org.graalvm.compiler.nodes

Class GuardNode

java.lang.Object

org.graalvm.compiler.graph.Node

org.graalvm.compiler.nodes.ValueNode

org.graalvm.compiler.nodes.calc.FloatingNode

org.graalvm.compiler.nodes.FloatingAnchoredNode

org.graalvm.compiler.nodes.GuardNode

All Implemented Interfaces:

Cloneable, Formattable, IterableNodeType, Node.ValueNumberable, CanonicalizableMarker, DeoptimizingGuard, GuardingNode, Canonicalizable, StaticDeoptimizingNode, ValueNodeInterface

public class GuardNode
extends FloatingAnchoredNode
implements Canonicalizable, GuardingNode, DeoptimizingGuard, IterableNodeType

A guard is a node that deoptimizes if its condition is false (unless it's negated in which case it deoptimizes when the condition is true). Guards are not attached to a certain frame state, they can move around freely and will always use the correct frame state when the nodes are scheduled (i.e., the last emitted frame state). The node that is guarded has a data dependency on the guard and the guard in turn has a data dependency on the condition. A guard may only be executed if it is guaranteed that the guarded node is executed too (if no exceptions are thrown). Therefore, an anchor is placed after a control flow split and the guard has a data dependency to the anchor. The anchor is the most distant node that is post-dominated by the guarded node and the guard can be scheduled anywhere between those two nodes. This ensures maximum flexibility for the guard node and guarantees that deoptimization occurs only if the control flow would have reached the guarded node (without taking exceptions into account).

Nested Class Summary

Nested classes/interfaces inherited from class org.graalvm.compiler.graph.Node

Node.ConstantNodeParameter, Node.EdgeVisitor, Node.IndirectCanonicalization, Node.InjectedNodeParameter, Node.Input, Node.NodeInsertionStackTrace, Node.NodeIntrinsic, Node.NodeIntrinsicFactory, Node.OptionalInput, Node.Successor, Node.ValueNumberable

Nested classes/interfaces inherited from interface org.graalvm.compiler.nodes.spi.Canonicalizable

Canonicalizable.Binary<T extends Node>, Canonicalizable.BinaryCommutative<T extends Node>, Canonicalizable.Ternary<T extends Node>, Canonicalizable.Unary<T extends Node>

Nested classes/interfaces inherited from interface org.graalvm.compiler.nodes.StaticDeoptimizingNode

StaticDeoptimizingNode.GuardPriority

Field Summary

Fields

Modifier and Type	Field and Description
protected DeoptimizationAction	action
protected LogicNode	condition
protected boolean	negated
protected NodeSourcePosition	noDeoptSuccessorPosition
protected DeoptimizationReason	reason
protected Speculation	speculation
static NodeClass<GuardNode>	TYPE

Fields inherited from class org.graalvm.compiler.nodes.FloatingAnchoredNode

anchor

Fields inherited from class org.graalvm.compiler.nodes.ValueNode

EMPTY_ARRAY, stamp

Fields inherited from class org.graalvm.compiler.graph.Node

NODE_LIST, NOT_ITERABLE, TRACK_CREATION_POSITION, WithAllEdges, WithNoEdges, WithOnlyInputEdges, WithOnlySucessorEdges

Constructor Summary

Constructors

Modifier	Constructor and Description
	GuardNode(LogicNode condition, AnchoringNode anchor, DeoptimizationReason reason, DeoptimizationAction action, boolean negated, Speculation speculation, NodeSourcePosition noDeoptSuccessorPosition)
protected	GuardNode(NodeClass<? extends GuardNode> c, LogicNode condition, AnchoringNode anchor, DeoptimizationReason reason, DeoptimizationAction action, boolean negated, Speculation speculation, NodeSourcePosition noDeoptSuccessorPosition)

Method Summary

Modifier and Type	Method and Description
Node	canonical(CanonicalizerTool tool) Implementations of this method can provide local optimizations like constant folding and strength reduction.
DeoptimizationAction	getAction()
LogicNode	getCondition() Gets the instruction that produces the tested boolean value.
NodeSourcePosition	getNoDeoptSuccessorPosition()
DeoptimizationReason	getReason()
Speculation	getSpeculation()
boolean	isNegated() Returns true iff the guard deoptimizes when its condition is true, false otherwise.
FixedWithNextNode	lowerGuard()
void	negate()
void	setAction(DeoptimizationAction invalidaterecompile)
void	setCondition(LogicNode x, boolean negated)
void	setNoDeoptSuccessorPosition(NodeSourcePosition noDeoptSuccessorPosition)
void	setReason(DeoptimizationReason reason)
void	setSpeculation(Speculation speculation)
String	toString(Verbosity verbosity) Creates a String representation for this with a given Verbosity.

Methods inherited from class org.graalvm.compiler.nodes.FloatingAnchoredNode

getAnchor, setAnchor

Methods inherited from class org.graalvm.compiler.nodes.ValueNode

asConstant, asJavaConstant, asNode, asSerializableConstant, checkReplaceAtUsagesInvariants, getStackKind, graph, hasUsagesOtherThan, inferStamp, isAllowedUsageType, isConstant, isConstantPredicate, isDefaultConstant, isIllegalConstant, isJavaConstant, isNullConstant, isSerializableConstant, recursivelyDataFlowEqualsUpTo, setStamp, stamp, updateStamp, updateUsagesInterface

