soot.jimple.toolkits.scalar.pre
Class LazyCodeMotion

java.lang.Object
  soot.Transformer
      soot.BodyTransformer
          soot.jimple.toolkits.scalar.pre.LazyCodeMotion

public class LazyCodeMotion
extends BodyTransformer

Performs a partial redundancy elimination (= code motion). This is done, by introducing helper-vars, that store an already computed value, or if a compuation only arrives partially (not from all predecessors) inserts a new computation on these paths afterwards).

In order to catch every redundant expression, this transformation must be done on a graph without critical edges. Therefore the first thing we do, is removing them. A subsequent pass can then easily remove the synthetic nodes we have introduced.

The term "lazy" refers to the fact, that we move computations only if necessary.

See Also:

CriticalEdgeRemover

Constructor Summary

LazyCodeMotion(Singletons.Global g)

Method Summary

protected void	internalTransform(Body b, String phaseName, Map opts) performs the lazy code motion.
static LazyCodeMotion	v()

Methods inherited from class soot.BodyTransformer

transform, transform, transform

Methods inherited from class java.lang.Object

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

Constructor Detail

LazyCodeMotion

public LazyCodeMotion(Singletons.Global g)

Method Detail

v

public static LazyCodeMotion v()

internalTransform

protected void internalTransform(Body b,
                                 String phaseName,
                                 Map opts)

performs the lazy code motion.

Specified by:

internalTransform in class BodyTransformer

Parameters:

b - the body on which to apply the transformation

phaseName - the phasename for this transform; not typically used by implementations.

opts - the actual computed options; a combination of default options and Scene specified options.