1 /*
2 * Copyright (c) 2009, 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.java;
24
25 import static org.graalvm.compiler.graph.iterators.NodePredicates.isNotA;
26
27 import org.graalvm.compiler.core.common.type.Stamp;
28 import org.graalvm.compiler.core.common.type.StampFactory;
29 import org.graalvm.compiler.core.common.type.StampPair;
30 import org.graalvm.compiler.graph.NodeClass;
31 import org.graalvm.compiler.graph.spi.Canonicalizable;
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.DeoptimizeNode;
36 import org.graalvm.compiler.nodes.PhiNode;
37 import org.graalvm.compiler.nodes.ValueNode;
38 import org.graalvm.compiler.nodes.ValuePhiNode;
39 import org.graalvm.compiler.nodes.spi.UncheckedInterfaceProvider;
40 import org.graalvm.compiler.nodes.spi.Virtualizable;
41 import org.graalvm.compiler.nodes.spi.VirtualizerTool;
42 import org.graalvm.compiler.nodes.type.StampTool;
43 import org.graalvm.compiler.nodes.util.ConstantFoldUtil;
44 import org.graalvm.compiler.nodes.virtual.VirtualInstanceNode;
45 import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
46
47 import jdk.vm.ci.meta.Assumptions;
48 import jdk.vm.ci.meta.DeoptimizationAction;
49 import jdk.vm.ci.meta.DeoptimizationReason;
50 import jdk.vm.ci.meta.JavaConstant;
51 import jdk.vm.ci.meta.MetaAccessProvider;
52 import jdk.vm.ci.meta.ResolvedJavaField;
53
54 /**
55 * The {@code LoadFieldNode} represents a read of a static or instance field.
56 */
57 @NodeInfo(nameTemplate = "LoadField#{p#field/s}")
58 public final class LoadFieldNode extends AccessFieldNode implements Canonicalizable.Unary<ValueNode>, Virtualizable, UncheckedInterfaceProvider {
59
60 public static final NodeClass<LoadFieldNode> TYPE = NodeClass.create(LoadFieldNode.class);
61
62 private final Stamp uncheckedStamp;
63
64 protected LoadFieldNode(StampPair stamp, ValueNode object, ResolvedJavaField field) {
65 super(TYPE, stamp.getTrustedStamp(), object, field);
66 this.uncheckedStamp = stamp.getUncheckedStamp();
67 }
68
69 public static LoadFieldNode create(Assumptions assumptions, ValueNode object, ResolvedJavaField field) {
70 return new LoadFieldNode(StampFactory.forDeclaredType(assumptions, field.getType(), false), object, field);
71 }
72
73 public static LoadFieldNode createOverrideStamp(StampPair stamp, ValueNode object, ResolvedJavaField field) {
74 return new LoadFieldNode(stamp, object, field);
75 }
76
77 @Override
78 public ValueNode getValue() {
79 return object();
80 }
81
82 @Override
83 public ValueNode canonical(CanonicalizerTool tool, ValueNode forObject) {
84 if (tool.allUsagesAvailable() && hasNoUsages() && !isVolatile() && (isStatic() || StampTool.isPointerNonNull(forObject.stamp()))) {
85 return null;
86 }
87 MetaAccessProvider metaAccess = tool.getMetaAccess();
88 if (tool.canonicalizeReads() && metaAccess != null) {
89 ConstantNode constant = asConstant(tool, forObject);
90 if (constant != null) {
91 return constant;
92 }
93 if (tool.allUsagesAvailable()) {
94 PhiNode phi = asPhi(tool, forObject);
95 if (phi != null) {
96 return phi;
97 }
98 }
99 }
100 if (!isStatic() && forObject.isNullConstant()) {
101 return new DeoptimizeNode(DeoptimizationAction.InvalidateReprofile, DeoptimizationReason.NullCheckException);
102 }
103 return this;
104 }
105
106 /**
107 * Gets a constant value for this load if possible.
108 */
109 public ConstantNode asConstant(CanonicalizerTool tool, ValueNode forObject) {
110 if (isStatic()) {
111 return ConstantFoldUtil.tryConstantFold(tool.getConstantFieldProvider(), tool.getConstantReflection(), tool.getMetaAccess(), field(), null);
112 } else if (forObject.isConstant() && !forObject.isNullConstant()) {
113 return ConstantFoldUtil.tryConstantFold(tool.getConstantFieldProvider(), tool.getConstantReflection(), tool.getMetaAccess(), field(), forObject.asJavaConstant());
114 }
115 return null;
116 }
117
118 public ConstantNode asConstant(CanonicalizerTool tool, JavaConstant constant) {
119 return ConstantFoldUtil.tryConstantFold(tool.getConstantFieldProvider(), tool.getConstantReflection(), tool.getMetaAccess(), field(), constant);
120 }
121
122 private PhiNode asPhi(CanonicalizerTool tool, ValueNode forObject) {
123 if (!isStatic() && field.isFinal() && forObject instanceof ValuePhiNode && ((ValuePhiNode) forObject).values().filter(isNotA(ConstantNode.class)).isEmpty()) {
124 PhiNode phi = (PhiNode) forObject;
125 ConstantNode[] constantNodes = new ConstantNode[phi.valueCount()];
126 for (int i = 0; i < phi.valueCount(); i++) {
127 ConstantNode constant = ConstantFoldUtil.tryConstantFold(tool.getConstantFieldProvider(), tool.getConstantReflection(), tool.getMetaAccess(), field(), phi.valueAt(i).asJavaConstant());
128 if (constant == null) {
129 return null;
130 }
131 constantNodes[i] = constant;
132 }
133 return new ValuePhiNode(stamp(), phi.merge(), constantNodes);
134 }
135 return null;
136 }
137
138 @Override
139 public void virtualize(VirtualizerTool tool) {
140 ValueNode alias = tool.getAlias(object());
141 if (alias instanceof VirtualObjectNode) {
142 int fieldIndex = ((VirtualInstanceNode) alias).fieldIndex(field());
143 if (fieldIndex != -1) {
144 tool.replaceWith(tool.getEntry((VirtualObjectNode) alias, fieldIndex));
145 }
146 }
147 }
148
149 @Override
150 public Stamp uncheckedStamp() {
151 return uncheckedStamp;
152 }
153 }