001/*
002 * Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.hotspot.replacements;
024
025import jdk.internal.jvmci.code.*;
026import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.*;
027import static com.oracle.graal.replacements.SnippetTemplate.*;
028
029import com.oracle.graal.hotspot.meta.*;
030import com.oracle.graal.nodes.extended.*;
031import com.oracle.graal.nodes.memory.HeapAccess.BarrierType;
032import com.oracle.graal.nodes.spi.*;
033import com.oracle.graal.replacements.*;
034import com.oracle.graal.replacements.SnippetTemplate.AbstractTemplates;
035import com.oracle.graal.replacements.SnippetTemplate.Arguments;
036import com.oracle.graal.replacements.SnippetTemplate.SnippetInfo;
037import com.oracle.graal.word.*;
038
039public class UnsafeLoadSnippets implements Snippets {
040
041    @Snippet
042    public static Object lowerUnsafeLoad(Object object, long offset) {
043        Object fixedObject = FixedValueAnchorNode.getObject(object);
044        if (object instanceof java.lang.ref.Reference && referentOffset() == offset) {
045            return Word.fromObject(fixedObject).readObject((int) offset, BarrierType.PRECISE);
046        } else {
047            return Word.fromObject(fixedObject).readObject((int) offset, BarrierType.NONE);
048        }
049    }
050
051    public static class Templates extends AbstractTemplates {
052
053        private final SnippetInfo unsafeLoad = snippet(UnsafeLoadSnippets.class, "lowerUnsafeLoad");
054
055        public Templates(HotSpotProviders providers, TargetDescription target) {
056            super(providers, providers.getSnippetReflection(), target);
057        }
058
059        public void lower(UnsafeLoadNode load, LoweringTool tool) {
060            Arguments args = new Arguments(unsafeLoad, load.graph().getGuardsStage(), tool.getLoweringStage());
061            args.add("object", load.object());
062            args.add("offset", load.offset());
063            template(args).instantiate(providers.getMetaAccess(), load, DEFAULT_REPLACER, args);
064        }
065    }
066}