org.jikesrvm.compilers.opt.escape

Class ObjectReplacer

java.lang.Object

org.jikesrvm.compilers.opt.escape.ObjectReplacer

All Implemented Interfaces:

AggregateReplacer

final class ObjectReplacer
extends Object
implements AggregateReplacer

Class that performs scalar replacement of aggregates for non-array objects

Field Summary

Fields

Modifier and Type	Field and Description
private IR	ir the IR
private RVMClass	klass type of the object
private Register	reg the register holding the object reference

Constructor Summary

Constructors

Modifier	Constructor and Description
private	ObjectReplacer(Register r, RVMClass _klass, IR i)

Method Summary

Modifier and Type	Method and Description
private static boolean	containsUnsupportedUse(IR ir, Register reg, RVMClass klass, Set<Register> visited) Some cases we don't handle yet.
private static ArrayList<RVMField>	getFieldsAsArrayList(RVMClass klass) Returns the instance fields of the object.
static ObjectReplacer	getReplacer(Instruction inst, IR ir) Return an object representing this transformation for a given allocation site
private void	scalarReplace(RegisterOperand use, RegisterOperand[] scalars, ArrayList<RVMField> fields, Set<Register> visited) Replace a given use of a object with its scalar equivalent
void	transform() Perform the transformation
private void	transform2(Register reg, Instruction defI, RegisterOperand[] scalars, ArrayList<RVMField> fields, Set<Register> visited)

Methods inherited from class java.lang.Object

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

Field Detail

klass

private final RVMClass klass

type of the object

ir

private final IR ir

the IR

reg

private final Register reg

the register holding the object reference

Constructor Detail

ObjectReplacer

private ObjectReplacer(Register r,
                       RVMClass _klass,
                       IR i)

Parameters:

r - the register holding the object reference

_klass - the type of the object to replace

i - the IR

Method Detail

getReplacer

public static ObjectReplacer getReplacer(Instruction inst,
                                         IR ir)

Return an object representing this transformation for a given allocation site

Parameters:

inst - the allocation site

ir - the governing IR

Returns:

the object, or null if illegal

transform

public void transform()

Description copied from interface: AggregateReplacer

Perform the transformation

Specified by:

transform in interface AggregateReplacer

transform2

private void transform2(Register reg,
                        Instruction defI,
                        RegisterOperand[] scalars,
                        ArrayList<RVMField> fields,
                        Set<Register> visited)

getFieldsAsArrayList

private static ArrayList<RVMField> getFieldsAsArrayList(RVMClass klass)

Returns the instance fields of the object.

Parameters:

klass - the type of the object

Returns:

a list holding the instance fields of the object

scalarReplace

private void scalarReplace(RegisterOperand use,
                           RegisterOperand[] scalars,
                           ArrayList<RVMField> fields,
                           Set<Register> visited)

Replace a given use of a object with its scalar equivalent

Parameters:

use - the use to replace

scalars - an array of scalar register operands to replace the object's fields with

fields - the object's fields

visited - the registers that were already seen

containsUnsupportedUse

private static boolean containsUnsupportedUse(IR ir,
                                              Register reg,
                                              RVMClass klass,
                                              Set<Register> visited)

Some cases we don't handle yet. TODO: handle them.

Parameters:

ir - the IR to check

reg - the register whose uses are being checked

klass - the class of the newly created object

visited - registers that were already seen

Returns:

true if the IR contains a case that we don't handle yet