coins.ssa
Class DeadCodeElimination

java.lang.Object
  coins.ssa.DeadCodeElimination

All Implemented Interfaces:

LocalTransformer, Transformer

class DeadCodeElimination

extends java.lang.Object

implements LocalTransformer

Dead code elimination:
If the expressions which are never used or reached, then these expressions are dead. This optimizer eliminate all dead expressions from the program.

Field Summary

static int

THR The threshold of the debug print

Constructor Summary

DeadCodeElimination(SsaEnvironment e)
Constructor

Method Summary

boolean	doIt(Data data, ImList args) Transform the DATA component.
boolean	doIt(Function function, ImList args) Do dead code elimination.
java.lang.String	name() Return the name of the transforming engine.
(package private) boolean	reachToAvailBlk(BasicBlk blk, BiList visited) If the basic block can be reached from the entrance of the current CFG, then return true.
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

DeadCodeElimination

public DeadCodeElimination(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 dead code elimination.

Specified by:

doIt in interface LocalTransformer

Parameters:

function - The current function

args - The list of options

Returns:

true if transformation suceeded.

reachToAvailBlk

boolean reachToAvailBlk(BasicBlk blk,
                        BiList visited)

If the basic block can be reached from the entrance of the current CFG, then return true.

Parameters:

blk - The current basic block

visited - The list of the basic blocks which are already visited

Returns:

If the current basic block can be reached, return true