soot.jimple.toolkits.scalar.pre
Class DelayabilityAnalysis

java.lang.Object
  soot.toolkits.scalar.AbstractFlowAnalysis<N,A>
      soot.toolkits.scalar.FlowAnalysis<N,A>
          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

filterUnitToAfterFlow, unitToAfterFlow

Fields inherited from class soot.toolkits.scalar.AbstractFlowAnalysis

filterUnitToBeforeFlow, graph, unitToBeforeFlow

Constructor Summary

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

DelayabilityAnalysis(DirectedGraph dg, EarliestnessComputation earliest, 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, 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(Object source, Object dest) Creates a copy of the source flow object in dest.
protected Object	entryInitialFlow() Returns the initial flow value for entry/exit graph nodes.
protected void	flowThrough(Object inValue, Object unit, Object outValue) Given the merge of the out sets, compute the in set for s (or in to out, depending on direction).
protected void	merge(Object in1, Object in2, Object out) Compute the merge of the in1 and in2 sets, putting the result into out.
protected Object	newInitialFlow() Returns the flow object corresponding to the initial values for each graph node.

Methods inherited from class soot.toolkits.scalar.ForwardFlowAnalysis

constructWorklist, doAnalysis, isForward

Methods inherited from class soot.toolkits.scalar.FlowAnalysis

constructOrderer, getFlowAfter

Methods inherited from class soot.toolkits.scalar.AbstractFlowAnalysis

getFlowBefore, merge, mergeInto, treatTrapHandlersAsEntries

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,
                            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 ExceptionalUnitGraph

earliest - the earliest-computation of the same graph.

equivRhsMap - the rhs of each unit (if assignment-stmt).

DelayabilityAnalysis

public DelayabilityAnalysis(DirectedGraph dg,
                            EarliestnessComputation earliest,
                            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 ExceptionalUnitGraph

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 Object newInitialFlow()

Description copied from class: AbstractFlowAnalysis

Returns the flow object corresponding to the initial values for each graph node.

Specified by:

newInitialFlow in class AbstractFlowAnalysis

entryInitialFlow

protected Object entryInitialFlow()

Description copied from class: AbstractFlowAnalysis

Returns the initial flow value for entry/exit graph nodes.

Specified by:

entryInitialFlow in class AbstractFlowAnalysis

flowThrough

protected void flowThrough(Object inValue,
                           Object unit,
                           Object outValue)

Description copied from class: FlowAnalysis

Given the merge of the out sets, compute the in set for s (or in to out, depending on direction). This function often causes confusion, because the same interface is used for both forward and backward flow analyses. The first parameter is always the argument to the flow function (i.e. it is the "in" set in a forward analysis and the "out" set in a backward analysis), and the third parameter is always the result of the flow function (i.e. it is the "out" set in a forward analysis and the "in" set in a backward analysis).

Specified by:

flowThrough in class FlowAnalysis

merge

protected void merge(Object in1,
                     Object in2,
                     Object out)

Description copied from class: AbstractFlowAnalysis

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 AbstractFlowAnalysis

copy

protected void copy(Object source,
                    Object dest)

Description copied from class: AbstractFlowAnalysis

Creates a copy of the source flow object in dest.

Specified by:

copy in class AbstractFlowAnalysis