org.jikesrvm.osr

Class VariableElement

java.lang.Object

org.jikesrvm.osr.VariableElement

public class VariableElement
extends Object

An instance of VariableElement represents a byte code variable (local or stack element). It is used to generate prologue to recover the runtime state. It refers to VM architecture.

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	kind the kind of this element : LOCAL or STACK
private char	num the number of element, e.g., with kind we can know it is L0 or S1.
private Object	ref for reference type value
private byte	tcode type code, can only be INT, FLOAT, LONG, DOUBLE, RET_ADDR, WORD or REF
private long	value The value of this element.

Constructor Summary

Constructors

Constructor and Description
VariableElement(boolean what_kind, int which_num, byte type, int ibits) Constructor for 32-bit value.
VariableElement(boolean what_kind, int which_num, byte type, long lbits) Constructor for 64-bit value.
VariableElement(boolean what_kind, int which_num, byte type, Object ref) Constructor for reference type.
VariableElement(boolean what_kind, int which_num, byte type, Word word) Constructor for word type.

Method Summary

Modifier and Type	Method and Description
(package private) int	getIntBits()
(package private) long	getLongBits()
(package private) char	getNumber()
(package private) Object	getObject()
(package private) byte	getTypeCode()
(package private) Word	getWord()
(package private) static boolean	isIBitsType(int tcode)
(package private) static boolean	isLBitsType(int tcode)
(package private) boolean	isLocal()
(package private) boolean	isRefType()
(package private) static boolean	isRefType(int tcode)
(package private) boolean	isWordType()
(package private) static boolean	isWordType(int tcode)
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

kind

private final boolean kind

the kind of this element : LOCAL or STACK

num

private final char num

the number of element, e.g., with kind we can know it is L0 or S1.

tcode

private final byte tcode

type code, can only be INT, FLOAT, LONG, DOUBLE, RET_ADDR, WORD or REF

value

private final long value

The value of this element. For type INT, FLOAT, RET_ADDR and WORD (32-bit), the lower 32 bits are valid. For type LONG and DOUBLE and WORD(64-bit), 64 bits are valid. For REF type, next field 'ref' is valid. For FLOAT, and DOUBLE, use Magic.intBitsAsFloat or Magic.longBitsAsDouble to convert bits to floating-point value.

ref

private final Object ref

for reference type value

Constructor Detail

VariableElement

public VariableElement(boolean what_kind,
                       int which_num,
                       byte type,
                       int ibits)

Constructor for 32-bit value.

Parameters:

what_kind - OSRConstants.LOCAL or OSRConstants.STACK

which_num - the variable's number

type - the variable's type code

ibits - the variable's value

VariableElement

public VariableElement(boolean what_kind,
                       int which_num,
                       byte type,
                       long lbits)

Constructor for 64-bit value.

Parameters:

what_kind - OSRConstants.LOCAL or OSRConstants.STACK

which_num - the variable's number

type - the variable's type code

lbits - the variable's value

VariableElement

public VariableElement(boolean what_kind,
                       int which_num,
                       byte type,
                       Object ref)

Constructor for reference type.

Parameters:

what_kind - OSRConstants.LOCAL or OSRConstants.STACK

which_num - the variable's number

type - the variable's type code

ref - the reference

VariableElement

public VariableElement(boolean what_kind,
                       int which_num,
                       byte type,
                       Word word)

Constructor for word type.

Parameters:

what_kind - OSRConstants.LOCAL or OSRConstants.STACK

which_num - the variable's number

type - the variable's type code

word - the word

Method Detail

isIBitsType

static boolean isIBitsType(int tcode)

isLBitsType

static boolean isLBitsType(int tcode)

isRefType

static boolean isRefType(int tcode)

isWordType

static boolean isWordType(int tcode)

isLocal

boolean isLocal()

Returns:

whether this is a local or stack element

getTypeCode

byte getTypeCode()

getNumber

char getNumber()

isRefType

boolean isRefType()

getObject

Object getObject()

isWordType

boolean isWordType()

getWord

Word getWord()

getIntBits

int getIntBits()

getLongBits

long getLongBits()

toString

public String toString()

Overrides:

toString in class Object