1 /*
2 * Copyright (c) 2011, 2015, 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.calc;
24
25 import org.graalvm.compiler.core.common.calc.Condition;
26 import org.graalvm.compiler.core.common.type.AbstractObjectStamp;
27 import org.graalvm.compiler.core.common.type.AbstractPointerStamp;
28 import org.graalvm.compiler.core.common.type.ObjectStamp;
29 import org.graalvm.compiler.core.common.type.TypeReference;
30 import org.graalvm.compiler.debug.GraalError;
31 import org.graalvm.compiler.graph.NodeClass;
32 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
33 import org.graalvm.compiler.nodeinfo.NodeInfo;
34 import org.graalvm.compiler.nodes.ConstantNode;
35 import org.graalvm.compiler.nodes.LogicConstantNode;
36 import org.graalvm.compiler.nodes.LogicNode;
37 import org.graalvm.compiler.nodes.ValueNode;
38 import org.graalvm.compiler.nodes.extended.GetClassNode;
39 import org.graalvm.compiler.nodes.java.InstanceOfNode;
40 import org.graalvm.compiler.nodes.spi.Virtualizable;
41 import org.graalvm.compiler.nodes.spi.VirtualizerTool;
42 import org.graalvm.compiler.nodes.virtual.VirtualBoxingNode;
43 import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
44
45 import jdk.vm.ci.meta.Constant;
46 import jdk.vm.ci.meta.ConstantReflectionProvider;
47 import jdk.vm.ci.meta.JavaConstant;
48 import jdk.vm.ci.meta.JavaKind;
49 import jdk.vm.ci.meta.MetaAccessProvider;
50 import jdk.vm.ci.meta.ResolvedJavaType;
51
52 @NodeInfo(shortName = "==")
53 public final class ObjectEqualsNode extends PointerEqualsNode implements Virtualizable {
54
55 public static final NodeClass<ObjectEqualsNode> TYPE = NodeClass.create(ObjectEqualsNode.class);
56
57 public ObjectEqualsNode(ValueNode x, ValueNode y) {
58 super(TYPE, x, y);
59 assert x.stamp() instanceof AbstractObjectStamp;
60 assert y.stamp() instanceof AbstractObjectStamp;
61 }
62
63 public static LogicNode create(ValueNode x, ValueNode y, ConstantReflectionProvider constantReflection) {
64 LogicNode result = CompareNode.tryConstantFold(Condition.EQ, x, y, constantReflection, false);
65 if (result != null) {
66 return result;
67 } else {
68 result = findSynonym(x, y);
69 if (result != null) {
70 return result;
71 }
72 return new ObjectEqualsNode(x, y);
73 }
74 }
75
76 @Override
77 protected ValueNode canonicalizeSymmetricConstant(CanonicalizerTool tool, Constant constant, ValueNode nonConstant, boolean mirrored) {
78 ResolvedJavaType type = tool.getConstantReflection().asJavaType(constant);
79 if (type != null && nonConstant instanceof GetClassNode) {
80 GetClassNode getClassNode = (GetClassNode) nonConstant;
81 ValueNode object = getClassNode.getObject();
82 assert ((ObjectStamp) object.stamp()).nonNull();
83 if (!type.isPrimitive() && (type.isConcrete() || type.isArray())) {
84 return InstanceOfNode.create(TypeReference.createExactTrusted(type), object);
85 }
86 return LogicConstantNode.forBoolean(false);
87 }
88 return super.canonicalizeSymmetricConstant(tool, constant, nonConstant, mirrored);
89 }
90
91 private void virtualizeNonVirtualComparison(VirtualObjectNode virtual, ValueNode other, VirtualizerTool tool) {
92 if (virtual instanceof VirtualBoxingNode && other.isConstant()) {
93 VirtualBoxingNode virtualBoxingNode = (VirtualBoxingNode) virtual;
