harpoon.IR.Tree
Class MEM

java.lang.Object
  harpoon.IR.Tree.Tree
      harpoon.IR.Tree.Exp
          harpoon.IR.Tree.MEM

All Implemented Interfaces:

HCodeElement, PreciselyTyped, Typed

public class MEM
extends Exp
implements PreciselyTyped

MEM objects are expressions which stand for the contents of a value in memory starting at the address specified by the subexpression. Note that when MEM is used as the left child of a MOVE or CALL, it means "store," but anywhere else it means "fetch."

Version:

$Id: MEM.java,v 1.4 2002/04/10 03:05:45 cananian Exp $

Author:

C. Scott Ananian <cananian@alumni.princeton.edu>, based on Modern Compiler Implementation in Java by Andrew Appel.

Nested Class Summary

Nested classes/interfaces inherited from class harpoon.IR.Tree.Tree

Tree.CloneCallback

Field Summary

boolean	isSmall
int	type The type of this memory reference expression.

Fields inherited from class harpoon.IR.Tree.Tree

arrayFactory, child

Fields inherited from interface harpoon.IR.Tree.Typed

DOUBLE, FLOAT, INT, LONG, POINTER

Constructor Summary

MEM(TreeFactory tf, HCodeElement source, int bitwidth, boolean signed, Exp exp)
Creates a MEM with a precisely defined type.

MEM(TreeFactory tf, HCodeElement source, int type, Exp exp)
Constructor.

Method Summary

void	accept(TreeVisitor v) Accept a visitor
int	bitwidth() Returns the size of the expression, in bits.
Exp	build(TreeFactory tf, ExpList kids)
Exp	getExp() Returns a subexpression evaluating to a memory reference location.
boolean	isSmall() Returns true if this is a sub-integer expression.
int	kind() Return an integer enumeration of the kind of this Tree.
Tree	rename(TreeFactory tf, TempMap tm, Tree.CloneCallback cb) Rename while cloning a subtree.
void	setExp(Exp exp) Sets the memory reference subexpression.
boolean	signed() Returns true if this is a signed expression, false otherwise.
String	toString()
int	type() Result type.

Methods inherited from class harpoon.IR.Tree.Exp

build, isDoubleWord, isFloatingPoint

Methods inherited from class harpoon.IR.Tree.Tree

clone, clone, getChild, getFactory, getFirstChild, getID, getLineNumber, getParent, getSibling, getSourceFile, hashCode, kids, rename, replace, setChild, unlink

Methods inherited from class java.lang.Object

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

Methods inherited from interface harpoon.IR.Tree.Typed

isDoubleWord, isFloatingPoint

Field Detail

type

public final int type

The type of this memory reference expression.

isSmall

public final boolean isSmall

Constructor Detail

MEM

public MEM(TreeFactory tf,
           HCodeElement source,
           int type,
           Exp exp)

Constructor.

MEM

public MEM(TreeFactory tf,
           HCodeElement source,
           int bitwidth,
           boolean signed,
           Exp exp)

Creates a MEM with a precisely defined type.

Parameters:

bitwidth - the width in bits of this MEM's type. Fails unless 0 <= bitwidth < 32.

signed - whether this MEM is signed

exp - the location at which to load or store

Method Detail

getExp

public Exp getExp()

Returns a subexpression evaluating to a memory reference location.

setExp

public void setExp(Exp exp)

Sets the memory reference subexpression.

kind

public int kind()

Description copied from class: Tree

Return an integer enumeration of the kind of this Tree. The enumerated values are defined in TreeKind.

Specified by:

kind in class Tree

build

public Exp build(TreeFactory tf,
                 ExpList kids)

Specified by:

build in class Exp

type

public int type()

Description copied from class: Exp

Result type.

Specified by:

type in interface Typed

Specified by:

type in class Exp

isSmall

public boolean isSmall()

Returns true if this is a sub-integer expression.

Specified by:

isSmall in interface PreciselyTyped

bitwidth

public int bitwidth()

Returns the size of the expression, in bits. Only valid if the isSmall()==true.

Specified by:

bitwidth in interface PreciselyTyped

signed

public boolean signed()

Returns true if this is a signed expression, false otherwise. Only valid if the isSmall()==true.

Specified by:

signed in interface PreciselyTyped

accept

public void accept(TreeVisitor v)

Accept a visitor

Specified by:

accept in class Tree

rename

public Tree rename(TreeFactory tf,
                   TempMap tm,
                   Tree.CloneCallback cb)

Description copied from class: Tree

Rename while cloning a subtree. This node and all child nodes are cloned; the 'temp' information of all TEMP nodes are renamed according to the supplied TempMap. Note that Temps not belonging to this.getFactory().tempFactory() are not affected. The callback() method of the supplied CloneCallback is invoked once on each subtree cloned, starting from the leaves and working back to the root in a post-order depth-first manner.

Specified by:

rename in class Tree

toString

public String toString()

Overrides:

toString in class Object