1 /*
2 * Copyright (c) 2012, 2015, 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 package org.graalvm.compiler.hotspot.replacements;
24
25 import static jdk.vm.ci.meta.DeoptimizationAction.InvalidateReprofile;
26 import static jdk.vm.ci.meta.DeoptimizationReason.OptimizedTypeCheckViolated;
27 import static org.graalvm.compiler.core.common.GraalOptions.GeneratePIC;
28 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.PRIMARY_SUPERS_LOCATION;
29 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.SECONDARY_SUPER_CACHE_LOCATION;
30 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.loadHubIntrinsic;
31 import static org.graalvm.compiler.hotspot.replacements.HotspotSnippetsOptions.TypeCheckMaxHints;
32 import static org.graalvm.compiler.hotspot.replacements.HotspotSnippetsOptions.TypeCheckMinProfileHitProbability;
33 import static org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.checkSecondarySubType;
34 import static org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.checkUnknownSubType;
35 import static org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.createHints;
36 import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.LIKELY_PROBABILITY;
37 import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.NOT_FREQUENT_PROBABILITY;
38 import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.NOT_LIKELY_PROBABILITY;
39 import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.probability;
40
41 import org.graalvm.compiler.api.replacements.Snippet;
42 import org.graalvm.compiler.api.replacements.Snippet.ConstantParameter;
43 import org.graalvm.compiler.api.replacements.Snippet.NonNullParameter;
44 import org.graalvm.compiler.api.replacements.Snippet.VarargsParameter;
45 import org.graalvm.compiler.core.common.type.ObjectStamp;
46 import org.graalvm.compiler.core.common.type.StampFactory;
47 import org.graalvm.compiler.debug.GraalError;
48 import org.graalvm.compiler.hotspot.meta.HotSpotProviders;
49 import org.graalvm.compiler.hotspot.nodes.type.KlassPointerStamp;
50 import org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.Counters;
51 import org.graalvm.compiler.hotspot.replacements.TypeCheckSnippetUtils.Hints;
52 import org.graalvm.compiler.hotspot.word.KlassPointer;
53 import org.graalvm.compiler.nodes.ConstantNode;
54 import org.graalvm.compiler.nodes.DeoptimizeNode;
55 import org.graalvm.compiler.nodes.PiNode;
56 import org.graalvm.compiler.nodes.SnippetAnchorNode;
57 import org.graalvm.compiler.nodes.StructuredGraph;
58 import org.graalvm.compiler.nodes.TypeCheckHints;
59 import org.graalvm.compiler.nodes.ValueNode;
60 import org.graalvm.compiler.nodes.extended.BranchProbabilityNode;
61 import org.graalvm.compiler.nodes.extended.GuardingNode;
62 import org.graalvm.compiler.nodes.java.ClassIsAssignableFromNode;
63 import org.graalvm.compiler.nodes.java.InstanceOfDynamicNode;
64 import org.graalvm.compiler.nodes.java.InstanceOfNode;
65 import org.graalvm.compiler.nodes.spi.LoweringTool;
66 import org.graalvm.compiler.options.OptionValues;
67 import org.graalvm.compiler.replacements.InstanceOfSnippetsTemplates;
68 import org.graalvm.compiler.replacements.SnippetCounter;
69 import org.graalvm.compiler.replacements.SnippetTemplate.Arguments;
70 import org.graalvm.compiler.replacements.SnippetTemplate.SnippetInfo;
71 import org.graalvm.compiler.replacements.Snippets;
72 import org.graalvm.compiler.replacements.nodes.ExplodeLoopNode;
73
74 import jdk.vm.ci.code.TargetDescription;
75 import jdk.vm.ci.hotspot.HotSpotResolvedObjectType;
76 import jdk.vm.ci.meta.Assumptions;
77 import jdk.vm.ci.meta.DeoptimizationAction;
78 import jdk.vm.ci.meta.DeoptimizationReason;
79 import jdk.vm.ci.meta.JavaKind;
80 import jdk.vm.ci.meta.JavaTypeProfile;
81 import jdk.vm.ci.meta.TriState;
82
83 /**
84 * Snippets used for implementing the type test of an instanceof instruction. Since instanceof is a
85 * floating node, it is lowered separately for each of its usages.
86 *
87 * The type tests implemented are described in the paper
88 * <a href="http://dl.acm.org/citation.cfm?id=583821"> Fast subtype checking in the HotSpot JVM</a>
89 * by Cliff Click and John Rose.
