com.ibm.wala.ssa

Class DefUse

java.lang.Object

com.ibm.wala.ssa.DefUse

public class DefUse
extends java.lang.Object

An object which represent Def-Use information for an SSA IR

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.ArrayList<SSAInstruction>	allInstructions A Mapping from integer -> Instruction

Constructor Summary

Constructors

Constructor and Description
DefUse(IR ir)

Method Summary

Modifier and Type	Method and Description
SSAInstruction	getDef(int v)
protected int	getDef(SSAInstruction s, int i) What is the ith value number defined by instruction s?
protected int	getMaxValueNumber()
protected int	getNumberOfDefs(SSAInstruction s) How many value numbers does instruction s def?
int	getNumberOfUses(int v)
protected int	getNumberOfUses(SSAInstruction s) How many value numbers does instruction s use?
protected int	getUse(SSAInstruction s, int i) What is the ith value number used by instruction s?
java.util.Iterator<SSAInstruction>	getUses(int v) Return all uses of the variable with the given value number
protected void	initAllInstructions() Initialize the allInstructions field with every SSAInstruction in the ir.
boolean	isUnused(int v)

Methods inherited from class java.lang.Object

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

Field Detail

allInstructions

protected final java.util.ArrayList<SSAInstruction> allInstructions

A Mapping from integer -> Instruction

Constructor Detail

DefUse

public DefUse(IR ir)

Parameters:

ir - an IR in SSA form.

Throws:

java.lang.IllegalArgumentException - if ir is null

Method Detail

getMaxValueNumber

protected int getMaxValueNumber()

Returns:

the maximum value number in a particular IR

initAllInstructions

protected void initAllInstructions()

Initialize the allInstructions field with every SSAInstruction in the ir.

getDef

protected int getDef(SSAInstruction s,
                     int i)

What is the ith value number defined by instruction s?

getUse

protected int getUse(SSAInstruction s,
                     int i)

What is the ith value number used by instruction s?

getNumberOfDefs

protected int getNumberOfDefs(SSAInstruction s)

How many value numbers does instruction s def?

getNumberOfUses

protected int getNumberOfUses(SSAInstruction s)

How many value numbers does instruction s use?

getDef

public SSAInstruction getDef(int v)

Returns:

the SSAInstruction that defines the variable with value number v.

getUses

public java.util.Iterator<SSAInstruction> getUses(int v)

Return all uses of the variable with the given value number

getNumberOfUses

public int getNumberOfUses(int v)

Parameters:

v - a value number

Returns:

the number of uses of the variable with the given value number

isUnused

public boolean isUnused(int v)

Parameters:

v - a value number

Returns:

true if the variable with the given value number has no uses