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comparison truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/ValueProfile.java @ 21951:9c8c0937da41

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Moving all sources into truffle subdirectory
author Jaroslav Tulach <jaroslav.tulach@oracle.com>
date Wed, 17 Jun 2015 10:58:08 +0200
parents graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/ValueProfile.java@f7b3b0c5c3e5
children dc83cc1f94f2
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21950:2a5011c7e641 21951:9c8c0937da41
1 /*
2 * Copyright (c) 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. 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.utilities;
26
27 import com.oracle.truffle.api.nodes.*;
28
29 /**
30 * Utility class to speculate on certain properties of values.
31 *
32 * Example usage:
33 *
34 * <pre>
35 * private final ValueProfile classProfile = ValueProfile.createClassProfile();
36 *
37 * return classProfile.profile(value);
38 * </pre>
39 *
40 * All instances of {@code ValueProfile} (and subclasses) must be held in {@code final} fields for
41 * compiler optimizations to take effect.
42 *
43 * @see #createPrimitiveProfile()
44 * @see #createIdentityProfile()
45 * @see #createClassProfile()
46 */
47 public abstract class ValueProfile extends NodeCloneable {
48
49 public abstract <T> T profile(T value);
50
51 /**
52 * Returns a {@link PrimitiveValueProfile} that speculates on the primitive equality or object
53 * identity of a value.
54 */
55 public static PrimitiveValueProfile createPrimitiveProfile() {
56 return new PrimitiveValueProfile();
57 }
58
59 /**
60 * Returns a {@link ValueProfile} that speculates on the exact class of a value.
61 */
62 public static ValueProfile createClassProfile() {
63 return new ExactClassValueProfile();
64 }
65
66 /**
67 * Returns a {@link ValueProfile} that speculates on the object identity of a value.
68 */
69 public static ValueProfile createIdentityProfile() {
70 return new IdentityValueProfile();
71 }
72
73 }