90 */
91 public class InstanceOfSnippets implements Snippets {
92
93 /**
94 * A test against a set of hints derived from a profile with 100% precise coverage of seen
95 * types. This snippet deoptimizes on hint miss paths.
96 */
97 @Snippet
98 public static Object instanceofWithProfile(Object object, @VarargsParameter KlassPointer[] hints, @VarargsParameter boolean[] hintIsPositive, Object trueValue, Object falseValue,
99 @ConstantParameter boolean nullSeen, @ConstantParameter Counters counters) {
100 if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
101 counters.isNull.inc();
102 if (!nullSeen) {
103 // See comment below for other deoptimization path; the
104 // same reasoning applies here.
105 DeoptimizeNode.deopt(InvalidateReprofile, OptimizedTypeCheckViolated);
106 }
107 return falseValue;
108 }
109 GuardingNode anchorNode = SnippetAnchorNode.anchor();
110 KlassPointer objectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
111 // if we get an exact match: succeed immediately
112 ExplodeLoopNode.explodeLoop();
113 for (int i = 0; i < hints.length; i++) {
114 KlassPointer hintHub = hints[i];
115 boolean positive = hintIsPositive[i];
116 if (probability(LIKELY_PROBABILITY, hintHub.equal(objectHub))) {
117 counters.hintsHit.inc();
118 return positive ? trueValue : falseValue;
119 }
120 counters.hintsMiss.inc();
121 }
122 // This maybe just be a rare event but it might also indicate a phase change
123 // in the application. Ideally we want to use DeoptimizationAction.None for
124 // the former but the cost is too high if indeed it is the latter. As such,
125 // we defensively opt for InvalidateReprofile.
126 DeoptimizeNode.deopt(DeoptimizationAction.InvalidateReprofile, OptimizedTypeCheckViolated);
127 return falseValue;
128 }
129
130 /**
131 * A test against a final type.
132 */
133 @Snippet
134 public static Object instanceofExact(Object object, KlassPointer exactHub, Object trueValue, Object falseValue, @ConstantParameter Counters counters) {
135 if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
136 counters.isNull.inc();
137 return falseValue;
138 }
139 GuardingNode anchorNode = SnippetAnchorNode.anchor();
140 KlassPointer objectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
141 if (probability(LIKELY_PROBABILITY, objectHub.notEqual(exactHub))) {
142 counters.exactMiss.inc();
143 return falseValue;
144 }
145 counters.exactHit.inc();
146 return trueValue;
147 }
148
149 /**
150 * A test against a primary type.
151 */
152 @Snippet
153 public static Object instanceofPrimary(KlassPointer hub, Object object, @ConstantParameter int superCheckOffset, Object trueValue, Object falseValue, @ConstantParameter Counters counters) {
154 if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
155 counters.isNull.inc();
156 return falseValue;
157 }
158 GuardingNode anchorNode = SnippetAnchorNode.anchor();
159 KlassPointer objectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
160 if (probability(NOT_LIKELY_PROBABILITY, objectHub.readKlassPointer(superCheckOffset, PRIMARY_SUPERS_LOCATION).notEqual(hub))) {
161 counters.displayMiss.inc();
162 return falseValue;
163 }
164 counters.displayHit.inc();
165 return trueValue;
166 }
167
168 /**
169 * A test against a restricted secondary type type.
170 */
171 @Snippet
172 public static Object instanceofSecondary(KlassPointer hub, Object object, @VarargsParameter KlassPointer[] hints, @VarargsParameter boolean[] hintIsPositive, Object trueValue, Object falseValue,
173 @ConstantParameter Counters counters) {
174 if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
175 counters.isNull.inc();
176 return falseValue;
177 }
178 GuardingNode anchorNode = SnippetAnchorNode.anchor();
179 KlassPointer objectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
180 // if we get an exact match: succeed immediately
181 ExplodeLoopNode.explodeLoop();
182 for (int i = 0; i < hints.length; i++) {
183 KlassPointer hintHub = hints[i];
184 boolean positive = hintIsPositive[i];
185 if (probability(NOT_FREQUENT_PROBABILITY, hintHub.equal(objectHub))) {
186 counters.hintsHit.inc();
187 return positive ? trueValue : falseValue;
188 }
189 }
190 counters.hintsMiss.inc();
191 if (!checkSecondarySubType(hub, objectHub, counters)) {
192 return falseValue;
193 }
194 return trueValue;
195 }
196
197 /**
198 * Type test used when the type being tested against is not known at compile time.
