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.StructuredGraph;
41 import org.graalvm.compiler.nodes.ValueNode;
42 import org.graalvm.compiler.nodes.extended.GetClassNode;
43 import org.graalvm.compiler.nodes.java.InstanceOfNode;
44 import org.graalvm.compiler.nodes.spi.Virtualizable;
45 import org.graalvm.compiler.nodes.spi.VirtualizerTool;
46 import org.graalvm.compiler.nodes.virtual.VirtualBoxingNode;
47 import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
48 import org.graalvm.compiler.options.OptionValues;
49
50 import jdk.vm.ci.meta.Constant;
51 import jdk.vm.ci.meta.ConstantReflectionProvider;
52 import jdk.vm.ci.meta.JavaConstant;
53 import jdk.vm.ci.meta.JavaKind;
54 import jdk.vm.ci.meta.MetaAccessProvider;
55 import jdk.vm.ci.meta.ResolvedJavaType;
56
57 @NodeInfo(shortName = "==")
58 public final class ObjectEqualsNode extends PointerEqualsNode implements Virtualizable {
59
60 public static final NodeClass<ObjectEqualsNode> TYPE = NodeClass.create(ObjectEqualsNode.class);
61 private static final ObjectEqualsOp OP = new ObjectEqualsOp();
62
63 public ObjectEqualsNode(ValueNode x, ValueNode y) {
64 super(TYPE, x, y);
65 assert x.stamp(NodeView.DEFAULT) instanceof AbstractObjectStamp;
66 assert y.stamp(NodeView.DEFAULT) instanceof AbstractObjectStamp;
67 }
68
69 public static LogicNode create(ValueNode x, ValueNode y, ConstantReflectionProvider constantReflection, NodeView view) {
70 LogicNode result = CompareNode.tryConstantFold(CanonicalCondition.EQ, x, y, constantReflection, false);
71 if (result != null) {
72 return result;
73 } else {
74 result = findSynonym(x, y, view);
75 if (result != null) {
76 return result;
77 }
78 return new ObjectEqualsNode(x, y);
79 }
80 }
81
82 public static LogicNode create(ConstantReflectionProvider constantReflection, MetaAccessProvider metaAccess, OptionValues options, ValueNode x, ValueNode y, NodeView view) {
83 LogicNode result = OP.canonical(constantReflection, metaAccess, options, null, CanonicalCondition.EQ, false, x, y, view);
84 if (result != null) {
85 return result;
86 }
87 return create(x, y, constantReflection, view);
88 }
89
90 @Override
91 public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
92 NodeView view = NodeView.from(tool);
93 ValueNode value = OP.canonical(tool.getConstantReflection(), tool.getMetaAccess(), tool.getOptions(), tool.smallestCompareWidth(), CanonicalCondition.EQ, false, forX, forY, view);
94 if (value != null) {
95 return value;
96 }
97 return this;
98 }
99
100 public static class ObjectEqualsOp extends PointerEqualsOp {
101
102 @Override
103 protected LogicNode canonicalizeSymmetricConstant(ConstantReflectionProvider constantReflection, MetaAccessProvider metaAccess, OptionValues options, Integer smallestCompareWidth,
104 CanonicalCondition condition, Constant constant, ValueNode nonConstant, boolean mirrored, boolean unorderedIsTrue, NodeView view) {
105 ResolvedJavaType type = constantReflection.asJavaType(constant);
106 if (type != null && nonConstant instanceof GetClassNode) {
107 GetClassNode getClassNode = (GetClassNode) nonConstant;
108 ValueNode object = getClassNode.getObject();
109 assert ((ObjectStamp) object.stamp(view)).nonNull();
110 if (!type.isPrimitive() && (type.isConcrete() || type.isArray())) {
111 return InstanceOfNode.create(TypeReference.createExactTrusted(type), object);
112 }
113 return LogicConstantNode.forBoolean(false);
114 }
115 return super.canonicalizeSymmetricConstant(constantReflection, metaAccess, options, smallestCompareWidth, condition, constant, nonConstant, mirrored, unorderedIsTrue, view);
116 }
117
118 @Override
119 protected CompareNode duplicateModified(ValueNode newX, ValueNode newY, boolean unorderedIsTrue, NodeView view) {
