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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
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*
* This code is distributed in the hope that it will be useful, but WITHOUT
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* 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.
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package org.graalvm.compiler.hotspot.replacements;
import static jdk.vm.ci.meta.DeoptimizationAction.InvalidateReprofile;
import static jdk.vm.ci.meta.DeoptimizationReason.OptimizedTypeCheckViolated;
import static org.graalvm.compiler.core.common.GraalOptions.GeneratePIC;
import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.PRIMARY_SUPERS_LOCATION;
import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.SECONDARY_SUPER_CACHE_LOCATION;
import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.loadHubIntrinsic;
import static org.graalvm.compiler.hotspot.replacements.HotspotSnippetsOptions.TypeCheckMaxHints;
import static org.graalvm.compiler.hotspot.replacements.HotspotSnippetsOptions.TypeCheckMinProfileHitProbability;
import static org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.checkSecondarySubType;
import static org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.checkUnknownSubType;
import static org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.createHints;
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.NOT_LIKELY_PROBABILITY;
import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.probability;
import org.graalvm.compiler.api.replacements.Snippet;
import org.graalvm.compiler.api.replacements.Snippet.ConstantParameter;
import org.graalvm.compiler.api.replacements.Snippet.NonNullParameter;
import org.graalvm.compiler.api.replacements.Snippet.VarargsParameter;
import org.graalvm.compiler.core.common.type.ObjectStamp;
import org.graalvm.compiler.core.common.type.StampFactory;
import org.graalvm.compiler.debug.GraalError;
import org.graalvm.compiler.hotspot.meta.HotSpotProviders;
import org.graalvm.compiler.hotspot.nodes.type.KlassPointerStamp;
import org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.Counters;
import org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.Hints;
import org.graalvm.compiler.hotspot.replacements.aot.ResolveConstantSnippets;
import org.graalvm.compiler.hotspot.word.KlassPointer;
import org.graalvm.compiler.nodes.ConstantNode;
import org.graalvm.compiler.nodes.DeoptimizeNode;
import org.graalvm.compiler.nodes.PiNode;
import org.graalvm.compiler.nodes.SnippetAnchorNode;
import org.graalvm.compiler.nodes.StructuredGraph;
import org.graalvm.compiler.nodes.TypeCheckHints;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.extended.BranchProbabilityNode;
import org.graalvm.compiler.nodes.extended.GuardingNode;
import org.graalvm.compiler.nodes.java.ClassIsAssignableFromNode;
import org.graalvm.compiler.nodes.java.InstanceOfDynamicNode;
import org.graalvm.compiler.nodes.java.InstanceOfNode;
import org.graalvm.compiler.nodes.spi.LoweringTool;
import org.graalvm.compiler.options.OptionValues;
import org.graalvm.compiler.replacements.InstanceOfSnippetsTemplates;
import org.graalvm.compiler.replacements.SnippetCounter;
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.ExplodeLoopNode;
import jdk.vm.ci.code.TargetDescription;
import jdk.vm.ci.hotspot.HotSpotResolvedObjectType;
import jdk.vm.ci.meta.Assumptions;
import jdk.vm.ci.meta.DeoptimizationAction;
import jdk.vm.ci.meta.DeoptimizationReason;
import jdk.vm.ci.meta.JavaKind;
import jdk.vm.ci.meta.JavaTypeProfile;
import jdk.vm.ci.meta.TriState;
/**
* Snippets used for implementing the type test of an instanceof instruction. Since instanceof is a
* floating node, it is lowered separately for each of its usages.
*
* The type tests implemented are described in the paper
* <a href="http://dl.acm.org/citation.cfm?id=583821"> Fast subtype checking in the HotSpot JVM</a>
* by Cliff Click and John Rose.
*/
public class InstanceOfSnippets implements Snippets {
/**
* A test against a set of hints derived from a profile with 100% precise coverage of seen
* types. This snippet deoptimizes on hint miss paths.
*/
@Snippet
public static Object instanceofWithProfile(Object object, @VarargsParameter KlassPointer[] hints, @VarargsParameter boolean[] hintIsPositive, Object trueValue, Object falseValue,
@ConstantParameter boolean nullSeen, @ConstantParameter Counters counters) {
if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
counters.isNull.inc();
if (!nullSeen) {
// See comment below for other deoptimization path; the
// same reasoning applies here.
