1 /*
   2  * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2019, Red Hat Inc. All rights reserved.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  */
  24 
  25 
  26 package org.graalvm.compiler.hotspot.gc.g1;
  27 
  28 import org.graalvm.compiler.debug.GraalError;
  29 import org.graalvm.compiler.hotspot.gc.shared.BarrierSet;
  30 import org.graalvm.compiler.nodes.StructuredGraph;
  31 import org.graalvm.compiler.nodes.ValueNode;
  32 import org.graalvm.compiler.nodes.extended.ArrayRangeWrite;
  33 import org.graalvm.compiler.nodes.java.AbstractCompareAndSwapNode;
  34 import org.graalvm.compiler.nodes.java.LoweredAtomicReadAndWriteNode;
  35 import org.graalvm.compiler.nodes.memory.FixedAccessNode;
  36 import org.graalvm.compiler.nodes.memory.HeapAccess;
  37 import org.graalvm.compiler.nodes.memory.ReadNode;
  38 import org.graalvm.compiler.nodes.memory.WriteNode;
  39 import org.graalvm.compiler.nodes.memory.address.AddressNode;
  40 import org.graalvm.compiler.nodes.type.StampTool;
  41 
  42 public class G1BarrierSet extends BarrierSet {
  43 
  44     @Override
  45     public void addReadNodeBarriers(ReadNode node, StructuredGraph graph) {
  46         if (node.getBarrierType() != HeapAccess.BarrierType.NONE) {
  47             assert (node.getBarrierType() == HeapAccess.BarrierType.PRECISE);
  48             G1ReferentFieldReadBarrier barrier = graph.add(new G1ReferentFieldReadBarrier(node.getAddress(), node, false));
  49             graph.addAfterFixed(node, barrier);
  50         }
  51     }
  52 
  53     @Override
  54     public void addWriteNodeBarriers(WriteNode node, StructuredGraph graph) {
  55         HeapAccess.BarrierType barrierType = node.getBarrierType();
  56         switch (barrierType) {
  57             case NONE:
  58                 // nothing to do
  59                 break;
  60             case IMPRECISE:
  61             case PRECISE:
  62                 boolean precise = barrierType == HeapAccess.BarrierType.PRECISE;
  63                 if (!node.getLocationIdentity().isInit()) {
  64                     // The pre barrier does nothing if the value being read is null, so it can
  65                     // be explicitly skipped when this is an initializing store.
  66                     addG1PreWriteBarrier(node, node.getAddress(), null, true, node.getNullCheck(), graph);
  67                 }
  68                 addG1PostWriteBarrier(node, node.getAddress(), node.value(), precise, graph);
  69                 break;
  70             default:
  71                 throw new GraalError("unexpected barrier type: " + barrierType);
  72         }
  73     }
  74 
  75     @Override
  76     public void addAtomicReadWriteNodeBarriers(LoweredAtomicReadAndWriteNode node, StructuredGraph graph) {
  77         HeapAccess.BarrierType barrierType = node.getBarrierType();
  78         switch (barrierType) {
  79             case NONE:
  80                 // nothing to do
  81                 break;
  82             case IMPRECISE:
  83             case PRECISE:
  84                 boolean precise = barrierType == HeapAccess.BarrierType.PRECISE;
  85                 addG1PreWriteBarrier(node, node.getAddress(), null, true, node.getNullCheck(), graph);
  86                 addG1PostWriteBarrier(node, node.getAddress(), node.getNewValue(), precise, graph);
  87                 break;
  88             default:
  89                 throw new GraalError("unexpected barrier type: " + barrierType);
  90         }
  91     }
  92 
  93     @Override
  94     public void addCASBarriers(AbstractCompareAndSwapNode node, StructuredGraph graph) {
  95         HeapAccess.BarrierType barrierType = node.getBarrierType();
  96         switch (barrierType) {
  97             case NONE:
  98                 // nothing to do
  99                 break;
 100             case IMPRECISE:
 101             case PRECISE:
 102                 boolean precise = barrierType == HeapAccess.BarrierType.PRECISE;
 103                 addG1PreWriteBarrier(node, node.getAddress(), node.getExpectedValue(), false, false, graph);
 104                 addG1PostWriteBarrier(node, node.getAddress(), node.getNewValue(), precise, graph);
 105                 break;
 106             default:
 107                 throw new GraalError("unexpected barrier type: " + barrierType);
 108         }
 109     }
 110 
 111     @Override
 112     public void addArrayRangeBarriers(ArrayRangeWrite write, StructuredGraph graph) {
 113         if (!write.isInitialization()) {
 114             // The pre barrier does nothing if the value being read is null, so it can
 115             // be explicitly skipped when this is an initializing store.
 116             G1ArrayRangePreWriteBarrier g1ArrayRangePreWriteBarrier = graph.add(new G1ArrayRangePreWriteBarrier(write.getAddress(), write.getLength(), write.getElementStride()));
 117             graph.addBeforeFixed(write.asNode(), g1ArrayRangePreWriteBarrier);
 118         }
 119         G1ArrayRangePostWriteBarrier g1ArrayRangePostWriteBarrier = graph.add(new G1ArrayRangePostWriteBarrier(write.getAddress(), write.getLength(), write.getElementStride()));
 120         graph.addAfterFixed(write.asNode(), g1ArrayRangePostWriteBarrier);
 121     }
 122 
 123     private static void addG1PreWriteBarrier(FixedAccessNode node, AddressNode address, ValueNode value, boolean doLoad, boolean nullCheck, StructuredGraph graph) {
 124         G1PreWriteBarrier preBarrier = graph.add(new G1PreWriteBarrier(address, value, doLoad, nullCheck));
 125         preBarrier.setStateBefore(node.stateBefore());
 126         node.setNullCheck(false);
 127         node.setStateBefore(null);
 128         graph.addBeforeFixed(node, preBarrier);
 129     }
 130 
 131     private static void addG1PostWriteBarrier(FixedAccessNode node, AddressNode address, ValueNode value, boolean precise, StructuredGraph graph) {
 132         final boolean alwaysNull = StampTool.isPointerAlwaysNull(value);
 133         graph.addAfterFixed(node, graph.add(new G1PostWriteBarrier(address, value, precise, alwaysNull)));
 134     }
 135 }