coins.ssa
Class CopyPropagation

java.lang.Object
  coins.ssa.CopyPropagation

All Implemented Interfaces:

LocalTransformer, Transformer

class CopyPropagation

extends java.lang.Object

implements LocalTransformer

Copy propagation
Step1:
Find copy assign expressions and store the right side variable of them to hash table as a value. The key which is corresponding to the value is the left side variable of copy assign expressions. Then, remove copy assign expressions from LIR list of BBlocks. Step2:
Rename variable names. This routine renames the variable names which is used in left side of copy assign expressions to the variable names which is used in right side of the same copy assign expression.

Field Summary

static int

THR The threshold of the debug print

Constructor Summary

CopyPropagation(SsaEnvironment e)
Constructor

Method Summary

boolean	doIt(Data data, ImList args) Transform the DATA component.
boolean	doIt(Function function, ImList args) Do copy propagation.
java.lang.String	name() Return the name of the transforming engine.
java.lang.String	subject() Return brief description of the tranformation.

Methods inherited from class java.lang.Object

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

Field Detail

THR

public static final int THR

The threshold of the debug print

See Also:

Constant Field Values

Constructor Detail

CopyPropagation

public CopyPropagation(SsaEnvironment e)

Constructor

Parameters:

e - The environment of the SSA module

Method Detail

doIt

public boolean doIt(Data data,
                    ImList args)

Description copied from interface: LocalTransformer

Transform the DATA component.

Specified by:

doIt in interface LocalTransformer

Parameters:

data - DATA to be transformed.

args - list of optional arguments.

Returns:

true if transformation suceeded.

name

public java.lang.String name()

Description copied from interface: Transformer

Return the name of the transforming engine. Used for trace tag name.

Specified by:

name in interface Transformer

Returns:

the name of the transforming engine.

subject

public java.lang.String subject()

Description copied from interface: Transformer

Return brief description of the tranformation.

Specified by:

subject in interface Transformer

Returns:

brief description of the tranformation.

doIt

public boolean doIt(Function function,
                    ImList args)

Do copy propagation.

Specified by:

doIt in interface LocalTransformer

Parameters:

function - The current function

args - The list of options

Returns:

true if transformation suceeded.