Mercurial > hg > graal-jvmci-8
diff graal/com.oracle.graal.snippets/src/com/oracle/graal/replacements/InstanceOfSnippetsTemplates.java @ 8415:2361bf148c06
rename packages: *snippets* -> *replacements*
author | Doug Simon <doug.simon@oracle.com> |
---|---|
date | Wed, 20 Mar 2013 22:23:14 +0100 |
parents | graal/com.oracle.graal.snippets/src/com/oracle/graal/snippets/InstanceOfSnippetsTemplates.java@d9347ee39fbe |
children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/graal/com.oracle.graal.snippets/src/com/oracle/graal/replacements/InstanceOfSnippetsTemplates.java Wed Mar 20 22:23:14 2013 +0100 @@ -0,0 +1,338 @@ +/* + * Copyright (c) 2012, 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.replacements; + +import static com.oracle.graal.nodes.calc.CompareNode.*; + +import java.util.*; + +import com.oracle.graal.api.code.*; +import com.oracle.graal.api.meta.*; +import com.oracle.graal.graph.*; +import com.oracle.graal.nodes.*; +import com.oracle.graal.nodes.calc.*; +import com.oracle.graal.nodes.java.*; +import com.oracle.graal.nodes.spi.*; +import com.oracle.graal.nodes.util.*; +import com.oracle.graal.replacements.SnippetTemplate.*; + +/** + * Helper class for lowering {@link InstanceOfNode}s with snippets. The majority of the complexity + * in such a lowering derives from the fact that {@link InstanceOfNode} is a floating node. A + * snippet used to lower an {@link InstanceOfNode} will almost always incorporate control flow and + * replacing a floating node with control flow is not trivial. + * <p> + * The mechanism implemented in this class ensures that the graph for an instanceof snippet is + * instantiated once per {@link InstanceOfNode} being lowered. The result produced is then re-used + * by all usages of the node. Additionally, if there is a single usage that is an {@link IfNode}, + * the control flow in the snippet is connected directly to the true and false successors of the + * {@link IfNode}. This avoids materializing the instanceof test as a boolean which is then retested + * by the {@link IfNode}. + */ +public abstract class InstanceOfSnippetsTemplates<T extends Snippets> extends AbstractTemplates<T> { + + public InstanceOfSnippetsTemplates(MetaAccessProvider runtime, Assumptions assumptions, TargetDescription target, Class<T> snippetsClass) { + super(runtime, assumptions, target, snippetsClass); + } + + /** + * The key and arguments used to retrieve and instantiate an instanceof snippet template. + */ + public static class KeyAndArguments { + + public final Key key; + public final Arguments arguments; + + public KeyAndArguments(Key key, Arguments arguments) { + this.key = key; + this.arguments = arguments; + } + + } + + /** + * Gets the key and arguments used to retrieve and instantiate an instanceof snippet template. + */ + protected abstract KeyAndArguments getKeyAndArguments(InstanceOfUsageReplacer replacer, LoweringTool tool); + + public void lower(FloatingNode instanceOf, LoweringTool tool) { + assert instanceOf instanceof InstanceOfNode || instanceOf instanceof InstanceOfDynamicNode; + List<Node> usages = instanceOf.usages().snapshot(); + int nUsages = usages.size(); + + Instantiation instantiation = new Instantiation(); + for (Node usage : usages) { + final StructuredGraph graph = (StructuredGraph) usage.graph(); + + InstanceOfUsageReplacer replacer = createReplacer(instanceOf, tool, nUsages, instantiation, usage, graph); + + if (instantiation.isInitialized()) { + // No need to re-instantiate the snippet - just re-use its result + replacer.replaceUsingInstantiation(); + } else { + KeyAndArguments keyAndArguments = getKeyAndArguments(replacer, tool); + SnippetTemplate template = cache.get(keyAndArguments.key, assumptions); + template.instantiate(runtime, instanceOf, replacer, tool, keyAndArguments.arguments); + } + } + + assert instanceOf.usages().isEmpty(); + if (!instanceOf.isDeleted()) { + GraphUtil.killWithUnusedFloatingInputs(instanceOf); + } + } + + /** + * Gets