hotspot/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot/src/org/graalvm/compiler/hotspot/replacements/WriteBarrierSnippets.java
changeset 43972 1ade39b8381b
child 46344 694c102fd8ed
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot/src/org/graalvm/compiler/hotspot/replacements/WriteBarrierSnippets.java	Thu Feb 16 15:46:09 2017 -0800
@@ -0,0 +1,556 @@
+/*
+ * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package org.graalvm.compiler.hotspot.replacements;
+
+import static org.graalvm.compiler.core.common.GraalOptions.SnippetCounters;
+import static org.graalvm.compiler.hotspot.GraalHotSpotVMConfig.INJECTED_VMCONFIG;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.arrayBaseOffset;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.arrayIndexScale;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.cardTableShift;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.dirtyCardValue;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.g1CardQueueBufferOffset;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.g1CardQueueIndexOffset;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.g1SATBQueueBufferOffset;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.g1SATBQueueIndexOffset;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.g1SATBQueueMarkingOffset;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.g1YoungCardValue;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.registerAsWord;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.verifyOop;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.verifyOops;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.wordSize;
+import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.FREQUENT_PROBABILITY;
+import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.LIKELY_PROBABILITY;
+import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.NOT_FREQUENT_PROBABILITY;
+import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.probability;
+import static org.graalvm.compiler.replacements.SnippetTemplate.DEFAULT_REPLACER;
+import static jdk.vm.ci.code.MemoryBarriers.STORE_LOAD;
+
+import org.graalvm.compiler.api.replacements.Snippet;
+import org.graalvm.compiler.api.replacements.Snippet.ConstantParameter;
+import org.graalvm.compiler.core.common.GraalOptions;
+import org.graalvm.compiler.core.common.LocationIdentity;
+import org.graalvm.compiler.core.common.spi.ForeignCallDescriptor;
+import org.graalvm.compiler.graph.Node.ConstantNodeParameter;
+import org.graalvm.compiler.graph.Node.NodeIntrinsic;
+import org.graalvm.compiler.hotspot.CompressEncoding;
+import org.graalvm.compiler.hotspot.meta.HotSpotProviders;
+import org.graalvm.compiler.hotspot.meta.HotSpotRegistersProvider;
+import org.graalvm.compiler.hotspot.nodes.CompressionNode;
+import org.graalvm.compiler.hotspot.nodes.G1ArrayRangePostWriteBarrier;
+import org.graalvm.compiler.hotspot.nodes.G1ArrayRangePreWriteBarrier;
+import org.graalvm.compiler.hotspot.nodes.G1PostWriteBarrier;
+import org.graalvm.compiler.hotspot.nodes.G1PreWriteBarrier;
+import org.graalvm.compiler.hotspot.nodes.G1ReferentFieldReadBarrier;
+import org.graalvm.compiler.hotspot.nodes.GetObjectAddressNode;
+import org.graalvm.compiler.hotspot.nodes.GraalHotSpotVMConfigNode;
+import org.graalvm.compiler.hotspot.nodes.SerialArrayRangeWriteBarrier;
+import org.graalvm.compiler.hotspot.nodes.SerialWriteBarrier;
+import org.graalvm.compiler.hotspot.nodes.type.NarrowOopStamp;
+import org.graalvm.compiler.nodes.NamedLocationIdentity;
+import org.graalvm.compiler.nodes.StructuredGraph;
+import org.graalvm.compiler.nodes.ValueNode;
+import org.graalvm.compiler.nodes.extended.FixedValueAnchorNode;
+import org.graalvm.compiler.nodes.extended.ForeignCallNode;
+import org.graalvm.compiler.nodes.extended.MembarNode;
+import org.graalvm.compiler.nodes.extended.NullCheckNode;
+import org.graalvm.compiler.nodes.memory.HeapAccess.BarrierType;
+import org.graalvm.compiler.nodes.memory.address.AddressNode;
+import org.graalvm.compiler.nodes.memory.address.AddressNode.Address;
+import org.graalvm.compiler.nodes.memory.address.OffsetAddressNode;
