
set - the shared set.
Method Detail

newInitialFlow

protected java.lang.Object newInitialFlow()
Description copied from class: FlowAnalysis
Returns the flow object corresponding to the initial values for each graph node.

Specified by:
newInitialFlow in class FlowAnalysis

customizeInitialFlowGraph

protected void customizeInitialFlowGraph()
Description copied from class: FlowAnalysis
Customize the initial flow graph. May be called from a concrete FlowAnalysis constructor to adjust, for instance, the value for the initial node.

Overrides:
customizeInitialFlowGraph in class FlowAnalysis

flowThrough

protected void flowThrough(java.lang.Object inValue,
                           java.lang.Object unit,
                           java.lang.Object outValue)
Description copied from class: FlowAnalysis
Given the merge of the out sets, compute the in set for s.

Specified by:
flowThrough in class FlowAnalysis

merge

protected void merge(java.lang.Object in1,
                     java.lang.Object in2,
                     java.lang.Object out)
Description copied from class: FlowAnalysis
Compute the merge of the in1 and in2 sets, putting the result into out. The behavior of this function depends on the implementation ( it may be necessary to check whether in1 and in2 are equal or aliased ). Used by the doAnalysis method.

Specified by:
merge in class FlowAnalysis

copy

protected void copy(java.lang.Object source,
                    java.lang.Object dest)
Description copied from class: FlowAnalysis
Creates a copy of the source flow object in dest.

Specified by:
copy in class FlowAnalysis