scale.score.expr
Class AdditionExpr

java.lang.Object
  extended by scale.common.Root
      extended by scale.score.Note
          extended by scale.score.expr.Expr
              extended by scale.score.expr.BinaryExpr
                  extended by scale.score.expr.AdditionExpr
All Implemented Interfaces:
AnnotationInterface, DisplayNode

public class AdditionExpr
extends BinaryExpr

This class represents the addition function.

$Id: AdditionExpr.java,v 1.72 2007-10-04 19:58:27 burrill Exp $

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


Field Summary
 
Fields inherited from class scale.score.expr.Expr
fpReorder, SE_DOMAIN, SE_NONE, SE_OVERFLOW, SE_STATE
 
Constructor Summary
AdditionExpr(Expr la, Expr ra)
          The expression type is the same as the type of expression la.
AdditionExpr(Type type, Expr la, Expr ra)
           
 
Method Summary
 Expr copy()
          Perform a deep copy of the expression tree.
static Expr create(Type type, Expr la, Expr ra)
          This method of creating a AdditionExpr instance will return a reduced expression if possible.
 int findLinearCoefficient(VariableDecl indexVar, LoopHeaderChord thisLoop)
          Return the coefficient of the addition operator.
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 isAssociative()
          Return true becuase addition is associative.
 boolean isCommutative()
          Return true becuase addition is commutative.
 boolean isSimpleExpr()
          Return true if this is a simple expression.
 Expr reduce()
          Return a simplied equivalent expression.
 int sideEffects()
          Return an indication of the side effects execution of this expression may cause.
 void visit(Predicate p)
          Process a node by calling its associated routine.
 
Methods inherited from class scale.score.expr.BinaryExpr
associativeSwapOperands, containsDeclaration, dependsOnDeclaration, equivalent, executionCostEstimate, getAliasAnnote, getDeclList, getExprList, getLeftArg, getLoadExprList, getOperand, getOperandArray, getRightArg, isLeftDistributive, isRightDistributive, loopClean, numOperands, optimizationCandidate, pushOperands, recordRefs, removeRefs, removeUseDef, replaceDecl, setLeftArg, setOperand, setRightArg, swapOperands, unlinkExpression, validate
 
Methods inherited from class scale.score.expr.Expr
addCast, addCast, canonical, changeInDataEdge, conditionalCopy, conditionalUnlinkExpression, deleteOutDataEdge, executionOrder, executionOrdinal, findCriticalChord, findSubscriptExpr, getAffineExpr, getCall, getCoreType, getCriticalChord, getDefExpr, getDisplayColorHint, getDisplayShapeHint, getDualExpr, getInDataEdge, getInDataEdgeArray, getLoopHeader, getLow, getLValue, getOutDataEdge, getPointedToCore, getReference, getReuseLevel, getRValue, getType, getUseDef, hasTrueFalseResult, isCast, isDefined, isDefined, isLiteralExpr, isLoopInvariant, isMatchExpr, isMemoryDef, isMemRefExpr, isScalar, mayGenerateCall, numInDataEdges, removeDualExprs, setCrossloopReuse, setOutDataEdge, setSpatialReuse, setStep, setTemporalReuse, setType, setUseDef, toStringSpecial, validLValue
 
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

AdditionExpr

public AdditionExpr(Type type,
                    Expr la,
                    Expr ra)

AdditionExpr

public AdditionExpr(Expr la,
                    Expr ra)
The expression type is the same as the type of expression la.

Method Detail

create

public static Expr create(Type type,
                          Expr la,
                          Expr ra)
This method of creating a AdditionExpr instance will return a reduced expression if possible. It will also make sure that the arguments of any add generated will have the same type.


copy

public Expr copy()
Description copied from class: Expr
Perform a deep copy of the expression tree. By deep copy, we mean that copies are made of the expression tree.

Specified by:
copy in class Expr
Returns:
a copy of this expression

sideEffects

public int sideEffects()
Return an indication of the side effects execution of this expression may cause.

Overrides:
sideEffects in class BinaryExpr
See Also:
Expr.SE_NONE

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

findLinearCoefficient

public int findLinearCoefficient(VariableDecl indexVar,
                                 LoopHeaderChord thisLoop)
Return the coefficient of the addition operator.

Overrides:
findLinearCoefficient in class Expr
Parameters:
indexVar - the index variable associated with the coefficient.
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

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

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

isCommutative

public boolean isCommutative()
Return true becuase addition is commutative.

Overrides:
isCommutative in class BinaryExpr

isAssociative

public boolean isAssociative()
Return true becuase addition is associative.

Overrides:
isAssociative in class BinaryExpr

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

reduce

public Expr reduce()
Return a simplied equivalent expression. For example, for
   ((a + c1) + c2)
 
 where c1 and c2 are constants,
 the result is
 
   (a + k)
 
where k is the sum of c1 and c2. This method may modify the original expression. This is used in the lowering of subscript expressions.

Overrides:
reduce in class Expr
See Also:
SubscriptExpr.lower()