1 /* 2 * Copyright (c) 2011, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package org.graalvm.compiler.nodes; 24 25 import java.util.EnumMap; 26 27 import org.graalvm.util.Equivalence; 28 import org.graalvm.word.LocationIdentity; 29 import org.graalvm.util.EconomicSet; 30 31 import jdk.vm.ci.meta.JavaKind; 32 import jdk.vm.ci.meta.JavaKind.FormatWithToString; 33 34 /** 35 * A {@link LocationIdentity} with a name. 36 */ 37 public class NamedLocationIdentity extends LocationIdentity implements FormatWithToString { 38 39 /** 40 * Map for asserting all {@link NamedLocationIdentity} instances have a unique name. 41 */ 42 static class DB { 43 private static final EconomicSet<String> map = EconomicSet.create(Equivalence.DEFAULT); 44 45 static boolean checkUnique(String name) { 46 if (!map.add(name)) { 47 throw new AssertionError("identity " + name + " already exists"); 48 } 49 return true; 50 } 51 } 52 53 /** 54 * Denotes the location of a value that is guaranteed to be unchanging. 55 */ 56 public static final LocationIdentity FINAL_LOCATION = NamedLocationIdentity.immutable("FINAL_LOCATION"); 57 58 /** 59 * Denotes the location of the length field of a Java array. 60 */ 61 public static final LocationIdentity ARRAY_LENGTH_LOCATION = NamedLocationIdentity.immutable("[].length"); 62 63 private final String name; 64 private final boolean immutable; 65 66 protected NamedLocationIdentity(String name, boolean immutable) { 67 this.name = name; 68 this.immutable = immutable; 69 assert DB.checkUnique(name); 70 } 71 72 /** 73 * Creates a named unique location identity for read and write operations against mutable 74 * memory. 75 * 76 * @param name the name of the new location identity 77 */ 78 public static NamedLocationIdentity mutable(String name) { 79 return create(name, false); 80 } 81 82 /** 83 * Creates a named unique location identity for read operations against immutable memory. 84 * Immutable memory will never have a visible write in the graph, which is more restictive than 85 * Java final. 86 * 87 * @param name the name of the new location identity 88 */ 89 public static NamedLocationIdentity immutable(String name) { 90 return create(name, true); 91 } 92 93 /** 94 * Creates a named unique location identity for read and write operations. 95 * 96 * @param name the name of the new location identity 97 * @param immutable true if the location is immutable 98 */ 99 private static NamedLocationIdentity create(String name, boolean immutable) { 100 return new NamedLocationIdentity(name, immutable); 101 } 102 103 @Override 104 public boolean isImmutable() { 105 return immutable; 106 } 107 108 @Override 109 public String toString() { 110 return name + (isImmutable() ? ":final" : ""); 111 } 112 113 /** 114 * Returns the named location identity for an array of the given element kind. Array accesses of 115 * the same kind must have the same location identity unless an alias analysis guarantees that 116 * two distinct arrays are accessed. 117 */ 118 public static LocationIdentity getArrayLocation(JavaKind elementKind) { 119 return ARRAY_LOCATIONS.get(elementKind); 120 } 121 122 private static final EnumMap<JavaKind, LocationIdentity> ARRAY_LOCATIONS = initArrayLocations(); 123 124 private static EnumMap<JavaKind, LocationIdentity> initArrayLocations() { 125 EnumMap<JavaKind, LocationIdentity> result = new EnumMap<>(JavaKind.class); 126 for (JavaKind kind : JavaKind.values()) { 127 result.put(kind, NamedLocationIdentity.mutable("Array: " + kind.getJavaName())); 128 } 129 return result; 130 } 131 }