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
24
25 package org.graalvm.compiler.nodes.calc;
26
27 import org.graalvm.compiler.core.common.calc.CanonicalCondition;
28 import org.graalvm.compiler.core.common.type.AbstractObjectStamp;
29 import org.graalvm.compiler.core.common.type.AbstractPointerStamp;
30 import org.graalvm.compiler.core.common.type.ObjectStamp;
31 import org.graalvm.compiler.core.common.type.TypeReference;
32 import org.graalvm.compiler.debug.GraalError;
33 import org.graalvm.compiler.graph.NodeClass;
34 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
35 import org.graalvm.compiler.nodeinfo.NodeInfo;
36 import org.graalvm.compiler.nodes.ConstantNode;
37 import org.graalvm.compiler.nodes.LogicConstantNode;
38 import org.graalvm.compiler.nodes.LogicNode;
39 import org.graalvm.compiler.nodes.NodeView;
40 import org.graalvm.compiler.nodes.ValueNode;
41 import org.graalvm.compiler.nodes.extended.GetClassNode;
42 import org.graalvm.compiler.nodes.java.InstanceOfNode;
43 import org.graalvm.compiler.nodes.spi.Virtualizable;
44 import org.graalvm.compiler.nodes.spi.VirtualizerTool;
45 import org.graalvm.compiler.nodes.virtual.VirtualBoxingNode;
46 import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
47 import org.graalvm.compiler.options.OptionValues;
48
49 import jdk.vm.ci.meta.Constant;
50 import jdk.vm.ci.meta.ConstantReflectionProvider;
51 import jdk.vm.ci.meta.JavaConstant;
52 import jdk.vm.ci.meta.JavaKind;
53 import jdk.vm.ci.meta.MetaAccessProvider;
54 import jdk.vm.ci.meta.ResolvedJavaType;
55
56 @NodeInfo(shortName = "==")
57 public final class ObjectEqualsNode extends PointerEqualsNode implements Virtualizable {
58
59 public static final NodeClass<ObjectEqualsNode> TYPE = NodeClass.create(ObjectEqualsNode.class);
60 private static final ObjectEqualsOp OP = new ObjectEqualsOp();
61
62 public ObjectEqualsNode(ValueNode x, ValueNode y) {
63 super(TYPE, x, y);
64 assert x.stamp(NodeView.DEFAULT) instanceof AbstractObjectStamp;
65 assert y.stamp(NodeView.DEFAULT) instanceof AbstractObjectStamp;
66 }
67
68 public static LogicNode create(ValueNode x, ValueNode y, ConstantReflectionProvider constantReflection, NodeView view) {
69 LogicNode result = CompareNode.tryConstantFold(CanonicalCondition.EQ, x, y, constantReflection, false);
70 if (result != null) {
71 return result;
72 } else {
73 result = findSynonym(x, y, view);
74 if (result != null) {
75 return result;
76 }
77 return new ObjectEqualsNode(x, y);
78 }
79 }
80
81 public static LogicNode create(ConstantReflectionProvider constantReflection, MetaAccessProvider metaAccess, OptionValues options, ValueNode x, ValueNode y, NodeView view) {
82 LogicNode result = OP.canonical(constantReflection, metaAccess, options, null, CanonicalCondition.EQ, false, x, y, view);
83 if (result != null) {
84 return result;
85 }
86 return create(x, y, constantReflection, view);
87 }
88
89 @Override
90 public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
91 NodeView view = NodeView.from(tool);
92 ValueNode value = OP.canonical(tool.getConstantReflection(), tool.getMetaAccess(), tool.getOptions(), tool.smallestCompareWidth(), CanonicalCondition.EQ, false, forX, forY, view);
93 if (value != null) {
94 return value;
95 }
96 return this;
97 }
98
99 public static class ObjectEqualsOp extends PointerEqualsOp {
100
101 @Override
102 protected LogicNode canonicalizeSymmetricConstant(ConstantReflectionProvider constantReflection, MetaAccessProvider metaAccess, OptionValues options, Integer smallestCompareWidth,
103 CanonicalCondition condition, Constant constant, ValueNode nonConstant, boolean mirrored, boolean unorderedIsTrue, NodeView view) {
104 ResolvedJavaType type = constantReflection.asJavaType(constant);
105 if (type != null && nonConstant instanceof GetClassNode) {
106 GetClassNode getClassNode = (GetClassNode) nonConstant;
107 ValueNode object = getClassNode.getObject();
108 assert ((ObjectStamp) object.stamp(view)).nonNull();
