1 /*
2 * Copyright (c) 2013, 2014, 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 org.graalvm.compiler.hotspot.GraalHotSpotVMConfig.INJECTED_VMCONFIG;
26 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.KLASS_SUPER_CHECK_OFFSET_LOCATION;
27 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.METASPACE_ARRAY_LENGTH_LOCATION;
28 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.PRIMARY_SUPERS_LOCATION;
29 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.SECONDARY_SUPERS_ELEMENT_LOCATION;
30 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.SECONDARY_SUPERS_LOCATION;
31 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.SECONDARY_SUPER_CACHE_LOCATION;
32 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.metaspaceArrayBaseOffset;
33 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.metaspaceArrayLengthOffset;
34 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.secondarySuperCacheOffset;
35 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.secondarySupersOffset;
36 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.superCheckOffsetOffset;
37 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.wordSize;
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 java.util.Arrays;
42
43 import org.graalvm.compiler.hotspot.nodes.type.KlassPointerStamp;
44 import org.graalvm.compiler.hotspot.word.KlassPointer;
45 import org.graalvm.compiler.nodes.ConstantNode;
46 import org.graalvm.compiler.nodes.StructuredGraph;
47 import org.graalvm.compiler.nodes.TypeCheckHints;
48 import org.graalvm.compiler.replacements.SnippetCounter;
49 import org.graalvm.compiler.replacements.SnippetCounter.Group;
50 import org.graalvm.compiler.word.Word;
51
52 import jdk.vm.ci.hotspot.HotSpotResolvedObjectType;
53 import jdk.vm.ci.meta.MetaAccessProvider;
54
55 //JaCoCo Exclude
56
57 /**
58 * Utilities and common code paths used by the type check snippets.
59 */
60 public class TypeCheckSnippetUtils {
61
62 static boolean checkSecondarySubType(KlassPointer t, KlassPointer sNonNull, Counters counters) {
63 // if (S.cache == T) return true
64 if (sNonNull.readKlassPointer(secondarySuperCacheOffset(INJECTED_VMCONFIG), SECONDARY_SUPER_CACHE_LOCATION).equal(t)) {
65 counters.cacheHit.inc();
66 return true;
67 }
68
69 return checkSelfAndSupers(t, sNonNull, counters);
70 }
71
72 static boolean checkUnknownSubType(KlassPointer t, KlassPointer sNonNull, Counters counters) {
73 // int off = T.offset
74 int superCheckOffset = t.readInt(superCheckOffsetOffset(INJECTED_VMCONFIG), KLASS_SUPER_CHECK_OFFSET_LOCATION);
75 boolean primary = superCheckOffset != secondarySuperCacheOffset(INJECTED_VMCONFIG);
76
77 // if (T = S[off]) return true
78 if (sNonNull.readKlassPointer(superCheckOffset, PRIMARY_SUPERS_LOCATION).equal(t)) {
79 if (primary) {
80 counters.cacheHit.inc();
81 } else {
82 counters.displayHit.inc();
83 }
84 return true;
85 }
86
87 // if (off != &cache) return false
88 if (primary) {
89 counters.displayMiss.inc();
90 return false;
91 }
92
93 return checkSelfAndSupers(t, sNonNull, counters);
94 }
95
96 private static boolean checkSelfAndSupers(KlassPointer t, KlassPointer s, Counters counters) {
97 // if (T == S) return true
98 if (s.equal(t)) {
99 counters.equalsSecondary.inc();
100 return true;
101 }
102
103 // if (S.scan_s_s_array(T)) { S.cache = T; return true; }
104 Word secondarySupers = s.readWord(secondarySupersOffset(INJECTED_VMCONFIG), SECONDARY_SUPERS_LOCATION);
105 int length = secondarySupers.readInt(metaspaceArrayLengthOffset(INJECTED_VMCONFIG), METASPACE_ARRAY_LENGTH_LOCATION);
