1 /*
2 * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24
25 package org.graalvm.compiler.hotspot.replacements;
26
27 import static jdk.vm.ci.meta.DeoptimizationAction.InvalidateReprofile;
28 import static jdk.vm.ci.meta.DeoptimizationReason.OptimizedTypeCheckViolated;
29 import static org.graalvm.compiler.core.common.GraalOptions.GeneratePIC;
30 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.PRIMARY_SUPERS_LOCATION;
31 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.SECONDARY_SUPER_CACHE_LOCATION;
32 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.loadHubIntrinsic;
33 import static org.graalvm.compiler.hotspot.replacements.HotspotSnippetsOptions.TypeCheckMaxHints;
34 import static org.graalvm.compiler.hotspot.replacements.HotspotSnippetsOptions.TypeCheckMinProfileHitProbability;
35 import static org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.checkSecondarySubType;
36 import static org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.checkUnknownSubType;
37 import static org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.createHints;
38 import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.LIKELY_PROBABILITY;
39 import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.NOT_FREQUENT_PROBABILITY;
40 import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.NOT_LIKELY_PROBABILITY;
41 import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.probability;
42
43 import org.graalvm.compiler.api.replacements.Snippet;
44 import org.graalvm.compiler.api.replacements.Snippet.ConstantParameter;
45 import org.graalvm.compiler.api.replacements.Snippet.NonNullParameter;
46 import org.graalvm.compiler.api.replacements.Snippet.VarargsParameter;
47 import org.graalvm.compiler.core.common.type.ObjectStamp;
48 import org.graalvm.compiler.core.common.type.StampFactory;
49 import org.graalvm.compiler.debug.DebugHandlersFactory;
50 import org.graalvm.compiler.debug.GraalError;
51 import org.graalvm.compiler.hotspot.meta.HotSpotProviders;
52 import org.graalvm.compiler.hotspot.nodes.type.KlassPointerStamp;
53 import org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.Counters;
54 import org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.Hints;
55 import org.graalvm.compiler.hotspot.word.KlassPointer;
56 import org.graalvm.compiler.nodes.ConstantNode;
57 import org.graalvm.compiler.nodes.DeoptimizeNode;
58 import org.graalvm.compiler.nodes.NodeView;
59 import org.graalvm.compiler.nodes.PiNode;
60 import org.graalvm.compiler.nodes.SnippetAnchorNode;
61 import org.graalvm.compiler.nodes.StructuredGraph;
62 import org.graalvm.compiler.nodes.TypeCheckHints;
63 import org.graalvm.compiler.nodes.ValueNode;
64 import org.graalvm.compiler.nodes.extended.BranchProbabilityNode;
65 import org.graalvm.compiler.nodes.extended.GuardingNode;
66 import org.graalvm.compiler.nodes.java.ClassIsAssignableFromNode;
67 import org.graalvm.compiler.nodes.java.InstanceOfDynamicNode;
68 import org.graalvm.compiler.nodes.java.InstanceOfNode;
69 import org.graalvm.compiler.nodes.spi.LoweringTool;
70 import org.graalvm.compiler.options.OptionValues;
71 import org.graalvm.compiler.replacements.InstanceOfSnippetsTemplates;
72 import org.graalvm.compiler.replacements.SnippetCounter;
73 import org.graalvm.compiler.replacements.SnippetTemplate.Arguments;
74 import org.graalvm.compiler.replacements.SnippetTemplate.SnippetInfo;
75 import org.graalvm.compiler.replacements.Snippets;
76 import org.graalvm.compiler.replacements.nodes.ExplodeLoopNode;
77
78 import jdk.vm.ci.code.TargetDescription;
79 import jdk.vm.ci.hotspot.HotSpotResolvedObjectType;
80 import jdk.vm.ci.meta.Assumptions;
81 import jdk.vm.ci.meta.DeoptimizationAction;
82 import jdk.vm.ci.meta.DeoptimizationReason;
83 import jdk.vm.ci.meta.JavaKind;
84 import jdk.vm.ci.meta.JavaTypeProfile;
85 import jdk.vm.ci.meta.TriState;
86
87 /**
88 * Snippets used for implementing the type test of an instanceof instruction. Since instanceof is a
89 * floating node, it is lowered separately for each of its usages.
90 *
91 * The type tests implemented are described in the paper
92 * <a href="http://dl.acm.org/citation.cfm?id=583821"> Fast subtype checking in the HotSpot JVM</a>
93 * by Cliff Click and John Rose.
