Package com.ibm.wala.cast.ir.ssa

Class AssignInstruction

java.lang.Object

com.ibm.wala.ssa.SSAInstruction

com.ibm.wala.ssa.SSAAbstractUnaryInstruction

com.ibm.wala.ssa.SSAUnaryOpInstruction

com.ibm.wala.cast.ir.ssa.AssignInstruction

public class AssignInstruction
extends SSAUnaryOpInstruction

A simple assignment statement. Only appears in the IR before SSA conversion, and temporarily when needed to undo copy propagation during processing of new lexical definitions and uses.

Author:

Julian Dolby (dolby@us.ibm.com)

Nested Class Summary

Nested classes/interfaces inherited from class com.ibm.wala.ssa.SSAInstruction

SSAInstruction.IVisitor, SSAInstruction.Visitor

Field Summary

Fields inherited from class com.ibm.wala.ssa.SSAAbstractUnaryInstruction

result, val

Fields inherited from class com.ibm.wala.ssa.SSAInstruction

NO_INDEX

Constructor Summary

Constructors

Constructor	Description
AssignInstruction(int iindex, int result, int val)	create the assignment v_result := v_val

Method Summary

Modifier and Type	Method	Description
SSAInstruction	copyForSSA(SSAInstructionFactory insts, int[] defs, int[] uses)	This method is meant to be used during SSA conversion for an IR that is not in SSA form.
int	getVal()
String	toString(SymbolTable symbolTable)
void	visit(SSAInstruction.IVisitor v)	Apply an IVisitor to this instruction.

Methods inherited from class com.ibm.wala.ssa.SSAUnaryOpInstruction

getOpcode

Methods inherited from class com.ibm.wala.ssa.SSAAbstractUnaryInstruction

getDef, getDef, getNumberOfDefs, getNumberOfUses, getUse, hasDef, hashCode, isFallThrough

Methods inherited from class com.ibm.wala.ssa.SSAInstruction

equals, getExceptionTypes, getValueString, iIndex, isPEI, setInstructionIndex, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

AssignInstruction

public AssignInstruction(int iindex,
 int result,
 int val)

create the assignment v_result := v_val

Method Details

copyForSSA

public SSAInstruction copyForSSA(SSAInstructionFactory insts,
 int[] defs,
 int[] uses)

Description copied from class: SSAInstruction

This method is meant to be used during SSA conversion for an IR that is not in SSA form. It creates a new SSAInstruction of the same type as the receiver, with a combination of the receiver's uses and defs and those from the method parameters.

In particular, if the 'defs' parameter is null, then the new instruction has the same defs as the receiver. If 'defs' is not null, it must be an array with a size equal to the number of defs that the receiver instruction has. In this case, the new instruction has defs taken from the array. The uses of the new instruction work in the same way with the 'uses' parameter.

Note that this only applies to CAst-based IR translation, since Java bytecode-based IR generation uses a different SSA construction mechanism.

TODO: move this into the SSAInstructionFactory

Overrides:

copyForSSA in class SSAUnaryOpInstruction

See Also:

• SSAInstruction.copyForSSA(SSAInstructionFactory, int[], int[])

toString

public String toString(SymbolTable symbolTable)

Overrides:

toString in class SSAUnaryOpInstruction

See Also:

• SSAInstruction.toString(SymbolTable)

visit

public void visit(SSAInstruction.IVisitor v)

Description copied from class: SSAInstruction

Apply an IVisitor to this instruction. We invoke the appropriate IVisitor method according to the type of this instruction.

Overrides:

visit in class SSAUnaryOpInstruction

See Also:

• SSAInstruction.visit(IVisitor)

getVal

public int getVal()