Mercurial > hg > truffle

comparison truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/profiles/LongValueProfile.java @ 22501:a63bda98cfdb

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Extract profiles into separate package. Add isProfilingEnabled in TruffleRuntime to disable profiling in the default runtime; Add low overhead profiles for primitives; Add LoopConditionProfile; Profile footprint/threadsafety improvements; Make toString implementations more consistent; Greatly enhanced javadoc documentation for profiles; Deprecate old profiles
author Christian Humer <christian.humer@oracle.com>
date Wed, 16 Dec 2015 16:38:13 +0100
parents
children
comparison
equal deleted inserted replaced
22500:fbe1eb7b4172 22501:a63bda98cfdb
1 /*
2 * Copyright (c) 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package com.oracle.truffle.api.profiles;
26
27 import com.oracle.truffle.api.CompilerDirectives;
28 import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
29 import com.oracle.truffle.api.Truffle;
30
31 /**
32 * <p>
33 * Specialized value profile to capture certain properties of <code>long</code> runtime values.
34 * Value profiles require a runtime check in their initialized state to verify their profiled
35 * assumption. Value profiles are limited to capture monomorphic profiles only. This means that if
36 * two or more values are profiled within a single profile then the profile has no effect. If the
37 * value assumption is invalidated in compiled code then it is invalidated.
38 * </p>
39 *
40 * <p>
41 * <b> Usage example: </b>
42 *
43 * <pre>
44 * class SampleNode extends Node {
45 *
46 * final LongValueProfile profile = LongValueProfile.createIdentityProfile();
47 *
48 * long execute(long input) {
49 * long profiledValue = profile.profile(input);
50 * // compiler may know now more about profiledValue
51 * return profiledValue;
52 * }
53 * }
54 * </pre>
55 * <p>
56 *
57 * {@inheritDoc}
58 *
59 * @see #createIdentityProfile()
60 * @see ValueProfile
61 */
62 public abstract class LongValueProfile extends Profile {
63
64 LongValueProfile() {
65 }
66
67 public abstract long profile(long value);
68
69 /**
70 * Returns a value profile that profiles the exact value of an <code>long</code>.
71 *
72 * @see LongValueProfile
73 */
74 public static LongValueProfile createIdentityProfile() {
75 if (Truffle.getRuntime().isProfilingEnabled()) {
76 return Enabled.create();
77 } else {
78 return Disabled.INSTANCE;
79 }
80 }
81
82 static final class Enabled extends LongValueProfile {
83
84 private static final byte UNINITIALIZED = 0;
85 private static final byte SPECIALIZED = 1;
86 private static final byte GENERIC = 2;
87
88 @CompilationFinal private long cachedValue;
89 @CompilationFinal private byte state = 0;
90
91 @Override
92 public long profile(long value) {
93 byte localState = this.state;
94 if (localState != GENERIC) {
95 if (localState == SPECIALIZED) {
96 long v = cachedValue;
97 if (v == value) {
98 return v;
99 }
100 }
101 CompilerDirectives.transferToInterpreterAndInvalidate();
102 if (localState == UNINITIALIZED) {
103 this.cachedValue = value;
104 this.state = SPECIALIZED;
105 } else {
106 this.state = GENERIC;
107 }
108 }
109 return value;
110 }
111
112 boolean isGeneric() {
113 return state == GENERIC;
114 }
115
116 boolean isUninitialized() {
117 return state == UNINITIALIZED;
118 }
119
120 long getCachedValue() {
121 return cachedValue;
122 }
123
124 @Override
125 public String toString() {
126 return toString(LongValueProfile.class, state == UNINITIALIZED, state == GENERIC, //
127 String.format("value == (long)%s", cachedValue));
128 }
129
130 /* Needed for lazy class loading. */
131 static LongValueProfile create() {
132 return new Enabled();
133 }
134 }
135
136 static final class Disabled extends LongValueProfile {
137
138 static final LongValueProfile INSTANCE = new Disabled();
139
140 @Override
141 protected Object clone() {
142 return INSTANCE;
143 }
144
145 @Override
146 public long profile(long value) {
147 return value;
148 }
149
150 @Override
151 public String toString() {
152 return toStringDisabled(LongValueProfile.class);
153 }
154
155 }
156 }