001/*
002 * Copyright (c) 2011, 2012, 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.virtual.phases.ea;
024
025import java.util.*;
026
027public abstract class EffectsBlockState<T extends EffectsBlockState<T>> {
028
029    /*
030     * This flag specifies whether this path that leads to this block is unreachable.
031     */
032    private boolean dead;
033
034    public EffectsBlockState() {
035        // emtpy
036    }
037
038    public EffectsBlockState(EffectsBlockState<T> other) {
039        this.dead = other.dead;
040    }
041
042    @Override
043    public String toString() {
044        return "";
045    }
046
047    protected abstract boolean equivalentTo(T other);
048
049    public boolean isDead() {
050        return dead;
051    }
052
053    public void markAsDead() {
054        this.dead = true;
055    }
056
057    protected static <K, V> boolean compareMaps(Map<K, V> left, Map<K, V> right) {
058        if (left.size() != right.size()) {
059            return false;
060        }
061        return compareMapsNoSize(left, right);
062    }
063
064    protected static <K, V> boolean compareMapsNoSize(Map<K, V> left, Map<K, V> right) {
065        if (left == right) {
066            return true;
067        }
068        for (Map.Entry<K, V> entry : right.entrySet()) {
069            K key = entry.getKey();
070            V value = entry.getValue();
071            assert value != null;
072            V otherValue = left.get(key);
073            if (otherValue != value && !value.equals(otherValue)) {
074                return false;
075            }
076        }
077        return true;
078    }
079
080    protected static <U, V> void meetMaps(Map<U, V> target, Map<U, V> source) {
081        Iterator<Map.Entry<U, V>> iter = target.entrySet().iterator();
082        while (iter.hasNext()) {
083            Map.Entry<U, V> entry = iter.next();
084            if (source.containsKey(entry.getKey())) {
085                assert source.get(entry.getKey()) == entry.getValue();
086            } else {
087                iter.remove();
088            }
089        }
090    }
091
092}