scale.score.trans
Class LoopPermute

java.lang.Object
  scale.score.trans.Optimization
      scale.score.trans.LoopTrans
          scale.score.trans.LoopPermute

public class LoopPermute
extends LoopTrans

This optimization permutes the loops of a routine based on cache order. $Id: LoopPermute.java,v 1.41 2007-10-04 19:58:36 burrill Exp $

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

See Improving Data Locality with Loop Transformation by Kathryn S. McKinley, Steve Carr, and Chau-wen Tseng, ACM Transactions on Programming Languages and Systems, 18(4):424-453, July 1996.

Field Summary

static boolean

classTrace True if traces are to be performed.

Fields inherited from class scale.score.trans.LoopTrans

floatType, intPointer, intType, unsignedPointer, unsignedType, voidp

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

LoopPermute(Scribble scribble)

Method Summary

Cost	computeRefCost(LoopHeaderChord loop, SubscriptExpr se)
void	perform() Perform the optimization.
int	requiresSSA() Return whether this optimization requires that the CFG be in SSA form.

Methods inherited from class scale.score.trans.LoopTrans

cleanup, findIndexInc, findIndexInit, initializeTransform, performLoopInterchange, performLoopStripMining, performLoopTile, permutedLoops, tripProduct

Methods inherited from class scale.score.trans.Optimization

assertTrace, assertTrace, assertTrace, assertTrace, assertTrace, genTemp, insertStores, 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.

Constructor Detail

LoopPermute

public LoopPermute(Scribble scribble)

Parameters:

scribble - is the CFG containing the loops

Method Detail

perform

public void perform()

Description copied from class: Optimization

Perform the optimization. Each optimization must specify

• if the CFG is left in valid SSA form
• if the dominance information is still valid
• if the variable reference information is still valid

after it completes. The Scribble class provides methods that may be used to sepcify this information.

Specified by:

perform in class Optimization

computeRefCost

public Cost computeRefCost(LoopHeaderChord loop,
                           SubscriptExpr se)

requiresSSA

public int requiresSSA()

Return whether this optimization requires that the CFG be in SSA form. It returns either

NO_SSA

the CFG must not be in SSA form,

IN_SSA

the CFG must be in SSA form,

VALID_SSA

the CFG must be in valid SSA form, or

NA_SSA

the CFG does not need to be in valid SSA form.

Overrides:

requiresSSA in class Optimization