94 */
95 public class InstanceOfSnippets implements Snippets {
96
97 /**
98 * A test against a set of hints derived from a profile with 100% precise coverage of seen
99 * types. This snippet deoptimizes on hint miss paths.
100 */
101 @Snippet
102 public static Object instanceofWithProfile(Object object, @VarargsParameter KlassPointer[] hints, @VarargsParameter boolean[] hintIsPositive, Object trueValue, Object falseValue,
103 @ConstantParameter boolean nullSeen, @ConstantParameter Counters counters) {
104 if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
105 counters.isNull.inc();
106 if (!nullSeen) {
107 // See comment below for other deoptimization path; the
108 // same reasoning applies here.
109 DeoptimizeNode.deopt(InvalidateReprofile, OptimizedTypeCheckViolated);
110 }
111 return falseValue;
112 }
113 GuardingNode anchorNode = SnippetAnchorNode.anchor();
114 KlassPointer objectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
115 // if we get an exact match: succeed immediately
116 ExplodeLoopNode.explodeLoop();
117 for (int i = 0; i < hints.length; i++) {
118 KlassPointer hintHub = hints[i];
119 boolean positive = hintIsPositive[i];
120 if (probability(LIKELY_PROBABILITY, hintHub.equal(objectHub))) {
121 counters.hintsHit.inc();
122 return positive ? trueValue : falseValue;
123 }
124 counters.hintsMiss.inc();
125 }
126 // This maybe just be a rare event but it might also indicate a phase change
127 // in the application. Ideally we want to use DeoptimizationAction.None for
128 // the former but the cost is too high if indeed it is the latter. As such,
129 // we defensively opt for InvalidateReprofile.
130 DeoptimizeNode.deopt(DeoptimizationAction.InvalidateReprofile, OptimizedTypeCheckViolated);
131 return falseValue;
132 }
133
134 /**
135 * A test against a final type.
136 */
137 @Snippet
138 public static Object instanceofExact(Object object, KlassPointer exactHub, Object trueValue, Object falseValue, @ConstantParameter Counters counters) {
139 if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
140 counters.isNull.inc();
141 return falseValue;
142 }
143 GuardingNode anchorNode = SnippetAnchorNode.anchor();
144 KlassPointer objectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
145 if (probability(LIKELY_PROBABILITY, objectHub.notEqual(exactHub))) {
146 counters.exactMiss.inc();
147 return falseValue;
148 }
149 counters.exactHit.inc();
150 return trueValue;
151 }
152
153 /**
154 * A test against a primary type.
155 */
156 @Snippet
157 public static Object instanceofPrimary(KlassPointer hub, Object object, @ConstantParameter int superCheckOffset, Object trueValue, Object falseValue, @ConstantParameter Counters counters) {
158 if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
159 counters.isNull.inc();
160 return falseValue;
161 }
162 GuardingNode anchorNode = SnippetAnchorNode.anchor();
163 KlassPointer objectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
164 if (probability(NOT_LIKELY_PROBABILITY, objectHub.readKlassPointer(superCheckOffset, PRIMARY_SUPERS_LOCATION).notEqual(hub))) {
165 counters.displayMiss.inc();
166 return falseValue;
167 }
168 counters.displayHit.inc();
169 return trueValue;
170 }
171
172 /**
173 * A test against a restricted secondary type type.
174 */
175 @Snippet
176 public static Object instanceofSecondary(KlassPointer hub, Object object, @VarargsParameter KlassPointer[] hints, @VarargsParameter boolean[] hintIsPositive, Object trueValue, Object falseValue,
177 @ConstantParameter Counters counters) {
178 if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
179 counters.isNull.inc();
180 return falseValue;
181 }
182 GuardingNode anchorNode = SnippetAnchorNode.anchor();
183 KlassPointer objectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
184 // if we get an exact match: succeed immediately
185 ExplodeLoopNode.explodeLoop();
186 for (int i = 0; i < hints.length; i++) {
187 KlassPointer hintHub = hints[i];
188 boolean positive = hintIsPositive[i];
189 if (probability(NOT_FREQUENT_PROBABILITY, hintHub.equal(objectHub))) {
190 counters.hintsHit.inc();
191 return positive ? trueValue : falseValue;
192 }
193 }
194 counters.hintsMiss.inc();
195 if (!checkSecondarySubType(hub, objectHub, counters)) {
196 return falseValue;
197 }
198 return trueValue;
199 }
200
201 /**
202 * Type test used when the type being tested against is not known at compile time.
