| /* |
| * Copyright (c) 2009, 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.type.AbstractPointerStamp; |
| import org.graalvm.compiler.core.common.type.ObjectStamp; |
| import org.graalvm.compiler.core.common.type.Stamp; |
| import org.graalvm.compiler.core.common.type.StampFactory; |
| import org.graalvm.compiler.graph.NodeClass; |
| import org.graalvm.compiler.graph.spi.CanonicalizerTool; |
| import org.graalvm.compiler.nodeinfo.NodeCycles; |
| import org.graalvm.compiler.nodeinfo.NodeInfo; |
| import org.graalvm.compiler.nodes.LogicConstantNode; |
| import org.graalvm.compiler.nodes.LogicNode; |
| import org.graalvm.compiler.nodes.PiNode; |
| import org.graalvm.compiler.nodes.UnaryOpLogicNode; |
| import org.graalvm.compiler.nodes.ValueNode; |
| import org.graalvm.compiler.nodes.spi.LIRLowerable; |
| import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool; |
| import org.graalvm.compiler.nodes.spi.PiPushable; |
| import org.graalvm.compiler.nodes.spi.Virtualizable; |
| import org.graalvm.compiler.nodes.spi.VirtualizerTool; |
| import org.graalvm.compiler.nodes.type.StampTool; |
| |
| import jdk.vm.ci.meta.TriState; |
| |
| /** |
| * An IsNullNode will be true if the supplied value is null, and false if it is non-null. |
| */ |
| @NodeInfo(cycles = NodeCycles.CYCLES_2) |
| public final class IsNullNode extends UnaryOpLogicNode implements LIRLowerable, Virtualizable, PiPushable { |
| |
| public static final NodeClass<IsNullNode> TYPE = NodeClass.create(IsNullNode.class); |
| |
| public IsNullNode(ValueNode object) { |
| super(TYPE, object); |
| assert object != null; |
| } |
| |
| public static LogicNode create(ValueNode forValue) { |
| LogicNode result = tryCanonicalize(forValue); |
| return result == null ? new IsNullNode(forValue) : result; |
| } |
| |
| public static LogicNode tryCanonicalize(ValueNode forValue) { |
| if (StampTool.isPointerAlwaysNull(forValue)) { |
| return LogicConstantNode.tautology(); |
| } else if (StampTool.isPointerNonNull(forValue)) { |
| return LogicConstantNode.contradiction(); |
| } |
| return null; |
| } |
| |
| @Override |
| public void generate(NodeLIRBuilderTool gen) { |
| // Nothing to do. |
| } |
| |
| @Override |
| public boolean verify() { |
| assertTrue(getValue() != null, "is null input must not be null"); |
| assertTrue(getValue().stamp() instanceof AbstractPointerStamp, "input must be a pointer not %s", getValue().stamp()); |
| return super.verify(); |
| } |
| |
| @Override |
| public ValueNode canonical(CanonicalizerTool tool, ValueNode forValue) { |
| LogicNode result = tryCanonicalize(forValue); |
| return result == null ? this : result; |
| } |
| |
| @Override |
| public void virtualize(VirtualizerTool tool) { |
| ValueNode alias = tool.getAlias(getValue()); |
| TriState fold = tryFold(alias.stamp()); |
| if (fold != TriState.UNKNOWN) { |
| tool.replaceWithValue(LogicConstantNode.forBoolean(fold.isTrue(), graph())); |
| } |
| } |
| |
| @Override |
| public boolean push(PiNode parent) { |
| if (parent.stamp() instanceof ObjectStamp && parent.object().stamp() instanceof ObjectStamp) { |
| ObjectStamp piStamp = (ObjectStamp) parent.stamp(); |
| ObjectStamp piValueStamp = (ObjectStamp) parent.object().stamp(); |
| if (piStamp.nonNull() == piValueStamp.nonNull() && piStamp.alwaysNull() == piValueStamp.alwaysNull()) { |
| replaceFirstInput(parent, parent.object()); |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| @NodeIntrinsic |
| public static native IsNullNode isNull(Object object); |
| |
| @Override |
| public Stamp getSucceedingStampForValue(boolean negated) { |
| return negated ? getValue().stamp().join(StampFactory.objectNonNull()) : StampFactory.alwaysNull(); |
| } |
| |
| @Override |
| public TriState tryFold(Stamp valueStamp) { |
| if (valueStamp instanceof ObjectStamp) { |
| ObjectStamp objectStamp = (ObjectStamp) valueStamp; |
| if (objectStamp.alwaysNull()) { |
| return TriState.TRUE; |
| } else if (objectStamp.nonNull()) { |
| return TriState.FALSE; |
| } |
| } |
| return TriState.UNKNOWN; |
| } |
| } |