# HG changeset patch # User Christos Kotselidis # Date 1374085416 -7200 # Node ID 4bfbd4be6e7a86404426db6680a9157cd794fe68 # Parent 69e305a5cf09d02ff453ff75b5c7396920ab7e88 Replace custom graph building with snippet for unsafe load lowering diff -r 69e305a5cf09 -r 4bfbd4be6e7a graal/com.oracle.graal.hotspot.test/src/com/oracle/graal/hotspot/test/WriteBarrierAdditionTest.java --- a/graal/com.oracle.graal.hotspot.test/src/com/oracle/graal/hotspot/test/WriteBarrierAdditionTest.java Wed Jul 17 19:52:20 2013 +0200 +++ b/graal/com.oracle.graal.hotspot.test/src/com/oracle/graal/hotspot/test/WriteBarrierAdditionTest.java Wed Jul 17 20:23:36 2013 +0200 @@ -160,7 +160,7 @@ } /** - * The following test concern the runtime checks of the unsafe loads. In this test, we unsafely + * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely * load the java.lang.ref.Reference.referent field so the pre barier has to be executed. */ @Test @@ -169,7 +169,7 @@ } /** - * The following test concern the runtime checks of the unsafe loads. In this test, we unsafely + * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely * load a matching offset of a wrong object so the pre barier must not be executed. */ @Test @@ -178,7 +178,7 @@ } /** - * The following test concern the runtime checks of the unsafe loads. In this test, we unsafely + * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely * load a non-matching offset field of the java.lang.ref.Reference object so the pre barier must * not be executed. */ @@ -187,9 +187,30 @@ test2("test6Snippet", wr, new Long(32), null); } - @SuppressWarnings("unused") + /** + * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely + * load a matching offset+disp field of the java.lang.ref.Reference object so the pre barier + * must be executed. + */ + @Test + public void test10() throws Exception { + test2("test6Snippet", wr, new Long(8), new Integer(8)); + } + + /** + * The following test concerns the runtime checks of the unsafe loads. In this test, we unsafely + * load a non-matching offset+disp field of the java.lang.ref.Reference object so the pre barier + * must not be executed. + */ + @Test + public void test9() throws Exception { + test2("test6Snippet", wr, new Long(16), new Integer(16)); + } + public static Object test6Snippet(Object a, Object b, Object c) throws Exception { - return UnsafeLoadNode.load(a, 0, ((Long) b).longValue(), Kind.Object); + final int offset = (c == null ? 0 : ((Integer) c).intValue()); + final long displacement = (b == null ? 0 : ((Long) b).longValue()); + return UnsafeLoadNode.load(a, offset, displacement, Kind.Object); } private HotSpotInstalledCode getInstalledCode(String name) throws Exception { diff -r 69e305a5cf09 -r 4bfbd4be6e7a graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/meta/HotSpotRuntime.java --- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/meta/HotSpotRuntime.java Wed Jul 17 19:52:20 2013 +0200 +++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/meta/HotSpotRuntime.java Wed Jul 17 20:23:36 2013 +0200 @@ -115,6 +115,7 @@ private WriteBarrierSnippets.Templates writeBarrierSnippets; private BoxingSnippets.Templates boxingSnippets; private LoadExceptionObjectSnippets.Templates exceptionObjectSnippets; + private UnsafeLoadSnippets.Templates unsafeLoadSnippets; private final Map foreignCalls = new HashMap<>(); @@ -330,6 +331,7 @@ writeBarrierSnippets = new WriteBarrierSnippets.Templates(this, r, graalRuntime.getTarget()); boxingSnippets = new BoxingSnippets.Templates(this, r, graalRuntime.getTarget()); exceptionObjectSnippets = new LoadExceptionObjectSnippets.Templates(this, r, graalRuntime.getTarget()); + unsafeLoadSnippets = new UnsafeLoadSnippets.Templates(this, r, graalRuntime.getTarget()); r.registerSnippetTemplateCache(new UnsafeArrayCopySnippets.Templates(this, r, graalRuntime.getTarget())); } @@ -626,7 +628,17 @@ } else if (n instanceof UnsafeLoadNode) { UnsafeLoadNode load = (UnsafeLoadNode) n; assert load.kind() != Kind.Illegal; - lowerUnsafeLoad(load, tool); + boolean compress = (!load.object().isNullConstant() && load.accessKind() == Kind.Object); + if (addReadBarrier(load, tool)) { + unsafeLoadSnippets.lower(load, tool); + } else { + IndexedLocationNode location = IndexedLocationNode.create(ANY_LOCATION, load.accessKind(), load.displacement(), load.offset(), graph, 1); + ReadNode memoryRead = graph.add(new ReadNode(load.object(), location, load.stamp(), WriteBarrierType.NONE, compress)); + // An unsafe read must not float outside its block otherwise + // it may float above an explicit null check on its object. + memoryRead.setGuard(AbstractBeginNode.prevBegin(load)); + graph.replaceFixedWithFixed(load, memoryRead); + } } else if (n instanceof UnsafeStoreNode) { UnsafeStoreNode store = (UnsafeStoreNode) n; IndexedLocationNode location = IndexedLocationNode.create(ANY_LOCATION, store.accessKind(), store.displacement(), store.offset(), graph, 1); @@ -823,6 +835,11 @@ } } + private static boolean addReadBarrier(UnsafeLoadNode load, LoweringTool tool) { + return useG1GC() && load.object().kind() == Kind.Object && load.accessKind() == Kind.Object && !load.object().objectStamp().alwaysNull() && load.object().objectStamp().type() != null && + !(load.object().objectStamp().type().isArray()) && tool.getLoweringType() == LoweringType.BEFORE_GUARDS; + } + private static ReadNode createReadVirtualMethod(StructuredGraph graph, Kind wordKind, ValueNode hub, ResolvedJavaMethod method) { HotSpotResolvedJavaMethod hsMethod = (HotSpotResolvedJavaMethod) method; assert !hsMethod.getDeclaringClass().isInterface(); @@ -849,92 +866,6 @@ return graph.add(new WriteNode(object, value, location, WriteBarrierType.NONE, config.useCompressedKlassPointers)); } - /** - * The following method lowers the unsafe load node. If any GC besides G1 is used, the unsafe - * load is lowered normally to a read node. However, if the G1 is used and the unsafe load could - * not be canonicalized to a load field, a runtime check has to be inserted in order to a add a - * g1-pre barrier if the loaded field is the referent field of the java.lang.ref.Reference - * class. The following code constructs the runtime check: - * - * 
-     * if (offset == referentOffset() && type == java.lang.ref.Reference) {
-     *     read;
-     *     G1PreWriteBarrier(read);
-     * } else {
-     *     read;
-     * }
-     * 
-     *
- * - * TODO (ck): Replace the code below with a snippet, properly fix the issue with the unsafe - * loads generated by the array copy intrinsics (robust assertions). - * - */ - private void lowerUnsafeLoad(UnsafeLoadNode load, LoweringTool tool) { - StructuredGraph graph = load.graph(); - boolean compress = (!load.object().isNullConstant() && load.accessKind() == Kind.Object); - if (config().useG1GC && load.object().kind() == Kind.Object && load.accessKind() == Kind.Object && !load.object().objectStamp().alwaysNull() && load.object().objectStamp().type() != null && - !(load.object().objectStamp().type().isArray()) && tool.getLoweringType() != LoweringType.AFTER_GUARDS) { - IndexedLocationNode location = IndexedLocationNode.create(ANY_LOCATION, load.accessKind(), load.displacement(), load.offset(), graph, 1); - // Calculate offset+displacement - IntegerAddNode addNode = graph.add(new IntegerAddNode(Kind.Long, load.offset(), ConstantNode.forLong(load.displacement(), graph))); - // Compare previous result with referent offset (16) - CompareNode offsetCondition = CompareNode.createCompareNode(Condition.EQ, addNode, ConstantNode.forLong(referentOffset(), graph)); - // Instance of unsafe load is java.lang.ref.Reference - InstanceOfNode instanceOfNode = graph.add(new InstanceOfNode(lookupJavaType(java.lang.ref.Reference.class), load.object(), null)); - // The two barriers - ReadNode memoryReadNoBarrier = graph.add(new ReadNode(load.object(), location, load.stamp(), WriteBarrierType.NONE, compress)); - ReadNode memoryReadBarrier = graph.add(new ReadNode(load.object(), location, load.stamp(), WriteBarrierType.PRECISE, compress)); - - // EndNodes - EndNode leftTrue = graph.add(new EndNode()); - EndNode