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comparison truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/BranchProfile.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/BranchProfile.java@62aac33db669
children dc83cc1f94f2
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21950:2a5011c7e641 21951:9c8c0937da41
1 /*
2 * Copyright (c) 2013, 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.*;
28 import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
29 import com.oracle.truffle.api.nodes.*;
30
31 /**
32 * Utility class to speculate on branches to be never visited. If the {@link #enter()} method is
33 * invoked first the optimized code is invalidated and the branch where {@link #enter()} is invoked
34 * is enabled for compilation. Otherwise if the {@link #enter()} method was never invoked the branch
35 * will not get compiled.
36 *
37 * All {@code BranchProfile} instances must be held in {@code final} fields for compiler
38 * optimizations to take effect.
39 */
40 public final class BranchProfile extends NodeCloneable {
41
42 @CompilationFinal private boolean visited;
43
44 private BranchProfile() {
45 }
46
47 public void enter() {
48 if (!visited) {
49 CompilerDirectives.transferToInterpreterAndInvalidate();
50 visited = true;
51 }
52 }
53
54 public boolean isVisited() {
55 return visited;
56 }
57
58 public static BranchProfile create() {
59 return new BranchProfile();
60 }
61
62 @Override
63 public String toString() {
64 return String.format("%s(%s)@%x", getClass().getSimpleName(), visited ? "visited" : "not-visited", hashCode());
65 }
66 }