org.jruby.ir.dataflow.analyses

Class LiveVariableNode

java.lang.Object

org.jruby.ir.dataflow.FlowGraphNode

org.jruby.ir.dataflow.analyses.LiveVariableNode

public class LiveVariableNode
extends FlowGraphNode

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.BitSet	in
private java.util.BitSet	out
private int	setSize

Fields inherited from class org.jruby.ir.dataflow.FlowGraphNode

basicBlock, problem

Constructor Summary

Constructors

Constructor and Description
LiveVariableNode(DataFlowProblem prob, BasicBlock n)

Method Summary

Modifier and Type	Method and Description
private void	addDFVar(Variable v)
boolean	applyTransferFunction() Compute "OUT/IN" for the current node! The choice of "IN/OUT" is determined by the direction of data flow.
void	buildDataFlowVars(Instr i) Builds the data-flow variables (or facts) for a particular instruction.
void	compute_MEET(Edge e, BasicBlock source, FlowGraphNode pred) "MEET" current solution of "IN/OUT" with "OUT/IN(pred)", where "pred" is a predecessor of the current node! The choice of "IN/OUT" is determined by the direction of data flow.
(package private) java.util.BitSet	getLiveInBitSet()
(package private) java.util.BitSet	getLiveOutBitSet()
void	init() Initialize this data flow node for solving the current problem This is done after building dataflow variables for the problem.
void	initSolnForNode() Initialize this data flow node to compute the new solution This is done before iteratively calling the MEET operator.
private void	makeOutExceptionVariablesLiving(java.util.BitSet living) Collect variables live out of the exception target node.
private void	markAllVariablesLive(LiveVariablesProblem lvp, java.util.BitSet living, java.util.Collection<? extends Variable> variableList)
(package private) void	markDeadInstructions()
private void	markVariableLive(LiveVariablesProblem lvp, java.util.BitSet living, Variable x)
java.lang.String	toString()

Methods inherited from class org.jruby.ir.dataflow.FlowGraphNode

buildDataFlowVars, computeDataFlowInfo, finalizeSolnForNode, getBB, getExceptionTargetNode, getNonExitBBExceptionTargetNode, hasExceptionsRescued

Methods inherited from class java.lang.Object

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

Field Detail

in

private java.util.BitSet in

out

private java.util.BitSet out

setSize

private int setSize

Constructor Detail

LiveVariableNode

public LiveVariableNode(DataFlowProblem prob,
                        BasicBlock n)

Method Detail

init

public void init()

Description copied from class: FlowGraphNode

Initialize this data flow node for solving the current problem This is done after building dataflow variables for the problem.

Overrides:

init in class FlowGraphNode

addDFVar

private void addDFVar(Variable v)

buildDataFlowVars

public void buildDataFlowVars(Instr i)

Description copied from class: FlowGraphNode

Builds the data-flow variables (or facts) for a particular instruction.

Specified by:

buildDataFlowVars in class FlowGraphNode

initSolnForNode

public void initSolnForNode()

Description copied from class: FlowGraphNode

Initialize this data flow node to compute the new solution This is done before iteratively calling the MEET operator.

Specified by:

initSolnForNode in class FlowGraphNode

compute_MEET

public void compute_MEET(Edge e,
                         BasicBlock source,
                         FlowGraphNode pred)

Description copied from class: FlowGraphNode

"MEET" current solution of "IN/OUT" with "OUT/IN(pred)", where "pred" is a predecessor of the current node! The choice of "IN/OUT" is determined by the direction of data flow.

Specified by:

compute_MEET in class FlowGraphNode

markAllVariablesLive

private void markAllVariablesLive(LiveVariablesProblem lvp,
                                  java.util.BitSet living,
                                  java.util.Collection<? extends Variable> variableList)

markVariableLive

private void markVariableLive(LiveVariablesProblem lvp,
                              java.util.BitSet living,
                              Variable x)

applyTransferFunction

public boolean applyTransferFunction()

Description copied from class: FlowGraphNode

Compute "OUT/IN" for the current node! The choice of "IN/OUT" is determined by the direction of data flow. OUT/IN = transfer-function (facts at start/end of node, instructions of current node processed in fwd/reverse dirn)

Specified by:

applyTransferFunction in class FlowGraphNode

makeOutExceptionVariablesLiving

private void makeOutExceptionVariablesLiving(java.util.BitSet living)

Collect variables live out of the exception target node. Since this instr. can directly jump to the rescue block (or scope exit) without executing the rest of the instructions in this bb, we have a control-flow edge from this instr. to that block. Since we dont want to add a control-flow edge from pretty much every instr. to the rescuer/exit BB, we are handling it implicitly here.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

markDeadInstructions

void markDeadInstructions()

getLiveInBitSet

java.util.BitSet getLiveInBitSet()

getLiveOutBitSet

java.util.BitSet getLiveOutBitSet()