serp.bytecode
Class MathInstruction

java.lang.Object
  serp.bytecode.Instruction
      serp.bytecode.TypedInstruction
          serp.bytecode.MathInstruction

All Implemented Interfaces:

BCEntity, VisitAcceptor

public class MathInstruction
extends TypedInstruction

One of the math operations defined in the Constants interface. Changing the type or operation of the instruction will automatically update the underlying opcode.

Author:

Abe White

Method Summary

void	acceptVisit(BCVisitor visit) Accept a visit from a BCVisitor, calling the appropriate methods to notify the visitor that it has entered this entity, and to provide it with the proper callbacks for each sub-entity owned by this one.
boolean	equalsInstruction(Instruction other) MathInstructions are equal if they have the same operation and type, or the operation and type of either is unset.
int	getLogicalStackChange() Return the logical number of stack positions changed by this instruction.
int	getOperation() Return the operation for this math instruction; will be one of the math constant defined in Constants, or -1 if unset.
int	getStackChange() Return the number of stack positions this instruction pushes or pops during its execution.
String	getTypeName() Return the type name for this instruction.
MathInstruction	setOperation(int operation) Set the math operation to be performed.
TypedInstruction	setType(String type) Set the type of this instruction.

Methods inherited from class serp.bytecode.TypedInstruction

getType, getTypeBC, setType, setType

Methods inherited from class serp.bytecode.Instruction

getByteIndex, getClassLoader, getCode, getLineNumber, getName, getOpcode, getPool, getProject, isValid

Methods inherited from class java.lang.Object

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

Method Detail

getStackChange

public int getStackChange()

Description copied from class: Instruction

Return the number of stack positions this instruction pushes or pops during its execution.

Overrides:

getStackChange in class Instruction

Returns:

0 if the stack is not affected by this instruction, a positive number if it pushes onto the stack, and a negative number if it pops from the stack

getLogicalStackChange

public int getLogicalStackChange()

Description copied from class: Instruction

Return the logical number of stack positions changed by this instruction. In other words, ignore weirdness with longs and doubles taking two stack positions.

Overrides:

getLogicalStackChange in class Instruction

getTypeName

public String getTypeName()

Description copied from class: TypedInstruction

Return the type name for this instruction. If the type has not been set, this method will return null.

Specified by:

getTypeName in class TypedInstruction

setType

public TypedInstruction setType(String type)

Description copied from class: TypedInstruction

Set the type of this instruction. Types that have no direct support will be converted accordingly.

Specified by:

setType in class TypedInstruction

Returns:

this instruction, for method chaining

setOperation

public MathInstruction setOperation(int operation)

Set the math operation to be performed. This should be one of the math constant defined in Constants.

Returns:

this instruction, for method chaining

getOperation

public int getOperation()

Return the operation for this math instruction; will be one of the math constant defined in Constants, or -1 if unset.

equalsInstruction

public boolean equalsInstruction(Instruction other)

MathInstructions are equal if they have the same operation and type, or the operation and type of either is unset.

Overrides:

equalsInstruction in class Instruction

acceptVisit

public void acceptVisit(BCVisitor visit)

Description copied from interface: VisitAcceptor

Accept a visit from a BCVisitor, calling the appropriate methods to notify the visitor that it has entered this entity, and to provide it with the proper callbacks for each sub-entity owned by this one.

Specified by:

acceptVisit in interface VisitAcceptor

Overrides:

acceptVisit in class Instruction