Mercurial > hg > graal-jvmci-8
view graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/calc/ObjectEqualsNode.java @ 16212:51c7c676d41a
implement Canonicalizable.Binary in the BinaryOpLogicNode hierarchy
author | Lukas Stadler <lukas.stadler@oracle.com> |
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date | Wed, 25 Jun 2014 11:21:44 +0200 |
parents | df6f2365b153 |
children | 5d468add216f |
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/* * Copyright (c) 2011, 2014, 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 com.oracle.graal.nodes.calc; import com.oracle.graal.api.meta.*; import com.oracle.graal.compiler.common.calc.*; import com.oracle.graal.graph.*; import com.oracle.graal.graph.spi.*; import com.oracle.graal.nodes.*; import com.oracle.graal.nodes.spi.*; import com.oracle.graal.nodes.type.*; import com.oracle.graal.nodes.util.*; @NodeInfo(shortName = "==") public final class ObjectEqualsNode extends CompareNode implements Virtualizable { /** * Constructs a new object equality comparison node. * * @param x the instruction producing the first input to the instruction * @param y the instruction that produces the second input to this instruction */ public ObjectEqualsNode(ValueNode x, ValueNode y) { super(x, y); assert x.getKind() == Kind.Object; assert y.getKind() == Kind.Object; } @Override public Condition condition() { return Condition.EQ; } @Override public boolean unorderedIsTrue() { return false; } @Override public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) { ValueNode result = super.canonical(tool, forX, forY); if (result != this) { return result; } if (GraphUtil.unproxify(forX) == GraphUtil.unproxify(forY)) { return LogicConstantNode.tautology(); } else if (forX.stamp().alwaysDistinct(forY.stamp())) { return LogicConstantNode.contradiction(); } if (StampTool.isObjectAlwaysNull(forX)) { return new IsNullNode(forY); } else if (StampTool.isObjectAlwaysNull(forY)) { return new IsNullNode(forX); } return this; } private void virtualizeNonVirtualComparison(State state, ValueNode other, VirtualizerTool tool) { if (!state.getVirtualObject().hasIdentity() && state.getVirtualObject().entryKind(0) == Kind.Boolean) { if (other.isConstant()) { Constant otherUnboxed = tool.getConstantReflectionProvider().unboxPrimitive(other.asConstant()); if (otherUnboxed != null && otherUnboxed.getKind() == Kind.Boolean) { int expectedValue = otherUnboxed.asBoolean() ? 1 : 0; IntegerEqualsNode equals = new IntegerEqualsNode(state.getEntry(0), ConstantNode.forInt(expectedValue, graph())); tool.addNode(equals); tool.replaceWithValue(equals); } else { tool.replaceWithValue(LogicConstantNode.contradiction(graph())); } } } else { // one of them is virtual: they can never be the same objects tool.replaceWithValue(LogicConstantNode.contradiction(graph())); } } @Override public void virtualize(VirtualizerTool tool) { State stateX = tool.getObjectState(getX()); State stateY = tool.getObjectState(getY()); boolean xVirtual = stateX != null && stateX.getState() == EscapeState.Virtual; boolean yVirtual = stateY != null && stateY.getState() == EscapeState.Virtual; if (xVirtual && !yVirtual) { virtualizeNonVirtualComparison(stateX, stateY != null ? stateY.getMaterializedValue() : getY(), tool); } else if (!xVirtual && yVirtual) { virtualizeNonVirtualComparison(stateY, stateX != null ? stateX.getMaterializedValue() : getX(), tool); } else if (xVirtual && yVirtual) { boolean xIdentity = stateX.getVirtualObject().hasIdentity(); boolean yIdentity = stateY.getVirtualObject().hasIdentity(); if (xIdentity ^ yIdentity) { /* * One of the two objects has identity, the other doesn't. In code, this looks like * "Integer.valueOf(a) == new Integer(b)", which is always false. * * In other words: an object created via valueOf can never be equal to one created * by new in the same compilation unit. */ tool.replaceWithValue(LogicConstantNode.contradiction(graph())); } else if (!xIdentity && !yIdentity) { // both are virtual without identity: check contents assert stateX.getVirtualObject().entryCount() == 1 && stateY.getVirtualObject().entryCount() == 1; assert stateX.getVirtualObject().type().equals(stateY.getVirtualObject().type()); assert stateX.getVirtualObject().entryKind(0).getStackKind() == Kind.Int || stateX.getVirtualObject().entryKind(0) == Kind.Long; IntegerEqualsNode equals = new IntegerEqualsNode(stateX.getEntry(0), stateY.getEntry(0)); tool.addNode(equals); tool.replaceWithValue(equals); } else { // both are virtual with identity: check if they refer to the same object tool.replaceWithValue(LogicConstantNode.forBoolean(stateX == stateY, graph())); } } } @Override protected CompareNode duplicateModified(ValueNode newX, ValueNode newY) { return new ObjectEqualsNode(newX, newY); } }