scale.score.trans
Class PRE

java.lang.Object
  scale.score.trans.Optimization
      scale.score.trans.PRE

public class PRE
extends Optimization

Perform the Partial Redundancy Elimination optimization.

$Id: PRE.java,v 1.90 2007-10-04 19:58:37 burrill Exp $

Copyright 2008 by the Scale Compiler Group,
Department of Computer Science
University of Massachusetts Amherst MA. 01003, USA
All Rights Reserved.

The algorithm is based Fred Chow's PLDI paper, "A New Algorithm for Partial Redundancy Elimination based on SSA Form".

Field Summary

static boolean	classTrace True if traces are to be performed.
static boolean	useHeuristics If true, use heuristics that prune the cases where the optimization is applied.

Fields inherited from class scale.score.trans.Optimization

dChanged, fpReorder, hasDummyAliases, IN_SSA, minimumExecutionCost, NA_SSA, NO_SSA, rChanged, scribble, signedIntsWrapOnOverflow, trace, un, unsafe, unsignedIntsWrapOnOverflow, VALID_SSA

Constructor Summary

PRE(Scribble scribble)

Method Summary

static int	deadCFGNodes() Return the number of dead nodes removed.
static int	newCFGNodes() Return the number of new nodes created.
void	perform() Perform PRE on the SSA form of a Scribble graph.
static int	removedOperations() Return the number of operations removed.

Methods inherited from class scale.score.trans.Optimization

assertTrace, assertTrace, assertTrace, assertTrace, assertTrace, genTemp, insertStores, requiresSSA, setTrace, sort

Methods inherited from class java.lang.Object

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

Field Detail

classTrace

public static boolean classTrace

True if traces are to be performed.

useHeuristics

public static boolean useHeuristics

If true, use heuristics that prune the cases where the optimization is applied.

Constructor Detail

PRE

public PRE(Scribble scribble)

Parameters:

scribble - is the Scribble CFG in SSA form

Method Detail

deadCFGNodes

public static int deadCFGNodes()

Return the number of dead nodes removed.

newCFGNodes

public static int newCFGNodes()

Return the number of new nodes created.

removedOperations

public static int removedOperations()

Return the number of operations removed.

perform

public void perform()

Perform PRE on the SSA form of a Scribble graph. The algorithm is based Fred Chow's PLDI paper, A New Algorithm for Partial Redundancy Elimination based on SSA Form

Specified by:

perform in class Optimization