+import org.graalvm.compiler.nodes.spi.LoweringTool;
+import org.graalvm.compiler.replacements.Log;
+import org.graalvm.compiler.replacements.SnippetCounter;
+import org.graalvm.compiler.replacements.SnippetTemplate.AbstractTemplates;
+import org.graalvm.compiler.replacements.SnippetTemplate.Arguments;
+import org.graalvm.compiler.replacements.SnippetTemplate.SnippetInfo;
+import org.graalvm.compiler.replacements.Snippets;
+import org.graalvm.compiler.replacements.nodes.DirectObjectStoreNode;
+import org.graalvm.compiler.replacements.nodes.DirectStoreNode;
+import org.graalvm.compiler.word.Pointer;
+import org.graalvm.compiler.word.Unsigned;
+import org.graalvm.compiler.word.Word;
+
+import jdk.vm.ci.code.Register;
+import jdk.vm.ci.code.TargetDescription;
+import jdk.vm.ci.meta.JavaKind;
+
+public class WriteBarrierSnippets implements Snippets {
+
+    private static final SnippetCounter.Group countersWriteBarriers = SnippetCounters.getValue() ? new SnippetCounter.Group("WriteBarriers") : null;
+    private static final SnippetCounter serialWriteBarrierCounter = new SnippetCounter(countersWriteBarriers, "serialWriteBarrier", "Number of Serial Write Barriers");
+    private static final SnippetCounter g1AttemptedPreWriteBarrierCounter = new SnippetCounter(countersWriteBarriers, "g1AttemptedPreWriteBarrier", "Number of attempted G1 Pre Write Barriers");
+    private static final SnippetCounter g1EffectivePreWriteBarrierCounter = new SnippetCounter(countersWriteBarriers, "g1EffectivePreWriteBarrier", "Number of effective G1 Pre Write Barriers");
+    private static final SnippetCounter g1ExecutedPreWriteBarrierCounter = new SnippetCounter(countersWriteBarriers, "g1ExecutedPreWriteBarrier", "Number of executed G1 Pre Write Barriers");
+    private static final SnippetCounter g1AttemptedPostWriteBarrierCounter = new SnippetCounter(countersWriteBarriers, "g1AttemptedPostWriteBarrier", "Number of attempted G1 Post Write Barriers");
+    private static final SnippetCounter g1EffectiveAfterXORPostWriteBarrierCounter = new SnippetCounter(countersWriteBarriers, "g1EffectiveAfterXORPostWriteBarrier",
+                    "Number of effective G1 Post Write Barriers (after passing the XOR test)");
+    private static final SnippetCounter g1EffectiveAfterNullPostWriteBarrierCounter = new SnippetCounter(countersWriteBarriers, "g1EffectiveAfterNullPostWriteBarrier",
+                    "Number of effective G1 Post Write Barriers (after passing the NULL test)");
+    private static final SnippetCounter g1ExecutedPostWriteBarrierCounter = new SnippetCounter(countersWriteBarriers, "g1ExecutedPostWriteBarrier", "Number of executed G1 Post Write Barriers");
+
+    public static final LocationIdentity GC_CARD_LOCATION = NamedLocationIdentity.mutable("GC-Card");
+    public static final LocationIdentity GC_LOG_LOCATION = NamedLocationIdentity.mutable("GC-Log");
+    public static final LocationIdentity GC_INDEX_LOCATION = NamedLocationIdentity.mutable("GC-Index");
+
+    private static void serialWriteBarrier(Pointer ptr) {
+        serialWriteBarrierCounter.inc();
+        final long startAddress = GraalHotSpotVMConfigNode.cardTableAddress();
+        Word base = (Word) ptr.unsignedShiftRight(cardTableShift(INJECTED_VMCONFIG));
+        if (((int) startAddress) == startAddress && GraalHotSpotVMConfigNode.isCardTableAddressConstant()) {
+            base.writeByte((int) startAddress, (byte) 0, GC_CARD_LOCATION);
+        } else {
+            base.writeByte(Word.unsigned(startAddress), (byte) 0, GC_CARD_LOCATION);
+        }
+    }
+
+    @Snippet
+    public static void serialImpreciseWriteBarrier(Object object) {
+        serialWriteBarrier(Word.objectToTrackedPointer(object));
+    }
+
+    @Snippet
+    public static void serialPreciseWriteBarrier(Address address) {
+        serialWriteBarrier(Word.fromAddress(address));
+    }
+
+    @Snippet
+    public static void serialArrayRangeWriteBarrier(Object object, int startIndex, int length) {
+        if (length == 0) {
+            return;
+        }
