scale.score.chords
Class LoopExitChord

java.lang.Object
  scale.common.Root
      scale.score.Note
          scale.score.chords.Chord
              scale.score.chords.SequentialChord
                  scale.score.chords.LoopExitChord

All Implemented Interfaces:

AnnotationInterface, DisplayNode

public class LoopExitChord
extends SequentialChord

This class is used to mark the exit point of loops.

$Id: LoopExitChord.java,v 1.32 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.

This class represents a non-action. No code is generated for this node. Not all loops have LoopExitChord nodes. Some may have more than one.

 int sumfor2(int n)
 {
   int sum, i;
   sum = 0;
   for (i = 0; i < n; i++) {
     sum += i;
     if (sum > 100)
       return -1;
   }
   return sum;
 }
 
 

 
 





See Also:
LoopHeaderChord, 
LoopPreHeaderChord, 
LoopHeaderChord, 
LoopTailChord, 
LoopInitChord






Field Summary

 
Fields inherited from class scale.score.chords.Chord
lineNumber
 



Constructor Summary
LoopExitChord(LoopHeaderChord header)



           
LoopExitChord(LoopHeaderChord header,
              Chord next)



           
 



Method Summary




 Chord
copy()



          Make a copy of this CFG node with the same out-going CFG edges.



 LoopExitChord
findLoopExit(LoopHeaderChord header)



          Return the LoopExitChord, for the specified loop, that is  reachable from this Chord.



 DColor
getDisplayColorHint()



          Return a String specifying the color to use for coloring this node in a graphical display.



 LoopHeaderChord
getLoopHeader()



          Return the LoopHeaderChord associated with this loop exit.



 boolean
isLoopExit()



          Return true if this chord is a LoopExitChord.



 boolean
isSpecial()



          Return true if this is chord was added for the convenience of the compiler
 and does not correspond to actual source code in the user program.



 void
setLoopHeader(LoopHeaderChord header)



          Specify the loop header of this loop.



 java.lang.String
toStringSpecial()



          Return a String containing additional information about this Chord.



 void
unlinkChord()



          Break any un-needed links from a Chord that is being deleted.



 void
validate()



          Check this node for validity.



 void
visit(Predicate p)



          Process a node by calling its associated routine.


 
Methods inherited from class scale.score.chords.SequentialChord
changeOutCfgEdge, clearEdge, clearEdgeMarkers, deleteInDataEdges, deleteOutCfgEdges, edgeMarked, executionCostEstimate, getDeclList, getExprList, getLoadExprList, getNextChord, getOutCfgEdge, getOutCfgEdgeArray, getTarget, indexOfOutCfgEdge, isLastInBasicBlock, isSequential, linkSubgraph, linkTo, markEdge, numOutCfgEdges, pushAllOutCfgEdges, pushOutCfgEdges, pushOutCfgEdges, pushSortedOutCfgEdges, pushSortedOutCfgEdges, removeUseDef, replaceDecl, replaceOutCfgEdge, setTarget, setTargetUnsafe
 
Methods inherited from class scale.score.chords.Chord
addInCfgEdge, changeInDataEdge, changeParentOutCfgEdge, copySourceLine, deadCFGNodes, deletedCFGNodes, deleteInCfgEdge, executionOrder, expungeFromCfg, extractFromCfg, findPhiChords, firstInBasicBlock, getCall, getDefExpr, getDisplayLabel, getDisplayShapeHint, getFirstInCfgEdge, getInCfgEdge, getInCfgEdge, getInCfgEdgeArray, getInDataEdge, getInDataEdgeArray, getLabel, getLoopHeader, getLoopNumber, getSourceLineNumber, gotoCFGNodes, inBasicBlock, indexOfInCfgEdge, insertAfterOutCfg, insertBeforeInCfg, isAssignChord, isBranch, isExprChord, isFirstInBasicBlock, isLoopHeader, isLoopPreHeader, isLoopTail, isMarker, isPhiExpr, lastInBasicBlock, loopClean, nextVisit, nthIndexOfInCfgEdge, nullCFGNodes, numInCfgEdges, numInDataEdges, numOfInCfgEdge, parentsFinished, parentsVisited, pushAllInCfgEdges, pushChordWhenReady, pushChordWhenReady, pushInCfgEdges, pushInCfgEdges, pushInDataEdges, recordRefs, removeDeadCode, removeDualExprs, removeFromCfg, removeRefs, reorderInCfgEdgesOfCopy, replaceInCfgEdge, setLabel, setSourceLineNumber, setVisited, visited
 
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



LoopExitChord
public LoopExitChord(LoopHeaderChord header,
                     Chord next)





LoopExitChord
public LoopExitChord(LoopHeaderChord header)






Method Detail



getLoopHeader
public LoopHeaderChord getLoopHeader()

Return the LoopHeaderChord associated with this loop exit.


Overrides:
getLoopHeader in class Chord








setLoopHeader
public void setLoopHeader(LoopHeaderChord header)

Specify the loop header of this loop.


Parameters:
header - is the loop header of this loop





copy
public Chord copy()

Description copied from class: Chord
Make a copy of this CFG node with the same out-going CFG edges.
 The validity of the CFG graph is maintained.


Specified by:
copy in class Chord



Returns:
a copy of this node





unlinkChord
public void unlinkChord()

Break any un-needed links from a Chord that is being deleted.


Overrides:
unlinkChord in class Chord








isSpecial
public boolean isSpecial()

Return true if this is chord was added for the convenience of the compiler
 and does not correspond to actual source code in the user program.


Overrides:
isSpecial in class Chord








isLoopExit
public final boolean isLoopExit()

Return true if this chord is a LoopExitChord.


Overrides:
isLoopExit in class Chord








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





toStringSpecial
public java.lang.String toStringSpecial()

Return a String containing additional information about this Chord.


Overrides:
toStringSpecial in class Chord








findLoopExit
public final LoopExitChord findLoopExit(LoopHeaderChord header)

Return the LoopExitChord, for the specified loop, that is  reachable from this Chord.
 Return null if none is found.


Overrides:
findLoopExit in class Chord








getDisplayColorHint
public DColor getDisplayColorHint()

Return a String specifying the color to use for coloring this node in a graphical display.


Specified by:
getDisplayColorHint in interface DisplayNode
Overrides:
getDisplayColorHint in class Chord


See Also:
DColor





validate
public void validate()

Check this node for validity.
 This method throws an exception if the node is not linked properly.


Overrides:
validate in class Note