scale.score.analyses
Class VirtualVar

java.lang.Object
  scale.common.Root
      scale.clef.Node
          scale.clef.decl.Declaration
              scale.clef.decl.ValueDecl
                  scale.clef.decl.VariableDecl
                      scale.score.analyses.VirtualVar

All Implemented Interfaces:

java.lang.Comparable, AnnotationInterface, DisplayNode

Direct Known Subclasses:

SubVirtualVar, SuperVirtualVar

public class VirtualVar
extends VariableDecl

A class that represents a virtual variable which is used to handle aliasing and indirect operations in SSA form.

$Id: VirtualVar.java,v 1.28 2006-02-28 16:37:08 burrill Exp $

Copyright 2005 by the Scale Compiler Group,
Department of Computer Science
University of Massachusetts,
Amherst MA. 01003, USA
All Rights Reserved.

A virtual variable is a pseudo-declaration. We don't actually generate code for the declaration, but we treat it like a declaration in the representation.

Field Summary

protected ECR

var A virtual variable represents a group of variables with similar alias characteristics.

Fields inherited from class scale.clef.decl.VariableDecl

ignoreAddressTaken

Constructor Summary

VirtualVar(java.lang.String name, ECR v)
Create a new virtual variable with a given name and associated ECR.

Method Summary

Declaration	copy(java.lang.String name) Make a copy of this declaration using a new name.
static int	created() Return the number of instances of this class created.
java.lang.String	getDisplayLabel() Return a String suitable for labeling this node in a graphical display.
ECR	getECR()
VirtualVar	getSubset(int i) Return the specified subset variable.
VirtualVar	getSuperset() Return the superset virtual variable.
boolean	inSubsets(VirtualVar vv) Return true if vv is in the subset.
boolean	isSuper() Return true if this is a superset virtual variable.
boolean	isVirtual() Return true if the declaration is a virtual variable.
int	numSubsets() Return the number of subsets of the super virtual variable.
boolean	subsetEquiv(VirtualVar vv) Return true if virtual variable param is equal to this, or this is a superset.

Methods inherited from class scale.clef.decl.VariableDecl

addressTaken, computeAttributes, declareFtnResultVar, getAddressRegister, getConstantValue, getDisplacement, getInitialValue, getOriginal, getStorageLoc, getValueRegister, hasHiddenAliases, hasHiddenPtrAliases, hasInvalidArrayReferences, inMemory, isCommonBaseVar, isCommonBaseVariable, isConst, isFtnResultVar, isNotAliasCandidate, isNotSSACandidate, isReferenced, isRestricted, isStatic, isStorageLocSet, isTemporary, isVariableDecl, isVolatile, optimizationCandidate, residency, returnVariableDecl, setAddressRegister, setAddressTaken, setDisplacement, setHiddenAliases, setHiddenPtrAliases, setInitialValue, setInvalidArrayReferences, setReferenced, setResidency, setStorageLoc, setTemporary, setType, setValue, setValueRegister, setVisibility, shouldBeInRegister, specifyCommonBaseVariable, toStringSpecial, valueRegMode, visit

Methods inherited from class scale.clef.decl.ValueDecl

getChild, getValue, isValueDecl, numChildren, returnValueDecl

Methods inherited from class scale.clef.decl.Declaration

accessibility, compareTo, getActualType, getAlias, getCoreType, getDecl, getDisplayColorHint, getDisplayShapeHint, getMode, getName, getPointedToCore, getTag, getType, hashCode, isCaseLabelDecl, isEnumElementDecl, isEquivalenceDecl, isExceptionDecl, isFieldDecl, isFileDecl, isFormalDecl, isForwardProcedureDecl, isGlobal, isLabelDecl, isProcedureDecl, isPure, isRenamed, isRenamedVariableDecl, isRoutineDecl, isStmtFtnDecl, isTypeDecl, isTypeName, isUnknownFormals, isWeak, returnCaseLabelDecl, returnEnumElementDecl, returnEquivalenceDecl, returnExceptionDecl, returnFieldDecl, returnFileDecl, returnFormalDecl, returnForwardProcedureDecl, returnLabelDecl, returnProcedureDecl, returnRenamedVariableDecl, returnRoutineDecl, returnStmtFtnDecl, returnTypeDecl, returnTypeName, returnUnknownFormals, setAccessibility, setAlias, setName, setTag, setWeak, visibility

Methods inherited from class scale.clef.Node

getSourceLineNumber, setAnnotationLevel, setReportLevel, setSourceLineNumber, toString, toString, toStringChildren

Methods inherited from class scale.common.Root

addAnnotation, allAnnotations, allMatchingAnnotations, getAnnotation, getDisplayName, getDisplayString, getNodeCount, getNodeID, hasAnnotation, hasEqualAnnotation, removeAnnotation, removeAnnotations, toStringAnnotations, toStringClass, trace, trace, trace

Methods inherited from class java.lang.Object

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

Field Detail

var

protected ECR var

A virtual variable represents a group of variables with similar alias characteristics. We represent the group of variables using Steensgaard's ECR data structure.

Constructor Detail

VirtualVar

public VirtualVar(java.lang.String name,
                  ECR v)

Create a new virtual variable with a given name and associated ECR. The virtual variable does not have a type.

Method Detail

created

public static int created()

Return the number of instances of this class created.

getDisplayLabel

public java.lang.String getDisplayLabel()

Description copied from class: Declaration

Return a String suitable for labeling this node in a graphical display. This method should be over-ridden as it simplay returns the class name.

Specified by:

getDisplayLabel in interface DisplayNode

Overrides:

getDisplayLabel in class Declaration

getSuperset

public VirtualVar getSuperset()

Return the superset virtual variable.

isSuper

public boolean isSuper()

Return true if this is a superset virtual variable.

isVirtual

public boolean isVirtual()

Return true if the declaration is a virtual variable.

Overrides:

isVirtual in class Declaration

inSubsets

public boolean inSubsets(VirtualVar vv)

Return true if vv is in the subset.

numSubsets

public int numSubsets()

Return the number of subsets of the super virtual variable.

getSubset

public VirtualVar getSubset(int i)

Return the specified subset variable.

subsetEquiv

public boolean subsetEquiv(VirtualVar vv)

Return true if virtual variable param is equal to this, or this is a superset.

copy

public Declaration copy(java.lang.String name)

Make a copy of this declaration using a new name.

Overrides:

copy in class VariableDecl

getECR

public ECR getECR()