+        Object dest = FixedValueAnchorNode.getObject(object);
+        int cardShift = cardTableShift(INJECTED_VMCONFIG);
+        final long cardStart = GraalHotSpotVMConfigNode.cardTableAddress();
+        final int scale = arrayIndexScale(JavaKind.Object);
+        int header = arrayBaseOffset(JavaKind.Object);
+        long dstAddr = GetObjectAddressNode.get(dest);
+        long start = (dstAddr + header + (long) startIndex * scale) >>> cardShift;
+        long end = (dstAddr + header + ((long) startIndex + length - 1) * scale) >>> cardShift;
+        long count = end - start + 1;
+        while (count-- > 0) {
+            DirectStoreNode.storeBoolean((start + cardStart) + count, false, JavaKind.Boolean);
+        }
+    }
+
+    @Snippet
+    public static void g1PreWriteBarrier(Address address, Object object, Object expectedObject, @ConstantParameter boolean doLoad, @ConstantParameter boolean nullCheck,
+                    @ConstantParameter Register threadRegister, @ConstantParameter boolean trace) {
+        if (nullCheck) {
+            NullCheckNode.nullCheck(address);
+        }
+        Word thread = registerAsWord(threadRegister);
+        verifyOop(object);
+        Object fixedExpectedObject = FixedValueAnchorNode.getObject(expectedObject);
+        Pointer field = Word.fromAddress(address);
+        Pointer previousOop = Word.objectToTrackedPointer(fixedExpectedObject);
+        byte markingValue = thread.readByte(g1SATBQueueMarkingOffset(INJECTED_VMCONFIG));
+        int gcCycle = 0;
+        if (trace) {
+            gcCycle = (int) Word.unsigned(HotSpotReplacementsUtil.gcTotalCollectionsAddress(INJECTED_VMCONFIG)).readLong(0);
+            log(trace, "[%d] G1-Pre Thread %p Object %p\n", gcCycle, thread.rawValue(), Word.objectToTrackedPointer(object).rawValue());
+            log(trace, "[%d] G1-Pre Thread %p Expected Object %p\n", gcCycle, thread.rawValue(), Word.objectToTrackedPointer(fixedExpectedObject).rawValue());
+            log(trace, "[%d] G1-Pre Thread %p Field %p\n", gcCycle, thread.rawValue(), field.rawValue());
+            log(trace, "[%d] G1-Pre Thread %p Marking %d\n", gcCycle, thread.rawValue(), markingValue);
+            log(trace, "[%d] G1-Pre Thread %p DoLoad %d\n", gcCycle, thread.rawValue(), doLoad ? 1L : 0L);
+        }
+        g1AttemptedPreWriteBarrierCounter.inc();
+        // If the concurrent marker is enabled, the barrier is issued.
+        if (probability(NOT_FREQUENT_PROBABILITY, markingValue != (byte) 0)) {
+            // If the previous value has to be loaded (before the write), the load is issued.
+            // The load is always issued except the cases of CAS and referent field.
+            if (probability(LIKELY_PROBABILITY, doLoad)) {
+                previousOop = Word.objectToTrackedPointer(field.readObject(0, BarrierType.NONE));
+                if (trace) {
+                    log(trace, "[%d] G1-Pre Thread %p Previous Object %p\n ", gcCycle, thread.rawValue(), previousOop.rawValue());
+                    verifyOop(previousOop.toObject());
+                }
+            }
+            g1EffectivePreWriteBarrierCounter.inc();
+            // If the previous value is null the barrier should not be issued.
+            if (probability(FREQUENT_PROBABILITY, previousOop.notEqual(0))) {
+                g1ExecutedPreWriteBarrierCounter.inc();
+                // If the thread-local SATB buffer is full issue a native call which will
+                // initialize a new one and add the entry.
+                Word indexAddress = thread.add(g1SATBQueueIndexOffset(INJECTED_VMCONFIG));
+                Word indexValue = indexAddress.readWord(0);
+                if (probability(FREQUENT_PROBABILITY, indexValue.notEqual(0))) {
+                    Word bufferAddress = thread.readWord(g1SATBQueueBufferOffset(INJECTED_VMCONFIG));
+                    Word nextIndex = indexValue.subtract(wordSize());
+                    Word logAddress = bufferAddress.add(nextIndex);
+                    // Log the object to be marked as well as update the SATB's buffer next index.
