/*

 * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package org.graalvm.compiler.hotspot.replacements;

import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.referentOffset;

import static org.graalvm.compiler.replacements.SnippetTemplate.DEFAULT_REPLACER;

import org.graalvm.compiler.api.replacements.Snippet;

import org.graalvm.compiler.debug.DebugHandlersFactory;

import org.graalvm.compiler.hotspot.meta.HotSpotProviders;

import org.graalvm.compiler.nodes.extended.FixedValueAnchorNode;

import org.graalvm.compiler.nodes.extended.RawLoadNode;

import org.graalvm.compiler.nodes.memory.HeapAccess.BarrierType;

import org.graalvm.compiler.nodes.spi.LoweringTool;

import org.graalvm.compiler.options.OptionValues;

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 org.graalvm.compiler.word.Word;

import jdk.vm.ci.code.TargetDescription;

public class UnsafeLoadSnippets implements Snippets {

    @Snippet

    public static Object lowerUnsafeLoad(Object object, long offset) {

        Object fixedObject = FixedValueAnchorNode.getObject(object);

            return Word.objectToTrackedPointer(fixedObject).readObject((int) offset, BarrierType.PRECISE);

        } else {

            return Word.objectToTrackedPointer(fixedObject).readObject((int) offset, BarrierType.NONE);

        }

    }

    public static class Templates extends AbstractTemplates {

        private final SnippetInfo unsafeLoad = snippet(UnsafeLoadSnippets.class, "lowerUnsafeLoad");

        public Templates(OptionValues options, Iterable<DebugHandlersFactory> factories, HotSpotProviders providers, TargetDescription target) {

            super(options, factories, providers, providers.getSnippetReflection(), target);

        }

        public void lower(RawLoadNode load, LoweringTool tool) {

            Arguments args = new Arguments(unsafeLoad, load.graph().getGuardsStage(), tool.getLoweringStage());

            args.add("object", load.object());

            args.add("offset", load.offset());

            template(load, args).instantiate(providers.getMetaAccess(), load, DEFAULT_REPLACER, args);

        }

    }

}