Mercurial > hg > graal-compiler
diff graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/IdentityValueProfile.java @ 17039:1e542561783e
Truffle: new value profiles prototype.
author | Christian Humer <christian.humer@gmail.com> |
---|---|
date | Wed, 03 Sep 2014 14:58:53 +0200 |
parents | |
children |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/IdentityValueProfile.java Wed Sep 03 14:58:53 2014 +0200 @@ -0,0 +1,80 @@ +/* + * 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 java.util.*; + +import com.oracle.truffle.api.*; +import com.oracle.truffle.api.CompilerDirectives.CompilationFinal; + +/** + * Represents a {@link ValueProfile} that speculates on the object identity of a value. + */ +public final class IdentityValueProfile extends ValueProfile { + + private static final Object UNINITIALIZED = new Object(); + private static final Object GENERIC = new Object(); + + @CompilationFinal protected Object cachedValue = UNINITIALIZED; + + IdentityValueProfile() { + } + + @Override + @SuppressWarnings("unchecked") + public <T> T profile(T value) { + if (cachedValue != GENERIC) { + if (cachedValue == value) { + return (T) cachedValue; + } else { + CompilerDirectives.transferToInterpreterAndInvalidate(); + if (cachedValue == UNINITIALIZED) { + cachedValue = value; + } else { + cachedValue = GENERIC; + } + } + } + return value; + } + + public boolean isGeneric() { + return getCachedValue() == GENERIC; + } + + public boolean isUninitialized() { + return getCachedValue() == UNINITIALIZED; + } + + public Object getCachedValue() { + return cachedValue; + } + + @Override + public String toString() { + return String.format("%s(%s)@%x", getClass().getSimpleName(), isUninitialized() ? "uninitialized" : (isGeneric() ? "generic" : String.format("@%x", Objects.hash(cachedValue))), hashCode()); + } + +}