1 /*
2 * Copyright (c) 2012, 2018, 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;
26
27 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_0;
28 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_0;
29
30 import org.graalvm.compiler.core.common.type.AbstractPointerStamp;
31 import org.graalvm.compiler.core.common.type.ObjectStamp;
32 import org.graalvm.compiler.core.common.type.Stamp;
33 import org.graalvm.compiler.core.common.type.StampFactory;
34 import org.graalvm.compiler.core.common.type.TypeReference;
35 import org.graalvm.compiler.debug.DebugContext;
36 import org.graalvm.compiler.graph.IterableNodeType;
37 import org.graalvm.compiler.graph.Node;
38 import org.graalvm.compiler.graph.NodeClass;
39 import org.graalvm.compiler.graph.spi.Canonicalizable;
40 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
41 import org.graalvm.compiler.nodeinfo.NodeInfo;
42 import org.graalvm.compiler.nodes.extended.GuardingNode;
43 import org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderContext;
44 import org.graalvm.compiler.nodes.memory.ReadNode;
45 import org.graalvm.compiler.nodes.spi.LIRLowerable;
46 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
47 import org.graalvm.compiler.nodes.spi.ValueProxy;
48 import org.graalvm.compiler.nodes.spi.Virtualizable;
49 import org.graalvm.compiler.nodes.spi.VirtualizerTool;
50 import org.graalvm.compiler.nodes.type.StampTool;
51 import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
52
53 import jdk.vm.ci.meta.JavaKind;
54 import jdk.vm.ci.meta.ResolvedJavaMethod;
55 import jdk.vm.ci.meta.ResolvedJavaType;
56
57 //JaCoCo Exclude
58
59 /**
60 * A node that changes the type of its input, usually narrowing it. For example, a {@link PiNode}
61 * refines the type of a receiver during type-guarded inlining to be the type tested by the guard.
62 *
63 * In contrast to a {@link GuardedValueNode}, a {@link PiNode} is useless as soon as the type of its
64 * input is as narrow or narrower than the {@link PiNode}'s type. The {@link PiNode}, and therefore
65 * also the scheduling restriction enforced by the guard, will go away.
66 */
67 @NodeInfo(cycles = CYCLES_0, size = SIZE_0)
68 public class PiNode extends FloatingGuardedNode implements LIRLowerable, Virtualizable, IterableNodeType, Canonicalizable, ValueProxy {
69
70 public static final NodeClass<PiNode> TYPE = NodeClass.create(PiNode.class);
71 @Input ValueNode object;
72 protected Stamp piStamp;
73
74 public ValueNode object() {
75 return object;
76 }
77
78 protected PiNode(NodeClass<? extends PiNode> c, ValueNode object, Stamp stamp, GuardingNode guard) {
79 super(c, stamp, guard);
80 this.object = object;
81 this.piStamp = stamp;
82 assert piStamp.isCompatible(object.stamp(NodeView.DEFAULT)) : "Object stamp not compatible to piStamp";
83 inferStamp();
84 }
85
86 public PiNode(ValueNode object, Stamp stamp) {
87 this(object, stamp, null);
88 }
89
90 public PiNode(ValueNode object, Stamp stamp, ValueNode guard) {
91 this(TYPE, object, stamp, (GuardingNode) guard);
92 }
93
94 public PiNode(ValueNode object, ValueNode guard) {
95 this(object, AbstractPointerStamp.pointerNonNull(object.stamp(NodeView.DEFAULT)), guard);
96 }
97
98 public PiNode(ValueNode object, ResolvedJavaType toType, boolean exactType, boolean nonNull) {
99 this(object, StampFactory.object(exactType ? TypeReference.createExactTrusted(toType) : TypeReference.createWithoutAssumptions(toType),
100 nonNull || StampTool.isPointerNonNull(object.stamp(NodeView.DEFAULT))));
101 }
102
103 public static ValueNode create(ValueNode object, Stamp stamp) {
104 ValueNode value = canonical(object, stamp, null, null);
105 if (value != null) {
106 return value;
107 }
108 return new PiNode(object, stamp);
109 }
110
111 public static ValueNode create(ValueNode object, Stamp stamp, ValueNode guard) {