DeoptimizeNode.deopt(InvalidateReprofile, OptimizedTypeCheckViolated);
}
return falseValue;
}
GuardingNode anchorNode = SnippetAnchorNode.anchor();
KlassPointer objectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
// if we get an exact match: succeed immediately
ExplodeLoopNode.explodeLoop();
for (int i = 0; i < hints.length; i++) {
KlassPointer hintHub = hints[i];
boolean positive = hintIsPositive[i];
if (probability(LIKELY_PROBABILITY, hintHub.equal(objectHub))) {
counters.hintsHit.inc();
return positive ? trueValue : falseValue;
}
counters.hintsMiss.inc();
}
// This maybe just be a rare event but it might also indicate a phase change
// in the application. Ideally we want to use DeoptimizationAction.None for
// the former but the cost is too high if indeed it is the latter. As such,
// we defensively opt for InvalidateReprofile.
DeoptimizeNode.deopt(DeoptimizationAction.InvalidateReprofile, OptimizedTypeCheckViolated);
return falseValue;
}
/**
* A test against a final type.
*/
@Snippet
public static Object instanceofExact(Object object, KlassPointer exactHub, Object trueValue, Object falseValue, @ConstantParameter Counters counters) {
if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
counters.isNull.inc();
return falseValue;
}
GuardingNode anchorNode = SnippetAnchorNode.anchor();
KlassPointer objectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
if (probability(LIKELY_PROBABILITY, objectHub.notEqual(exactHub))) {
counters.exactMiss.inc();
return falseValue;
}
counters.exactHit.inc();
return trueValue;
}
@Snippet
public static Object instanceofExactPIC(Object object, KlassPointer exactHub, Object trueValue, Object falseValue, @ConstantParameter Counters counters) {
KlassPointer exactHubPIC = ResolveConstantSnippets.resolveKlassConstant(exactHub);
return instanceofExact(object, exactHubPIC, trueValue, falseValue, counters);
}
/**
* A test against a primary type.
*/
@Snippet
public static Object instanceofPrimary(KlassPointer hub, Object object, @ConstantParameter int superCheckOffset, Object trueValue, Object falseValue, @ConstantParameter Counters counters) {
if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
counters.isNull.inc();
return falseValue;
}
GuardingNode anchorNode = SnippetAnchorNode.anchor();
KlassPointer objectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
if (probability(NOT_LIKELY_PROBABILITY, objectHub.readKlassPointer(superCheckOffset, PRIMARY_SUPERS_LOCATION).notEqual(hub))) {
counters.displayMiss.inc();
return falseValue;
}
counters.displayHit.inc();
return trueValue;
}
@Snippet
public static Object instanceofPrimaryPIC(KlassPointer hub, Object object, @ConstantParameter int superCheckOffset, Object trueValue, Object falseValue, @ConstantParameter Counters counters) {
KlassPointer resolvedHub = ResolveConstantSnippets.resolveKlassConstant(hub);
return instanceofPrimary(resolvedHub, object, superCheckOffset, trueValue, falseValue, counters);
}
/**
* A test against a restricted secondary type type.
*/
@Snippet
public static Object instanceofSecondary(KlassPointer hub, Object object, @VarargsParameter KlassPointer[] hints, @VarargsParameter boolean[] hintIsPositive, Object trueValue, Object falseValue,
@ConstantParameter Counters counters) {
if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
counters.isNull.inc();
return falseValue;
}
GuardingNode anchorNode = SnippetAnchorNode.anchor();
KlassPointer objectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
// if we get an exact match: succeed immediately
ExplodeLoopNode.explodeLoop();
for (int i = 0; i < hints.length; i++) {
KlassPointer hintHub = hints[i];
boolean positive = hintIsPositive[i];
if (probability(NOT_FREQUENT_PROBABILITY, hintHub.equal(objectHub))) {
counters.hintsHit.inc();
return positive ? trueValue : falseValue;
}
}
counters.hintsMiss.inc();
if (!checkSecondarySubType(hub, objectHub, counters)) {
return falseValue;
}
return trueValue;
}
@Snippet
public static Object instanceofSecondaryPIC(KlassPointer hub, Object object, @VarargsParameter KlassPointer[] hints, @VarargsParameter boolean[] hintIsPositive, Object trueValue,
Object falseValue, @ConstantParameter Counters counters) {
KlassPointer resolvedHub = ResolveConstantSnippets.resolveKlassConstant(hub);
return instanceofSecondary(resolvedHub, object, hints, hintIsPositive, trueValue, falseValue, counters);
}
/**
* Type test used when the type being tested against is not known at compile time.