+                    logAddress.writeWord(0, previousOop, GC_LOG_LOCATION);
+                    indexAddress.writeWord(0, nextIndex, GC_INDEX_LOCATION);
+                } else {
+                    g1PreBarrierStub(G1WBPRECALL, previousOop.toObject());
+                }
+            }
+        }
+    }
+
+    @Snippet
+    public static void g1PostWriteBarrier(Address address, Object object, Object value, @ConstantParameter boolean usePrecise, @ConstantParameter Register threadRegister,
+                    @ConstantParameter boolean trace) {
+        Word thread = registerAsWord(threadRegister);
+        Object fixedValue = FixedValueAnchorNode.getObject(value);
+        verifyOop(object);
+        verifyOop(fixedValue);
+        validateObject(object, fixedValue);
+        Pointer oop;
+        if (usePrecise) {
+            oop = Word.fromAddress(address);
+        } else {
+            oop = Word.objectToTrackedPointer(object);
+        }
+        int gcCycle = 0;
+        if (trace) {
+            gcCycle = (int) Word.unsigned(HotSpotReplacementsUtil.gcTotalCollectionsAddress(INJECTED_VMCONFIG)).readLong(0);
+            log(trace, "[%d] G1-Post Thread: %p Object: %p\n", gcCycle, thread.rawValue(), Word.objectToTrackedPointer(object).rawValue());
+            log(trace, "[%d] G1-Post Thread: %p Field: %p\n", gcCycle, thread.rawValue(), oop.rawValue());
+        }
+        Pointer writtenValue = Word.objectToTrackedPointer(fixedValue);
+        // The result of the xor reveals whether the installed pointer crosses heap regions.
+        // In case it does the write barrier has to be issued.
+        final int logOfHeapRegionGrainBytes = GraalHotSpotVMConfigNode.logOfHeapRegionGrainBytes();
+        Unsigned xorResult = (oop.xor(writtenValue)).unsignedShiftRight(logOfHeapRegionGrainBytes);
+
+        // Calculate the address of the card to be enqueued to the
+        // thread local card queue.
+        Unsigned cardBase = oop.unsignedShiftRight(cardTableShift(INJECTED_VMCONFIG));
+        final long startAddress = GraalHotSpotVMConfigNode.cardTableAddress();
+        int displacement = 0;
+        if (((int) startAddress) == startAddress && GraalHotSpotVMConfigNode.isCardTableAddressConstant()) {
+            displacement = (int) startAddress;
+        } else {
+            cardBase = cardBase.add(Word.unsigned(startAddress));
+        }
+        Word cardAddress = (Word) cardBase.add(displacement);
+
+        g1AttemptedPostWriteBarrierCounter.inc();
+        if (probability(FREQUENT_PROBABILITY, xorResult.notEqual(0))) {
+            g1EffectiveAfterXORPostWriteBarrierCounter.inc();
+
+            // If the written value is not null continue with the barrier addition.
+            if (probability(FREQUENT_PROBABILITY, writtenValue.notEqual(0))) {
+                byte cardByte = cardAddress.readByte(0, GC_CARD_LOCATION);
+                g1EffectiveAfterNullPostWriteBarrierCounter.inc();
+
+                // If the card is already dirty, (hence already enqueued) skip the insertion.
+                if (probability(NOT_FREQUENT_PROBABILITY, cardByte != g1YoungCardValue(INJECTED_VMCONFIG))) {
+                    MembarNode.memoryBarrier(STORE_LOAD, GC_CARD_LOCATION);
+                    byte cardByteReload = cardAddress.readByte(0, GC_CARD_LOCATION);
+                    if (probability(NOT_FREQUENT_PROBABILITY, cardByteReload != dirtyCardValue(INJECTED_VMCONFIG))) {
+                        log(trace, "[%d] G1-Post Thread: %p Card: %p \n", gcCycle, thread.rawValue(), Word.unsigned(cardByte).rawValue());
+                        cardAddress.writeByte(0, (byte) 0, GC_CARD_LOCATION);
+                        g1ExecutedPostWriteBarrierCounter.inc();
+
+                        // If the thread local card queue is full, issue a native call which will
+                        // initialize a new one and add the card entry.
