HotSpotNarrowOopStamp.java revision 13083:b9a173f12fe6 
1/*
2 * Copyright (c) 2014, 2016, 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.nodes.type;
24
25import org.graalvm.compiler.core.common.CompressEncoding;
26import org.graalvm.compiler.core.common.type.AbstractObjectStamp;
27import org.graalvm.compiler.core.common.type.ObjectStamp;
28import org.graalvm.compiler.core.common.type.Stamp;
29import org.graalvm.compiler.debug.GraalError;
30import org.graalvm.compiler.nodes.CompressionNode.CompressionOp;
31import org.graalvm.compiler.nodes.type.NarrowOopStamp;
32
33import jdk.vm.ci.hotspot.HotSpotCompressedNullConstant;
34import jdk.vm.ci.hotspot.HotSpotMemoryAccessProvider;
35import jdk.vm.ci.hotspot.HotSpotObjectConstant;
36import jdk.vm.ci.meta.Constant;
37import jdk.vm.ci.meta.JavaConstant;
38import jdk.vm.ci.meta.MemoryAccessProvider;
39import jdk.vm.ci.meta.ResolvedJavaType;
40
41public final class HotSpotNarrowOopStamp extends NarrowOopStamp {
42    private HotSpotNarrowOopStamp(ResolvedJavaType type, boolean exactType, boolean nonNull, boolean alwaysNull, CompressEncoding encoding) {
43        super(type, exactType, nonNull, alwaysNull, encoding);
44    }
45
46    @Override
47    protected AbstractObjectStamp copyWith(ResolvedJavaType type, boolean exactType, boolean nonNull, boolean alwaysNull) {
48        return new HotSpotNarrowOopStamp(type, exactType, nonNull, alwaysNull, getEncoding());
49    }
50
51    public static Stamp compressed(AbstractObjectStamp stamp, CompressEncoding encoding) {
52        return new HotSpotNarrowOopStamp(stamp.type(), stamp.isExactType(), stamp.nonNull(), stamp.alwaysNull(), encoding);
53    }
54
55    @Override
56    public Constant readConstant(MemoryAccessProvider provider, Constant base, long displacement) {
57        try {
58            HotSpotMemoryAccessProvider hsProvider = (HotSpotMemoryAccessProvider) provider;
59            return hsProvider.readNarrowOopConstant(base, displacement);
60        } catch (IllegalArgumentException e) {
61            return null;
62        }
63    }
64
65    @Override
66    public JavaConstant asConstant() {
67        if (alwaysNull()) {
68            return HotSpotCompressedNullConstant.COMPRESSED_NULL;
69        } else {
70            return null;
71        }
72    }
73
74    @Override
75    public boolean isCompatible(Constant other) {
76        if (other instanceof HotSpotObjectConstant) {
77            return ((HotSpotObjectConstant) other).isCompressed();
78        }
79        return true;
80    }
81
82    public static Stamp mkStamp(CompressionOp op, Stamp input, CompressEncoding encoding) {
83        switch (op) {
84            case Compress:
85                if (input instanceof ObjectStamp) {
86                    // compressed oop
87                    return HotSpotNarrowOopStamp.compressed((ObjectStamp) input, encoding);
88                } else if (input instanceof KlassPointerStamp) {
89                    // compressed klass pointer
90                    return ((KlassPointerStamp) input).compressed(encoding);
91                }
92                break;
93            case Uncompress:
94                if (input instanceof NarrowOopStamp) {
95                    // oop
96                    assert encoding.equals(((NarrowOopStamp) input).getEncoding());
97                    return ((NarrowOopStamp) input).uncompressed();
98                } else if (input instanceof KlassPointerStamp) {
99                    // metaspace pointer
100                    assert encoding.equals(((KlassPointerStamp) input).getEncoding());
101                    return ((KlassPointerStamp) input).uncompressed();
102                }
103                break;
104        }
105        throw GraalError.shouldNotReachHere(String.format("Unexpected input stamp %s", input));
106    }
107
108}
109