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package org.graalvm.compiler.nodes.extended;

import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_0;
import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_0;

import org.graalvm.compiler.graph.Node;
import org.graalvm.compiler.graph.NodeClass;
import org.graalvm.compiler.graph.spi.Canonicalizable;
import org.graalvm.compiler.graph.spi.CanonicalizerTool;
import org.graalvm.compiler.nodeinfo.InputType;
import org.graalvm.compiler.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.FrameState;
import org.graalvm.compiler.nodes.StateSplit;
import org.graalvm.compiler.nodes.ValueNode;

This node provides a state split along with the functionality of FixedValueAnchorNode. This is used to capture a state for deoptimization when a node has side effects which aren't easily represented. The anchored value is usually part of the FrameState since this forces uses of the value below this node so they will consume this frame state instead of an earlier one.
/** * This node provides a state split along with the functionality of {@link FixedValueAnchorNode}. * This is used to capture a state for deoptimization when a node has side effects which aren't * easily represented. The anchored value is usually part of the FrameState since this forces uses * of the value below this node so they will consume this frame state instead of an earlier one. */
@NodeInfo(cycles = CYCLES_0, size = SIZE_0) public final class StateSplitProxyNode extends FixedValueAnchorNode implements Canonicalizable, StateSplit { public static final NodeClass<StateSplitProxyNode> TYPE = NodeClass.create(StateSplitProxyNode.class); @OptionalInput(InputType.State) FrameState stateAfter;
Disallows elimination of this node until after the FrameState has been consumed.
/** * Disallows elimination of this node until after the FrameState has been consumed. */
private final boolean delayElimination; public StateSplitProxyNode(ValueNode object) { this(object, false); } public StateSplitProxyNode(ValueNode object, boolean delayElimination) { super(TYPE, object); this.delayElimination = delayElimination; } @Override public FrameState stateAfter() { return stateAfter; } @Override public void setStateAfter(FrameState x) { assert x == null || x.isAlive() : "frame state must be in a graph"; updateUsages(stateAfter, x); stateAfter = x; } @Override public boolean hasSideEffect() { return true; } @Override public Node canonical(CanonicalizerTool tool) { if (!delayElimination && (object != null && object.isConstant()) || stateAfter == null) { return object; } return this; } }