scale.score.expr
Class LoadDeclValueExpr

java.lang.Object
  scale.common.Root
      scale.score.Note
          scale.score.expr.Expr
              scale.score.expr.LoadExpr
                  scale.score.expr.LoadDeclValueExpr

All Implemented Interfaces:

AnnotationInterface, DisplayNode

public class LoadDeclValueExpr
extends LoadExpr

This class represents the value of a declaration.

$Id: LoadDeclValueExpr.java,v 1.96 2007-10-04 19:58:31 burrill Exp $

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

The type of an IdAddressOp is always the same as the declaration type.

Field Summary

Fields inherited from class scale.score.expr.Expr

fpReorder, SE_DOMAIN, SE_NONE, SE_OVERFLOW, SE_STATE

Constructor Summary

LoadDeclValueExpr(Declaration decl)

Method Summary

Expr	copy() Make a copy of this load expression.
Expr	copyNoUD() Make a copy of this load expression without the use - def information.
int	executionCostEstimate() Return a relative cost estimate for executing the expression.
protected Chord	findCriticalChord(HashMap<Expr,Chord> lMap, Chord independent) Return the Chord with the highest label value from the set of Chords that must be executed before this expression.
int	findLinearCoefficient(VariableDecl indexVar, LoopHeaderChord thisLoop) Determine the coefficent of a linear expression.
protected AffineExpr	getAffineRepresentation(HashMap<Expr,AffineExpr> affines, LoopHeaderChord thisLoop) Return the affine representation for this expression.
Literal	getConstantValue() Return the constant value of the expression.
Literal	getConstantValue(HashMap<Expr,Literal> cvMap) Return the constant value of the expression.
java.lang.String	getDisplayLabel() Return a String suitable for labeling this node in a graphical display.
boolean	isLoopInvariant(LoopHeaderChord loop) Return true if this expression is loop invariant.
boolean	isSimpleExpr() Return true if this is a simple expression.
boolean	optimizationCandidate() Return true if the expression can be moved without problems.
void	visit(Predicate p) Process a node by calling its associated routine.

Methods inherited from class scale.score.expr.LoadExpr

addMayUse, canonical, containsDeclaration, dependsOnDeclaration, equivalent, findSubscriptExpr, getAliasAnnote, getDecl, getDeclList, getExprList, getLoadExprList, getMayUse, getName, getObject, getOperandArray, getReference, getReuseLevel, getSubsetDecl, getUseDef, isMemoryDef, isMemRefExpr, loopClean, numOperands, pushOperands, recordRefs, referencesVariableInCommon, removeRefs, removeUseDef, replaceDecl, setCrossloopReuse, setDecl, setSpatialReuse, setStep, setTemporalReuse, setUseDef, setUseMayUse, setUseOriginal, sideEffects, unlinkExpression, validate, validLValue

Methods inherited from class scale.score.expr.Expr

addCast, addCast, changeInDataEdge, conditionalCopy, conditionalUnlinkExpression, deleteOutDataEdge, executionOrder, executionOrdinal, getAffineExpr, getCall, getCoreType, getCriticalChord, getDefExpr, getDisplayColorHint, getDisplayShapeHint, getDualExpr, getInDataEdge, getInDataEdgeArray, getLoopHeader, getLow, getLValue, getOperand, getOutDataEdge, getPointedToCore, getRValue, getType, hasTrueFalseResult, isCast, isDefined, isDefined, isLiteralExpr, isMatchExpr, isScalar, mayGenerateCall, numInDataEdges, reduce, removeDualExprs, setOperand, setOutDataEdge, setType, toStringSpecial

Methods inherited from class scale.score.Note

getChord, getEssentialUse, setAnnotationLevel, setReportLevel, toString

Methods inherited from class scale.common.Root

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

Methods inherited from class java.lang.Object

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

Constructor Detail

LoadDeclValueExpr

public LoadDeclValueExpr(Declaration decl)

Method Detail

copy

public Expr copy()

Make a copy of this load expression. The use - def information is copied too.

Specified by:

copy in class Expr

Returns:

a copy of this expression

copyNoUD

public Expr copyNoUD()

Make a copy of this load expression without the use - def information.

Specified by:

copyNoUD in class LoadExpr

visit

public void visit(Predicate p)

Description copied from class: Note

Process a node by calling its associated routine. See the "visitor" design pattern in Design Patterns: Elements of Reusable Object-Oriented Software by E. Gamma, et al, Addison Wesley, ISBN 0-201-63361-2.

Each class has a visit(Predicate p) method. For example, in class ABC:

   public void visit(Predicate p)
   {
     p.visitABC(this);
   }
 

and the class that implements Predicate has a method

   public void visitABC(Note n)
   {
     ABC a = (ABC) n;
     ...
   }
 

Thus, the class that implements Predicate can call

   n.visit(this);
 

where n is a Note sub-class without determining which specific sub-class n is. The visit pattern basically avoids implementing a large switch statement or defining different methods in each class for some purpose.

Specified by:

visit in class Note

See Also:

Predicate

getDisplayLabel

public java.lang.String getDisplayLabel()

Description copied from class: Expr

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 Expr

getConstantValue

public Literal getConstantValue(HashMap<Expr,Literal> cvMap)

Return the constant value of the expression. Follow use-def links.

Overrides:

getConstantValue in class Expr

See Also:

Lattice, ValueDecl

getConstantValue

public Literal getConstantValue()

Return the constant value of the expression. Do not follow use-def links.

Overrides:

getConstantValue in class Expr

See Also:

Lattice, ValueDecl

findLinearCoefficient

public int findLinearCoefficient(VariableDecl indexVar,
                                 LoopHeaderChord thisLoop)

Determine the coefficent of a linear expression.

Overrides:

findLinearCoefficient in class Expr

Parameters:

indexVar - is the index variable associated with the coefficient.

thisLoop - is the loop containing the index variable reference

Returns:

the coefficient value.

getAffineRepresentation

protected AffineExpr getAffineRepresentation(HashMap<Expr,AffineExpr> affines,
                                             LoopHeaderChord thisLoop)

Description copied from class: Expr

Return the affine representation for this expression. This method should be called only from the getAffineExpr() method. This method never returns null.

Overrides:

getAffineRepresentation in class Expr

Parameters:

affines - is a mapping from an expression to its representation and is used to avoid combinatorial explosion through use-def links

thisLoop - the loop for which this expression may be affine

See Also:

AffineExpr, AffineExpr.notAffine

findCriticalChord

protected Chord findCriticalChord(HashMap<Expr,Chord> lMap,
                                  Chord independent)

Return the Chord with the highest label value from the set of Chords that must be executed before this expression. Return 0 if none found.

Overrides:

findCriticalChord in class Expr

Parameters:

lMap - is used to memoize the expression to critical Chord information

independent - is returned if the expression is not dependent on anything

optimizationCandidate

public boolean optimizationCandidate()

Return true if the expression can be moved without problems. Expressions that reference global variables, non-atomic variables, etc are not optimization candidates.

Specified by:

optimizationCandidate in class Expr

executionCostEstimate

public int executionCostEstimate()

Return a relative cost estimate for executing the expression.

Specified by:

executionCostEstimate in class Note

isLoopInvariant

public boolean isLoopInvariant(LoopHeaderChord loop)

Return true if this expression is loop invariant.

Overrides:

isLoopInvariant in class Expr

Parameters:

loop - is the loop

isSimpleExpr

public boolean isSimpleExpr()

Return true if this is a simple expression. A simple expression consists solely of local scalar variables, constants, and numeric operations such as add, subtract, multiply, and divide.

Overrides:

isSimpleExpr in class Expr