leftFalse = graph.add(new EndNode()); - EndNode rightFirst = graph.add(new EndNode()); - EndNode rightSecond = graph.add(new EndNode()); - - // MergeNodes - MergeNode mergeNoBarrier = graph.add(new MergeNode()); - MergeNode mergeFinal = graph.add(new MergeNode()); - - // IfNodes - IfNode ifNodeType = graph.add(new IfNode(instanceOfNode, memoryReadBarrier, leftFalse, 0.1)); - IfNode ifNodeOffset = graph.add(new IfNode(offsetCondition, ifNodeType, rightFirst, 0.1)); - - // Both branches are true (i.e. Add the barrier) - memoryReadBarrier.setNext(leftTrue); - mergeNoBarrier.addForwardEnd(rightFirst); - mergeNoBarrier.addForwardEnd(leftFalse); - mergeNoBarrier.setNext(memoryReadNoBarrier); - memoryReadNoBarrier.setNext(rightSecond); - mergeFinal.addForwardEnd(leftTrue); - mergeFinal.addForwardEnd(rightSecond); - - PhiNode phiNode = graph.add(new PhiNode(load.accessKind(), mergeFinal)); - phiNode.addInput(memoryReadBarrier); - phiNode.addInput(memoryReadNoBarrier); - - // An unsafe read must not floating outside its block as may float above an explicit - // null check on its object. - memoryReadNoBarrier.setGuard(AbstractBeginNode.prevBegin(memoryReadNoBarrier)); - memoryReadBarrier.setGuard(AbstractBeginNode.prevBegin(memoryReadBarrier)); - - assert load.successors().count() == 1; - Node next = load.successors().first(); - load.replaceAndDelete(ifNodeOffset); - mergeFinal.setNext((FixedNode) next); - ifNodeOffset.replaceAtUsages(phiNode); - } else { - IndexedLocationNode location = IndexedLocationNode.create(ANY_LOCATION, load.accessKind(), load.displacement(), load.offset(), graph, 1); - // Unsafe access to a metaspace or to any - // absolute address do not perform uncompression. - ReadNode memoryRead = graph.add(new ReadNode(load.object(), location, load.stamp(), WriteBarrierType.NONE, compress)); - // An unsafe read must not float outside its block otherwise - // it may float above an explicit null check on its object. - memoryRead.setGuard(AbstractBeginNode.prevBegin(load)); - graph.replaceFixedWithFixed(load, memoryRead); - } - } - private static WriteBarrierType getFieldLoadBarrierType(HotSpotResolvedJavaField loadField) { WriteBarrierType barrierType = WriteBarrierType.NONE; if (config().useG1GC && loadField.getKind() == Kind.Object && loadField.getDeclaringClass().mirror() == java.lang.ref.Reference.class && loadField.getName().equals("referent")) { diff -r 69e305a5cf09 -r 4bfbd4be6e7a graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/UnsafeLoadSnippets.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/UnsafeLoadSnippets.java Wed Jul 17 20:23:36 2013 +0200 @@ -0,0 +1,65 @@ +/* + * Copyright (c) 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.replacements.SnippetTemplate.*; + +import com.oracle.graal.api.code.*; +import com.oracle.graal.nodes.extended.*; +import com.oracle.graal.nodes.spi.*; +import com.oracle.graal.replacements.*; +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.word.*; + +public class UnsafeLoadSnippets implements Snippets { + + @Snippet + public static Object lowerUnsafeLoad(Object object, long offset, int disp) { + long displacement = disp + offset; + if (object instanceof java.lang.ref.Reference && referentOffset() == displacement) { + return Word.fromObject(object).readObject((int) displacement, 1, true); + } else { + return Word.fromObject(object).readObject((int) displacement, 0, true); + } + } + + public static class Templates extends AbstractTemplates { + + private final SnippetInfo unsafeLoad = snippet(UnsafeLoadSnippets.class, "lowerUnsafeLoad"); + + public Templates(CodeCacheProvider runtime, Replacements replacements, TargetDescription target) { + super(runtime, replacements, target); + } + + public void lower(UnsafeLoadNode load, @SuppressWarnings("unused") LoweringTool tool) { + Arguments args = new Arguments(unsafeLoad); + args.add("object", load.object()); + args.add("offset", load.offset()); + args.add("disp", load.displacement()); + template(args).instantiate(runtime, load, DEFAULT_REPLACER, args); + } + } +}