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comparison graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/CountingConditionProfile.java @ 16852:3c114b3e08c3

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Truffle: renamed BooleanConditionProfile to BinaryConditionProfile and IntegerConditionProfile to CountingConditionProfile.
author Christian Humer <christian.humer@gmail.com>
date Mon, 18 Aug 2014 19:00:20 +0200
parents graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/IntegerConditionProfile.java@2834af86f398
children fa5e62620593
comparison
equal deleted inserted replaced
16851:2db61eddcb97 16852:3c114b3e08c3
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.*;
28 import com.oracle.truffle.api.CompilerDirectives.*;
29
30 /**
31 * Utility class to speculate on conditions to be never true or to be never false. Additionally to
32 * {@link BinaryConditionProfile} this implementation of {@link ConditionProfile} also counts the
33 * number of times the condition was true and false. This information is reported to the underlying
34 * optimization system using {@link CompilerDirectives#injectBranchProbability(double, boolean)}.
35 * Condition profiles are intended to be used as part of if conditions.
36 *
37 * Example usage:
38 *
39 * <pre>
40 * private final ConditionProfile zero = new IntegerConditionProfile();
41 *
42 * int value = ...;
43 * if (zero.profile(value == 0)) {
44 * return 0;
45 * } else {
46 * return value;
47 * }
48 *
49 * </pre>
50 *
51 * @see ConditionProfile
52 * @see CountingConditionProfile
53 */
54 public class CountingConditionProfile extends ConditionProfile {
55
56 @CompilationFinal private int trueCount;
57 @CompilationFinal private int falseCount;
58
59 @Override
60 public boolean profile(boolean value) {
61 if (value) {
62 if (trueCount == 0) {
63 CompilerDirectives.transferToInterpreterAndInvalidate();
64 }
65 if (CompilerDirectives.inInterpreter()) {
66 trueCount++;
67 }
68 } else {
69 if (falseCount == 0) {
70 CompilerDirectives.transferToInterpreterAndInvalidate();
71 }
72 if (CompilerDirectives.inInterpreter()) {
73 falseCount++;
74 }
75 }
76 return CompilerDirectives.injectBranchProbability((double) trueCount / (double) (trueCount + falseCount), value);
77 }
78
79 public int getTrueCount() {
80 return trueCount;
81 }
82
83 public int getFalseCount() {
84 return falseCount;
85 }
86
87 @Override
88 public String toString() {
89 return String.format("%s(trueCount=%s, falseCount=%s)@%x", getClass().getSimpleName(), trueCount, falseCount, hashCode());
90 }
91 }