*/
@Snippet
public static Object instanceofDynamic(KlassPointer hub, Object object, Object trueValue, Object falseValue, @ConstantParameter boolean allowNull, @ConstantParameter Counters counters) {
if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
counters.isNull.inc();
if (allowNull) {
return trueValue;
} else {
return falseValue;
}
}
GuardingNode anchorNode = SnippetAnchorNode.anchor();
KlassPointer nonNullObjectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
// The hub of a primitive type can be null => always return false in this case.
if (BranchProbabilityNode.probability(BranchProbabilityNode.FAST_PATH_PROBABILITY, !hub.isNull())) {
if (checkUnknownSubType(hub, nonNullObjectHub, counters)) {
return trueValue;
}
}
return falseValue;
}
@Snippet
public static Object isAssignableFrom(@NonNullParameter Class<?> thisClassNonNull, Class<?> otherClass, Object trueValue, Object falseValue, @ConstantParameter Counters counters) {
if (otherClass == null) {
DeoptimizeNode.deopt(DeoptimizationAction.InvalidateReprofile, DeoptimizationReason.NullCheckException);
return false;
}
GuardingNode anchorNode = SnippetAnchorNode.anchor();
Class<?> otherClassNonNull = PiNode.piCastNonNullClass(otherClass, anchorNode);
if (BranchProbabilityNode.probability(BranchProbabilityNode.NOT_LIKELY_PROBABILITY, thisClassNonNull == otherClassNonNull)) {
return trueValue;
}
KlassPointer thisHub = ClassGetHubNode.readClass(thisClassNonNull);
KlassPointer otherHub = ClassGetHubNode.readClass(otherClassNonNull);
if (BranchProbabilityNode.probability(BranchProbabilityNode.FAST_PATH_PROBABILITY, !thisHub.isNull())) {
if (BranchProbabilityNode.probability(BranchProbabilityNode.FAST_PATH_PROBABILITY, !otherHub.isNull())) {
GuardingNode guardNonNull = SnippetAnchorNode.anchor();
KlassPointer nonNullOtherHub = ClassGetHubNode.piCastNonNull(otherHub, guardNonNull);
if (TypeCheckSnippetUtils.checkUnknownSubType(thisHub, nonNullOtherHub, counters)) {
return trueValue;
}
}
}
// If either hub is null, one of them is a primitive type and given that the class is not
// equal, return false.
return falseValue;
}
public static class Templates extends InstanceOfSnippetsTemplates {
private final SnippetInfo instanceofWithProfile = snippet(InstanceOfSnippets.class, "instanceofWithProfile");
private final SnippetInfo instanceofExact = snippet(InstanceOfSnippets.class, "instanceofExact");
private final SnippetInfo instanceofExactPIC = snippet(InstanceOfSnippets.class, "instanceofExactPIC");
private final SnippetInfo instanceofPrimary = snippet(InstanceOfSnippets.class, "instanceofPrimary");
private final SnippetInfo instanceofPrimaryPIC = snippet(InstanceOfSnippets.class, "instanceofPrimaryPIC");
private final SnippetInfo instanceofSecondary = snippet(InstanceOfSnippets.class, "instanceofSecondary", SECONDARY_SUPER_CACHE_LOCATION);
private final SnippetInfo instanceofSecondaryPIC = snippet(InstanceOfSnippets.class, "instanceofSecondaryPIC", SECONDARY_SUPER_CACHE_LOCATION);
private final SnippetInfo instanceofDynamic = snippet(InstanceOfSnippets.class, "instanceofDynamic", SECONDARY_SUPER_CACHE_LOCATION);
private final SnippetInfo isAssignableFrom = snippet(InstanceOfSnippets.class, "isAssignableFrom", SECONDARY_SUPER_CACHE_LOCATION);
private final Counters counters;
public Templates(OptionValues options, SnippetCounter.Group.Factory factory, HotSpotProviders providers, TargetDescription target) {
super(options, providers, providers.getSnippetReflection(), target);
this.counters = new Counters(factory);
}
@Override
protected Arguments makeArguments(InstanceOfUsageReplacer replacer, LoweringTool tool) {
if (replacer.instanceOf instanceof InstanceOfNode) {
InstanceOfNode instanceOf = (InstanceOfNode) replacer.instanceOf;
ValueNode object = instanceOf.getValue();
Assumptions assumptions = instanceOf.graph().getAssumptions();
OptionValues localOptions = instanceOf.getOptions();
JavaTypeProfile profile = instanceOf.profile();
if (GeneratePIC.getValue(localOptions)) {
// FIXME: We can't embed constants in hints. We can't really load them from GOT
// either. Hard problem.
