1 /*
2 * Copyright (c) 2013, 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.replacements;
24
25 import static org.graalvm.compiler.core.common.GraalOptions.SnippetCounters;
26 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_IGNORED;
27 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_IGNORED;
28 import static org.graalvm.compiler.replacements.SnippetTemplate.DEFAULT_REPLACER;
29
30 import java.lang.reflect.Field;
31 import java.util.Arrays;
32
33 import org.graalvm.compiler.api.replacements.Fold;
34 import org.graalvm.compiler.api.replacements.Snippet;
35 import org.graalvm.compiler.api.replacements.Snippet.ConstantParameter;
36 import org.graalvm.compiler.api.replacements.SnippetReflectionProvider;
37 import org.graalvm.compiler.core.common.LocationIdentity;
38 import org.graalvm.compiler.core.common.type.StampFactory;
39 import org.graalvm.compiler.debug.GraalError;
40 import org.graalvm.compiler.graph.NodeClass;
41 import org.graalvm.compiler.nodeinfo.NodeInfo;
42 import org.graalvm.compiler.nodes.FixedWithNextNode;
43 import org.graalvm.compiler.nodes.NamedLocationIdentity;
44 import org.graalvm.compiler.nodes.StructuredGraph;
45 import org.graalvm.compiler.nodes.ValueNode;
46 import org.graalvm.compiler.nodes.spi.Lowerable;
47 import org.graalvm.compiler.nodes.spi.LoweringTool;
48 import org.graalvm.compiler.phases.util.Providers;
49 import org.graalvm.compiler.replacements.SnippetTemplate.AbstractTemplates;
50 import org.graalvm.compiler.replacements.SnippetTemplate.Arguments;
51 import org.graalvm.compiler.replacements.SnippetTemplate.SnippetInfo;
52 import org.graalvm.compiler.word.ObjectAccess;
53
54 import jdk.vm.ci.code.TargetDescription;
55 import sun.misc.Unsafe;
56
57 /**
58 * This node can be used to add a counter to the code that will estimate the dynamic number of calls
59 * by adding an increment to the compiled code. This should of course only be used for
60 * debugging/testing purposes.
61 *
62 * A unique counter will be created for each unique name passed to the constructor. Depending on the
63 * value of withContext, the name of the root method is added to the counter's name.
64 */
65 @NodeInfo(cycles = CYCLES_IGNORED, size = SIZE_IGNORED)
66 public class SnippetCounterNode extends FixedWithNextNode implements Lowerable {
67
68 public static final NodeClass<SnippetCounterNode> TYPE = NodeClass.create(SnippetCounterNode.class);
69
70 @Input protected ValueNode increment;
71
72 protected final SnippetCounter counter;
73
74 public SnippetCounterNode(SnippetCounter counter, ValueNode increment) {
75 super(TYPE, StampFactory.forVoid());
76 this.counter = counter;
77 this.increment = increment;
78 }
79
80 public SnippetCounter getCounter() {
81 return counter;
82 }
83
84 public ValueNode getIncrement() {
85 return increment;
86 }
87
88 @NodeIntrinsic
89 public static native void add(@ConstantNodeParameter SnippetCounter counter, int increment);
90
91 public static void increment(@ConstantNodeParameter SnippetCounter counter) {
92 add(counter, 1);
93 }
94
95 @Override
96 public void lower(LoweringTool tool) {
97 if (graph().getGuardsStage().areFrameStatesAtDeopts()) {
98 SnippetCounterSnippets.Templates templates = tool.getReplacements().getSnippetTemplateCache(SnippetCounterSnippets.Templates.class);
99 templates.lower(this, tool);
100 }
101 }
102
103 /**
104 * When {@link #SnippetCounters} are enabled make sure {@link #SNIPPET_COUNTER_LOCATION} is part
105 * of the private locations.
106 *
107 * @param privateLocations
108 * @return a copy of privateLocations with any needed locations added
109 */
110 public static LocationIdentity[] addSnippetCounters(LocationIdentity[] privateLocations) {
111 if (SnippetCounters.getValue()) {
112 for (LocationIdentity location : privateLocations) {
113 if (location.equals(SNIPPET_COUNTER_LOCATION)) {
114 return privateLocations;
115 }
116 }
117 LocationIdentity[] result = Arrays.copyOf(privateLocations, privateLocations.length + 1);
118 result[result.length - 1] = SnippetCounterNode.SNIPPET_COUNTER_LOCATION;
119 return result;
120 }
121 return privateLocations;
122 }
123
124 /**
125 * We do not want to use the {@link LocationIdentity} of the {@link SnippetCounter#value} field,
126 * so that the usage in snippets is always possible. If a method accesses the counter via the
127 * field and the snippet, the result might not be correct though.
128 */
129 public static final LocationIdentity SNIPPET_COUNTER_LOCATION = NamedLocationIdentity.mutable("SnippetCounter");
130
131 static class SnippetCounterSnippets implements Snippets {
132
133 @Fold
134 static int countOffset() {
135 try {
136 return (int) UNSAFE.objectFieldOffset(SnippetCounter.class.getDeclaredField("value"));
137 } catch (Exception e) {
138 throw new GraalError(e);
139 }
140 }
141
142 @Snippet
143 public static void add(@ConstantParameter SnippetCounter counter, int increment) {
144 long loadedValue = ObjectAccess.readLong(counter, countOffset(), SNIPPET_COUNTER_LOCATION);
145 ObjectAccess.writeLong(counter, countOffset(), loadedValue + increment, SNIPPET_COUNTER_LOCATION);
146 }
147
148 public static class Templates extends AbstractTemplates {
149
150 private final SnippetInfo add = snippet(SnippetCounterSnippets.class, "add", SNIPPET_COUNTER_LOCATION);
151
152 Templates(Providers providers, SnippetReflectionProvider snippetReflection, TargetDescription target) {
153 super(providers, snippetReflection, target);
154 }
155
156 public void lower(SnippetCounterNode counter, LoweringTool tool) {
157 StructuredGraph graph = counter.graph();
158 Arguments args = new Arguments(add, graph.getGuardsStage(), tool.getLoweringStage());
159 args.addConst("counter", counter.getCounter());
160 args.add("increment", counter.getIncrement());
161
162 template(args).instantiate(providers.getMetaAccess(), counter, DEFAULT_REPLACER, args);
163 }
164 }
165 }
166
167 private static final Unsafe UNSAFE = initUnsafe();
168
169 private static Unsafe initUnsafe() {
170 try {
171 return Unsafe.getUnsafe();
172 } catch (SecurityException se) {
173 try {
174 Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");
175 theUnsafe.setAccessible(true);
176 return (Unsafe) theUnsafe.get(Unsafe.class);
177 } catch (Exception e) {
178 throw new RuntimeException("exception while trying to get Unsafe", e);
179 }
180 }
181 }
182 }