Mercurial > hg > truffle
view graal/com.oracle.jvmci.meta/src/com/oracle/jvmci/meta/LocationIdentity.java @ 21643:2081f8f294fe
Fixed some javadoc
author | Tom Rodriguez <tom.rodriguez@oracle.com> |
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date | Mon, 01 Jun 2015 11:49:57 -0700 |
parents | 48c1ebd24120 |
children |
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/* * Copyright (c) 2011, 2012, 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.jvmci.meta; import java.util.*; // JaCoCo Exclude /** * Marker interface for location identities. Apart from the special values {@link #ANY_LOCATION} and * {@link #FINAL_LOCATION}, a different location identity of two memory accesses guarantees that the * two accesses do not interfere. * * Clients of {@link LocationIdentity} must use {@link #equals(Object)}, not {@code ==}, when * comparing two {@link LocationIdentity} values for equality. Likewise, they must not use * {@link IdentityHashMap}s with {@link LocationIdentity} values as keys. */ public abstract class LocationIdentity { /** * Denotes any location. A write to such a location kills all values in a memory map during an * analysis of memory accesses. A read from this location cannot be moved or coalesced with * other reads because its interaction with other reads is not known. */ private static final LocationIdentity ANY_LOCATION = NamedLocationIdentity.mutable("ANY_LOCATION"); /** * Denotes the location of a value that is guaranteed to be unchanging. */ public static final LocationIdentity FINAL_LOCATION = NamedLocationIdentity.immutable("FINAL_LOCATION"); /** * Denotes the location of the length field of a Java array. */ public static final LocationIdentity ARRAY_LENGTH_LOCATION = NamedLocationIdentity.immutable("[].length"); public static LocationIdentity any() { return ANY_LOCATION; } /** * Denotes a location is unchanging in all cases. Not that this is different than the Java * notion of final which only requires definite assignment. */ public abstract boolean isImmutable(); public final boolean isMutable() { return !isImmutable(); } public final boolean isAny() { return this == ANY_LOCATION; } public final boolean isSingle() { return this != ANY_LOCATION; } public final boolean overlaps(LocationIdentity other) { return isAny() || other.isAny() || this.equals(other); } }