106 for (int i = 0; i < length; i++) {
107 if (probability(NOT_LIKELY_PROBABILITY, t.equal(loadSecondarySupersElement(secondarySupers, i)))) {
108 s.writeKlassPointer(secondarySuperCacheOffset(INJECTED_VMCONFIG), t, SECONDARY_SUPER_CACHE_LOCATION);
109 counters.secondariesHit.inc();
110 return true;
111 }
112 }
113 counters.secondariesMiss.inc();
114 return false;
115 }
116
117 static class Counters {
118 final SnippetCounter hintsHit;
119 final SnippetCounter hintsMiss;
120 final SnippetCounter exactHit;
121 final SnippetCounter exactMiss;
122 final SnippetCounter isNull;
123 final SnippetCounter cacheHit;
124 final SnippetCounter secondariesHit;
125 final SnippetCounter secondariesMiss;
126 final SnippetCounter displayHit;
127 final SnippetCounter displayMiss;
128 final SnippetCounter equalsSecondary;
129
130 Counters(SnippetCounter.Group.Factory factory) {
131 Group group = factory.createSnippetCounterGroup("TypeCheck");
132 hintsHit = new SnippetCounter(group, "hintsHit", "hit a hint type");
133 hintsMiss = new SnippetCounter(group, "hintsMiss", "missed a hint type");
134 exactHit = new SnippetCounter(group, "exactHit", "exact type test succeeded");
135 exactMiss = new SnippetCounter(group, "exactMiss", "exact type test failed");
136 isNull = new SnippetCounter(group, "isNull", "object tested was null");
137 cacheHit = new SnippetCounter(group, "cacheHit", "secondary type cache hit");
138 secondariesHit = new SnippetCounter(group, "secondariesHit", "secondaries scan succeeded");
139 secondariesMiss = new SnippetCounter(group, "secondariesMiss", "secondaries scan failed");
140 displayHit = new SnippetCounter(group, "displayHit", "primary type test succeeded");
141 displayMiss = new SnippetCounter(group, "displayMiss", "primary type test failed");
142 equalsSecondary = new SnippetCounter(group, "T_equals_S", "object type was equal to secondary type");
143 }
144 }
145
146 /**
147 * A set of type check hints ordered by decreasing probabilities.
148 */
149 public static class Hints {
150
151 /**
152 * The hubs of the hint types.
153 */
154 public final ConstantNode[] hubs;
155
156 /**
157 * A predicate over {@link #hubs} specifying whether the corresponding hint type is a
158 * sub-type of the checked type.
159 */
160 public final boolean[] isPositive;
161
162 Hints(ConstantNode[] hints, boolean[] hintIsPositive) {
163 this.hubs = hints;
164 this.isPositive = hintIsPositive;
165 }
166 }
167
168 static Hints createHints(TypeCheckHints hints, MetaAccessProvider metaAccess, boolean positiveOnly, StructuredGraph graph) {
169 ConstantNode[] hubs = new ConstantNode[hints.hints.length];
170 boolean[] isPositive = new boolean[hints.hints.length];
171 int index = 0;
172 for (int i = 0; i < hubs.length; i++) {
173 if (!positiveOnly || hints.hints[i].positive) {
174 hubs[index] = ConstantNode.forConstant(KlassPointerStamp.klassNonNull(), ((HotSpotResolvedObjectType) hints.hints[i].type).klass(), metaAccess, graph);
175 isPositive[index] = hints.hints[i].positive;
176 index++;
177 }
178 }
179 if (positiveOnly && index != hubs.length) {
180 assert index < hubs.length;
181 hubs = Arrays.copyOf(hubs, index);
182 isPositive = Arrays.copyOf(isPositive, index);
183 }
184 return new Hints(hubs, isPositive);
185 }
186
187 static KlassPointer loadSecondarySupersElement(Word metaspaceArray, int index) {
188 return KlassPointer.fromWord(metaspaceArray.readWord(metaspaceArrayBaseOffset(INJECTED_VMCONFIG) + index * wordSize(), SECONDARY_SUPERS_ELEMENT_LOCATION));
189 }
190 }