+                        Word indexAddress = thread.add(g1CardQueueIndexOffset(INJECTED_VMCONFIG));
+                        Word indexValue = thread.readWord(g1CardQueueIndexOffset(INJECTED_VMCONFIG));
+                        if (probability(FREQUENT_PROBABILITY, indexValue.notEqual(0))) {
+                            Word bufferAddress = thread.readWord(g1CardQueueBufferOffset(INJECTED_VMCONFIG));
+                            Word nextIndex = indexValue.subtract(wordSize());
+                            Word logAddress = bufferAddress.add(nextIndex);
+                            // Log the object to be scanned as well as update
+                            // the card queue's next index.
+                            logAddress.writeWord(0, cardAddress, GC_LOG_LOCATION);
+                            indexAddress.writeWord(0, nextIndex, GC_INDEX_LOCATION);
+                        } else {
+                            g1PostBarrierStub(G1WBPOSTCALL, cardAddress);
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    @Snippet
+    public static void g1ArrayRangePreWriteBarrier(Object object, int startIndex, int length, @ConstantParameter Register threadRegister) {
+        Word thread = registerAsWord(threadRegister);
+        byte markingValue = thread.readByte(g1SATBQueueMarkingOffset(INJECTED_VMCONFIG));
+        // If the concurrent marker is not enabled or the vector length is zero, return.
+        if (markingValue == (byte) 0 || length == 0) {
+            return;
+        }
+        Object dest = FixedValueAnchorNode.getObject(object);
+        Word bufferAddress = thread.readWord(g1SATBQueueBufferOffset(INJECTED_VMCONFIG));
+        Word indexAddress = thread.add(g1SATBQueueIndexOffset(INJECTED_VMCONFIG));
+        long dstAddr = GetObjectAddressNode.get(dest);
+        long indexValue = indexAddress.readWord(0).rawValue();
+        final int scale = arrayIndexScale(JavaKind.Object);
+        int header = arrayBaseOffset(JavaKind.Object);
+
+        for (int i = startIndex; i < length; i++) {
+            long address = dstAddr + header + (i * scale);
+            Pointer oop = Word.objectToTrackedPointer(Word.unsigned(address).readObject(0, BarrierType.NONE));
+            verifyOop(oop.toObject());
+            if (oop.notEqual(0)) {
+                if (indexValue != 0) {
+                    indexValue = indexValue - wordSize();
+                    Word logAddress = bufferAddress.add(Word.unsigned(indexValue));
+                    // Log the object to be marked as well as update the SATB's buffer next index.
+                    logAddress.writeWord(0, oop, GC_LOG_LOCATION);
+                    indexAddress.writeWord(0, Word.unsigned(indexValue), GC_INDEX_LOCATION);
+                } else {
+                    g1PreBarrierStub(G1WBPRECALL, oop.toObject());
+                }
+            }
+        }
+    }
+
+    @Snippet
+    public static void g1ArrayRangePostWriteBarrier(Object object, int startIndex, int length, @ConstantParameter Register threadRegister) {
+        if (length == 0) {
+            return;
+        }
+        Object dest = FixedValueAnchorNode.getObject(object);
+        Word thread = registerAsWord(threadRegister);
+        Word bufferAddress = thread.readWord(g1CardQueueBufferOffset(INJECTED_VMCONFIG));
+        Word indexAddress = thread.add(g1CardQueueIndexOffset(INJECTED_VMCONFIG));
+        long indexValue = thread.readWord(g1CardQueueIndexOffset(INJECTED_VMCONFIG)).rawValue();
+
+        int cardShift = cardTableShift(INJECTED_VMCONFIG);
+        final long cardStart = GraalHotSpotVMConfigNode.cardTableAddress();
+        final int scale = arrayIndexScale(JavaKind.Object);
+        int header = arrayBaseOffset(JavaKind.Object);
+        long dstAddr = GetObjectAddressNode.get(dest);
+        long start = (dstAddr + header + (long) startIndex * scale) >>> cardShift;
+        long end = (dstAddr + header + ((long) startIndex + length - 1) * scale) >>> cardShift;
+        long count = end - start + 1;
+
+        while (count-- > 0) {
+            Word cardAddress = Word.unsigned((start + cardStart) + count);
+            byte cardByte = cardAddress.readByte(0, GC_CARD_LOCATION);
+            // If the card is already dirty, (hence already enqueued) skip the insertion.