109 if (!type.isPrimitive() && (type.isConcrete() || type.isArray())) {
110 return InstanceOfNode.create(TypeReference.createExactTrusted(type), object);
111 }
112 return LogicConstantNode.forBoolean(false);
113 }
114 return super.canonicalizeSymmetricConstant(constantReflection, metaAccess, options, smallestCompareWidth, condition, constant, nonConstant, mirrored, unorderedIsTrue, view);
115 }
116
117 @Override
118 protected CompareNode duplicateModified(ValueNode newX, ValueNode newY, boolean unorderedIsTrue, NodeView view) {
119 if (newX.stamp(view) instanceof ObjectStamp && newY.stamp(view) instanceof ObjectStamp) {
120 return new ObjectEqualsNode(newX, newY);
121 } else if (newX.stamp(view) instanceof AbstractPointerStamp && newY.stamp(view) instanceof AbstractPointerStamp) {
122 return new PointerEqualsNode(newX, newY);
123 }
124 throw GraalError.shouldNotReachHere();
125 }
126 }
127
128 private void virtualizeNonVirtualComparison(VirtualObjectNode virtual, ValueNode other, VirtualizerTool tool) {
129 if (virtual instanceof VirtualBoxingNode && other.isConstant()) {
130 VirtualBoxingNode virtualBoxingNode = (VirtualBoxingNode) virtual;
131 if (virtualBoxingNode.getBoxingKind() == JavaKind.Boolean) {
132 JavaConstant otherUnboxed = tool.getConstantReflectionProvider().unboxPrimitive(other.asJavaConstant());
133 if (otherUnboxed != null && otherUnboxed.getJavaKind() == JavaKind.Boolean) {
134 int expectedValue = otherUnboxed.asBoolean() ? 1 : 0;
135 IntegerEqualsNode equals = new IntegerEqualsNode(virtualBoxingNode.getBoxedValue(tool), ConstantNode.forInt(expectedValue, graph()));
136 tool.addNode(equals);
137 tool.replaceWithValue(equals);
138 } else {
139 tool.replaceWithValue(LogicConstantNode.contradiction(graph()));
140 }
141 }
142 }
143 if (virtual.hasIdentity()) {
144 // one of them is virtual: they can never be the same objects
145 tool.replaceWithValue(LogicConstantNode.contradiction(graph()));
146 }
147 }
148
149 @Override
150 public void virtualize(VirtualizerTool tool) {
151 ValueNode xAlias = tool.getAlias(getX());
152 ValueNode yAlias = tool.getAlias(getY());
153
154 VirtualObjectNode xVirtual = xAlias instanceof VirtualObjectNode ? (VirtualObjectNode) xAlias : null;
155 VirtualObjectNode yVirtual = yAlias instanceof VirtualObjectNode ? (VirtualObjectNode) yAlias : null;
156
157 if (xVirtual != null && yVirtual == null) {
158 virtualizeNonVirtualComparison(xVirtual, yAlias, tool);
159 } else if (xVirtual == null && yVirtual != null) {
160 virtualizeNonVirtualComparison(yVirtual, xAlias, tool);
161 } else if (xVirtual != null && yVirtual != null) {
162 if (xVirtual.hasIdentity() ^ yVirtual.hasIdentity()) {
163 /*
164 * One of the two objects has identity, the other doesn't. In code, this looks like
165 * "Integer.valueOf(a) == new Integer(b)", which is always false.
166 *
167 * In other words: an object created via valueOf can never be equal to one created
168 * by new in the same compilation unit.
169 */
170 tool.replaceWithValue(LogicConstantNode.contradiction(graph()));
171 } else if (!xVirtual.hasIdentity() && !yVirtual.hasIdentity()) {
172 ResolvedJavaType type = xVirtual.type();
173 if (type.equals(yVirtual.type())) {
174 MetaAccessProvider metaAccess = tool.getMetaAccessProvider();
175 if (type.equals(metaAccess.lookupJavaType(Integer.class)) || type.equals(metaAccess.lookupJavaType(Long.class))) {
176 // both are virtual without identity: check contents
177 assert xVirtual.entryCount() == 1 && yVirtual.entryCount() == 1;
178 assert xVirtual.entryKind(0).getStackKind() == JavaKind.Int || xVirtual.entryKind(0) == JavaKind.Long;
179 IntegerEqualsNode equals = new IntegerEqualsNode(tool.getEntry(xVirtual, 0), tool.getEntry(yVirtual, 0));
180 tool.addNode(equals);
181 tool.replaceWithValue(equals);
182 }
183 }
184 } else {
185 // both are virtual with identity: check if they refer to the same object
186 tool.replaceWithValue(LogicConstantNode.forBoolean(xVirtual == yVirtual, graph()));
187 }
188 }
189 }
190 }