com.oracle.graal.nodes

Class LoopBeginNode

java.lang.Object

com.oracle.graal.graph.Node

com.oracle.graal.nodes.ValueNode

com.oracle.graal.nodes.FixedNode

com.oracle.graal.nodes.FixedWithNextNode

com.oracle.graal.nodes.AbstractBeginNode

com.oracle.graal.nodes.BeginStateSplitNode

com.oracle.graal.nodes.AbstractMergeNode

com.oracle.graal.nodes.LoopBeginNode

All Implemented Interfaces:

IterableNodeType, NodeInterface, Simplifiable, AnchoringNode, GuardingNode, LIRLowerable, NodeWithState, StateSplit, Cloneable, Formattable, KindProvider

public final class LoopBeginNode
extends AbstractMergeNode
implements IterableNodeType, LIRLowerable

Nested Class Summary

Nested classes/interfaces inherited from class com.oracle.graal.graph.Node

Node.ConstantNodeParameter, Node.InjectedNodeParameter, Node.Input, Node.NodeIntrinsic, Node.OptionalInput, Node.Successor, Node.ValueNumberable

Field Summary

Fields

Modifier and Type	Field and Description
protected int	inversionCount
protected double	loopFrequency
protected int	nextEndIndex
private static int	NO_INCREMENT
(package private) GuardingNode	overflowGuard
static NodeClass<LoopBeginNode>	TYPE
protected int	unswitches

Fields inherited from class com.oracle.graal.nodes.AbstractMergeNode

ends

Fields inherited from class com.oracle.graal.nodes.BeginStateSplitNode

stateAfter

Fields inherited from class com.oracle.graal.nodes.FixedWithNextNode

next

Fields inherited from class com.oracle.graal.nodes.ValueNode

stamp

Fields inherited from class com.oracle.graal.graph.Node

NODE_LIST, NOT_ITERABLE, USE_UNSAFE_TO_CLONE, WithAllEdges, WithNoEdges, WithOnlyInputEdges, WithOnlySucessorEdges

Constructor Summary

Constructors

Constructor and Description
LoopBeginNode()

Method Summary

Modifier and Type	Method and Description
NodeIterable<Node>	anchored()
void	canonicalizePhis(SimplifierTool tool) Coalesces loop phis that represent the same value (which is not handled by normal Global Value Numbering).
protected void	deleteEnd(AbstractEndNode end)
AbstractEndNode	forwardEnd()
void	generate(NodeLIRBuilderTool gen)
int	getInversionCount()
int	getLoopEndCount()
GuardingNode	getOverflowGuard()
private static int[]	getSelfIncrements(PhiNode phi) Returns an array with one entry for each input of the phi, which is either NO_INCREMENT or the increment, i.e., the value by which the phi is incremented in the corresponding branch.
void	incrementUnswitches()
boolean	isLoopExit(AbstractBeginNode begin)
NodeIterable<LoopEndNode>	loopEnds() Returns the unordered set of LoopEndNode that correspond to back-edges for this loop.
NodeIterable<LoopExitNode>	loopExits()
double	loopFrequency()
(package private) int	nextEndIndex()
LoopEndNode[]	orderedLoopEnds() Returns the set of LoopEndNode that correspond to back-edges for this loop, in increasing phiPredecessorIndex(com.oracle.graal.nodes.AbstractEndNode) order.
AbstractEndNode	phiPredecessorAt(int index)
int	phiPredecessorCount()
int	phiPredecessorIndex(AbstractEndNode pred)
void	removeDeadPhis() Removes dead phi nodes hanging from this node.
void	removeExits()
void	setInversionCount(int count)
void	setLoopFrequency(double loopFrequency)
void	setOverflowGuard(GuardingNode overflowGuard)
void	simplify(SimplifierTool tool) This simplify method can deal with a null value for tool, so that it can be used outside of canonicalization.
int	unswitches()
boolean	verify()

Methods inherited from class com.oracle.graal.nodes.AbstractMergeNode

addForwardEnd, cfgPredecessors, clearEnds, forwardEndAt, forwardEndCount, forwardEndIndex, forwardEnds, isPhiAtMerge, phis, removeEnd, valuePhis

Methods inherited from class com.oracle.graal.nodes.BeginStateSplitNode

hasSideEffect, setStateAfter, stateAfter

Methods inherited from class com.oracle.graal.nodes.AbstractBeginNode

getBlockNodes, guards, prepareDelete, prepareDelete, prevBegin, proxies, removeProxies

Methods inherited from class com.oracle.graal.nodes.FixedWithNextNode

asNode, next, setNext

Methods inherited from class com.oracle.graal.nodes.ValueNode

asConstant, asJavaConstant, getKind, graph, inferStamp, isAllowedUsageType, isConstant, isConstantPredicate, isNullConstant, setStamp, stamp, updateStamp

