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