Mercurial > hg > graal-compiler
diff graal/com.oracle.truffle.api/src/com/oracle/truffle/api/CompilerDirectives.java @ 9244:8f540423a5be
Added two new classes to the Truffle API: CompilerDirectives and CompilerAsserts.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
---|---|
date | Tue, 23 Apr 2013 11:20:53 +0200 |
parents | |
children | f5e58a1eca55 |
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/CompilerDirectives.java Tue Apr 23 11:20:53 2013 +0200 @@ -0,0 +1,80 @@ +/* + * Copyright (c) 2013, 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. + * + * 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; + +import java.util.concurrent.*; + +/** + * Directives that influence the optimizations of the Truffle compiler. All of the operations have + * no effect when executed in the Truffle interpreter. + */ +public class CompilerDirectives { + + private static final double SLOWPATH_PROBABILITY = 0.0001; + + /** + * Directive for the compiler to discontinue compilation at this code position and instead + * insert a transfer to the interpreter. + */ + public static void transferToInterpreter() { + } + + /** + * Directive for the compiler that the given runnable should only be executed in the interpreter + * and ignored in the compiled code. + * + * @param runnable the closure that should only be executed in the interpreter + */ + public static void interpreterOnly(Runnable runnable) { + runnable.run(); + } + + /** + * Directive for the compiler that the given callable should only be executed in the + * interpreter. + * + * @param callable the closure that should only be executed in the interpreter + * @return the result of executing the closure in the interpreter and null in the compiled code + * @throws Exception If the closure throws an exception when executed in the interpreter. + */ + public static <T> T interpreterOnly(Callable<T> callable) throws Exception { + return callable.call(); + } + + /** + * Directive for the compiler that the current path has a very low probability to be executed. + */ + public static void slowpath() { + injectBranchProbability(SLOWPATH_PROBABILITY); + } + + /** + * Injects a probability for the current path into the probability information of the + * immediately preceeding branch instruction. + * + * @param probability the probability value between 0.0 and 1.0 that should be injected + */ + public static void injectBranchProbability(double probability) { + assert probability >= 0.0 && probability <= 1.0; + } +}