112 ValueNode value = canonical(object, stamp, (GuardingNode) guard, null);
113 if (value != null) {
114 return value;
115 }
116 return new PiNode(object, stamp, guard);
117 }
118
119 public static ValueNode create(ValueNode object, ValueNode guard) {
120 Stamp stamp = AbstractPointerStamp.pointerNonNull(object.stamp(NodeView.DEFAULT));
121 ValueNode value = canonical(object, stamp, (GuardingNode) guard, null);
122 if (value != null) {
123 return value;
124 }
125 return new PiNode(object, stamp, guard);
126 }
127
128 @SuppressWarnings("unused")
129 public static boolean intrinsify(GraphBuilderContext b, ResolvedJavaMethod method, ValueNode object, ValueNode guard) {
130 Stamp stamp = AbstractPointerStamp.pointerNonNull(object.stamp(NodeView.DEFAULT));
131 ValueNode value = canonical(object, stamp, (GuardingNode) guard, null);
132 if (value == null) {
133 value = new PiNode(object, stamp, guard);
134 }
135 b.push(JavaKind.Object, b.append(value));
136 return true;
137 }
138
139 @SuppressWarnings("unused")
140 public static boolean intrinsify(GraphBuilderContext b, ResolvedJavaMethod method, ValueNode object, ResolvedJavaType toType, boolean exactType, boolean nonNull) {
141 Stamp stamp = StampFactory.object(exactType ? TypeReference.createExactTrusted(toType) : TypeReference.createWithoutAssumptions(toType),
142 nonNull || StampTool.isPointerNonNull(object.stamp(NodeView.DEFAULT)));
143 ValueNode value = canonical(object, stamp, null, null);
144 if (value == null) {
145 value = new PiNode(object, stamp);
146 }
147 b.push(JavaKind.Object, b.append(value));
148 return true;
149 }
150
151 public final Stamp piStamp() {
152 return piStamp;
153 }
154
155 public void strengthenPiStamp(Stamp newPiStamp) {
156 assert this.piStamp.join(newPiStamp).equals(newPiStamp) : "stamp can only improve";
157 this.piStamp = newPiStamp;
158 }
159
160 @Override
161 public void generate(NodeLIRBuilderTool generator) {
162 if (generator.hasOperand(object)) {
163 generator.setResult(this, generator.operand(object));
164 }
165 }
166
167 @Override
168 public boolean inferStamp() {
169 return updateStamp(computeStamp());
170 }
171
172 private Stamp computeStamp() {
173 return piStamp.improveWith(object().stamp(NodeView.DEFAULT));
174 }
175
176 @Override
177 public void virtualize(VirtualizerTool tool) {
178 ValueNode alias = tool.getAlias(object());
179 if (alias instanceof VirtualObjectNode) {
180 VirtualObjectNode virtual = (VirtualObjectNode) alias;
181 ResolvedJavaType type = StampTool.typeOrNull(this, tool.getMetaAccess());
182 if (type != null && type.isAssignableFrom(virtual.type())) {
183 tool.replaceWithVirtual(virtual);
184 } else {
185 tool.getDebug().log(DebugContext.INFO_LEVEL, "could not virtualize Pi because of type mismatch: %s %s vs %s", this, type, virtual.type());
186 }
187 }
188 }
189
190 public static ValueNode canonical(ValueNode object, Stamp stamp, GuardingNode guard, PiNode self) {
191 // Use most up to date stamp.
192 Stamp computedStamp = stamp.improveWith(object.stamp(NodeView.DEFAULT));
193
194 // The pi node does not give any additional information => skip it.
195 if (computedStamp.equals(object.stamp(NodeView.DEFAULT))) {
196 return object;
197 }
198
199 if (guard == null) {
200 // Try to merge the pi node with a load node.
201 if (object instanceof ReadNode && !object.hasMoreThanOneUsage()) {
202 ReadNode readNode = (ReadNode) object;
203 readNode.setStamp(readNode.stamp(NodeView.DEFAULT).improveWith(stamp));
204 return readNode;
205 }
206 } else {
207 for (Node n : guard.asNode().usages()) {
208 if (n instanceof PiNode && n != self) {
209 PiNode otherPi = (PiNode) n;
210 assert otherPi.guard == guard;
211 if (object == otherPi.object() && computedStamp.equals(otherPi.stamp(NodeView.DEFAULT))) {
212 /*
213 * Two PiNodes with the same guard and same result, so return the one with
214 * the more precise piStamp.