203 */
204 @Snippet
205 public static Object instanceofDynamic(KlassPointer hub, Object object, Object trueValue, Object falseValue, @ConstantParameter boolean allowNull, @ConstantParameter Counters counters) {
206 if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
207 counters.isNull.inc();
208 if (allowNull) {
209 return trueValue;
210 } else {
211 return falseValue;
212 }
213 }
214 GuardingNode anchorNode = SnippetAnchorNode.anchor();
215 KlassPointer nonNullObjectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
216 // The hub of a primitive type can be null => always return false in this case.
217 if (BranchProbabilityNode.probability(BranchProbabilityNode.FAST_PATH_PROBABILITY, !hub.isNull())) {
218 if (checkUnknownSubType(hub, nonNullObjectHub, counters)) {
219 return trueValue;
220 }
221 }
222 return falseValue;
223 }
224
225 @Snippet
226 public static Object isAssignableFrom(@NonNullParameter Class<?> thisClassNonNull, Class<?> otherClass, Object trueValue, Object falseValue, @ConstantParameter Counters counters) {
227 if (otherClass == null) {
228 DeoptimizeNode.deopt(DeoptimizationAction.InvalidateReprofile, DeoptimizationReason.NullCheckException);
229 return false;
230 }
231 GuardingNode anchorNode = SnippetAnchorNode.anchor();
232 Class<?> otherClassNonNull = PiNode.piCastNonNullClass(otherClass, anchorNode);
233
234 if (BranchProbabilityNode.probability(BranchProbabilityNode.NOT_LIKELY_PROBABILITY, thisClassNonNull == otherClassNonNull)) {
235 return trueValue;
236 }
237
238 KlassPointer thisHub = ClassGetHubNode.readClass(thisClassNonNull);
239 KlassPointer otherHub = ClassGetHubNode.readClass(otherClassNonNull);
240 if (BranchProbabilityNode.probability(BranchProbabilityNode.FAST_PATH_PROBABILITY, !thisHub.isNull())) {
241 if (BranchProbabilityNode.probability(BranchProbabilityNode.FAST_PATH_PROBABILITY, !otherHub.isNull())) {
242 GuardingNode guardNonNull = SnippetAnchorNode.anchor();
243 KlassPointer nonNullOtherHub = ClassGetHubNode.piCastNonNull(otherHub, guardNonNull);
244 if (TypeCheckSnippetUtils.checkUnknownSubType(thisHub, nonNullOtherHub, counters)) {
245 return trueValue;
246 }
247 }
248 }
249
250 // If either hub is null, one of them is a primitive type and given that the class is not
251 // equal, return false.
252 return falseValue;
253 }
254
255 public static class Templates extends InstanceOfSnippetsTemplates {
256
257 private final SnippetInfo instanceofWithProfile = snippet(InstanceOfSnippets.class, "instanceofWithProfile");
258 private final SnippetInfo instanceofExact = snippet(InstanceOfSnippets.class, "instanceofExact");
259 private final SnippetInfo instanceofPrimary = snippet(InstanceOfSnippets.class, "instanceofPrimary");
260 private final SnippetInfo instanceofSecondary = snippet(InstanceOfSnippets.class, "instanceofSecondary", SECONDARY_SUPER_CACHE_LOCATION);
261 private final SnippetInfo instanceofDynamic = snippet(InstanceOfSnippets.class, "instanceofDynamic", SECONDARY_SUPER_CACHE_LOCATION);
262 private final SnippetInfo isAssignableFrom = snippet(InstanceOfSnippets.class, "isAssignableFrom", SECONDARY_SUPER_CACHE_LOCATION);
263
264 private final Counters counters;
265
266 public Templates(OptionValues options, Iterable<DebugHandlersFactory> factories, SnippetCounter.Group.Factory factory, HotSpotProviders providers, TargetDescription target) {
267 super(options, factories, providers, providers.getSnippetReflection(), target);
268 this.counters = new Counters(factory);
269 }
270
271 @Override
272 protected Arguments makeArguments(InstanceOfUsageReplacer replacer, LoweringTool tool) {
273 if (replacer.instanceOf instanceof InstanceOfNode) {
274 InstanceOfNode instanceOf = (InstanceOfNode) replacer.instanceOf;
275 ValueNode object = instanceOf.getValue();
276 Assumptions assumptions = instanceOf.graph().getAssumptions();
277
278 OptionValues localOptions = instanceOf.getOptions();
279 JavaTypeProfile profile = instanceOf.profile();
280 if (GeneratePIC.getValue(localOptions)) {
281 // FIXME: We can't embed constants in hints. We can't really load them from GOT
282 // either. Hard problem.