199 */
200 @Snippet
201 public static Object instanceofDynamic(KlassPointer hub, Object object, Object trueValue, Object falseValue, @ConstantParameter boolean allowNull, @ConstantParameter Counters counters) {
202 if (probability(NOT_FREQUENT_PROBABILITY, object == null)) {
203 counters.isNull.inc();
204 if (allowNull) {
205 return trueValue;
206 } else {
207 return falseValue;
208 }
209 }
210 GuardingNode anchorNode = SnippetAnchorNode.anchor();
211 KlassPointer nonNullObjectHub = loadHubIntrinsic(PiNode.piCastNonNull(object, anchorNode));
212 // The hub of a primitive type can be null => always return false in this case.
213 if (BranchProbabilityNode.probability(BranchProbabilityNode.FAST_PATH_PROBABILITY, !hub.isNull())) {
214 if (checkUnknownSubType(hub, nonNullObjectHub, counters)) {
215 return trueValue;
216 }
217 }
218 return falseValue;
219 }
220
221 @Snippet
222 public static Object isAssignableFrom(@NonNullParameter Class<?> thisClassNonNull, Class<?> otherClass, Object trueValue, Object falseValue, @ConstantParameter Counters counters) {
223 if (otherClass == null) {
224 DeoptimizeNode.deopt(DeoptimizationAction.InvalidateReprofile, DeoptimizationReason.NullCheckException);
225 return false;
226 }
227 GuardingNode anchorNode = SnippetAnchorNode.anchor();
228 Class<?> otherClassNonNull = PiNode.piCastNonNullClass(otherClass, anchorNode);
229
230 if (BranchProbabilityNode.probability(BranchProbabilityNode.NOT_LIKELY_PROBABILITY, thisClassNonNull == otherClassNonNull)) {
231 return trueValue;
232 }
233
234 KlassPointer thisHub = ClassGetHubNode.readClass(thisClassNonNull);
235 KlassPointer otherHub = ClassGetHubNode.readClass(otherClassNonNull);
236 if (BranchProbabilityNode.probability(BranchProbabilityNode.FAST_PATH_PROBABILITY, !thisHub.isNull())) {
237 if (BranchProbabilityNode.probability(BranchProbabilityNode.FAST_PATH_PROBABILITY, !otherHub.isNull())) {
238 GuardingNode guardNonNull = SnippetAnchorNode.anchor();
239 KlassPointer nonNullOtherHub = ClassGetHubNode.piCastNonNull(otherHub, guardNonNull);
240 if (TypeCheckSnippetUtils.checkUnknownSubType(thisHub, nonNullOtherHub, counters)) {
241 return trueValue;
242 }
243 }
244 }
245
246 // If either hub is null, one of them is a primitive type and given that the class is not
247 // equal, return false.
248 return falseValue;
249 }
250
251 public static class Templates extends InstanceOfSnippetsTemplates {
252
253 private final SnippetInfo instanceofWithProfile = snippet(InstanceOfSnippets.class, "instanceofWithProfile");
254 private final SnippetInfo instanceofExact = snippet(InstanceOfSnippets.class, "instanceofExact");
255 private final SnippetInfo instanceofPrimary = snippet(InstanceOfSnippets.class, "instanceofPrimary");
256 private final SnippetInfo instanceofSecondary = snippet(InstanceOfSnippets.class, "instanceofSecondary", SECONDARY_SUPER_CACHE_LOCATION);
257 private final SnippetInfo instanceofDynamic = snippet(InstanceOfSnippets.class, "instanceofDynamic", SECONDARY_SUPER_CACHE_LOCATION);
258 private final SnippetInfo isAssignableFrom = snippet(InstanceOfSnippets.class, "isAssignableFrom", SECONDARY_SUPER_CACHE_LOCATION);
259
260 private final Counters counters;
261
262 public Templates(OptionValues options, SnippetCounter.Group.Factory factory, HotSpotProviders providers, TargetDescription target) {
263 super(options, providers, providers.getSnippetReflection(), target);
264 this.counters = new Counters(factory);
265 }
266
267 @Override
268 protected Arguments makeArguments(InstanceOfUsageReplacer replacer, LoweringTool tool) {
269 if (replacer.instanceOf instanceof InstanceOfNode) {
270 InstanceOfNode instanceOf = (InstanceOfNode) replacer.instanceOf;
271 ValueNode object = instanceOf.getValue();
272 Assumptions assumptions = instanceOf.graph().getAssumptions();
273
274 OptionValues localOptions = instanceOf.getOptions();
275 JavaTypeProfile profile = instanceOf.profile();
276 if (GeneratePIC.getValue(localOptions)) {
277 // FIXME: We can't embed constants in hints. We can't really load them from GOT
278 // either. Hard problem.