+            if (probability(NOT_FREQUENT_PROBABILITY, cardByte != g1YoungCardValue(INJECTED_VMCONFIG))) {
+                MembarNode.memoryBarrier(STORE_LOAD, GC_CARD_LOCATION);
+                byte cardByteReload = cardAddress.readByte(0, GC_CARD_LOCATION);
+                if (probability(NOT_FREQUENT_PROBABILITY, cardByteReload != dirtyCardValue(INJECTED_VMCONFIG))) {
+                    cardAddress.writeByte(0, (byte) 0, GC_CARD_LOCATION);
+                    // If the thread local card queue is full, issue a native call which will
+                    // initialize a new one and add the card entry.
+                    if (indexValue != 0) {
+                        indexValue = indexValue - wordSize();
+                        Word logAddress = bufferAddress.add(Word.unsigned(indexValue));
+                        // Log the object to be scanned as well as update
+                        // the card queue's next index.
+                        logAddress.writeWord(0, cardAddress, GC_LOG_LOCATION);
+                        indexAddress.writeWord(0, Word.unsigned(indexValue), GC_INDEX_LOCATION);
+                    } else {
+                        g1PostBarrierStub(G1WBPOSTCALL, cardAddress);
+                    }
+                }
+            }
+        }
+    }
+
+    public static final ForeignCallDescriptor G1WBPRECALL = new ForeignCallDescriptor("write_barrier_pre", void.class, Object.class);
+
+    @NodeIntrinsic(ForeignCallNode.class)
+    private static native void g1PreBarrierStub(@ConstantNodeParameter ForeignCallDescriptor descriptor, Object object);
+
+    public static final ForeignCallDescriptor G1WBPOSTCALL = new ForeignCallDescriptor("write_barrier_post", void.class, Word.class);
+
+    @NodeIntrinsic(ForeignCallNode.class)
+    public static native void g1PostBarrierStub(@ConstantNodeParameter ForeignCallDescriptor descriptor, Word card);
+
+    public static class Templates extends AbstractTemplates {
+
+        private final SnippetInfo serialImpreciseWriteBarrier = snippet(WriteBarrierSnippets.class, "serialImpreciseWriteBarrier", GC_CARD_LOCATION);
+        private final SnippetInfo serialPreciseWriteBarrier = snippet(WriteBarrierSnippets.class, "serialPreciseWriteBarrier", GC_CARD_LOCATION);
+        private final SnippetInfo serialArrayRangeWriteBarrier = snippet(WriteBarrierSnippets.class, "serialArrayRangeWriteBarrier");
+        private final SnippetInfo g1PreWriteBarrier = snippet(WriteBarrierSnippets.class, "g1PreWriteBarrier", GC_INDEX_LOCATION, GC_LOG_LOCATION);
+        private final SnippetInfo g1ReferentReadBarrier = snippet(WriteBarrierSnippets.class, "g1PreWriteBarrier", GC_INDEX_LOCATION, GC_LOG_LOCATION);
+        private final SnippetInfo g1PostWriteBarrier = snippet(WriteBarrierSnippets.class, "g1PostWriteBarrier", GC_CARD_LOCATION, GC_INDEX_LOCATION, GC_LOG_LOCATION);
+        private final SnippetInfo g1ArrayRangePreWriteBarrier = snippet(WriteBarrierSnippets.class, "g1ArrayRangePreWriteBarrier", GC_INDEX_LOCATION, GC_LOG_LOCATION);
+        private final SnippetInfo g1ArrayRangePostWriteBarrier = snippet(WriteBarrierSnippets.class, "g1ArrayRangePostWriteBarrier", GC_CARD_LOCATION, GC_INDEX_LOCATION, GC_LOG_LOCATION);
+
+        private final CompressEncoding oopEncoding;
+
+        public Templates(HotSpotProviders providers, TargetDescription target, CompressEncoding oopEncoding) {
+            super(providers, providers.getSnippetReflection(), target);
+            this.oopEncoding = oopEncoding;
+        }
+
+        public void lower(SerialWriteBarrier writeBarrier, LoweringTool tool) {
+            Arguments args;
+            if (writeBarrier.usePrecise()) {
+                args = new Arguments(serialPreciseWriteBarrier, writeBarrier.graph().getGuardsStage(), tool.getLoweringStage());
+                args.add("address", writeBarrier.getAddress());
+            } else {
+                args = new Arguments(serialImpreciseWriteBarrier, writeBarrier.graph().getGuardsStage(), tool.getLoweringStage());
+                OffsetAddressNode address = (OffsetAddressNode) writeBarrier.getAddress();
+                args.add("object", address.getBase());
