scale.score.analyses
Class PlaceIndirectOpsSteen

java.lang.Object
  scale.score.pred.Supertype
      scale.score.pred.TraceChords
          scale.score.analyses.PlaceIndirectOps
              scale.score.analyses.PlaceIndirectOpsSteen

All Implemented Interfaces:

Predicate

public class PlaceIndirectOpsSteen
extends PlaceIndirectOps

This class visits nodes and places information, at specific nodes, which is used to represent aliases and indirect operations in SSA form.

$Id: PlaceIndirectOpsSteen.java,v 1.23 2007-10-04 19:58:21 burrill Exp $

Copyright 2007 by the Scale Compiler Group,
Department of Computer Science
University of Massachusetts,
Amherst MA. 01003, USA
All Rights Reserved.

We expect that alias analysis has been performed before we add information for indirection operations to the SSA form.

For now, we expect that Steensgaard's algorithm is used to create alias groups. An alias group is a collection of variables (and access paths) that contain the same alias relationships.

Field Summary

Fields inherited from class scale.score.analyses.PlaceIndirectOps

aliases, classTrace, trace

Fields inherited from class scale.score.pred.TraceChords

rl, thisChord, wl

Constructor Summary

PlaceIndirectOpsSteen(Aliases aliases)
Construct an object to place special annotations in a Scribble graph so that we can correctly handle indirect operations and aliases.

Method Summary

void	visitCallExpr(CallExpr e) We add Chi and Mu operators to routine calls to mark the use and definition of variables accross calls.
void	visitDualExpr(DualExpr e) Don't do anything here - but we don't want to default to visitExpr A Dual expression does not effect the placement of indirect operators.
void	visitExprChord(ExprChord c) We add a Chi operator to store operations that assign to indirect variables.
void	visitFieldExpr(FieldExpr e) Don't do anything here - but we don't want to default to visitExpr
void	visitLoadDeclValueExpr(LoadDeclValueExpr e) Add annotations to handle simple variable references that are aliases.
void	visitLoadValueIndirectExpr(LoadValueIndirectExpr e) We add a Mu operator to a use of an indirect variable.
void	visitSubscriptExpr(SubscriptExpr e) We don't need to do anything at a subscript expression.

Methods inherited from class scale.score.analyses.PlaceIndirectOps

addMayUse, addMayUse, addMayUse, addMayUse, createMayDefInfo, createMayDefInfo, getAliasVar, getAliasVar, getVirtualVar, setTrace

Methods inherited from class scale.score.pred.TraceChords

getChord, setChord, visitChord

Methods inherited from class scale.score.pred.Supertype

visitAbsoluteValueExpr, visitAdditionExpr, visitAllocateExpr, visitAndExpr, visitArrayIndexExpr, visitBeginChord, visitBinaryExpr, visitBitAndExpr, visitBitComplementExpr, visitBitOrExpr, visitBitShiftExpr, visitBitXorExpr, visitBranchChord, visitCallFunctionExpr, visitCallMethodExpr, visitCompareExpr, visitComplexValueExpr, visitConditionalExpr, visitConversionExpr, visitDecisionChord, visitDivisionExpr, visitEndChord, visitEqualityExpr, visitExitChord, visitExponentiationExpr, visitExpr, visitExprPhiExpr, visitGotoChord, visitGreaterEqualExpr, visitGreaterExpr, visitIfThenElseChord, visitLeaveChord, visitLessEqualExpr, visitLessExpr, visitLiteralExpr, visitLoadDeclAddressExpr, visitLoadExpr, visitLoadFieldAddressExpr, visitLoadFieldValueExpr, visitLoopExitChord, visitLoopHeaderChord, visitLoopInitChord, visitLoopPreHeaderChord, visitLoopTailChord, visitMarkerChord, visitMaxExpr, visitMinExpr, visitMultiplicationExpr, visitNaryExpr, visitNegativeExpr, visitNilExpr, visitNote, visitNotEqualExpr, visitNotExpr, visitNullChord, visitOrExpr, visitPhiExpr, visitPhiExprChord, visitRemainderExpr, visitReturnChord, visitSequentialChord, visitSubtractionExpr, visitSwitchChord, visitTernaryExpr, visitTranscendental2Expr, visitTranscendentalExpr, visitUnaryExpr, visitVaArgExpr, visitVaEndExpr, visitValueExpr, visitVarArgExpr, visitVaStartExpr, visitVectorExpr

Methods inherited from class java.lang.Object

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

Constructor Detail

PlaceIndirectOpsSteen

public PlaceIndirectOpsSteen(Aliases aliases)

Construct an object to place special annotations in a Scribble graph so that we can correctly handle indirect operations and aliases.

Method Detail

visitLoadDeclValueExpr

public void visitLoadDeclValueExpr(LoadDeclValueExpr e)

Add annotations to handle simple variable references that are aliases. We add a Mu operator for a use. Definitions are handled by Chi operators that are added to the ExprChord expression.

Specified by:

visitLoadDeclValueExpr in interface Predicate

Overrides:

visitLoadDeclValueExpr in class Supertype

visitLoadValueIndirectExpr

public void visitLoadValueIndirectExpr(LoadValueIndirectExpr e)

We add a Mu operator to a use of an indirect variable. Note that we handle assignments through indirect variables elsewhere. The Mu operator represents any variable that may be used via the indirect variable.

A LoadValueIndirectExpr represents a *expr operation.

Specified by:

visitLoadValueIndirectExpr in interface Predicate

Overrides:

visitLoadValueIndirectExpr in class Supertype

See Also:

LoadValueIndirectExpr

visitCallExpr

public void visitCallExpr(CallExpr e)

We add Chi and Mu operators to routine calls to mark the use and definition of variables accross calls. In the absence of MOD/REF information, we must assume that a function call defines and uses any global variable. Also, we must assume that the function call defines any parameter that is passed by address.

Overrides:

visitCallExpr in class Supertype

visitExprChord

public void visitExprChord(ExprChord c)

We add a Chi operator to store operations that assign to indirect variables. The Chi operator represents any variable that may be defined by the store (via the indirect variable).

Specified by:

visitExprChord in interface Predicate

Overrides:

visitExprChord in class Supertype

visitFieldExpr

public void visitFieldExpr(FieldExpr e)

Don't do anything here - but we don't want to default to visitExpr

Overrides:

visitFieldExpr in class Supertype

visitSubscriptExpr

public void visitSubscriptExpr(SubscriptExpr e)

We don't need to do anything at a subscript expression. So we just leave this function undefined - otherwise the visitExpr method is called.

Specified by:

visitSubscriptExpr in interface Predicate

Overrides:

visitSubscriptExpr in class Supertype

visitDualExpr

public void visitDualExpr(DualExpr e)

Don't do anything here - but we don't want to default to visitExpr A Dual expression does not effect the placement of indirect operators.

Specified by:

visitDualExpr in interface Predicate

Overrides:

visitDualExpr in class Supertype