harpoon.IR.Tree
Class CONST

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

All Implemented Interfaces:

HCodeElement, HDataElement, PreciselyTyped, Typed

public class CONST
extends Exp
implements PreciselyTyped, HDataElement

CONST objects are expressions which stand for a constant value. CONSTs should be used to represent numeric types only. The one notable exception is the constant null, which is represented by a CONST with value == null and type == POINTER.

Version:

$Id: CONST.java,v 1.4 2002/04/10 03:05:40 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 CONST expression.
Number	value The constant value of this CONST 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

CONST(TreeFactory tf, HCodeElement source)
Creates a CONST representing the constant null.

CONST(TreeFactory tf, HCodeElement source, double dval)

CONST(TreeFactory tf, HCodeElement source, float fval)

CONST(TreeFactory tf, HCodeElement source, int ival)

CONST(TreeFactory tf, HCodeElement source, int bitwidth, boolean signed, int val)
Creates a CONST with a precisely defined type.

CONST(TreeFactory tf, HCodeElement source, long lval)

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)
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.
boolean	signed() Returns true if this is a signed expression, false otherwise.
String	toString()
int	type() Result type.
Number	value() Return the constant value of this CONST expression.

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

Methods inherited from interface harpoon.ClassFile.HDataElement

getID, getSourceFile

Field Detail

value

public final Number value

The constant value of this CONST expression.

type

public final int type

The type of this CONST expression.

isSmall

public final boolean isSmall

Constructor Detail

CONST

public CONST(TreeFactory tf,
             HCodeElement source,
             int ival)

CONST

public CONST(TreeFactory tf,
             HCodeElement source,
             long lval)

CONST

public CONST(TreeFactory tf,
             HCodeElement source,
             float fval)

CONST

public CONST(TreeFactory tf,
             HCodeElement source,
             double dval)

CONST

public CONST(TreeFactory tf,
             HCodeElement source)

Creates a CONST representing the constant null.

CONST

public CONST(TreeFactory tf,
             HCodeElement source,
             int bitwidth,
             boolean signed,
             int val)

Creates a CONST with a precisely defined type. For example, CONST(tf, src, 8, true, 0xFF) corresponds to the value -1, as a byte. CONST(tf, src, 8, true, -1) also corresponds to the value -1 as a byte.

Parameters:

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

signed - whether this CONST is signed

val - the value of this CONST. Note that only the lower bitwidth bits of this parameter will actually be used.

Method Detail

value

public Number value()

Return the constant value of this CONST expression.

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