Mercurial > hg > graal-compiler
comparison graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/IdentityValueProfile.java @ 17039:1e542561783e
Truffle: new value profiles prototype.
author | Christian Humer <christian.humer@gmail.com> |
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date | Wed, 03 Sep 2014 14:58:53 +0200 |
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17038:3b3e768a2b92 | 17039:1e542561783e |
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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 java.util.*; | |
28 | |
29 import com.oracle.truffle.api.*; | |
30 import com.oracle.truffle.api.CompilerDirectives.CompilationFinal; | |
31 | |
32 /** | |
33 * Represents a {@link ValueProfile} that speculates on the object identity of a value. | |
34 */ | |
35 public final class IdentityValueProfile extends ValueProfile { | |
36 | |
37 private static final Object UNINITIALIZED = new Object(); | |
38 private static final Object GENERIC = new Object(); | |
39 | |
40 @CompilationFinal protected Object cachedValue = UNINITIALIZED; | |
41 | |
42 IdentityValueProfile() { | |
43 } | |
44 | |
45 @Override | |
46 @SuppressWarnings("unchecked") | |
47 public <T> T profile(T value) { | |
48 if (cachedValue != GENERIC) { | |
49 if (cachedValue == value) { | |
50 return (T) cachedValue; | |
51 } else { | |
52 CompilerDirectives.transferToInterpreterAndInvalidate(); | |
53 if (cachedValue == UNINITIALIZED) { | |
54 cachedValue = value; | |
55 } else { | |
56 cachedValue = GENERIC; | |
57 } | |
58 } | |
59 } | |
60 return value; | |
61 } | |
62 | |
63 public boolean isGeneric() { | |
64 return getCachedValue() == GENERIC; | |
65 } | |
66 | |
67 public boolean isUninitialized() { | |
68 return getCachedValue() == UNINITIALIZED; | |
69 } | |
70 | |
71 public Object getCachedValue() { | |
72 return cachedValue; | |
73 } | |
74 | |
75 @Override | |
76 public String toString() { | |
77 return String.format("%s(%s)@%x", getClass().getSimpleName(), isUninitialized() ? "uninitialized" : (isGeneric() ? "generic" : String.format("@%x", Objects.hash(cachedValue))), hashCode()); | |
78 } | |
79 | |
80 } |