soot.toolkits.graph

Class MHGDominatorsFinder<N>

java.lang.Object

soot.toolkits.graph.MHGDominatorsFinder<N>

All Implemented Interfaces:

DominatorsFinder<N>

Direct Known Subclasses:

MHGPostDominatorsFinder

public class MHGDominatorsFinder<N>
extends java.lang.Object
implements DominatorsFinder<N>

Calculate dominators for basic blocks.

Uses the algorithm contained in Dragon book, pg. 670-1.

       D(n0) := { n0 }
       for n in N - { n0 } do D(n) := N;
       while changes to any D(n) occur do
         for n in N - {n0} do
             D(n) := {n} U (intersect of D(p) over all predecessors p of n)
 

2007/07/03 - updated to use BitSets instead of HashSets, as the most expensive operation in this algorithm used to be cloning of the fullSet, which is very cheap for BitSets.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.BitSet	fullSet
protected DirectedGraph<N>	graph
protected java.util.List<N>	heads
protected java.util.Map<java.lang.Integer,N>	indexToNode
protected int	lastIndex
protected java.util.Map<N,java.util.BitSet>	nodeToFlowSet
protected java.util.Map<N,java.lang.Integer>	nodeToIndex

Constructor Summary

Constructors

Constructor and Description
MHGDominatorsFinder(DirectedGraph<N> graph)

Method Summary

Modifier and Type	Method and Description
protected void	doAnalysis()
java.util.List<N>	getDominators(N node) Returns a list of dominators for the given node in the graph.
DirectedGraph<N>	getGraph() Returns the graph to which the analysis pertains.
N	getImmediateDominator(N node) Returns the immediate dominator of node or null if the node has no immediate dominator.
protected int	indexOf(N o)
boolean	isDominatedBy(N node, N dominator) True if "node" is dominated by "dominator" in the graph.
boolean	isDominatedByAll(N node, java.util.Collection<N> dominators) True if "node" is dominated by all nodes in "dominators" in the graph.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

graph

protected DirectedGraph<N> graph

fullSet

protected java.util.BitSet fullSet

heads

protected java.util.List<N> heads

nodeToFlowSet

protected java.util.Map<N,java.util.BitSet> nodeToFlowSet

nodeToIndex

protected java.util.Map<N,java.lang.Integer> nodeToIndex

indexToNode

protected java.util.Map<java.lang.Integer,N> indexToNode

lastIndex

protected int lastIndex

Constructor Detail

MHGDominatorsFinder

public MHGDominatorsFinder(DirectedGraph<N> graph)

Method Detail

doAnalysis

protected void doAnalysis()

indexOf

protected int indexOf(N o)

getGraph

public DirectedGraph<N> getGraph()

Description copied from interface: DominatorsFinder

Returns the graph to which the analysis pertains.

Specified by:

getGraph in interface DominatorsFinder<N>

getDominators

public java.util.List<N> getDominators(N node)

Description copied from interface: DominatorsFinder

Returns a list of dominators for the given node in the graph.

Specified by:

getDominators in interface DominatorsFinder<N>

getImmediateDominator

public N getImmediateDominator(N node)

Description copied from interface: DominatorsFinder

Returns the immediate dominator of node or null if the node has no immediate dominator.

Specified by:

getImmediateDominator in interface DominatorsFinder<N>

isDominatedBy

public boolean isDominatedBy(N node,
                             N dominator)

Description copied from interface: DominatorsFinder

True if "node" is dominated by "dominator" in the graph.

Specified by:

isDominatedBy in interface DominatorsFinder<N>

isDominatedByAll

public boolean isDominatedByAll(N node,
                                java.util.Collection<N> dominators)

Description copied from interface: DominatorsFinder

True if "node" is dominated by all nodes in "dominators" in the graph.

Specified by:

isDominatedByAll in interface DominatorsFinder<N>