94 if (virtualBoxingNode.getBoxingKind() == JavaKind.Boolean) {
95 JavaConstant otherUnboxed = tool.getConstantReflectionProvider().unboxPrimitive(other.asJavaConstant());
96 if (otherUnboxed != null && otherUnboxed.getJavaKind() == JavaKind.Boolean) {
97 int expectedValue = otherUnboxed.asBoolean() ? 1 : 0;
98 IntegerEqualsNode equals = new IntegerEqualsNode(virtualBoxingNode.getBoxedValue(tool), ConstantNode.forInt(expectedValue, graph()));
99 tool.addNode(equals);
100 tool.replaceWithValue(equals);
101 } else {
102 tool.replaceWithValue(LogicConstantNode.contradiction(graph()));
103 }
104 }
105 }
106 if (virtual.hasIdentity()) {
107 // one of them is virtual: they can never be the same objects
108 tool.replaceWithValue(LogicConstantNode.contradiction(graph()));
109 }
110 }
111
112 @Override
113 public void virtualize(VirtualizerTool tool) {
114 ValueNode xAlias = tool.getAlias(getX());
115 ValueNode yAlias = tool.getAlias(getY());
116
117 VirtualObjectNode xVirtual = xAlias instanceof VirtualObjectNode ? (VirtualObjectNode) xAlias : null;
118 VirtualObjectNode yVirtual = yAlias instanceof VirtualObjectNode ? (VirtualObjectNode) yAlias : null;
119
120 if (xVirtual != null && yVirtual == null) {
121 virtualizeNonVirtualComparison(xVirtual, yAlias, tool);
122 } else if (xVirtual == null && yVirtual != null) {
123 virtualizeNonVirtualComparison(yVirtual, xAlias, tool);
124 } else if (xVirtual != null && yVirtual != null) {
125 if (xVirtual.hasIdentity() ^ yVirtual.hasIdentity()) {
126 /*
127 * One of the two objects has identity, the other doesn't. In code, this looks like
128 * "Integer.valueOf(a) == new Integer(b)", which is always false.
129 *
130 * In other words: an object created via valueOf can never be equal to one created
131 * by new in the same compilation unit.
132 */
133 tool.replaceWithValue(LogicConstantNode.contradiction(graph()));
134 } else if (!xVirtual.hasIdentity() && !yVirtual.hasIdentity()) {
135 ResolvedJavaType type = xVirtual.type();
136 if (type.equals(yVirtual.type())) {
137 MetaAccessProvider metaAccess = tool.getMetaAccessProvider();
138 if (type.equals(metaAccess.lookupJavaType(Integer.class)) || type.equals(metaAccess.lookupJavaType(Long.class))) {
139 // both are virtual without identity: check contents
140 assert xVirtual.entryCount() == 1 && yVirtual.entryCount() == 1;
141 assert xVirtual.entryKind(0).getStackKind() == JavaKind.Int || xVirtual.entryKind(0) == JavaKind.Long;
142 IntegerEqualsNode equals = new IntegerEqualsNode(tool.getEntry(xVirtual, 0), tool.getEntry(yVirtual, 0));
143 tool.addNode(equals);
144 tool.replaceWithValue(equals);
145 }
146 }
147 } else {
148 // both are virtual with identity: check if they refer to the same object
149 tool.replaceWithValue(LogicConstantNode.forBoolean(xVirtual == yVirtual, graph()));
150 }
151 }
152 }
153
154 @Override
155 protected CompareNode duplicateModified(ValueNode newX, ValueNode newY) {
156 if (newX.stamp() instanceof ObjectStamp && newY.stamp() instanceof ObjectStamp) {
157 return new ObjectEqualsNode(newX, newY);
158 } else if (newX.stamp() instanceof AbstractPointerStamp && newY.stamp() instanceof AbstractPointerStamp) {
159 return new PointerEqualsNode(newX, newY);
160 }
161 throw GraalError.shouldNotReachHere();
162 }
163 }