| /* |
| * Copyright (c) 2013, 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.word; |
| |
| import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_1; |
| import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1; |
| |
| import org.graalvm.compiler.core.common.LIRKind; |
| import org.graalvm.compiler.core.common.type.AbstractPointerStamp; |
| import org.graalvm.compiler.core.common.type.IntegerStamp; |
| 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.Node; |
| import org.graalvm.compiler.graph.NodeClass; |
| import org.graalvm.compiler.graph.spi.Canonicalizable; |
| import org.graalvm.compiler.graph.spi.CanonicalizerTool; |
| import org.graalvm.compiler.lir.ConstantValue; |
| import org.graalvm.compiler.nodeinfo.NodeInfo; |
| import org.graalvm.compiler.nodes.ConstantNode; |
| import org.graalvm.compiler.nodes.FixedWithNextNode; |
| import org.graalvm.compiler.nodes.NodeView; |
| import org.graalvm.compiler.nodes.ValueNode; |
| import org.graalvm.compiler.nodes.spi.LIRLowerable; |
| import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool; |
| |
| import jdk.vm.ci.meta.AllocatableValue; |
| import jdk.vm.ci.meta.JavaConstant; |
| import jdk.vm.ci.meta.JavaKind; |
| import jdk.vm.ci.meta.Value; |
| import jdk.vm.ci.meta.ValueKind; |
| |
| /** |
| * Casts between Word and Object exposed by the {@link Word#fromAddress}, |
| * {@link Word#objectToTrackedPointer}, {@link Word#objectToUntrackedPointer} and |
| * {@link Word#toObject()} operations. It has an impact on the pointer maps for the GC, so it must |
| * not be scheduled or optimized away. |
| */ |
| @NodeInfo(cycles = CYCLES_1, size = SIZE_1) |
| public final class WordCastNode extends FixedWithNextNode implements LIRLowerable, Canonicalizable { |
| |
| public static final NodeClass<WordCastNode> TYPE = NodeClass.create(WordCastNode.class); |
| |
| @Input ValueNode input; |
| private final boolean trackedPointer; |
| |
| public static WordCastNode wordToObject(ValueNode input, JavaKind wordKind) { |
| assert input.getStackKind() == wordKind; |
| return new WordCastNode(objectStampFor(input), input); |
| } |
| |
| public static WordCastNode wordToObjectNonNull(ValueNode input, JavaKind wordKind) { |
| assert input.getStackKind() == wordKind; |
| return new WordCastNode(StampFactory.objectNonNull(), input); |
| } |
| |
| public static WordCastNode addressToWord(ValueNode input, JavaKind wordKind) { |
| assert input.stamp(NodeView.DEFAULT) instanceof AbstractPointerStamp; |
| return new WordCastNode(StampFactory.forKind(wordKind), input); |
| } |
| |
| public static WordCastNode objectToTrackedPointer(ValueNode input, JavaKind wordKind) { |
| assert input.stamp(NodeView.DEFAULT) instanceof ObjectStamp; |
| return new WordCastNode(StampFactory.forKind(wordKind), input); |
| } |
| |
| public static WordCastNode objectToUntrackedPointer(ValueNode input, JavaKind wordKind) { |
| assert input.stamp(NodeView.DEFAULT) instanceof ObjectStamp; |
| return new WordCastNode(StampFactory.forKind(wordKind), input, false); |
| } |
| |
| private WordCastNode(Stamp stamp, ValueNode input) { |
| this(stamp, input, true); |
| } |
| |
| protected WordCastNode(Stamp stamp, ValueNode input, boolean trackedPointer) { |
| super(TYPE, stamp); |
| this.input = input; |
| this.trackedPointer = trackedPointer; |
| } |
| |
| public ValueNode getInput() { |
| return input; |
| } |
| |
| private static boolean isZeroConstant(ValueNode value) { |
| JavaConstant constant = value.asJavaConstant(); |
| return constant.getJavaKind().isNumericInteger() && constant.asLong() == 0; |
| } |
| |
| private static Stamp objectStampFor(ValueNode input) { |
| Stamp inputStamp = input.stamp(NodeView.DEFAULT); |
| if (inputStamp instanceof AbstractPointerStamp) { |
| AbstractPointerStamp pointerStamp = (AbstractPointerStamp) inputStamp; |
| if (pointerStamp.alwaysNull()) { |
| return StampFactory.alwaysNull(); |
| } else if (pointerStamp.nonNull()) { |
| return StampFactory.objectNonNull(); |
| } |
| } else if (inputStamp instanceof IntegerStamp && !((IntegerStamp) inputStamp).contains(0)) { |
| return StampFactory.objectNonNull(); |
| } else if (input.isConstant() && isZeroConstant(input)) { |
| return StampFactory.alwaysNull(); |
| } |
| return StampFactory.object(); |
| } |
| |
| @Override |
| public boolean inferStamp() { |
| if (stamp.equals(StampFactory.object())) { |
| return updateStamp(objectStampFor(input)); |
| } |
| return false; |
| } |
| |
| @Override |
| public Node canonical(CanonicalizerTool tool) { |
| if (tool.allUsagesAvailable() && hasNoUsages()) { |
| /* If the cast is unused, it can be eliminated. */ |
| return input; |
| } |
| |
| assert !stamp(NodeView.DEFAULT).isCompatible(input.stamp(NodeView.DEFAULT)); |
| if (input.isConstant()) { |
| /* Null pointers are uncritical for GC, so they can be constant folded. */ |
| if (input.asJavaConstant().isNull()) { |
| return ConstantNode.forIntegerStamp(stamp(NodeView.DEFAULT), 0); |
| } else if (isZeroConstant(input)) { |
| return ConstantNode.forConstant(stamp(NodeView.DEFAULT), JavaConstant.NULL_POINTER, tool.getMetaAccess()); |
| } |
| } |
| |
| return this; |
| } |
| |
| @Override |
| public void generate(NodeLIRBuilderTool generator) { |
| Value value = generator.operand(input); |
| ValueKind<?> kind = generator.getLIRGeneratorTool().getLIRKind(stamp(NodeView.DEFAULT)); |
| assert kind.getPlatformKind().getSizeInBytes() == value.getPlatformKind().getSizeInBytes(); |
| |
| if (trackedPointer && LIRKind.isValue(kind) && !LIRKind.isValue(value)) { |
| // just change the PlatformKind, but don't drop reference information |
| kind = value.getValueKind().changeType(kind.getPlatformKind()); |
| } |
| |
| if (kind.equals(value.getValueKind()) && !(value instanceof ConstantValue)) { |
| generator.setResult(this, value); |
| } else { |
| AllocatableValue result = generator.getLIRGeneratorTool().newVariable(kind); |
| if (stamp.equals(StampFactory.object())) { |
| generator.getLIRGeneratorTool().emitConvertZeroToNull(result, value); |
| } else if (!trackedPointer && !((ObjectStamp) input.stamp(NodeView.DEFAULT)).nonNull()) { |
| generator.getLIRGeneratorTool().emitConvertNullToZero(result, value); |
| } else { |
| generator.getLIRGeneratorTool().emitMove(result, value); |
| } |
| generator.setResult(this, result); |
| } |
| } |
| } |
