1 /*

     2  * Copyright (c) 2015, 2018, 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  */

    23 

    24 

    25 package org.graalvm.compiler.phases.schedule;

    26 

    27 import java.util.List;

    28 

    29 import jdk.internal.vm.compiler.collections.EconomicSet;

    30 import jdk.internal.vm.compiler.collections.Equivalence;

    31 import org.graalvm.compiler.core.common.cfg.BlockMap;

    32 import org.graalvm.compiler.core.common.cfg.Loop;

    33 import org.graalvm.compiler.debug.DebugContext;

    34 import org.graalvm.compiler.graph.Node;

    35 import org.graalvm.compiler.nodes.AbstractBeginNode;

    36 import org.graalvm.compiler.nodes.AbstractMergeNode;

    37 import org.graalvm.compiler.nodes.LoopBeginNode;

    38 import org.graalvm.compiler.nodes.PhiNode;

    39 import org.graalvm.compiler.nodes.cfg.Block;

    40 import org.graalvm.compiler.nodes.cfg.HIRLoop;

    41 import org.graalvm.compiler.nodes.memory.FloatingReadNode;

    42 import org.graalvm.compiler.nodes.memory.MemoryCheckpoint;

    43 import org.graalvm.compiler.nodes.memory.MemoryNode;

    44 import org.graalvm.compiler.nodes.memory.MemoryPhiNode;

    45 import org.graalvm.compiler.phases.graph.ReentrantBlockIterator;

    46 import org.graalvm.compiler.phases.graph.ReentrantBlockIterator.BlockIteratorClosure;

    47 import jdk.internal.vm.compiler.word.LocationIdentity;

    48 

    49 public final class MemoryScheduleVerification extends BlockIteratorClosure<EconomicSet<FloatingReadNode>> {

    50 

    51     private final BlockMap<List<Node>> blockToNodesMap;

    52 

    53     public static boolean check(Block startBlock, BlockMap<List<Node>> blockToNodesMap) {

    54         ReentrantBlockIterator.apply(new MemoryScheduleVerification(blockToNodesMap), startBlock);

    55         return true;

    56     }

    57 

    58     private MemoryScheduleVerification(BlockMap<List<Node>> blockToNodesMap) {

    59         this.blockToNodesMap = blockToNodesMap;

    60     }

    61 

    62     @Override

    63     protected EconomicSet<FloatingReadNode> getInitialState() {

    64         return EconomicSet.create(Equivalence.IDENTITY);

    65     }

    66 

    67     @Override

    68     protected EconomicSet<FloatingReadNode> processBlock(Block block, EconomicSet<FloatingReadNode> currentState) {

    69         AbstractBeginNode beginNode = block.getBeginNode();

    70         if (beginNode instanceof AbstractMergeNode) {

    71             AbstractMergeNode abstractMergeNode = (AbstractMergeNode) beginNode;

    72             for (PhiNode phi : abstractMergeNode.phis()) {

    73                 if (phi instanceof MemoryPhiNode) {

    74                     MemoryPhiNode memoryPhiNode = (MemoryPhiNode) phi;

    75                     addFloatingReadUsages(currentState, memoryPhiNode);

    76                 }

    77             }

    78         }

    79         for (Node n : blockToNodesMap.get(block)) {

    80             if (n instanceof MemoryCheckpoint) {

    81                 if (n instanceof MemoryCheckpoint.Single) {

    82                     MemoryCheckpoint.Single single = (MemoryCheckpoint.Single) n;

    83                     processLocation(n, single.getLocationIdentity(), currentState);

    84                 } else if (n instanceof MemoryCheckpoint.Multi) {

    85                     MemoryCheckpoint.Multi multi = (MemoryCheckpoint.Multi) n;

    86                     for (LocationIdentity location : multi.getLocationIdentities()) {

    87                         processLocation(n, location, currentState);

    88                     }

    89                 }

    90 

    91                 addFloatingReadUsages(currentState, n);

    92             } else if (n instanceof MemoryNode) {

    93                 addFloatingReadUsages(currentState, n);

    94             } else if (n instanceof FloatingReadNode) {

    95                 FloatingReadNode floatingReadNode = (FloatingReadNode) n;

    96                 if (floatingReadNode.getLastLocationAccess() != null && floatingReadNode.getLocationIdentity().isMutable()) {

    97                     if (currentState.contains(floatingReadNode)) {

    98                         // Floating read was found in the state.

    99                         currentState.remove(floatingReadNode);

   100                     } else {

   101                         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=" +

   102                                         block + ", block begin: " + block.getBeginNode() + " block loop: " + block.getLoop() + ", " + blockToNodesMap.get(block).get(0));

   103                     }

   104                 }

   105 

   106             }

   107         }

   108         return currentState;

   109     }

   110 

   111     private static void addFloatingReadUsages(EconomicSet<FloatingReadNode> currentState, Node n) {

   112         for (FloatingReadNode read : n.usages().filter(FloatingReadNode.class)) {

   113             if (read.getLastLocationAccess() == n && read.getLocationIdentity().isMutable()) {

   114                 currentState.add(read);

   115             }

   116         }

   117     }

   118 

   119     private void processLocation(Node n, LocationIdentity location, EconomicSet<FloatingReadNode> currentState) {

   120         assert n != null;

   121         if (location.isImmutable()) {

   122             return;

   123         }

   124 

   125         for (FloatingReadNode r : cloneState(currentState)) {

   126             if (r.getLocationIdentity().overlaps(location)) {

   127                 // This read is killed by this location.

   128                 r.getDebug().log(DebugContext.VERBOSE_LEVEL, "%s removing %s from state", n, r);

   129                 currentState.remove(r);

   130             }

   131         }

   132     }

   133 

   134     @Override

   135     protected EconomicSet<FloatingReadNode> merge(Block merge, List<EconomicSet<FloatingReadNode>> states) {

   136         EconomicSet<FloatingReadNode> result = states.get(0);

   137         for (int i = 1; i < states.size(); ++i) {

   138             result.retainAll(states.get(i));

   139         }

   140         return result;

   141     }

   142 

   143     @Override

   144     protected EconomicSet<FloatingReadNode> cloneState(EconomicSet<FloatingReadNode> oldState) {

   145         EconomicSet<FloatingReadNode> result = EconomicSet.create(Equivalence.IDENTITY);

   146         if (oldState != null) {

   147             result.addAll(oldState);

   148         }

   149         return result;

   150     }

   151 

   152     @Override

   153     protected List<EconomicSet<FloatingReadNode>> processLoop(Loop<Block> loop, EconomicSet<FloatingReadNode> initialState) {

   154         HIRLoop l = (HIRLoop) loop;

   155         for (MemoryPhiNode memoryPhi : ((LoopBeginNode) l.getHeader().getBeginNode()).memoryPhis()) {

   156             for (FloatingReadNode r : cloneState(initialState)) {

   157                 if (r.getLocationIdentity().overlaps(memoryPhi.getLocationIdentity())) {

   158                     initialState.remove(r);

   159                 }

   160             }

   161         }

   162         return ReentrantBlockIterator.processLoop(this, loop, initialState).exitStates;

   163     }

   164 }