Package com.tonic.analysis.ssa.analysis

Class DefUseChains

java.lang.Object

com.tonic.analysis.ssa.analysis.DefUseChains

public class DefUseChains
extends Object

Def-use chains mapping each SSA value to its defining instruction and its uses.

Constructor Summary

Constructors

Constructor	Description
DefUseChains(IRMethod method)	Creates empty chains for the given method.

Method Summary

Modifier and Type	Method	Description
void	compute()	Computes def-use chains for all values in the method.
SSAValue	getDefinedValue(IRInstruction instr)	Gets the value defined by the specified instruction.
IRInstruction	getDefinition(SSAValue value)	Gets the instruction that defines the specified value.
Map<SSAValue,IRInstruction>	getDefinitions()
Map<IRInstruction,SSAValue>	getInstrDefs()
Map<IRInstruction,Set<SSAValue>>	getInstrUses()
IRMethod	getMethod()
int	getUseCount(SSAValue value)	Gets the number of uses of the specified value.
Set<SSAValue>	getUsedValues(IRInstruction instr)	Gets all values used by the specified instruction.
Map<SSAValue,Set<IRInstruction>>	getUses()
Set<IRInstruction>	getUses(SSAValue value)	Gets all instructions that use the specified value.
boolean	hasUses(SSAValue value)	Checks if the specified value has any uses.
boolean	isDeadCode(IRInstruction instr)	Checks if an instruction is dead code.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefUseChains

public DefUseChains(IRMethod method)

Creates empty chains for the given method.

Parameters:

method - the method to analyze

Method Detail

getMethod

public IRMethod getMethod()

Returns:

the method

getDefinitions

public Map<SSAValue,IRInstruction> getDefinitions()

Returns:

the definitions

getUses

public Map<SSAValue,Set<IRInstruction>> getUses()

Returns:

the uses

getInstrUses

public Map<IRInstruction,Set<SSAValue>> getInstrUses()

Returns:

the instr uses

getInstrDefs

public Map<IRInstruction,SSAValue> getInstrDefs()

Returns:

the instr defs

compute

public void compute()

Computes def-use chains for all values in the method.

getDefinition

public IRInstruction getDefinition(SSAValue value)

Gets the instruction that defines the specified value.

Parameters:

value - the value to query

Returns:

the defining instruction, or null if none exists

getUses

public Set<IRInstruction> getUses(SSAValue value)

Gets all instructions that use the specified value.

Parameters:

value - the value to query

Returns:

the set of instructions that use the value

getUsedValues

public Set<SSAValue> getUsedValues(IRInstruction instr)

Gets all values used by the specified instruction.

Parameters:

instr - the instruction to query

Returns:

the set of values used by the instruction

getDefinedValue

public SSAValue getDefinedValue(IRInstruction instr)

Gets the value defined by the specified instruction.

Parameters:

instr - the instruction to query

Returns:

the defined value, or null if the instruction defines no value

hasUses

public boolean hasUses(SSAValue value)

Checks if the specified value has any uses.

Parameters:

value - the value to check

Returns:

true if the value has at least one use

getUseCount

public int getUseCount(SSAValue value)

Gets the number of uses of the specified value.

Parameters:

value - the value to query

Returns:

the use count

isDeadCode

public boolean isDeadCode(IRInstruction instr)

Checks if an instruction is dead code.

Parameters:

instr - the instruction to check

Returns:

true if the instruction defines a value that has no uses