+            }
+            template(args).instantiate(providers.getMetaAccess(), writeBarrier, DEFAULT_REPLACER, args);
+        }
+
+        public void lower(SerialArrayRangeWriteBarrier arrayRangeWriteBarrier, LoweringTool tool) {
+            Arguments args = new Arguments(serialArrayRangeWriteBarrier, arrayRangeWriteBarrier.graph().getGuardsStage(), tool.getLoweringStage());
+            args.add("object", arrayRangeWriteBarrier.getObject());
+            args.add("startIndex", arrayRangeWriteBarrier.getStartIndex());
+            args.add("length", arrayRangeWriteBarrier.getLength());
+            template(args).instantiate(providers.getMetaAccess(), arrayRangeWriteBarrier, DEFAULT_REPLACER, args);
+        }
+
+        public void lower(G1PreWriteBarrier writeBarrierPre, HotSpotRegistersProvider registers, LoweringTool tool) {
+            Arguments args = new Arguments(g1PreWriteBarrier, writeBarrierPre.graph().getGuardsStage(), tool.getLoweringStage());
+            AddressNode address = writeBarrierPre.getAddress();
+            args.add("address", address);
+            if (address instanceof OffsetAddressNode) {
+                args.add("object", ((OffsetAddressNode) address).getBase());
+            } else {
+                args.add("object", null);
+            }
+
+            ValueNode expected = writeBarrierPre.getExpectedObject();
+            if (expected != null && expected.stamp() instanceof NarrowOopStamp) {
+                assert oopEncoding != null;
+                expected = CompressionNode.uncompress(expected, oopEncoding);
+            }
+            args.add("expectedObject", expected);
+
+            args.addConst("doLoad", writeBarrierPre.doLoad());
+            args.addConst("nullCheck", writeBarrierPre.getNullCheck());
+            args.addConst("threadRegister", registers.getThreadRegister());
+            args.addConst("trace", traceBarrier());
+            template(args).instantiate(providers.getMetaAccess(), writeBarrierPre, DEFAULT_REPLACER, args);
+        }
+
+        public void lower(G1ReferentFieldReadBarrier readBarrier, HotSpotRegistersProvider registers, LoweringTool tool) {
+            Arguments args = new Arguments(g1ReferentReadBarrier, readBarrier.graph().getGuardsStage(), tool.getLoweringStage());
+            AddressNode address = readBarrier.getAddress();
+            args.add("address", address);
+            if (address instanceof OffsetAddressNode) {
+                args.add("object", ((OffsetAddressNode) address).getBase());
+            } else {
+                args.add("object", null);
+            }
+
+            ValueNode expected = readBarrier.getExpectedObject();
+            if (expected != null && expected.stamp() instanceof NarrowOopStamp) {
+                assert oopEncoding != null;
+                expected = CompressionNode.uncompress(expected, oopEncoding);
+            }
+
+            args.add("expectedObject", expected);
+            args.addConst("doLoad", readBarrier.doLoad());
+            args.addConst("nullCheck", false);
+            args.addConst("threadRegister", registers.getThreadRegister());
+            args.addConst("trace", traceBarrier());
+            template(args).instantiate(providers.getMetaAccess(), readBarrier, DEFAULT_REPLACER, args);
+        }
+
+        public void lower(G1PostWriteBarrier writeBarrierPost, HotSpotRegistersProvider registers, LoweringTool tool) {
+            StructuredGraph graph = writeBarrierPost.graph();
+            if (writeBarrierPost.alwaysNull()) {
+                graph.removeFixed(writeBarrierPost);
+                return;
+            }
+            Arguments args = new Arguments(g1PostWriteBarrier, graph.getGuardsStage(), tool.getLoweringStage());
+            AddressNode address = writeBarrierPost.getAddress();
+            args.add("address", address);
+            if (address instanceof OffsetAddressNode) {
+                args.add("object", ((OffsetAddressNode) address).getBase());
+            } else {
+                assert writeBarrierPost.usePrecise() : "found imprecise barrier that's not an object access " + writeBarrierPost;