the specific replacer object used to replace the usage of an instanceof node with the + * result of an instantiated instanceof snippet. + */ + protected InstanceOfUsageReplacer createReplacer(FloatingNode instanceOf, LoweringTool tool, int nUsages, Instantiation instantiation, Node usage, final StructuredGraph graph) { + InstanceOfUsageReplacer replacer; + if (usage instanceof IfNode) { + replacer = new IfUsageReplacer(instantiation, ConstantNode.forInt(1, graph), ConstantNode.forInt(0, graph), instanceOf, (IfNode) usage, nUsages == 1, tool); + } else { + assert usage instanceof ConditionalNode : "unexpected usage of " + instanceOf + ": " + usage; + ConditionalNode c = (ConditionalNode) usage; + replacer = new ConditionalUsageReplacer(instantiation, c.trueValue(), c.falseValue(), instanceOf, c); + } + return replacer; + } + + /** + * The result of an instantiating an instanceof snippet. This enables a snippet instantiation to + * be re-used which reduces compile time and produces better code. + */ + public static final class Instantiation { + + private PhiNode result; + private CompareNode condition; + private ValueNode trueValue; + private ValueNode falseValue; + + /** + * Determines if the instantiation has occurred. + */ + boolean isInitialized() { + return result != null; + } + + void initialize(PhiNode phi, ValueNode t, ValueNode f) { + assert !isInitialized(); + this.result = phi; + this.trueValue = t; + this.falseValue = f; + } + + /** + * Gets the result of this instantiation as a condition. + * + * @param testValue the returned condition is true if the result is equal to this value + */ + CompareNode asCondition(ValueNode testValue) { + assert isInitialized(); + if (condition == null || condition.y() != testValue) { + // Re-use previously generated condition if the trueValue for the test is the same + condition = createCompareNode(Condition.EQ, result, testValue); + } + return condition; + } + + /** + * Gets the result of the instantiation as a materialized value. + * + * @param t the true value for the materialization + * @param f the false value for the materialization + */ + ValueNode asMaterialization(ValueNode t, ValueNode f) { + assert isInitialized(); + if (t == this.trueValue && f == this.falseValue) { + // Can simply use the phi result if the same materialized values are expected. + return result; + } else { + return t.graph().unique(new ConditionalNode(asCondition(trueValue), t, f)); + } + } + } + + /** + * Replaces a usage of an {@link InstanceOfNode} or {@link InstanceOfDynamicNode}. + */ + public abstract static class InstanceOfUsageReplacer implements UsageReplacer { + + public final Instantiation instantiation; + public final FloatingNode instanceOf; + public final ValueNode trueValue; + public final ValueNode falseValue; + + public InstanceOfUsageReplacer(Instantiation instantiation, FloatingNode instanceOf, ValueNode trueValue, ValueNode falseValue) { + assert instanceOf instanceof InstanceOfNode || instanceOf instanceof InstanceOfDynamicNode; + this.instantiation = instantiation; + this.instanceOf = instanceOf; + this.trueValue = trueValue; + this.falseValue = falseValue; + } + + /** + * Does the replacement based on a previously snippet instantiation. + */ + public abstract void replaceUsingInstantiation(); + } + + /** + * Replaces an {@link IfNode} usage of an {@link InstanceOfNode} or + * {@link InstanceOfDynamicNode}. + */ + public static class IfUsageReplacer extends InstanceOfUsageReplacer { + + private final boolean solitaryUsage; + private final IfNode usage; + private final boolean sameBlock; + + public IfUsageReplacer(Instantiation instantiation, ValueNode trueValue, ValueNode falseValue, FloatingNode instanceOf, IfNode usage, boolean solitaryUsage, LoweringTool tool) { + super(instantiation, instanceOf, trueValue, falseValue); + this.sameBlock = tool.getBlockFor(usage) == tool.getBlockFor(instanceOf); + this.solitaryUsage = solitaryUsage; + this.usage = usage; + } + + @Override + public void replaceUsingInstantiation() { + usage.replaceFirstInput(instanceOf, instantiation.asCondition(trueValue)); + } + + private boolean usageFollowsInstantiation() { + return instantiation.result != null && instantiation.result.merge().next() == usage; + } + + @Override + public void replace(ValueNode oldNode, ValueNode newNode) { + assert newNode instanceof PhiNode; + assert oldNode == instanceOf; + if (sameBlock && solitaryUsage && usageFollowsInstantiation()) { + removeIntermediateMaterialization(newNode); + } else { + newNode.inferStamp(); + instantiation.initialize((PhiNode) newNode, trueValue, falseValue); + usage.replaceFirstInput(oldNode, instantiation.asCondition(trueValue)); + } + } + + /** + * Directly wires the incoming edges of the merge at the end of the snippet to the outgoing + * edges of the IfNode that uses the materialized result. + */ + private void removeIntermediateMaterialization(ValueNode newNode) { + IfNode ifNode = usage; + PhiNode phi = (PhiNode) newNode; + MergeNode merge = phi.merge(); + assert merge.stateAfter() == null; + + List<EndNode> mergePredecessors = merge.cfgPredecessors().snapshot(); + assert phi.valueCount() == mergePredecessors.size(); + + List<EndNode> falseEnds = new ArrayList<>(mergePredecessors.size()); + List<EndNode> trueEnds = new ArrayList<>(mergePredecessors.size()); + + int endIndex = 0; + for (EndNode end : mergePredecessors) { + ValueNode endValue = phi.valueAt(endIndex++); + if (endValue == trueValue) { + trueEnds.add(end); + } else { + assert endValue == falseValue; + falseEnds.add(end); + } + } + + BeginNode trueSuccessor = ifNode.trueSuccessor(); + BeginNode falseSuccessor = ifNode.falseSuccessor(); + ifNode.setTrueSuccessor(null); + ifNode.setFalseSuccessor(null); + + connectEnds(merge, trueEnds, trueSuccessor); + connectEnds(merge, falseEnds, falseSuccessor); + + GraphUtil.killCFG(merge); + GraphUtil.killCFG(ifNode); + + assert !merge.isAlive() : merge; + assert !phi.isAlive() : phi; + } + + private static void connectEnds(MergeNode merge, List<EndNode> ends, BeginNode successor) { + if (ends.size() == 0) { + // InstanceOf has been lowered to always true or always false - this successor is + // therefore unreachable. + GraphUtil.killCFG(successor); + } else if (ends.size() == 1) { + EndNode end = ends.get(0); + ((FixedWithNextNode) end.predecessor()).setNext(successor); + merge.removeEnd(end); + GraphUtil.killCFG(end); + } else { + assert ends.size() > 1; + MergeNode newMerge = merge.graph().add(new MergeNode()); + + for (EndNode end : ends) { + newMerge.addForwardEnd(end); + } + newMerge.setNext(successor); + } + } + } + + /** + * Replaces a {@link ConditionalNode} usage of an {@link InstanceOfNode} or + * {@link InstanceOfDynamicNode}. + */ + public static class ConditionalUsageReplacer extends InstanceOfUsageReplacer { + + public final ConditionalNode usage; + + public ConditionalUsageReplacer(Instantiation instantiation, ValueNode trueValue, ValueNode falseValue, FloatingNode instanceOf, ConditionalNode usage) { + super(instantiation, instanceOf, trueValue, falseValue); + this.usage = usage; + } + + @Override + public void replaceUsingInstantiation() { + ValueNode newValue = instantiation.asMaterialization(trueValue, falseValue); + usage.replaceAtUsages(newValue); + usage.clearInputs(); + assert usage.usages().isEmpty(); + GraphUtil.killWithUnusedFloatingInputs(usage); + } + + @Override + public void replace(ValueNode oldNode, ValueNode newNode) { + assert newNode instanceof PhiNode; + assert oldNode == instanceOf; + newNode.inferStamp(); + instantiation.initialize((PhiNode) newNode, trueValue, falseValue); + usage.replaceAtUsages(newNode); + usage.clearInputs(); + assert usage.usages().isEmpty(); + GraphUtil.killWithUnusedFloatingInputs(usage); + } + } +}