Mercurial > hg > graal-jvmci-8
view graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/CountingConditionProfile.java @ 21468:99942eac9c6d
Introducing TruffleVM - a central place to invoke code in any registered TruffleLanguage.
author | Jaroslav Tulach <jaroslav.tulach@oracle.com> |
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date | Fri, 22 May 2015 13:41:10 +0200 |
parents | fa5e62620593 |
children | b1530a6cce8c |
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/* * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.oracle.truffle.api.utilities; import com.oracle.truffle.api.*; import com.oracle.truffle.api.CompilerDirectives.*; /** * Utility class to speculate on conditions to be never true or to be never false. Additionally to * {@link BinaryConditionProfile} this implementation of {@link ConditionProfile} also counts the * number of times the condition was true and false. This information is reported to the underlying * optimization system using {@link CompilerDirectives#injectBranchProbability(double, boolean)}. * Condition profiles are intended to be used as part of if conditions. * * @see ConditionProfile#createCountingProfile() */ public final class CountingConditionProfile extends ConditionProfile { @CompilationFinal private int trueCount; @CompilationFinal private int falseCount; CountingConditionProfile() { /* package protected constructor */ } @Override public boolean profile(boolean value) { if (value) { if (trueCount == 0) { CompilerDirectives.transferToInterpreterAndInvalidate(); } if (CompilerDirectives.inInterpreter()) { trueCount++; } } else { if (falseCount == 0) { CompilerDirectives.transferToInterpreterAndInvalidate(); } if (CompilerDirectives.inInterpreter()) { falseCount++; } } return CompilerDirectives.injectBranchProbability((double) trueCount / (double) (trueCount + falseCount), value); } public int getTrueCount() { return trueCount; } public int getFalseCount() { return falseCount; } @Override public String toString() { return String.format("%s(trueCount=%s, falseCount=%s)@%x", getClass().getSimpleName(), trueCount, falseCount, hashCode()); } }