215 */
216 Stamp newStamp = stamp.join(otherPi.piStamp);
217 if (newStamp.equals(otherPi.piStamp)) {
218 return otherPi;
219 }
220 }
221 }
222 }
223 }
224 return null;
225 }
226
227 @Override
228 public Node canonical(CanonicalizerTool tool) {
229 Node value = canonical(object(), piStamp(), getGuard(), this);
230 if (value != null) {
231 return value;
232 }
233 return this;
234 }
235
236 @Override
237 public ValueNode getOriginalNode() {
238 return object;
239 }
240
241 public void setOriginalNode(ValueNode newNode) {
242 this.updateUsages(object, newNode);
243 this.object = newNode;
244 assert piStamp.isCompatible(object.stamp(NodeView.DEFAULT)) : "New object stamp not compatible to piStamp";
245 }
246
247 /**
248 * Casts an object to have an exact, non-null stamp representing {@link Class}.
249 */
250 public static Class<?> asNonNullClass(Object object) {
251 return asNonNullClassIntrinsic(object, Class.class, true, true);
252 }
253
254 /**
255 * Casts an object to have an exact, non-null stamp representing {@link Class}.
256 */
257 public static Class<?> asNonNullObject(Object object) {
258 return asNonNullClassIntrinsic(object, Object.class, false, true);
259 }
260
261 @NodeIntrinsic(PiNode.class)
262 private static native Class<?> asNonNullClassIntrinsic(Object object, @ConstantNodeParameter Class<?> toType, @ConstantNodeParameter boolean exactType, @ConstantNodeParameter boolean nonNull);
263
264 /**
265 * Changes the stamp of an object inside a snippet to be the stamp of the node replaced by the
266 * snippet.
267 */
268 @NodeIntrinsic(PiNode.Placeholder.class)
269 public static native Object piCastToSnippetReplaceeStamp(Object object);
270
271 /**
272 * Changes the stamp of an object and ensures the newly stamped value is non-null and does not
273 * float above a given guard.
274 */
275 @NodeIntrinsic
276 public static native Object piCastNonNull(Object object, GuardingNode guard);
277
278 /**
279 * Changes the stamp of an object and ensures the newly stamped value is non-null and does not
280 * float above a given guard.
281 */
282 @NodeIntrinsic
283 public static native Class<?> piCastNonNullClass(Class<?> type, GuardingNode guard);
284
285 /**
286 * Changes the stamp of an object to represent a given type and to indicate that the object is
287 * not null.
288 */
289 public static Object piCastNonNull(Object object, @ConstantNodeParameter ResolvedJavaType toType) {
290 return piCast(object, toType, false, true);
291 }
292
293 @NodeIntrinsic
294 public static native Object piCast(Object object, @ConstantNodeParameter ResolvedJavaType toType, @ConstantNodeParameter boolean exactType, @ConstantNodeParameter boolean nonNull);
295
296 /**
297 * A placeholder node in a snippet that will be replaced with a {@link PiNode} when the snippet
298 * is instantiated.
299 */
300 @NodeInfo(cycles = CYCLES_0, size = SIZE_0)
301 public static class Placeholder extends FloatingGuardedNode {
302
303 public static final NodeClass<Placeholder> TYPE = NodeClass.create(Placeholder.class);
304 @Input ValueNode object;
305
306 public ValueNode object() {
307 return object;
308 }
309
310 protected Placeholder(NodeClass<? extends Placeholder> c, ValueNode object) {
311 super(c, PlaceholderStamp.SINGLETON, null);
312 this.object = object;
313 }
314
315 public Placeholder(ValueNode object) {
316 this(TYPE, object);
317 }
318
319 /**
320 * Replaces this node with a {@link PiNode} during snippet instantiation.
321 *
322 * @param snippetReplaceeStamp the stamp of the node being replace by the snippet
323 */
324 public void makeReplacement(Stamp snippetReplaceeStamp) {
325 ValueNode value = graph().maybeAddOrUnique(PiNode.create(object(), snippetReplaceeStamp, null));
326 replaceAndDelete(value);
327 }
328 }
329
330 /**
331 * A stamp for {@link Placeholder} nodes which are only used in snippets. It is replaced by an
332 * actual stamp when the snippet is instantiated.
333 */
334 public static final class PlaceholderStamp extends ObjectStamp {
335 private static final PlaceholderStamp SINGLETON = new PlaceholderStamp();
336
337 public static PlaceholderStamp singleton() {
338 return SINGLETON;
339 }
340
341 private PlaceholderStamp() {
342 super(null, false, false, false);
343 }
344
345 @Override
346 public int hashCode() {
347 return System.identityHashCode(this);
348 }
349
350 @Override
351 public boolean equals(Object obj) {
352 return this == obj;
353 }
354
355 @Override
356 public String toString() {
357 return "PlaceholderStamp";
358 }
359 }
360 }