| /* |
| * Copyright (c) 2011, 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package org.graalvm.compiler.nodes.calc; |
| |
| import org.graalvm.compiler.core.common.calc.Condition; |
| import org.graalvm.compiler.core.common.type.AbstractPointerStamp; |
| import org.graalvm.compiler.core.common.type.ObjectStamp; |
| import org.graalvm.compiler.core.common.type.Stamp; |
| import org.graalvm.compiler.graph.NodeClass; |
| import org.graalvm.compiler.graph.spi.Canonicalizable.BinaryCommutative; |
| import org.graalvm.compiler.graph.spi.CanonicalizerTool; |
| import org.graalvm.compiler.nodeinfo.NodeInfo; |
| import org.graalvm.compiler.nodes.LogicConstantNode; |
| import org.graalvm.compiler.nodes.LogicNode; |
| import org.graalvm.compiler.nodes.ValueNode; |
| import org.graalvm.compiler.nodes.extended.LoadHubNode; |
| import org.graalvm.compiler.nodes.extended.LoadMethodNode; |
| import org.graalvm.compiler.nodes.type.StampTool; |
| import org.graalvm.compiler.nodes.util.GraphUtil; |
| |
| import jdk.vm.ci.meta.ResolvedJavaMethod; |
| import jdk.vm.ci.meta.ResolvedJavaType; |
| import jdk.vm.ci.meta.TriState; |
| |
| @NodeInfo(shortName = "==") |
| public class PointerEqualsNode extends CompareNode implements BinaryCommutative<ValueNode> { |
| |
| public static final NodeClass<PointerEqualsNode> TYPE = NodeClass.create(PointerEqualsNode.class); |
| |
| public PointerEqualsNode(ValueNode x, ValueNode y) { |
| this(TYPE, x, y); |
| } |
| |
| public static LogicNode create(ValueNode x, ValueNode y) { |
| LogicNode result = findSynonym(x, y); |
| if (result != null) { |
| return result; |
| } |
| return new PointerEqualsNode(x, y); |
| } |
| |
| protected PointerEqualsNode(NodeClass<? extends PointerEqualsNode> c, ValueNode x, ValueNode y) { |
| super(c, Condition.EQ, false, x, y); |
| assert x.stamp() instanceof AbstractPointerStamp; |
| assert y.stamp() instanceof AbstractPointerStamp; |
| } |
| |
| /** |
| * Determines if this is a comparison used to determine whether dispatching on a receiver could |
| * select a certain method and if so, returns {@code true} if the answer is guaranteed to be |
| * false. Otherwise, returns {@code false}. |
| */ |
| private boolean isAlwaysFailingVirtualDispatchTest(ValueNode forX, ValueNode forY) { |
| if (forY.isConstant()) { |
| if (forX instanceof LoadMethodNode && condition == Condition.EQ) { |
| LoadMethodNode lm = ((LoadMethodNode) forX); |
| if (lm.getMethod().getEncoding().equals(forY.asConstant())) { |
| if (lm.getHub() instanceof LoadHubNode) { |
| ValueNode object = ((LoadHubNode) lm.getHub()).getValue(); |
| ResolvedJavaType type = StampTool.typeOrNull(object); |
| ResolvedJavaType declaringClass = lm.getMethod().getDeclaringClass(); |
| if (type != null && !type.equals(declaringClass) && declaringClass.isAssignableFrom(type)) { |
| ResolvedJavaMethod override = type.resolveMethod(lm.getMethod(), lm.getCallerType()); |
| if (override != null && override != lm.getMethod()) { |
| assert declaringClass.isAssignableFrom(override.getDeclaringClass()); |
| return true; |
| } |
| } |
| } |
| } |
| } |
| } |
| return false; |
| } |
| |
| @Override |
| public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) { |
| LogicNode result = findSynonym(forX, forY); |
| if (result != null) { |
| return result; |
| } |
| if (isAlwaysFailingVirtualDispatchTest(forX, forY)) { |
| return LogicConstantNode.contradiction(); |
| } |
| return super.canonical(tool, forX, forY); |
| } |
| |
| public static LogicNode findSynonym(ValueNode forX, ValueNode forY) { |
| if (GraphUtil.unproxify(forX) == GraphUtil.unproxify(forY)) { |
| return LogicConstantNode.tautology(); |
| } else if (forX.stamp().alwaysDistinct(forY.stamp())) { |
| return LogicConstantNode.contradiction(); |
| } else if (((AbstractPointerStamp) forX.stamp()).alwaysNull()) { |
| return IsNullNode.create(forY); |
| } else if (((AbstractPointerStamp) forY.stamp()).alwaysNull()) { |
| return IsNullNode.create(forX); |
| } else { |
| return null; |
| } |
| } |
| |
| @Override |
| protected CompareNode duplicateModified(ValueNode newX, ValueNode newY) { |
| return new PointerEqualsNode(newX, newY); |
| } |
| |
| @Override |
| public Stamp getSucceedingStampForX(boolean negated) { |
| if (!negated) { |
| Stamp xStamp = getX().stamp(); |
| Stamp newStamp = xStamp.join(getY().stamp()); |
| if (!newStamp.equals(xStamp)) { |
| return newStamp; |
| } |
| } |
| return null; |
| } |
| |
| @Override |
| public Stamp getSucceedingStampForY(boolean negated) { |
| if (!negated) { |
| Stamp yStamp = getY().stamp(); |
| Stamp newStamp = yStamp.join(getX().stamp()); |
| if (!newStamp.equals(yStamp)) { |
| return newStamp; |
| } |
| } |
| return null; |
| } |
| |
| @Override |
| public TriState tryFold(Stamp xStampGeneric, Stamp yStampGeneric) { |
| if (xStampGeneric instanceof ObjectStamp && yStampGeneric instanceof ObjectStamp) { |
| ObjectStamp xStamp = (ObjectStamp) xStampGeneric; |
| ObjectStamp yStamp = (ObjectStamp) yStampGeneric; |
| if (xStamp.alwaysDistinct(yStamp)) { |
| return TriState.FALSE; |
| } else if (xStamp.neverDistinct(yStamp)) { |
| return TriState.TRUE; |
| } |
| } |
| return TriState.UNKNOWN; |
| } |
| } |