edu.jmu.decaf

Class ILOCInstruction

java.lang.Object

edu.jmu.decaf.ILOCInstruction

All Implemented Interfaces:

Cloneable

public class ILOCInstruction
extends Object
implements Cloneable

Represents a single ILOC instruction in a pseudo-triple format, including a "form" indicator (enum) and up to three operands, which can represent virtual register IDs, special registers, constants, or jump/call targets. Boolean constants are represented using zero for false and any other value for true.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ILOCInstruction.Form Possible forms of an ILOC instruction

Field Summary

Fields

Modifier and Type	Field and Description
String	comment Optional human-readable comment for this instruction
ILOCInstruction.Form	form Instruction form
ILOCOperand[]	operands Instruction operands
String	variableName Debug information for data flow analysis

Constructor Summary

Constructors

Constructor and Description
ILOCInstruction(ILOCInstruction.Form form, ILOCOperand[] operands) Create a new instruction
ILOCInstruction(ILOCInstruction.Form form, ILOCOperand[] operands, String comment) Create a new instruction

Method Summary

Modifier and Type	Method and Description
Object	clone() Create a *deep copy* of this instruction.
List<ILOCOperand>	getReadOperands() Returns a list of ILOCOperands read by this instruction.
List<ILOCOperand>	getReadOperands(boolean includeLiterals) Returns a list of ILOCOperands read by this instruction.
ILOCOperand	getWriteOperand() Returns a single ILOCOperands written by this instruction.
List<ILOCOperand>	getWriteOperands() Returns a list of ILOCOperands written by this instruction.
String	toString() Builds a standardized string representation of an ILOC instruction
String	toString(boolean showComments) Builds a standardized string representation of an ILOC instruction

Methods inherited from class java.lang.Object

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

Field Detail

variableName

public String variableName

Debug information for data flow analysis

form

public ILOCInstruction.Form form

Instruction form

operands

public ILOCOperand[] operands

Instruction operands

comment

public String comment

Optional human-readable comment for this instruction

Constructor Detail

ILOCInstruction

public ILOCInstruction(ILOCInstruction.Form form,
                       ILOCOperand[] operands)

Create a new instruction

Parameters:

form - Instruction form

operands - Instruction operands

ILOCInstruction

public ILOCInstruction(ILOCInstruction.Form form,
                       ILOCOperand[] operands,
                       String comment)

Create a new instruction

Parameters:

form - Instruction form

operands - Instruction operands

comment - Human-readable comment

Method Detail

clone

public Object clone()
             throws CloneNotSupportedException

Create a *deep copy* of this instruction. This is important for register/label renumbering; otherwise, the shared ILOCOperand ID info interferes with the renumbering.

Overrides:

clone in class Object

Throws:

CloneNotSupportedException

getReadOperands

public List<ILOCOperand> getReadOperands()

Returns a list of ILOCOperands read by this instruction. Reports only register or memory operands.

Returns:

List of read operands

getReadOperands

public List<ILOCOperand> getReadOperands(boolean includeLiterals)

Returns a list of ILOCOperands read by this instruction. Reports only register or memory operands, unless the given flag is true in which case it also returns literal operands.

Parameters:

includeLiterals - Return literal operands as well

Returns:

List of read operands

getWriteOperands

public List<ILOCOperand> getWriteOperands()

Returns a list of ILOCOperands written by this instruction. Reports only register or memory operands.

Returns:

List of written operands

getWriteOperand

public ILOCOperand getWriteOperand()

Returns a single ILOCOperands written by this instruction. This should be called only when it is known that the instruction only writes a single operand.

Returns:

Single written operand

toString

public String toString()

Builds a standardized string representation of an ILOC instruction

Overrides:

toString in class Object

toString

public String toString(boolean showComments)

Builds a standardized string representation of an ILOC instruction

Parameters:

showComments - Include comments

Returns:

String representation of instruction