283 profile = null;
284 }
285 TypeCheckHints hintInfo = new TypeCheckHints(instanceOf.type(), profile, assumptions, TypeCheckMinProfileHitProbability.getValue(localOptions),
286 TypeCheckMaxHints.getValue(localOptions));
287 final HotSpotResolvedObjectType type = (HotSpotResolvedObjectType) instanceOf.type().getType();
288 ConstantNode hub = ConstantNode.forConstant(KlassPointerStamp.klassNonNull(), type.klass(), providers.getMetaAccess(), instanceOf.graph());
289
290 Arguments args;
291
292 StructuredGraph graph = instanceOf.graph();
293 if (hintInfo.hintHitProbability >= 1.0 && hintInfo.exact == null) {
294 Hints hints = createHints(hintInfo, providers.getMetaAccess(), false, graph);
295 args = new Arguments(instanceofWithProfile, graph.getGuardsStage(), tool.getLoweringStage());
296 args.add("object", object);
297 args.addVarargs("hints", KlassPointer.class, KlassPointerStamp.klassNonNull(), hints.hubs);
298 args.addVarargs("hintIsPositive", boolean.class, StampFactory.forKind(JavaKind.Boolean), hints.isPositive);
299 } else if (hintInfo.exact != null) {
300 args = new Arguments(instanceofExact, graph.getGuardsStage(), tool.getLoweringStage());
301 args.add("object", object);
302 args.add("exactHub", ConstantNode.forConstant(KlassPointerStamp.klassNonNull(), ((HotSpotResolvedObjectType) hintInfo.exact).klass(), providers.getMetaAccess(), graph));
303 } else if (type.isPrimaryType()) {
304 args = new Arguments(instanceofPrimary, graph.getGuardsStage(), tool.getLoweringStage());
305 args.add("hub", hub);
306 args.add("object", object);
307 args.addConst("superCheckOffset", type.superCheckOffset());
308 } else {
309 Hints hints = createHints(hintInfo, providers.getMetaAccess(), false, graph);
310 args = new Arguments(instanceofSecondary, graph.getGuardsStage(), tool.getLoweringStage());
311 args.add("hub", hub);
312 args.add("object", object);
313 args.addVarargs("hints", KlassPointer.class, KlassPointerStamp.klassNonNull(), hints.hubs);
314 args.addVarargs("hintIsPositive", boolean.class, StampFactory.forKind(JavaKind.Boolean), hints.isPositive);
315 }
316 args.add("trueValue", replacer.trueValue);
317 args.add("falseValue", replacer.falseValue);
318 if (hintInfo.hintHitProbability >= 1.0 && hintInfo.exact == null) {
319 args.addConst("nullSeen", hintInfo.profile.getNullSeen() != TriState.FALSE);
320 }
321 args.addConst("counters", counters);
322 return args;
323 } else if (replacer.instanceOf instanceof InstanceOfDynamicNode) {
324 InstanceOfDynamicNode instanceOf = (InstanceOfDynamicNode) replacer.instanceOf;
325 ValueNode object = instanceOf.getObject();
326
327 Arguments args = new Arguments(instanceofDynamic, instanceOf.graph().getGuardsStage(), tool.getLoweringStage());
328 args.add("hub", instanceOf.getMirrorOrHub());
329 args.add("object", object);
330 args.add("trueValue", replacer.trueValue);
331 args.add("falseValue", replacer.falseValue);
332 args.addConst("allowNull", instanceOf.allowsNull());
333 args.addConst("counters", counters);
334 return args;
335 } else if (replacer.instanceOf instanceof ClassIsAssignableFromNode) {
336 ClassIsAssignableFromNode isAssignable = (ClassIsAssignableFromNode) replacer.instanceOf;
337 Arguments args = new Arguments(isAssignableFrom, isAssignable.graph().getGuardsStage(), tool.getLoweringStage());
338 assert ((ObjectStamp) isAssignable.getThisClass().stamp(NodeView.DEFAULT)).nonNull();
339 args.add("thisClassNonNull", isAssignable.getThisClass());
340 args.add("otherClass", isAssignable.getOtherClass());
341 args.add("trueValue", replacer.trueValue);
342 args.add("falseValue", replacer.falseValue);
343 args.addConst("counters", counters);
344 return args;
345 } else {
346 throw GraalError.shouldNotReachHere();
347 }
348 }
349 }
350 }