Methods inherited from class com.oracle.graal.graph.Node

acceptInputs, acceptSuccessors, afterClone, assertFalse, assertTrue, cfgSuccessors, clearInputs, clearSuccessors, copyWithInputs, copyWithInputs, equals, fail, formatTo, getDebugProperties, getDebugProperties, getId, getNodeClass, getUsageAt, getUsageCount, hashCode, hasNoUsages, hasUsages, inputs, isAlive, isDeleted, markDeleted, modCount, newIdentityMap, newIdentityMap, newIdentityMap, newMap, newMap, newMap, newSet, newSet, predecessor, pushInputs, removeUsage, replaceAndDelete, replaceAtMatchingUsages, replaceAtPredecessor, replaceAtUsages, replaceAtUsages, replaceAtUsages, replaceFirstInput, replaceFirstSuccessor, safeDelete, successors, toString, toString, updatePredecessor, updateUsages, updateUsagesInterface, usages, valueEquals, verifyEdges, verifyInputs

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.oracle.graal.nodes.StateSplit

asNode

Methods inherited from interface com.oracle.graal.nodes.spi.NodeWithState

states

Methods inherited from interface com.oracle.graal.nodes.extended.GuardingNode

asNode

Methods inherited from interface com.oracle.graal.nodes.extended.AnchoringNode

asNode

Field Detail

TYPE

public static final NodeClass<LoopBeginNode> TYPE

loopFrequency

protected double loopFrequency

nextEndIndex

protected int nextEndIndex

unswitches

protected int unswitches

inversionCount

protected int inversionCount

overflowGuard

GuardingNode overflowGuard

NO_INCREMENT

private static final int NO_INCREMENT

See Also:

Constant Field Values

Constructor Detail

LoopBeginNode

public LoopBeginNode()

Method Detail

loopFrequency

public double loopFrequency()

setLoopFrequency

public void setLoopFrequency(double loopFrequency)

loopEnds

public NodeIterable<LoopEndNode> loopEnds()

Returns the unordered set of LoopEndNode that correspond to back-edges for this loop. The order of the back-edges is unspecified, if you need to get an ordering compatible for PhiNode creation, use orderedLoopEnds().

Returns:

the set of LoopEndNode that correspond to back-edges for this loop

loopExits

public NodeIterable<LoopExitNode> loopExits()

anchored

public NodeIterable<Node> anchored()

Overrides:

anchored in class AbstractMergeNode

orderedLoopEnds

public LoopEndNode[] orderedLoopEnds()

Returns the set of LoopEndNode that correspond to back-edges for this loop, in increasing phiPredecessorIndex(com.oracle.graal.nodes.AbstractEndNode) order. This method is suited to create new loop PhiNode.
For example a new PhiNode may be added as follow:

 PhiNode phi = new ValuePhiNode(stamp, loop);
 phi.addInput(forwardEdgeValue);
 for (LoopEndNode loopEnd : loop.orderedLoopEnds()) {
     phi.addInput(backEdgeValue(loopEnd));
 }
 

Returns:

the set of LoopEndNode that correspond to back-edges for this loop

forwardEnd

public AbstractEndNode forwardEnd()

generate

public void generate(NodeLIRBuilderTool gen)

Specified by:

generate in interface LIRLowerable

Overrides:

generate in class AbstractMergeNode

deleteEnd

protected void deleteEnd(AbstractEndNode end)

Overrides:

deleteEnd in class AbstractMergeNode

phiPredecessorCount

public int phiPredecessorCount()

Overrides:

phiPredecessorCount in class AbstractMergeNode

phiPredecessorIndex

public int phiPredecessorIndex(AbstractEndNode pred)

Overrides:

phiPredecessorIndex in class AbstractMergeNode

phiPredecessorAt

public AbstractEndNode phiPredecessorAt(int index)

Overrides:

phiPredecessorAt in class AbstractMergeNode

verify

public boolean verify()

Overrides:

verify in class AbstractBeginNode

nextEndIndex

int nextEndIndex()

getLoopEndCount

public int getLoopEndCount()

unswitches

public int unswitches()

incrementUnswitches

public void incrementUnswitches()

getInversionCount

public int getInversionCount()

setInversionCount

public void setInversionCount(int count)

simplify

public void simplify(SimplifierTool tool)

Description copied from class: AbstractMergeNode

This simplify method can deal with a null value for tool, so that it can be used outside of canonicalization.

Specified by:

simplify in interface Simplifiable

Overrides:

simplify in class AbstractMergeNode

isLoopExit

public boolean isLoopExit(AbstractBeginNode begin)

removeExits

public void removeExits()

getOverflowGuard

public GuardingNode getOverflowGuard()

setOverflowGuard

public void setOverflowGuard(GuardingNode overflowGuard)

removeDeadPhis

public void removeDeadPhis()

Removes dead phi nodes hanging from this node. This method uses the heuristic that any node which not a phi node of this LoopBeginNode is alive. This allows the removal of dead phi loops.

getSelfIncrements

private static int[] getSelfIncrements(PhiNode phi)

Returns an array with one entry for each input of the phi, which is either NO_INCREMENT or the increment, i.e., the value by which the phi is incremented in the corresponding branch.

canonicalizePhis

public void canonicalizePhis(SimplifierTool tool)

Coalesces loop phis that represent the same value (which is not handled by normal Global Value Numbering).