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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * accompanied this code).
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package org.graalvm.compiler.hotspot.replacements;

import static org.graalvm.compiler.hotspot.GraalHotSpotVMConfig.INJECTED_VMCONFIG;
import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.KLASS_ACCESS_FLAGS_LOCATION;
import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.jvmAccHasFinalizer;
import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.klassAccessFlagsOffset;
import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.loadHub;
import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.SLOW_PATH_PROBABILITY;
import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.probability;

import org.graalvm.compiler.api.replacements.Snippet;
import org.graalvm.compiler.debug.DebugHandlersFactory;
import org.graalvm.compiler.hotspot.meta.HotSpotProviders;
import org.graalvm.compiler.hotspot.word.KlassPointer;
import org.graalvm.compiler.nodes.StructuredGraph;
import org.graalvm.compiler.nodes.java.LoweredRegisterFinalizerNode;
import org.graalvm.compiler.nodes.java.RegisterFinalizerNode;
import org.graalvm.compiler.nodes.spi.LoweringTool;
import org.graalvm.compiler.options.OptionValues;
import org.graalvm.compiler.replacements.SnippetTemplate;
import org.graalvm.compiler.replacements.SnippetTemplate.AbstractTemplates;
import org.graalvm.compiler.replacements.SnippetTemplate.Arguments;
import org.graalvm.compiler.replacements.SnippetTemplate.SnippetInfo;
import org.graalvm.compiler.replacements.Snippets;

import jdk.vm.ci.code.TargetDescription;

Performs conditional finalizer registration via a runtime call. The condition will be constant
folded if the exact class is available.
See Also:
RegisterFinalizerNode/**
 * Performs conditional finalizer registration via a runtime call. The condition will be constant
 * folded if the exact class is available.
 *
 * @see RegisterFinalizerNode
 */
public class RegisterFinalizerSnippets implements Snippets {

    @Snippet
    public static void registerFinalizerSnippet(final Object thisObj) {
        KlassPointer klass = loadHub(thisObj);
        if (probability(SLOW_PATH_PROBABILITY, (klass.readInt(klassAccessFlagsOffset(INJECTED_VMCONFIG), KLASS_ACCESS_FLAGS_LOCATION) & jvmAccHasFinalizer(INJECTED_VMCONFIG)) != 0)) {
            LoweredRegisterFinalizerNode.registerFinalizer(thisObj);
        }
    }

    public static class Templates extends AbstractTemplates {

        private final SnippetInfo registerFinalizerSnippet = snippet(RegisterFinalizerSnippets.class, "registerFinalizerSnippet", HotSpotReplacementsUtil.KLASS_ACCESS_FLAGS_LOCATION);

        public Templates(OptionValues options, Iterable<DebugHandlersFactory> factories, HotSpotProviders providers, TargetDescription target) {
            super(options, factories, providers, providers.getSnippetReflection(), target);
        }

        public void lower(RegisterFinalizerNode node, LoweringTool tool) {
            assert !(node instanceof LoweredRegisterFinalizerNode);
            StructuredGraph graph = node.graph();
            Arguments args = new Arguments(registerFinalizerSnippet, graph.getGuardsStage(), tool.getLoweringStage());
            args.add("thisObj", node.getValue());
            SnippetTemplate template = template(node, args);
            template.instantiate(providers.getMetaAccess(), node, SnippetTemplate.DEFAULT_REPLACER, args);
        }

    }

}