Mercurial > hg > graal-compiler
view graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/WriteBarrierSnippets.java @ 10547:01c902c59e38
Replace unsafe load with readCompressed while reading the previous value in G1 pre barriers (Avoids guard insertion after guard lowering)
author | Christos Kotselidis <christos.kotselidis@oracle.com> |
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date | Thu, 27 Jun 2013 11:23:34 +0200 |
parents | 499f21a3bb81 |
children | ca8efaf18f27 |
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/* * Copyright (c) 2012, 2013, 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 com.oracle.graal.hotspot.replacements; import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.*; import static com.oracle.graal.phases.GraalOptions.*; import static com.oracle.graal.replacements.SnippetTemplate.*; import com.oracle.graal.api.code.*; import com.oracle.graal.api.meta.*; import com.oracle.graal.graph.Node.*; import com.oracle.graal.hotspot.nodes.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.extended.*; import com.oracle.graal.nodes.spi.*; import com.oracle.graal.replacements.*; import com.oracle.graal.replacements.Snippet.ConstantParameter; import com.oracle.graal.replacements.SnippetTemplate.AbstractTemplates; import com.oracle.graal.replacements.SnippetTemplate.Arguments; import com.oracle.graal.replacements.SnippetTemplate.SnippetInfo; import com.oracle.graal.replacements.nodes.*; import com.oracle.graal.word.*; public class WriteBarrierSnippets implements Snippets { private static final SnippetCounter.Group countersWriteBarriers = SnippetCounters.getValue() ? new SnippetCounter.Group("WriteBarriers") : null; private static final SnippetCounter serialFieldWriteBarrierCounter = new SnippetCounter(countersWriteBarriers, "serialFieldWriteBarrier", "Number of Serial Field Write Barriers"); private static final SnippetCounter serialArrayWriteBarrierCounter = new SnippetCounter(countersWriteBarriers, "serialArrayWriteBarrier", "Number of Serial Array Write Barriers"); @Snippet public static void serialArrayWriteBarrier(Object obj, Object location, @ConstantParameter boolean usePrecise) { Object object = FixedValueAnchorNode.getObject(obj); Pointer oop; if (usePrecise) { oop = Word.fromArray(object, location); serialArrayWriteBarrierCounter.inc(); } else { oop = Word.fromObject(object); serialFieldWriteBarrierCounter.inc(); } Word base = (Word) oop.unsignedShiftRight(cardTableShift()); long startAddress = cardTableStart(); int displacement = 0; if (((int) startAddress) == startAddress) { displacement = (int) startAddress; } else { base = base.add(Word.unsigned(cardTableStart())); } base.writeByte(displacement, (byte) 0); } @Snippet public static void serialArrayRangeWriteBarrier(Object object, int startIndex, int length) { Object dest = FixedValueAnchorNode.getObject(object); int cardShift = cardTableShift(); long cardStart = cardTableStart(); final int scale = arrayIndexScale(Kind.Object); int header = arrayBaseOffset(Kind.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.store((start + cardStart) + count, false, Kind.Boolean); } } /** * Log method of debugging purposes. */ static void log(boolean enabled, String format, WordBase value) { if (enabled) { Log.printf(format, value.rawValue()); } } @Snippet public static void g1PreWriteBarrier(Object object, Object expectedObject, Object location, @ConstantParameter boolean doLoad) { Word thread = thread(); Object fixedObject = FixedValueAnchorNode.getObject(object); Object fixedExpectedObject = FixedValueAnchorNode.getObject(expectedObject); Word field = (Word) Word.fromArray(fixedObject, location); Word previousOop = (Word) Word.fromObject(fixedExpectedObject); byte markingValue = thread.readByte(g1SATBQueueMarkingOffset()); Word bufferAddress = thread.readWord(g1SATBQueueBufferOffset()); Word indexAddress = thread.add(g1SATBQueueIndexOffset()); Word indexValue = indexAddress.readWord(0); // If the concurrent marker is enabled, the barrier is issued. if (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 (doLoad) { previousOop = (Word) Word.fromObject(field.readObjectCompressed(0)); } // If the previous value is null the barrier should not be issued. if (previousOop.notEqual(0)) { // If the thread-local SATB buffer is full issue a native call which will // initialize a new one and add the entry. if (indexValue.notEqual(0)) { 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); indexAddress.writeWord(0, nextIndex); } else { g1PreBarrierStub(G1WBPRECALL, previousOop.toObject()); } } } } @Snippet public static void g1PostWriteBarrier(Object object, Object value, Object location, @ConstantParameter boolean usePrecise) { Word thread = thread(); Object fixedObject = FixedValueAnchorNode.getObject(object); Object fixedValue = FixedValueAnchorNode.getObject(value); Word oop = (Word) Word.fromObject(fixedObject); Word field; if (usePrecise) { field = (Word) Word.fromArray(fixedObject, location); } else { field = oop; } Word writtenValue = (Word) Word.fromObject(fixedValue); Word bufferAddress = thread.readWord(g1CardQueueBufferOffset()); Word indexAddress = thread.add(g1CardQueueIndexOffset()); Word indexValue = thread.readWord(g1CardQueueIndexOffset()); // The result of the xor reveals whether the installed pointer crosses heap regions. // In case it does the write barrier has to be issued. Word xorResult = (field.xor(writtenValue)).unsignedShiftRight(logOfHeapRegionGrainBytes()); // Calculate the address of the card to be enqueued to the // thread local card queue. Word cardBase = field.unsignedShiftRight(cardTableShift()); long startAddress = cardTableStart(); int displacement = 0; if (((int) startAddress) == startAddress) { displacement = (int) startAddress; } else { cardBase = cardBase.add(Word.unsigned(cardTableStart())); } Word cardAddress = cardBase.add(displacement); if (xorResult.notEqual(0)) { // If the written value is not null continue with the barrier addition. if (writtenValue.notEqual(0)) { byte cardByte = cardAddress.readByte(0); // If the card is already dirty, (hence already enqueued) skip the insertion. if (cardByte != (byte) 0) { cardAddress.writeByte(0, (byte) 0); // 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.notEqual(0)) { 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); indexAddress.writeWord(0, nextIndex); } 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) private static native void g1PostBarrierStub(@ConstantNodeParameter ForeignCallDescriptor descriptor, Word card); public static class Templates extends AbstractTemplates { private final SnippetInfo serialArrayWriteBarrier = snippet(WriteBarrierSnippets.class, "serialArrayWriteBarrier"); private final SnippetInfo serialArrayRangeWriteBarrier = snippet(WriteBarrierSnippets.class, "serialArrayRangeWriteBarrier"); private final SnippetInfo g1PreWriteBarrier = snippet(WriteBarrierSnippets.class, "g1PreWriteBarrier"); private final SnippetInfo g1PostWriteBarrier = snippet(WriteBarrierSnippets.class, "g1PostWriteBarrier"); public Templates(CodeCacheProvider runtime, Replacements replacements, TargetDescription target) { super(runtime, replacements, target); } public void lower(SerialWriteBarrier arrayWriteBarrier, @SuppressWarnings("unused") LoweringTool tool) { Arguments args = new Arguments(serialArrayWriteBarrier); args.add("obj", arrayWriteBarrier.getObject()); args.add("location", arrayWriteBarrier.getLocation()); args.addConst("usePrecise", arrayWriteBarrier.usePrecise()); template(args).instantiate(runtime, arrayWriteBarrier, DEFAULT_REPLACER, args); } public void lower(SerialArrayRangeWriteBarrier arrayRangeWriteBarrier, @SuppressWarnings("unused") LoweringTool tool) { Arguments args = new Arguments(serialArrayRangeWriteBarrier); args.add("object", arrayRangeWriteBarrier.getObject()); args.add("startIndex", arrayRangeWriteBarrier.getStartIndex()); args.add("length", arrayRangeWriteBarrier.getLength()); template(args).instantiate(runtime, arrayRangeWriteBarrier, DEFAULT_REPLACER, args); } public void lower(G1PreWriteBarrier writeBarrierPre, @SuppressWarnings("unused") LoweringTool tool) { Arguments args = new Arguments(g1PreWriteBarrier); args.add("object", writeBarrierPre.getObject()); args.add("expectedObject", writeBarrierPre.getExpectedObject()); args.add("location", writeBarrierPre.getLocation()); args.addConst("doLoad", writeBarrierPre.doLoad()); template(args).instantiate(runtime, writeBarrierPre, DEFAULT_REPLACER, args); } public void lower(G1PostWriteBarrier writeBarrierPost, @SuppressWarnings("unused") LoweringTool tool) { Arguments args = new Arguments(g1PostWriteBarrier); args.add("object", writeBarrierPost.getObject()); args.add("value", writeBarrierPost.getValue()); args.add("location", writeBarrierPost.getLocation()); args.addConst("usePrecise", writeBarrierPost.usePrecise()); template(args).instantiate(runtime, writeBarrierPost, DEFAULT_REPLACER, args); } } }