UnsafeLoadSnippets.java revision 13264:48566d838608 
1/*
2 * Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23package org.graalvm.compiler.hotspot.replacements;
24
25import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.referentOffset;
26import static org.graalvm.compiler.replacements.SnippetTemplate.DEFAULT_REPLACER;
27
28import org.graalvm.compiler.api.replacements.Snippet;
29import org.graalvm.compiler.debug.DebugHandlersFactory;
30import org.graalvm.compiler.hotspot.meta.HotSpotProviders;
31import org.graalvm.compiler.nodes.extended.FixedValueAnchorNode;
32import org.graalvm.compiler.nodes.extended.RawLoadNode;
33import org.graalvm.compiler.nodes.memory.HeapAccess.BarrierType;
34import org.graalvm.compiler.nodes.spi.LoweringTool;
35import org.graalvm.compiler.options.OptionValues;
36import org.graalvm.compiler.replacements.SnippetTemplate.AbstractTemplates;
37import org.graalvm.compiler.replacements.SnippetTemplate.Arguments;
38import org.graalvm.compiler.replacements.SnippetTemplate.SnippetInfo;
39import org.graalvm.compiler.replacements.Snippets;
40import org.graalvm.compiler.word.Word;
41
42import jdk.vm.ci.code.TargetDescription;
43
44public class UnsafeLoadSnippets implements Snippets {
45
46    @Snippet
47    public static Object lowerUnsafeLoad(Object object, long offset) {
48        Object fixedObject = FixedValueAnchorNode.getObject(object);
49        if (object instanceof java.lang.ref.Reference && referentOffset() == offset) {
50            return Word.objectToTrackedPointer(fixedObject).readObject((int) offset, BarrierType.PRECISE);
51        } else {
52            return Word.objectToTrackedPointer(fixedObject).readObject((int) offset, BarrierType.NONE);
53        }
54    }
55
56    public static class Templates extends AbstractTemplates {
57
58        private final SnippetInfo unsafeLoad = snippet(UnsafeLoadSnippets.class, "lowerUnsafeLoad");
59
60        public Templates(OptionValues options, Iterable<DebugHandlersFactory> factories, HotSpotProviders providers, TargetDescription target) {
61            super(options, factories, providers, providers.getSnippetReflection(), target);
62        }
63
64        public void lower(RawLoadNode load, LoweringTool tool) {
65            Arguments args = new Arguments(unsafeLoad, load.graph().getGuardsStage(), tool.getLoweringStage());
66            args.add("object", load.object());
67            args.add("offset", load.offset());
68            template(load.getDebug(), args).instantiate(providers.getMetaAccess(), load, DEFAULT_REPLACER, args);
69        }
70    }
71}
72