120 if (newX.stamp(view) instanceof ObjectStamp && newY.stamp(view) instanceof ObjectStamp) {
121 return new ObjectEqualsNode(newX, newY);
122 } else if (newX.stamp(view) instanceof AbstractPointerStamp && newY.stamp(view) instanceof AbstractPointerStamp) {
123 return new PointerEqualsNode(newX, newY);
124 }
125 throw GraalError.shouldNotReachHere();
126 }
127 }
128
129 private static LogicNode virtualizeNonVirtualComparison(VirtualObjectNode virtual, ValueNode other, StructuredGraph graph, VirtualizerTool tool) {
130 if (virtual instanceof VirtualBoxingNode && other.isConstant()) {
131 VirtualBoxingNode virtualBoxingNode = (VirtualBoxingNode) virtual;
132 if (virtualBoxingNode.getBoxingKind() == JavaKind.Boolean) {
133 JavaConstant otherUnboxed = tool.getConstantReflection().unboxPrimitive(other.asJavaConstant());
134 if (otherUnboxed != null && otherUnboxed.getJavaKind() == JavaKind.Boolean) {
135 int expectedValue = otherUnboxed.asBoolean() ? 1 : 0;
136 return new IntegerEqualsNode(virtualBoxingNode.getBoxedValue(tool), ConstantNode.forInt(expectedValue, graph));
137 } else {
138 return LogicConstantNode.contradiction(graph);
139 }
140 }
141 }
142 if (virtual.hasIdentity()) {
143 // one of them is virtual: they can never be the same objects
144 return LogicConstantNode.contradiction(graph);
145 }
146 return null;
147 }
148
149 public static LogicNode virtualizeComparison(ValueNode x, ValueNode y, StructuredGraph graph, VirtualizerTool tool) {
150 ValueNode xAlias = tool.getAlias(x);
151 ValueNode yAlias = tool.getAlias(y);
152
153 VirtualObjectNode xVirtual = xAlias instanceof VirtualObjectNode ? (VirtualObjectNode) xAlias : null;
154 VirtualObjectNode yVirtual = yAlias instanceof VirtualObjectNode ? (VirtualObjectNode) yAlias : null;
155
156 if (xVirtual != null && yVirtual == null) {
157 return virtualizeNonVirtualComparison(xVirtual, yAlias, graph, tool);
158 } else if (xVirtual == null && yVirtual != null) {
159 return virtualizeNonVirtualComparison(yVirtual, xAlias, graph, tool);
160 } else if (xVirtual != null && yVirtual != null) {
161 if (xVirtual.hasIdentity() ^ yVirtual.hasIdentity()) {
162 /*
163 * One of the two objects has identity, the other doesn't. In code, this looks like
164 * "Integer.valueOf(a) == new Integer(b)", which is always false.
165 *
166 * In other words: an object created via valueOf can never be equal to one created
167 * by new in the same compilation unit.
168 */
169 return LogicConstantNode.contradiction(graph);
170 } else if (!xVirtual.hasIdentity() && !yVirtual.hasIdentity()) {
171 ResolvedJavaType type = xVirtual.type();
172 if (type.equals(yVirtual.type())) {
173 MetaAccessProvider metaAccess = tool.getMetaAccess();
174 if (type.equals(metaAccess.lookupJavaType(Integer.class)) || type.equals(metaAccess.lookupJavaType(Long.class))) {
175 // both are virtual without identity: check contents
176 assert xVirtual.entryCount() == 1 && yVirtual.entryCount() == 1;
177 assert xVirtual.entryKind(0).getStackKind() == JavaKind.Int || xVirtual.entryKind(0) == JavaKind.Long;
178 return new IntegerEqualsNode(tool.getEntry(xVirtual, 0), tool.getEntry(yVirtual, 0));
179 }
180 }
181 } else {
182 // both are virtual with identity: check if they refer to the same object
183 return LogicConstantNode.forBoolean(xVirtual == yVirtual, graph);
184 }
185 }
186 return null;
187 }
188
189 @Override
190 public void virtualize(VirtualizerTool tool) {
191 ValueNode node = virtualizeComparison(getX(), getY(), graph(), tool);
192 if (node == null) {
193 return;
194 }
195 if (!node.isAlive()) {
196 tool.addNode(node);
197 }
198 tool.replaceWithValue(node);
199 }
200 }