001/*
002 * Copyright (c) 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.phases.common;
024
025import jdk.internal.jvmci.code.*;
026import static com.oracle.graal.graph.Graph.NodeEvent.*;
027
028import com.oracle.graal.graph.Graph.NodeEventScope;
029import com.oracle.graal.graph.*;
030import com.oracle.graal.graph.spi.*;
031import com.oracle.graal.nodes.*;
032import com.oracle.graal.phases.*;
033import com.oracle.graal.phases.common.util.*;
034import com.oracle.graal.phases.tiers.*;
035
036public class IterativeConditionalEliminationPhase extends BasePhase<PhaseContext> {
037
038    private static final int MAX_ITERATIONS = 256;
039
040    private final CanonicalizerPhase canonicalizer;
041    private final boolean fullSchedule;
042
043    public IterativeConditionalEliminationPhase(CanonicalizerPhase canonicalizer, boolean fullSchedule) {
044        this.canonicalizer = canonicalizer;
045        this.fullSchedule = fullSchedule;
046    }
047
048    @Override
049    protected void run(StructuredGraph graph, PhaseContext context) {
050        HashSetNodeEventListener listener = new HashSetNodeEventListener().exclude(NODE_ADDED).exclude(ZERO_USAGES);
051        int count = 0;
052        while (true) {
053            try (NodeEventScope nes = graph.trackNodeEvents(listener)) {
054                new DominatorConditionalEliminationPhase(fullSchedule).apply(graph);
055            }
056            if (listener.getNodes().isEmpty()) {
057                break;
058            }
059            for (Node node : graph.getNodes()) {
060                if (node instanceof Simplifiable) {
061                    listener.getNodes().add(node);
062                }
063            }
064            canonicalizer.applyIncremental(graph, context, listener.getNodes());
065            listener.getNodes().clear();
066            if (++count > MAX_ITERATIONS) {
067                throw new BailoutException("Number of iterations in ConditionalEliminationPhase phase exceeds %d", MAX_ITERATIONS);
068            }
069        }
070    }
071}