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 24 25 package org.graalvm.compiler.nodes; 26 27 import java.util.EnumMap; 28 29 import jdk.internal.vm.compiler.collections.EconomicSet; 30 import jdk.internal.vm.compiler.collections.Equivalence; 31 import jdk.internal.vm.compiler.word.LocationIdentity; 32 33 import jdk.vm.ci.meta.JavaKind; 34 import jdk.vm.ci.meta.JavaKind.FormatWithToString; 35 36 /** 37 * A {@link LocationIdentity} with a name. 38 */ 39 public class NamedLocationIdentity extends LocationIdentity implements FormatWithToString { 40 41 /** 42 * Map for asserting all {@link NamedLocationIdentity} instances have a unique name. 43 */ 44 static class DB { 45 private static final EconomicSet<String> map = EconomicSet.create(Equivalence.DEFAULT); 46 47 static boolean checkUnique(String name) { 48 if (!map.add(name)) { 49 throw new AssertionError("identity " + name + " already exists"); 50 } 51 return true; 52 } 53 } 54 55 /** 56 * Denotes the location of a value that is guaranteed to be unchanging. 57 */ 58 public static final LocationIdentity FINAL_LOCATION = NamedLocationIdentity.immutable("FINAL_LOCATION"); 59 60 /** 61 * Denotes the location of the length field of a Java array. 62 */ 63 public static final LocationIdentity ARRAY_LENGTH_LOCATION = NamedLocationIdentity.immutable("[].length"); 64 65 /** 66 * Denotes an off-heap address. 67 */ 68 public static final LocationIdentity OFF_HEAP_LOCATION = NamedLocationIdentity.mutable("OFF_HEAP_LOCATION"); 69 70 private final String name; 71 private final boolean immutable; 72 73 protected NamedLocationIdentity(String name, boolean immutable) { 74 this.name = name; 75 this.immutable = immutable; 76 assert DB.checkUnique(name); 77 } 78 79 /** 80 * Creates a named unique location identity for read and write operations against mutable 81 * memory. 82 * 83 * @param name the name of the new location identity 84 */ 85 public static NamedLocationIdentity mutable(String name) { 86 return create(name, false); 87 } 88 89 /** 90 * Creates a named unique location identity for read operations against immutable memory. 91 * Immutable memory will never have a visible write in the graph, which is more restrictive than 92 * Java final. 93 * 94 * @param name the name of the new location identity 95 */ 96 public static NamedLocationIdentity immutable(String name) { 97 return create(name, true); 98 } 99 100 /** 101 * Creates a named unique location identity for read and write operations. 102 * 103 * @param name the name of the new location identity 104 * @param immutable true if the location is immutable 105 */ 106 private static NamedLocationIdentity create(String name, boolean immutable) { 107 return new NamedLocationIdentity(name, immutable); 108 } 109 110 @Override 111 public boolean isImmutable() { 112 return immutable; 113 } 114 115 @Override 116 public String toString() { 117 return name + (isImmutable() ? ":final" : ""); 118 } 119 120 /** 121 * Returns the named location identity for an array of the given element kind. Array accesses of 122 * the same kind must have the same location identity unless an alias analysis guarantees that 123 * two distinct arrays are accessed. 124 */ 125 public static LocationIdentity getArrayLocation(JavaKind elementKind) { 126 return ARRAY_LOCATIONS.get(elementKind); 127 } 128 129 private static final EnumMap<JavaKind, LocationIdentity> ARRAY_LOCATIONS = initArrayLocations(); 130 131 private static EnumMap<JavaKind, LocationIdentity> initArrayLocations() { 132 EnumMap<JavaKind, LocationIdentity> result = new EnumMap<>(JavaKind.class); 133 for (JavaKind kind : JavaKind.values()) { 134 result.put(kind, NamedLocationIdentity.mutable("Array: " + kind.getJavaName())); 135 } 136 return result; 137 } 138 }