com.oracle.graal.java

Class ComputeLoopFrequenciesClosure

java.lang.Object

com.oracle.graal.phases.graph.ReentrantNodeIterator.NodeIteratorClosure<Double>

com.oracle.graal.java.ComputeLoopFrequenciesClosure

public final class ComputeLoopFrequenciesClosure
extends ReentrantNodeIterator.NodeIteratorClosure<Double>

Field Summary

Fields

Modifier and Type	Field and Description
private static ComputeLoopFrequenciesClosure	INSTANCE

Constructor Summary

Constructors

Modifier	Constructor and Description
private	ComputeLoopFrequenciesClosure()

Method Summary

Modifier and Type	Method and Description
protected Double	afterSplit(AbstractBeginNode node, Double oldState)
static void	compute(StructuredGraph graph) Computes the frequencies of all loops in the given graph.
protected Double	merge(AbstractMergeNode merge, List<Double> states)
static double	multiplySaturate(double a, double b) Multiplies a and b and saturates the result to 1/#MIN_PROBABILITY.
protected Map<LoopExitNode,Double>	processLoop(LoopBeginNode loop, Double initialState)
protected Double	processNode(FixedNode node, Double currentState)

Methods inherited from class com.oracle.graal.phases.graph.ReentrantNodeIterator.NodeIteratorClosure

continueIteration

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

private static final ComputeLoopFrequenciesClosure INSTANCE

Constructor Detail

ComputeLoopFrequenciesClosure

private ComputeLoopFrequenciesClosure()

Method Detail

processNode

protected Double processNode(FixedNode node,
                             Double currentState)

Specified by:

processNode in class ReentrantNodeIterator.NodeIteratorClosure<Double>

merge

protected Double merge(AbstractMergeNode merge,
                       List<Double> states)

Specified by:

merge in class ReentrantNodeIterator.NodeIteratorClosure<Double>

afterSplit

protected Double afterSplit(AbstractBeginNode node,
                            Double oldState)

Specified by:

afterSplit in class ReentrantNodeIterator.NodeIteratorClosure<Double>

processLoop

protected Map<LoopExitNode,Double> processLoop(LoopBeginNode loop,
                                               Double initialState)

Specified by:

processLoop in class ReentrantNodeIterator.NodeIteratorClosure<Double>

multiplySaturate

public static double multiplySaturate(double a,
                                      double b)

Multiplies a and b and saturates the result to 1/#MIN_PROBABILITY.

Returns:

a times b saturated to 1/#MIN_PROBABILITY

compute

public static void compute(StructuredGraph graph)

Computes the frequencies of all loops in the given graph. This is done by performing a reverse postorder iteration and computing the probability of all fixed nodes. The combined probability of all exits of a loop can be used to compute the loop's expected frequency.