Mercurial > hg > truffle
diff truffle/com.oracle.truffle.api.profiles/src/com/oracle/truffle/api/profiles/IntValueProfile.java @ 22503:828c67903db2
Moving profiles into their own project to ensure the core API doesn't reference these utility classes.
author | Jaroslav Tulach <jaroslav.tulach@oracle.com> |
---|---|
date | Thu, 17 Dec 2015 10:01:38 +0100 |
parents | truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/profiles/IntValueProfile.java@a63bda98cfdb |
children | d80a5ff56f51 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/truffle/com.oracle.truffle.api.profiles/src/com/oracle/truffle/api/profiles/IntValueProfile.java Thu Dec 17 10:01:38 2015 +0100 @@ -0,0 +1,158 @@ +/* + * 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; +import com.oracle.truffle.api.Truffle; + +/** + * <p> + * Specialized value profile to capture certain properties of <code>int</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 IntValueProfile profile = IntValueProfile.createIdentityProfile(); + * + * int execute(int input) { + * int profiledValue = profile.profile(input); + * // compiler may know now more about profiledValue + * return profiledValue; + * } + * } + * </pre> + * <p> + * + * + * {@inheritDoc} + * + * @see #createIdentityProfile() + * @see ValueProfile + */ +public abstract class IntValueProfile extends Profile { + + IntValueProfile() { + } + + public abstract int profile(int value); + + /** + * Returns a value profile that profiles the exact value of an <code>int</code>. + * + * @see IntValueProfile + */ + public static IntValueProfile createIdentityProfile() { + if (Truffle.getRuntime().isProfilingEnabled()) { + return Enabled.create(); + } else { + return Disabled.INSTANCE; + } + } + + static final class Enabled extends IntValueProfile { + + private static final byte UNINITIALIZED = 0; + private static final byte SPECIALIZED = 1; + private static final byte GENERIC = 2; + + @CompilationFinal private int cachedValue; + @CompilationFinal private byte state = 0; + + @Override + public int profile(int value) { + byte localState = this.state; + if (localState != GENERIC) { + if (localState == SPECIALIZED) { + int 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; + } + + int getCachedValue() { + return cachedValue; + } + + @Override + public String toString() { + return toString(IntValueProfile.class, isUninitialized(), isGeneric(), // + String.format("value == (int)%s", cachedValue)); + } + + /* Needed for lazy class loading. */ + static IntValueProfile create() { + return new Enabled(); + } + } + + static final class Disabled extends IntValueProfile { + + static final IntValueProfile INSTANCE = new Disabled(); + + @Override + protected Object clone() { + return INSTANCE; + } + + @Override + public int profile(int value) { + return value; + } + + @Override + public String toString() { + return toStringDisabled(IntValueProfile.class); + } + + } + +}