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.core.common.GraalOptions.SnippetCounters;
26 import static org.graalvm.compiler.hotspot.GraalHotSpotVMConfig.INJECTED_VMCONFIG;
27 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.KLASS_SUPER_CHECK_OFFSET_LOCATION;
28 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.METASPACE_ARRAY_LENGTH_LOCATION;
29 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.PRIMARY_SUPERS_LOCATION;
30 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.SECONDARY_SUPERS_ELEMENT_LOCATION;
31 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.SECONDARY_SUPERS_LOCATION;
32 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.SECONDARY_SUPER_CACHE_LOCATION;
33 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.metaspaceArrayBaseOffset;
34 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.metaspaceArrayLengthOffset;
35 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.secondarySuperCacheOffset;
36 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.secondarySupersOffset;
37 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.superCheckOffsetOffset;
38 import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.wordSize;
39 import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.NOT_LIKELY_PROBABILITY;
40 import static org.graalvm.compiler.nodes.extended.BranchProbabilityNode.probability;
41
42 import java.util.Arrays;
43
44 import org.graalvm.compiler.hotspot.nodes.type.KlassPointerStamp;
45 import org.graalvm.compiler.hotspot.word.KlassPointer;
46 import org.graalvm.compiler.nodes.ConstantNode;
47 import org.graalvm.compiler.nodes.StructuredGraph;
48 import org.graalvm.compiler.nodes.TypeCheckHints;
49 import org.graalvm.compiler.replacements.SnippetCounter;
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 s) {
63 // if (S.cache == T) return true
64 if (s.readKlassPointer(secondarySuperCacheOffset(INJECTED_VMCONFIG), SECONDARY_SUPER_CACHE_LOCATION).equal(t)) {
65 cacheHit.inc();
66 return true;
67 }
68
69 return checkSelfAndSupers(t, s);
70 }
71
72 static boolean checkUnknownSubType(KlassPointer t, KlassPointer s) {
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 (s.readKlassPointer(superCheckOffset, PRIMARY_SUPERS_LOCATION).equal(t)) {
79 if (primary) {
80 cacheHit.inc();
81 } else {
82 displayHit.inc();
83 }
84 return true;
85 }
86
87 // if (off != &cache) return false
88 if (primary) {
89 displayMiss.inc();
90 return false;
91 }
92
93 return checkSelfAndSupers(t, s);
94 }
95
96 private static boolean checkSelfAndSupers(KlassPointer t, KlassPointer s) {
97 // if (T == S) return true
98 if (s.equal(t)) {
99 T_equals_S.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 secondariesHit.inc();
110 return true;
111 }
112 }
113 secondariesMiss.inc();
114 return false;
115 }
116
117 /**
118 * A set of type check hints ordered by decreasing probabilities.
119 */
120 public static class Hints {
121
122 /**
123 * The hubs of the hint types.
124 */
125 public final ConstantNode[] hubs;
126
127 /**
128 * A predicate over {@link #hubs} specifying whether the corresponding hint type is a
129 * sub-type of the checked type.
130 */
131 public final boolean[] isPositive;
132
133 Hints(ConstantNode[] hints, boolean[] hintIsPositive) {
134 this.hubs = hints;
135 this.isPositive = hintIsPositive;
136 }
137 }
138
139 static Hints createHints(TypeCheckHints hints, MetaAccessProvider metaAccess, boolean positiveOnly, StructuredGraph graph) {
140 ConstantNode[] hubs = new ConstantNode[hints.hints.length];
141 boolean[] isPositive = new boolean[hints.hints.length];
142 int index = 0;
143 for (int i = 0; i < hubs.length; i++) {
144 if (!positiveOnly || hints.hints[i].positive) {
145 hubs[index] = ConstantNode.forConstant(KlassPointerStamp.klassNonNull(), ((HotSpotResolvedObjectType) hints.hints[i].type).klass(), metaAccess, graph);
146 isPositive[index] = hints.hints[i].positive;
147 index++;
148 }
149 }
150 if (positiveOnly && index != hubs.length) {
151 assert index < hubs.length;
152 hubs = Arrays.copyOf(hubs, index);
153 isPositive = Arrays.copyOf(isPositive, index);
154 }
155 return new Hints(hubs, isPositive);
156 }
157
158 static KlassPointer loadSecondarySupersElement(Word metaspaceArray, int index) {
159 return KlassPointer.fromWord(metaspaceArray.readWord(metaspaceArrayBaseOffset(INJECTED_VMCONFIG) + index * wordSize(), SECONDARY_SUPERS_ELEMENT_LOCATION));
160 }
161
162 private static final SnippetCounter.Group counters = SnippetCounters.getValue() ? new SnippetCounter.Group("TypeCheck") : null;
163 static final SnippetCounter hintsHit = new SnippetCounter(counters, "hintsHit", "hit a hint type");
164 static final SnippetCounter hintsMiss = new SnippetCounter(counters, "hintsMiss", "missed a hint type");
165 static final SnippetCounter exactHit = new SnippetCounter(counters, "exactHit", "exact type test succeeded");
166 static final SnippetCounter exactMiss = new SnippetCounter(counters, "exactMiss", "exact type test failed");
167 static final SnippetCounter isNull = new SnippetCounter(counters, "isNull", "object tested was null");
168 static final SnippetCounter cacheHit = new SnippetCounter(counters, "cacheHit", "secondary type cache hit");
169 static final SnippetCounter secondariesHit = new SnippetCounter(counters, "secondariesHit", "secondaries scan succeeded");
170 static final SnippetCounter secondariesMiss = new SnippetCounter(counters, "secondariesMiss", "secondaries scan failed");
171 static final SnippetCounter displayHit = new SnippetCounter(counters, "displayHit", "primary type test succeeded");
172 static final SnippetCounter displayMiss = new SnippetCounter(counters, "displayMiss", "primary type test failed");
173 static final SnippetCounter T_equals_S = new SnippetCounter(counters, "T_equals_S", "object type was equal to secondary type");
174
175 }