279 profile = null;
280 }
281 TypeCheckHints hintInfo = new TypeCheckHints(instanceOf.type(), profile, assumptions, TypeCheckMinProfileHitProbability.getValue(localOptions),
282 TypeCheckMaxHints.getValue(localOptions));
283 final HotSpotResolvedObjectType type = (HotSpotResolvedObjectType) instanceOf.type().getType();
284 ConstantNode hub = ConstantNode.forConstant(KlassPointerStamp.klassNonNull(), type.klass(), providers.getMetaAccess(), instanceOf.graph());
285
286 Arguments args;
287
288 StructuredGraph graph = instanceOf.graph();
289 if (hintInfo.hintHitProbability >= 1.0 && hintInfo.exact == null) {
290 Hints hints = createHints(hintInfo, providers.getMetaAccess(), false, graph);
291 args = new Arguments(instanceofWithProfile, graph.getGuardsStage(), tool.getLoweringStage());
292 args.add("object", object);
293 args.addVarargs("hints", KlassPointer.class, KlassPointerStamp.klassNonNull(), hints.hubs);
294 args.addVarargs("hintIsPositive", boolean.class, StampFactory.forKind(JavaKind.Boolean), hints.isPositive);
295 } else if (hintInfo.exact != null) {
296 args = new Arguments(instanceofExact, graph.getGuardsStage(), tool.getLoweringStage());
297 args.add("object", object);
298 args.add("exactHub", ConstantNode.forConstant(KlassPointerStamp.klassNonNull(), ((HotSpotResolvedObjectType) hintInfo.exact).klass(), providers.getMetaAccess(), graph));
299 } else if (type.isPrimaryType()) {
300 args = new Arguments(instanceofPrimary, graph.getGuardsStage(), tool.getLoweringStage());
301 args.add("hub", hub);
302 args.add("object", object);
303 args.addConst("superCheckOffset", type.superCheckOffset());
304 } else {
305 Hints hints = createHints(hintInfo, providers.getMetaAccess(), false, graph);
306 args = new Arguments(instanceofSecondary, graph.getGuardsStage(), tool.getLoweringStage());
307 args.add("hub", hub);
308 args.add("object", object);
309 args.addVarargs("hints", KlassPointer.class, KlassPointerStamp.klassNonNull(), hints.hubs);
310 args.addVarargs("hintIsPositive", boolean.class, StampFactory.forKind(JavaKind.Boolean), hints.isPositive);
311 }
312 args.add("trueValue", replacer.trueValue);
313 args.add("falseValue", replacer.falseValue);
314 if (hintInfo.hintHitProbability >= 1.0 && hintInfo.exact == null) {
315 args.addConst("nullSeen", hintInfo.profile.getNullSeen() != TriState.FALSE);
316 }
317 args.addConst("counters", counters);
318 return args;
319 } else if (replacer.instanceOf instanceof InstanceOfDynamicNode) {
320 InstanceOfDynamicNode instanceOf = (InstanceOfDynamicNode) replacer.instanceOf;
321 ValueNode object = instanceOf.getObject();
322
323 Arguments args = new Arguments(instanceofDynamic, instanceOf.graph().getGuardsStage(), tool.getLoweringStage());
324 args.add("hub", instanceOf.getMirrorOrHub());
325 args.add("object", object);
326 args.add("trueValue", replacer.trueValue);
327 args.add("falseValue", replacer.falseValue);
328 args.addConst("allowNull", instanceOf.allowsNull());
329 args.addConst("counters", counters);
330 return args;
331 } else if (replacer.instanceOf instanceof ClassIsAssignableFromNode) {
332 ClassIsAssignableFromNode isAssignable = (ClassIsAssignableFromNode) replacer.instanceOf;
333 Arguments args = new Arguments(isAssignableFrom, isAssignable.graph().getGuardsStage(), tool.getLoweringStage());
334 assert ((ObjectStamp) isAssignable.getThisClass().stamp()).nonNull();
335 args.add("thisClassNonNull", isAssignable.getThisClass());
336 args.add("otherClass", isAssignable.getOtherClass());
337 args.add("trueValue", replacer.trueValue);
338 args.add("falseValue", replacer.falseValue);
339 args.addConst("counters", counters);
340 return args;
341 } else {
342 throw GraalError.shouldNotReachHere();
343 }
344 }
345 }
346 }