001/*
002 * Copyright (c) 2014, 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.nodes.type;
024
025import jdk.internal.jvmci.hotspot.*;
026import jdk.internal.jvmci.meta.*;
027
028import com.oracle.graal.compiler.common.type.*;
029
030public final class MethodPointerStamp extends MetaspacePointerStamp {
031
032    private static final MethodPointerStamp METHOD = new MethodPointerStamp(false, false);
033
034    private static final MethodPointerStamp METHOD_NON_NULL = new MethodPointerStamp(true, false);
035
036    private static final MethodPointerStamp METHOD_ALWAYS_NULL = new MethodPointerStamp(false, true);
037
038    public static MethodPointerStamp method() {
039        return METHOD;
040    }
041
042    public static MethodPointerStamp methodNonNull() {
043        return METHOD_NON_NULL;
044    }
045
046    private MethodPointerStamp(boolean nonNull, boolean alwaysNull) {
047        super(nonNull, alwaysNull);
048    }
049
050    @Override
051    protected AbstractPointerStamp copyWith(boolean newNonNull, boolean newAlwaysNull) {
052        if (newNonNull) {
053            assert !newAlwaysNull;
054            return METHOD_NON_NULL;
055        } else if (newAlwaysNull) {
056            return METHOD_ALWAYS_NULL;
057        } else {
058            return METHOD;
059        }
060    }
061
062    @Override
063    public boolean isCompatible(Stamp otherStamp) {
064        if (this == otherStamp) {
065            return true;
066        }
067        return otherStamp instanceof MethodPointerStamp;
068    }
069
070    @Override
071    public Stamp constant(Constant c, MetaAccessProvider meta) {
072        if (JavaConstant.NULL_POINTER.equals(c)) {
073            return METHOD_ALWAYS_NULL;
074        } else {
075            assert c instanceof HotSpotMetaspaceConstant;
076            return METHOD_NON_NULL;
077        }
078    }
079
080    @Override
081    public Constant readConstant(MemoryAccessProvider provider, Constant base, long displacement) {
082        HotSpotMemoryAccessProvider hsProvider = (HotSpotMemoryAccessProvider) provider;
083        return hsProvider.readMethodPointerConstant(base, displacement);
084    }
085
086    @Override
087    public String toString() {
088        StringBuilder ret = new StringBuilder("Method*");
089        appendString(ret);
090        return ret.toString();
091    }
092}