Mercurial > hg > truffle
view truffle/com.oracle.truffle.api.profiles/src/com/oracle/truffle/api/profiles/LongValueProfile.java @ 22504:d80a5ff56f51
Storing the profiling enabled information in a static field; checking it only once; shielding against missing method in the TruffleRuntime interface
author | Jaroslav Tulach <jaroslav.tulach@oracle.com> |
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date | Thu, 17 Dec 2015 13:45:37 +0100 |
parents | 828c67903db2 |
children |
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/* * Copyright (c) 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; /** * <p> * Specialized value profile to capture certain properties of <code>long</code> runtime values. * Value profiles require a runtime check in their initialized state to verify their profiled * assumption. Value profiles are limited to capture monomorphic profiles only. This means that if * two or more values are profiled within a single profile then the profile has no effect. If the * value assumption is invalidated in compiled code then it is invalidated. * </p> * * <p> * <b> Usage example: </b> * * <pre> * class SampleNode extends Node { * * final LongValueProfile profile = LongValueProfile.createIdentityProfile(); * * long execute(long input) { * long profiledValue = profile.profile(input); * // compiler may know now more about profiledValue * return profiledValue; * } * } * </pre> * <p> * * {@inheritDoc} * * @see #createIdentityProfile() * @see ValueProfile */ public abstract class LongValueProfile extends Profile { LongValueProfile() { } public abstract long profile(long value); /** * Returns a value profile that profiles the exact value of an <code>long</code>. * * @see LongValueProfile */ public static LongValueProfile createIdentityProfile() { if (Profile.isProfilingEnabled()) { return Enabled.create(); } else { return Disabled.INSTANCE; } } static final class Enabled extends LongValueProfile { private static final byte UNINITIALIZED = 0; private static final byte SPECIALIZED = 1; private static final byte GENERIC = 2; @CompilationFinal private long cachedValue; @CompilationFinal private byte state = 0; @Override public long profile(long value) { byte localState = this.state; if (localState != GENERIC) { if (localState == SPECIALIZED) { long v = cachedValue; if (v == value) { return v; } } CompilerDirectives.transferToInterpreterAndInvalidate(); if (localState == UNINITIALIZED) { this.cachedValue = value; this.state = SPECIALIZED; } else { this.state = GENERIC; } } return value; } boolean isGeneric() { return state == GENERIC; } boolean isUninitialized() { return state == UNINITIALIZED; } long getCachedValue() { return cachedValue; } @Override public String toString() { return toString(LongValueProfile.class, state == UNINITIALIZED, state == GENERIC, // String.format("value == (long)%s", cachedValue)); } /* Needed for lazy class loading. */ static LongValueProfile create() { return new Enabled(); } } static final class Disabled extends LongValueProfile { static final LongValueProfile INSTANCE = new Disabled(); @Override protected Object clone() { return INSTANCE; } @Override public long profile(long value) { return value; } @Override public String toString() { return toStringDisabled(LongValueProfile.class); } } }