001/*
002 * Copyright (c) 2015, 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.phases.schedule;
024
025import java.util.*;
026
027import jdk.internal.jvmci.meta.*;
028
029import com.oracle.graal.compiler.common.*;
030import com.oracle.graal.compiler.common.cfg.*;
031import com.oracle.graal.graph.*;
032import com.oracle.graal.nodes.*;
033import com.oracle.graal.nodes.cfg.*;
034import com.oracle.graal.nodes.memory.*;
035import com.oracle.graal.phases.graph.*;
036import com.oracle.graal.phases.graph.ReentrantBlockIterator.BlockIteratorClosure;
037
038public final class MemoryScheduleVerification extends BlockIteratorClosure<Set<FloatingReadNode>> {
039
040    private final BlockMap<List<Node>> blockToNodesMap;
041
042    public static boolean check(Block startBlock, BlockMap<List<Node>> blockToNodesMap) {
043        ReentrantBlockIterator.apply(new MemoryScheduleVerification(blockToNodesMap), startBlock);
044        return true;
045    }
046
047    private MemoryScheduleVerification(BlockMap<List<Node>> blockToNodesMap) {
048        this.blockToNodesMap = blockToNodesMap;
049    }
050
051    @Override
052    protected Set<FloatingReadNode> getInitialState() {
053        return CollectionsFactory.newSet();
054    }
055
056    @Override
057    protected Set<FloatingReadNode> processBlock(Block block, Set<FloatingReadNode> currentState) {
058        AbstractBeginNode beginNode = block.getBeginNode();
059        if (beginNode instanceof AbstractMergeNode) {
060            AbstractMergeNode abstractMergeNode = (AbstractMergeNode) beginNode;
061            for (PhiNode phi : abstractMergeNode.phis()) {
062                if (phi instanceof MemoryPhiNode) {
063                    MemoryPhiNode memoryPhiNode = (MemoryPhiNode) phi;
064                    addFloatingReadUsages(currentState, memoryPhiNode);
065                }
066            }
067        }
068        for (Node n : blockToNodesMap.get(block)) {
069            if (n instanceof MemoryCheckpoint) {
070                if (n instanceof MemoryCheckpoint.Single) {
071                    MemoryCheckpoint.Single single = (MemoryCheckpoint.Single) n;
072                    processLocation(n, single.getLocationIdentity(), currentState);
073                } else if (n instanceof MemoryCheckpoint.Multi) {
074                    MemoryCheckpoint.Multi multi = (MemoryCheckpoint.Multi) n;
075                    for (LocationIdentity location : multi.getLocationIdentities()) {
076                        processLocation(n, location, currentState);
077                    }
078                }
079
080                addFloatingReadUsages(currentState, n);
081            } else if (n instanceof MemoryNode) {
082                addFloatingReadUsages(currentState, n);
083            } else if (n instanceof FloatingReadNode) {
084                FloatingReadNode floatingReadNode = (FloatingReadNode) n;
085                if (floatingReadNode.getLastLocationAccess() != null && floatingReadNode.getLocationIdentity().isMutable()) {
086                    if (currentState.contains(floatingReadNode)) {
087                        // Floating read was found in the state.
088                        currentState.remove(floatingReadNode);
089                    } else {
090                        throw new RuntimeException("Floating read node " + n + " was not found in the state, i.e., it was killed by a memory check point before its place in the schedule. Block=" +
091                                        block + ", block begin: " + block.getBeginNode() + " block loop: " + block.getLoop() + ", " + blockToNodesMap.get(block).get(0));
092                    }
093                }
094
095            }
096        }
097        return currentState;
098    }
099
100    private static void addFloatingReadUsages(Set<FloatingReadNode> currentState, Node n) {
101        for (FloatingReadNode read : n.usages().filter(FloatingReadNode.class)) {
102            if (read.getLastLocationAccess() == n && read.getLocationIdentity().isMutable()) {
103                currentState.add(read);
104            }
105        }
106    }
107
108    private void processLocation(Node n, LocationIdentity location, Set<FloatingReadNode> currentState) {
109        assert n != null;
110        if (location.isImmutable()) {
111            return;
112        }
113
114        for (FloatingReadNode r : cloneState(currentState)) {
115            if (r.getLocationIdentity().overlaps(location)) {
116                // This read is killed by this location.
117                currentState.remove(r);
118            }
119        }
120    }
121
122    @Override
123    protected Set<FloatingReadNode> merge(Block merge, List<Set<FloatingReadNode>> states) {
124        Set<FloatingReadNode> result = states.get(0);
125        for (int i = 1; i < states.size(); ++i) {
126            result.retainAll(states.get(i));
127        }
128        return result;
129    }
130
131    @Override
132    protected Set<FloatingReadNode> cloneState(Set<FloatingReadNode> oldState) {
133        Set<FloatingReadNode> result = CollectionsFactory.newSet();
134        result.addAll(oldState);
135        return result;
136    }
137
138    @Override
139    protected List<Set<FloatingReadNode>> processLoop(Loop<Block> loop, Set<FloatingReadNode> initialState) {
140        HIRLoop l = (HIRLoop) loop;
141        for (MemoryPhiNode memoryPhi : ((LoopBeginNode) l.getHeader().getBeginNode()).phis().filter(MemoryPhiNode.class)) {
142            for (FloatingReadNode r : cloneState(initialState)) {
143                if (r.getLocationIdentity().overlaps(memoryPhi.getLocationIdentity())) {
144                    initialState.remove(r);
145                }
146            }
147        }
148        return ReentrantBlockIterator.processLoop(this, loop, initialState).exitStates;
149    }
150}