001/*
002 *  This file is part of the Jikes RVM project (http://jikesrvm.org).
003 *
004 *  This file is licensed to You under the Eclipse Public License (EPL);
005 *  You may not use this file except in compliance with the License. You
006 *  may obtain a copy of the License at
007 *
008 *      http://www.opensource.org/licenses/eclipse-1.0.php
009 *
010 *  See the COPYRIGHT.txt file distributed with this work for information
011 *  regarding copyright ownership.
012 */
013package org.vmmagic;
014
015import java.lang.annotation.Retention;
016import java.lang.annotation.RetentionPolicy;
017import java.lang.annotation.Target;
018import java.lang.annotation.ElementType;
019import java.lang.annotation.Inherited;
020
021/**
022 * An intrinsic method is a method that is built in (that is, intrinsic) to the compiler
023 * rather than part of a class library. Intrinsic methods are an escape hatch to provide
024 * "magic" that is inexpressible int the Java programming language. A compiler intrinsic
025 * will usually generate a specific code sequence that is inlined and optimized as part
026 * by the compiler. Unless an intrinsic method is expected to be executed in a non-intrinsic
027 * aware compiler, the body of the method should be empty.
028 *
029 * <p>If the Intrinsic annotation is applied to a method then then the method is a compiler
030 * intrinsic. If the Intrinsic annotation is applied to a class then all the methods of
031 * the class AND all subclasses are intrinsic.</p>
032 *
033 * <p>NOTE: At the current time the Intrinsic annotation is only used for documentation
034 * purposes but in the near future it is expected that the semantics of the annotation will
035 * be enforced by the compiler.</p>
036 */
037@Retention(RetentionPolicy.RUNTIME)
038@Target({ElementType.TYPE,ElementType.METHOD})
039@Inherited
040public @interface Intrinsic { }