+                args.add("object", null);
+            }
+
+            ValueNode value = writeBarrierPost.getValue();
+            if (value.stamp() instanceof NarrowOopStamp) {
+                assert oopEncoding != null;
+                value = CompressionNode.uncompress(value, oopEncoding);
+            }
+            args.add("value", value);
+
+            args.addConst("usePrecise", writeBarrierPost.usePrecise());
+            args.addConst("threadRegister", registers.getThreadRegister());
+            args.addConst("trace", traceBarrier());
+            template(args).instantiate(providers.getMetaAccess(), writeBarrierPost, DEFAULT_REPLACER, args);
+        }
+
+        public void lower(G1ArrayRangePreWriteBarrier arrayRangeWriteBarrier, HotSpotRegistersProvider registers, LoweringTool tool) {
+            Arguments args = new Arguments(g1ArrayRangePreWriteBarrier, arrayRangeWriteBarrier.graph().getGuardsStage(), tool.getLoweringStage());
+            args.add("object", arrayRangeWriteBarrier.getObject());
+            args.add("startIndex", arrayRangeWriteBarrier.getStartIndex());
+            args.add("length", arrayRangeWriteBarrier.getLength());
+            args.addConst("threadRegister", registers.getThreadRegister());
+            template(args).instantiate(providers.getMetaAccess(), arrayRangeWriteBarrier, DEFAULT_REPLACER, args);
+        }
+
+        public void lower(G1ArrayRangePostWriteBarrier arrayRangeWriteBarrier, HotSpotRegistersProvider registers, LoweringTool tool) {
+            Arguments args = new Arguments(g1ArrayRangePostWriteBarrier, arrayRangeWriteBarrier.graph().getGuardsStage(), tool.getLoweringStage());
+            args.add("object", arrayRangeWriteBarrier.getObject());
+            args.add("startIndex", arrayRangeWriteBarrier.getStartIndex());
+            args.add("length", arrayRangeWriteBarrier.getLength());
+            args.addConst("threadRegister", registers.getThreadRegister());
+            template(args).instantiate(providers.getMetaAccess(), arrayRangeWriteBarrier, DEFAULT_REPLACER, args);
+        }
+    }
+
+    /**
+     * Log method of debugging purposes.
+     */
+    public static void log(boolean enabled, String format, long value) {
+        if (enabled) {
+            Log.printf(format, value);
+        }
+    }
+
+    public static void log(boolean enabled, String format, long value1, long value2) {
+        if (enabled) {
+            Log.printf(format, value1, value2);
+        }
+    }
+
+    public static void log(boolean enabled, String format, long value1, long value2, long value3) {
+        if (enabled) {
+            Log.printf(format, value1, value2, value3);
+        }
+    }
+
+    public static boolean traceBarrier() {
+        return GraalOptions.GCDebugStartCycle.getValue() > 0 &&
+                        ((int) Word.unsigned(HotSpotReplacementsUtil.gcTotalCollectionsAddress(INJECTED_VMCONFIG)).readLong(0) > GraalOptions.GCDebugStartCycle.getValue());
+    }
+
+    /**
+     * Validation helper method which performs sanity checks on write operations. The addresses of
+     * both the object and the value being written are checked in order to determine if they reside
+     * in a valid heap region. If an object is stale, an invalid access is performed in order to
+     * prematurely crash the VM and debug the stack trace of the faulty method.
+     */
+    public static void validateObject(Object parent, Object child) {
+        if (verifyOops(INJECTED_VMCONFIG) && child != null && !validateOop(VALIDATE_OBJECT, parent, child)) {
+            log(true, "Verification ERROR, Parent: %p Child: %p\n", Word.objectToTrackedPointer(parent).rawValue(), Word.objectToTrackedPointer(child).rawValue());
+            DirectObjectStoreNode.storeObject(null, 0, 0, null, LocationIdentity.any(), JavaKind.Object);
+        }
+    }
+
+    public static final ForeignCallDescriptor VALIDATE_OBJECT = new ForeignCallDescriptor("validate_object", boolean.class, Word.class, Word.class);
+
+    @NodeIntrinsic(ForeignCallNode.class)
+    private static native boolean validateOop(@ConstantNodeParameter ForeignCallDescriptor descriptor, Object parent, Object object);
+
+}