edu.umd.cs.findbugs.ba.vna
Class AvailableLoad

java.lang.Object
  edu.umd.cs.findbugs.ba.vna.AvailableLoad

All Implemented Interfaces:

java.lang.Comparable<AvailableLoad>

public class AvailableLoad
extends java.lang.Object
implements java.lang.Comparable<AvailableLoad>

An AvailableLoad indicates a field and (optionally) object reference for which a value is available. It is used to implement redundant load elimination and forward substitution in ValueNumberAnalysis. The idea is that programmers often reload fields unnecessarily when they "know" that the value will not change. In order to deduce the intended meaning of such code, our analyses need to figure out that such loads return the same value.

AvailableLoad objects may be used as keys in both hash and tree sets and maps.

Author:

David Hovemeyer

See Also:

ValueNumberAnalysis

Constructor Summary

AvailableLoad(ValueNumber reference, XField field)
Constructor from object reference and instance field.

AvailableLoad(XField staticField)
Constructor from static field.

Method Summary

int	compareTo(AvailableLoad other)
boolean	equals(java.lang.Object o)
XField	getField() Get the field for which a load is available.
ValueNumber	getReference() Get the ValueNumber of the object reference.
int	hashCode()
boolean	matchesReference(ValueNumber v)
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

AvailableLoad

public AvailableLoad(XField staticField)

Constructor from static field.

Parameters:

staticField - the StaticField

AvailableLoad

public AvailableLoad(ValueNumber reference,
                     XField field)

Constructor from object reference and instance field.

Parameters:

reference - the ValueNumber of the object reference

field - the InstanceField

Method Detail

getReference

public ValueNumber getReference()

Get the ValueNumber of the object reference.

Returns:

the ValueNumber, or null if this is a an available static field load

matchesReference

public boolean matchesReference(ValueNumber v)

getField

public XField getField()

Get the field for which a load is available.

Returns:

the XField

compareTo

public int compareTo(AvailableLoad other)

Specified by:

compareTo in interface java.lang.Comparable<AvailableLoad>

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object