profile = null;
}
TypeCheckHints hintInfo = new TypeCheckHints(instanceOf.type(), profile, assumptions, TypeCheckMinProfileHitProbability.getValue(localOptions),
TypeCheckMaxHints.getValue(localOptions));
final HotSpotResolvedObjectType type = (HotSpotResolvedObjectType) instanceOf.type().getType();
ConstantNode hub = ConstantNode.forConstant(KlassPointerStamp.klassNonNull(), type.klass(), providers.getMetaAccess(), instanceOf.graph());
Arguments args;
StructuredGraph graph = instanceOf.graph();
if (hintInfo.hintHitProbability >= 1.0 && hintInfo.exact == null) {
Hints hints = createHints(hintInfo, providers.getMetaAccess(), false, graph);
args = new Arguments(instanceofWithProfile, graph.getGuardsStage(), tool.getLoweringStage());
args.add("object", object);
args.addVarargs("hints", KlassPointer.class, KlassPointerStamp.klassNonNull(), hints.hubs);
args.addVarargs("hintIsPositive", boolean.class, StampFactory.forKind(JavaKind.Boolean), hints.isPositive);
} else if (hintInfo.exact != null) {
SnippetInfo snippet = GeneratePIC.getValue(localOptions) ? instanceofExactPIC : instanceofExact;
args = new Arguments(snippet, graph.getGuardsStage(), tool.getLoweringStage());
args.add("object", object);
args.add("exactHub", ConstantNode.forConstant(KlassPointerStamp.klassNonNull(), ((HotSpotResolvedObjectType) hintInfo.exact).klass(), providers.getMetaAccess(), graph));
} else if (type.isPrimaryType()) {
SnippetInfo snippet = GeneratePIC.getValue(localOptions) ? instanceofPrimaryPIC : instanceofPrimary;
args = new Arguments(snippet, graph.getGuardsStage(), tool.getLoweringStage());
args.add("hub", hub);
args.add("object", object);
args.addConst("superCheckOffset", type.superCheckOffset());
} else {
Hints hints = createHints(hintInfo, providers.getMetaAccess(), false, graph);
SnippetInfo snippet = GeneratePIC.getValue(localOptions) ? instanceofSecondaryPIC : instanceofSecondary;
args = new Arguments(snippet, graph.getGuardsStage(), tool.getLoweringStage());
args.add("hub", hub);
args.add("object", object);
args.addVarargs("hints", KlassPointer.class, KlassPointerStamp.klassNonNull(), hints.hubs);
args.addVarargs("hintIsPositive", boolean.class, StampFactory.forKind(JavaKind.Boolean), hints.isPositive);
}
args.add("trueValue", replacer.trueValue);
args.add("falseValue", replacer.falseValue);
if (hintInfo.hintHitProbability >= 1.0 && hintInfo.exact == null) {
args.addConst("nullSeen", hintInfo.profile.getNullSeen() != TriState.FALSE);
}
args.addConst("counters", counters);
return args;
} else if (replacer.instanceOf instanceof InstanceOfDynamicNode) {
InstanceOfDynamicNode instanceOf = (InstanceOfDynamicNode) replacer.instanceOf;
ValueNode object = instanceOf.getObject();
Arguments args = new Arguments(instanceofDynamic, instanceOf.graph().getGuardsStage(), tool.getLoweringStage());
args.add("hub", instanceOf.getMirrorOrHub());
args.add("object", object);
args.add("trueValue", replacer.trueValue);
args.add("falseValue", replacer.falseValue);
args.addConst("allowNull", instanceOf.allowsNull());
args.addConst("counters", counters);
return args;
} else if (replacer.instanceOf instanceof ClassIsAssignableFromNode) {
ClassIsAssignableFromNode isAssignable = (ClassIsAssignableFromNode) replacer.instanceOf;
Arguments args = new Arguments(isAssignableFrom, isAssignable.graph().getGuardsStage(), tool.getLoweringStage());
assert ((ObjectStamp) isAssignable.getThisClass().stamp()).nonNull();
args.add("thisClassNonNull", isAssignable.getThisClass());
args.add("otherClass", isAssignable.getOtherClass());
args.add("trueValue", replacer.trueValue);
args.add("falseValue", replacer.falseValue);
args.addConst("counters", counters);
return args;
} else {
throw GraalError.shouldNotReachHere();
}
}
}
}