Methods inherited from class org.graalvm.compiler.graph.Node

afterClone, applyInputs, applySuccessors, assertFalse, assertTrue, cfgPredecessors, cfgSuccessors, clearInputs, clearNodeSourcePosition, clearSuccessors, copyWithInputs, copyWithInputs, dataFlowEquals, dynamicNodeSizeEstimate, estimatedNodeCycles, estimatedNodeSize, fail, formatTo, getCreationPosition, getDebug, getDebugProperties, getDebugProperties, getInsertionPosition, getNodeClass, getNodeSourcePosition, getOptions, getUsageCount, hasExactlyOneUsage, hashCode, hasMoreThanOneUsage, hasNoUsages, hasOnlyUsagesOfType, hasUsages, hasUsagesOfType, inputPositions, inputs, isAlive, isDeleted, isUnregistered, markDeleted, maybeNotifyZeroUsages, modCount, predecessor, pushInputs, removeUsage, replaceAllInputs, replaceAndDelete, replaceAtAllUsages, replaceAtMatchingUsages, replaceAtPredecessor, replaceAtUsages, replaceAtUsages, replaceAtUsages, replaceAtUsages, replaceAtUsages, replaceAtUsagesAndDelete, replaceAtUsagesAndDelete, replaceFirstInput, replaceFirstSuccessor, safeDelete, setCreationPosition, setInsertionPosition, setNodeSourcePosition, singleUsage, successorPositions, successors, toString, updateNodeSourcePosition, updatePredecessor, updateUsages, usages, valueEquals, verify, verifyEdges, verifyInputs, verifySourcePosition, withNodeSourcePosition

Methods inherited from class java.lang.Object

clone, equals, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.graalvm.compiler.nodes.DeoptimizingGuard

addCallerToNoDeoptSuccessorPosition

Methods inherited from interface org.graalvm.compiler.nodes.StaticDeoptimizingNode

computePriority, mergeActions

Methods inherited from interface org.graalvm.compiler.nodes.ValueNodeInterface

asNode

Field Detail

TYPE

public static final NodeClass<GuardNode> TYPE

condition

protected LogicNode condition

reason

protected DeoptimizationReason reason

action

protected DeoptimizationAction action

speculation

protected Speculation speculation

negated

protected boolean negated

noDeoptSuccessorPosition

protected NodeSourcePosition noDeoptSuccessorPosition

Constructor Detail

GuardNode

public GuardNode(LogicNode condition,
                 AnchoringNode anchor,
                 DeoptimizationReason reason,
                 DeoptimizationAction action,
                 boolean negated,
                 Speculation speculation,
                 NodeSourcePosition noDeoptSuccessorPosition)

GuardNode

protected GuardNode(NodeClass<? extends GuardNode> c,
                    LogicNode condition,
                    AnchoringNode anchor,
                    DeoptimizationReason reason,
                    DeoptimizationAction action,
                    boolean negated,
                    Speculation speculation,
                    NodeSourcePosition noDeoptSuccessorPosition)

Method Detail

getCondition

public LogicNode getCondition()

Gets the instruction that produces the tested boolean value. The guard will deoptimize if the value is false (unless GuardNode.isNegated() returns true in which case it deoptimizes when the condition value is true).

Specified by:

getCondition in interface DeoptimizingGuard

setCondition

public void setCondition(LogicNode x,
                         boolean negated)

Specified by:

setCondition in interface DeoptimizingGuard

isNegated

public boolean isNegated()

Returns true iff the guard deoptimizes when its condition is true, false otherwise.

Specified by:

isNegated in interface DeoptimizingGuard

getReason

public DeoptimizationReason getReason()

Specified by:

getReason in interface StaticDeoptimizingNode

getAction

public DeoptimizationAction getAction()

Specified by:

getAction in interface StaticDeoptimizingNode

getSpeculation

public Speculation getSpeculation()

Specified by:

getSpeculation in interface StaticDeoptimizingNode

setSpeculation

public void setSpeculation(Speculation speculation)

toString

public String toString(Verbosity verbosity)

Description copied from class: Node

Creates a String representation for this with a given Verbosity.

Overrides:

toString in class Node

canonical

public Node canonical(CanonicalizerTool tool)

Description copied from interface: Canonicalizable

Implementations of this method can provide local optimizations like constant folding and strength reduction. Implementations should look at the properties and inputs of the current node and determine if there is a more optimal and always semantically correct replacement.
The return value determines the effect that the canonicalization will have:

• Returning an pre-existing node will replace the current node with the given one.
• Returning a newly created node (that was not yet added to the graph) will replace the current node with the given one, after adding it to the graph. If both the replacement and the replacee are anchored in control flow (fixed nodes), the replacement will be added to the control flow. It is invalid to replace a non-fixed node with a newly created fixed node (because its placement in the control flow cannot be determined without scheduling).
• Returning null will delete the current node and replace it with null at all usages. Note that it is not necessary to delete floating nodes that have no more usages this way - they will be deleted automatically.

Specified by:

canonical in interface Canonicalizable

Parameters:

tool - provides access to runtime interfaces like MetaAccessProvider

lowerGuard

public FixedWithNextNode lowerGuard()

negate

public void negate()

setAction

public void setAction(DeoptimizationAction invalidaterecompile)

Specified by:

setAction in interface StaticDeoptimizingNode

setReason

public void setReason(DeoptimizationReason reason)

Specified by:

setReason in interface StaticDeoptimizingNode

getNoDeoptSuccessorPosition

public NodeSourcePosition getNoDeoptSuccessorPosition()

Specified by:

getNoDeoptSuccessorPosition in interface DeoptimizingGuard

setNoDeoptSuccessorPosition

public void setNoDeoptSuccessorPosition(NodeSourcePosition noDeoptSuccessorPosition)

Specified by:

setNoDeoptSuccessorPosition in interface DeoptimizingGuard