1 /*
2 * Copyright (c) 2011, 2012, 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 jdk.vm.ci.meta;
24
25 import java.util.*;
26
27 import jdk.vm.ci.meta.JavaTypeProfile.*;
28
29 /**
30 * This profile object represents the type profile at a specific BCI. The precision of the supplied
31 * values may vary, but a runtime that provides this information should be aware that it will be
32 * used to guide performance-critical decisions like speculative inlining, etc.
33 */
34 public final class JavaTypeProfile extends AbstractJavaProfile<ProfiledType, ResolvedJavaType> {
35
36 private static final ProfiledType[] EMPTY_ARRAY = new ProfiledType[0];
37
38 private final TriState nullSeen;
39
40 public JavaTypeProfile(TriState nullSeen, double notRecordedProbability, ProfiledType[] pitems) {
41 super(notRecordedProbability, pitems);
42 this.nullSeen = nullSeen;
43 }
44
45 /**
46 * Returns whether a null value was at the type check.
47 */
48 public TriState getNullSeen() {
49 return nullSeen;
50 }
51
52 /**
53 * A list of types for which the runtime has recorded probability information. Note that this
54 * includes both positive and negative types where a positive type is a subtype of the checked
55 * type and a negative type is not.
56 */
57 public ProfiledType[] getTypes() {
58 return getItems();
59 }
60
61 public JavaTypeProfile restrict(JavaTypeProfile otherProfile) {
62 if (otherProfile.getNotRecordedProbability() > 0.0) {
63 // Not useful for restricting since there is an unknown set of types occurring.
64 return this;
65 }
66
67 if (this.getNotRecordedProbability() > 0.0) {
68 // We are unrestricted, so the other profile is always a better estimate.
69 return otherProfile;
70 }
71
72 ArrayList<ProfiledType> result = new ArrayList<>();
73 for (int i = 0; i < getItems().length; i++) {
74 ProfiledType ptype = getItems()[i];
75 ResolvedJavaType type = ptype.getItem();
76 if (otherProfile.isIncluded(type)) {
77 result.add(ptype);
78 }
79 }
80
81 TriState newNullSeen = (otherProfile.getNullSeen() == TriState.FALSE) ? TriState.FALSE : getNullSeen();
82 double newNotRecorded = getNotRecordedProbability();
83 return createAdjustedProfile(result, newNullSeen, newNotRecorded);
84 }
85
86 public JavaTypeProfile restrict(ResolvedJavaType declaredType, boolean nonNull) {
87 ArrayList<ProfiledType> result = new ArrayList<>();
88 for (int i = 0; i < getItems().length; i++) {
89 ProfiledType ptype = getItems()[i];
90 ResolvedJavaType type = ptype.getItem();
91 if (declaredType.isAssignableFrom(type)) {
92 result.add(ptype);
93 }
94 }
95
96 TriState newNullSeen = (nonNull) ? TriState.FALSE : getNullSeen();
97 double newNotRecorded = this.getNotRecordedProbability();
98 // Assume for the types not recorded, the incompatibility rate is the same.
99 if (getItems().length != 0) {
100 newNotRecorded *= ((double) result.size() / (double) getItems().length);
101 }
102 return createAdjustedProfile(result, newNullSeen, newNotRecorded);
103 }
104
105 private JavaTypeProfile createAdjustedProfile(ArrayList<ProfiledType> result, TriState newNullSeen, double newNotRecorded) {
106 if (result.size() != this.getItems().length || newNotRecorded != getNotRecordedProbability() || newNullSeen != getNullSeen()) {
107 if (result.size() == 0) {
108 return new JavaTypeProfile(newNullSeen, 1.0, EMPTY_ARRAY);
109 }
110 double factor;
111 if (result.size() == this.getItems().length) {
112 /* List of types did not change, no need to recompute probabilities. */
113 factor = 1.0;
114 } else {
115 double probabilitySum = 0.0;
116 for (int i = 0; i < result.size(); i++) {
117 probabilitySum += result.get(i).getProbability();
118 }
119 probabilitySum += newNotRecorded;
120
121 factor = 1.0 / probabilitySum; // Normalize to 1.0
122 assert factor >= 1.0;
123 }
124 ProfiledType[] newResult = new ProfiledType[result.size()];
125 for (int i = 0; i < newResult.length; ++i) {
126 ProfiledType curType = result.get(i);
127 newResult[i] = new ProfiledType(curType.getItem(), Math.min(1.0, curType.getProbability() * factor));
128 }
129 double newNotRecordedTypeProbability = Math.min(1.0, newNotRecorded * factor);
130 return new JavaTypeProfile(newNullSeen, newNotRecordedTypeProbability, newResult);
131 }
132 return this;
133 }
134
135 @Override
136 public boolean equals(Object other) {
137 return super.equals(other) && nullSeen.equals(((JavaTypeProfile) other).nullSeen);
138 }
139
140 @Override
141 public int hashCode() {
142 return nullSeen.hashCode() + super.hashCode();
143 }
144
145 public static class ProfiledType extends AbstractProfiledItem<ResolvedJavaType> {
146
147 public ProfiledType(ResolvedJavaType type, double probability) {
148 super(type, probability);
149 assert type.isArray() || type.isConcrete() : type;
150 }
151
152 /**
153 * Returns the type for this profile entry.
154 */
155 public ResolvedJavaType getType() {
156 return getItem();
157 }
158
159 @Override
160 public String toString() {
161 return String.format("%.6f#%s", probability, item);
162 }
163 }
164
165 @Override
166 public String toString() {
167 StringBuilder buf = new StringBuilder("JavaTypeProfile<nullSeen=").append(getNullSeen()).append(", types=[");
168 for (int j = 0; j < getTypes().length; j++) {
169 if (j != 0) {
170 buf.append(", ");
171 }
172 ProfiledType ptype = getTypes()[j];
173 buf.append(String.format("%.6f:%s", ptype.getProbability(), ptype.getType()));
174 }
175 return buf.append(String.format("], notRecorded:%.6f>", getNotRecordedProbability())).toString();
176 }
177
178 /**
179 * Returns {@code true} if all types seen at this location have been recorded in the profile.
180 */
181 public boolean allTypesRecorded() {
182 return this.getNotRecordedProbability() == 0.0;
183 }
184
185 /**
186 * Returns the single monormorphic type representing this profile or {@code null} if no such
187 * type exists.
188 */
189 public ResolvedJavaType asSingleType() {
190 if (allTypesRecorded() && this.getTypes().length == 1) {
191 return getTypes()[0].getType();
192 }
193 return null;
194 }
195 }