Mercurial > hg > truffle
view truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/profiles/ConditionProfile.java @ 22501:a63bda98cfdb
Extract profiles into separate package. Add isProfilingEnabled in TruffleRuntime to disable profiling in the default runtime; Add low overhead profiles for primitives; Add LoopConditionProfile; Profile footprint/threadsafety improvements; Make toString implementations more consistent; Greatly enhanced javadoc documentation for profiles; Deprecate old profiles
author | Christian Humer <christian.humer@oracle.com> |
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date | Wed, 16 Dec 2015 16:38:13 +0100 |
parents | truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/ConditionProfile.java@dc83cc1f94f2 |
children |
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/* * Copyright (c) 2014, 2015, 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.profiles; import com.oracle.truffle.api.CompilerDirectives; import com.oracle.truffle.api.CompilerDirectives.CompilationFinal; import com.oracle.truffle.api.Truffle; /** * <p> * ConditionProfiles are useful to profile the outcome of conditions. * </p> * * <p> * <b> Usage example: </b> * * <pre> * class AbsoluteNode extends Node { * * final ConditionProfile greaterZeroProfile = ConditionProfile.create{Binary,Counting}Profile(); * * void execute(int value) { * if (greaterZeroProfile.profile(value >= 0)) { * return value; * } else { * return -value; * } * } * } * </pre> * * {@inheritDoc} * * @see #createBinaryProfile() * @see #createCountingProfile() * @see LoopConditionProfile */ public abstract class ConditionProfile extends Profile { ConditionProfile() { } public abstract boolean profile(boolean value); /** * Returns a {@link ConditionProfile} that speculates on conditions to be never * <code>true</code> or to be never <code>false</code>. Additionally to a binary profile this * method returns a condition profile that 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 * @see #createBinaryProfile() */ public static ConditionProfile createCountingProfile() { if (Truffle.getRuntime().isProfilingEnabled()) { return Counting.create(); } else { return Disabled.INSTANCE; } } /** * Returns a {@link ConditionProfile} that speculates on conditions to be never * <code>true</code> or to be never <code>false</code>. Condition profiles are intended to be * used as part of if conditions. * * @see ConditionProfile * @see ConditionProfile#createCountingProfile() */ public static ConditionProfile createBinaryProfile() { if (Truffle.getRuntime().isProfilingEnabled()) { return Binary.create(); } else { return Disabled.INSTANCE; } } static final class Disabled extends ConditionProfile { static final ConditionProfile INSTANCE = new Disabled(); @Override protected Object clone() { return INSTANCE; } @Override public boolean profile(boolean value) { return value; } @Override public String toString() { return toStringDisabled(ConditionProfile.class); } } static final class Counting extends ConditionProfile { @CompilationFinal private int trueCount; @CompilationFinal private int falseCount; Counting() { /* package protected constructor */ } @Override public boolean profile(boolean value) { if (CompilerDirectives.inInterpreter()) { if (value) { // local required to guarantee no overflow in multi-threaded environments int t = trueCount; if (t < Integer.MAX_VALUE) { trueCount = t + 1; } } else { // local required to guarantee no overflow in multi-threaded environments int f = falseCount; if (f < Integer.MAX_VALUE) { falseCount = f + 1; } } // no branch probability calculation in the interpreter return value; } else { // use trueCount and falseCount as locals for compilation speed int t = trueCount; int f = falseCount; if (value) { if (t == 0) { CompilerDirectives.transferToInterpreterAndInvalidate(); t = 1; } } else { if (f == 0) { CompilerDirectives.transferToInterpreterAndInvalidate(); f = 1; } } return CompilerDirectives.injectBranchProbability((double) t / (double) (t + f), value); } } int getTrueCount() { return trueCount; } int getFalseCount() { return falseCount; } @Override public String toString() { int t = trueCount; int f = falseCount; return toString(ConditionProfile.class, trueCount == 0 && falseCount == 0, false, // String.format("trueProbability=%s (trueCount=%s, falseCount=%s)", (double) t / (double) (t + f), t, f)); } /* Needed for lazy class loading. */ static ConditionProfile create() { return new Counting(); } } /** * Utility class to speculate on conditions to be never true or to be never false. Condition * profiles are intended to be used as part of if conditions. * * @see ConditionProfile#createBinaryProfile() */ static final class Binary extends ConditionProfile { @CompilationFinal private boolean wasTrue; @CompilationFinal private boolean wasFalse; Binary() { /* package protected constructor */ } @Override public boolean profile(boolean value) { if (value) { if (!wasTrue) { CompilerDirectives.transferToInterpreterAndInvalidate(); wasTrue = true; } return true; } else { if (!wasFalse) { CompilerDirectives.transferToInterpreterAndInvalidate(); wasFalse = true; } return false; } } boolean wasTrue() { return wasTrue; } boolean wasFalse() { return wasFalse; } @Override public String toString() { return String.format("%s(wasTrue=%s, wasFalse=%s)@%x", getClass().getSimpleName(), wasTrue, wasFalse, hashCode()); } /* Needed for lazy class loading. */ static ConditionProfile create() { return new Binary(); } } }