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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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).
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 * 2 along with this work; if not, write to the Free Software Foundation,
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package org.graalvm.compiler.replacements.nodes;

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.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.ConstantNode;
import org.graalvm.compiler.nodes.ValueNode;

import jdk.vm.ci.meta.JavaConstant;
import jdk.vm.ci.meta.MetaAccessProvider;

This node class can be used to create MacroNodes for simple pure functions like System.identityHashCode(Object).
/** * This node class can be used to create {@link MacroNode}s for simple pure functions like * {@link System#identityHashCode(Object)}. */
@NodeInfo public abstract class PureFunctionMacroNode extends MacroStateSplitNode implements Canonicalizable { public static final NodeClass<PureFunctionMacroNode> TYPE = NodeClass.create(PureFunctionMacroNode.class); public PureFunctionMacroNode(NodeClass<? extends MacroNode> c, MacroParams p) { super(c, p); }
This method should return either a constant that represents the result of the function, or null if no such result could be determined.
/** * This method should return either a constant that represents the result of the function, or * null if no such result could be determined. */
protected abstract JavaConstant evaluate(JavaConstant param, MetaAccessProvider metaAccess); @Override public Node canonical(CanonicalizerTool tool) { if (tool.allUsagesAvailable() && hasNoUsages()) { return null; } else { ValueNode param = arguments.get(0); if (param.isConstant()) { JavaConstant constant = evaluate(param.asJavaConstant(), tool.getMetaAccess()); if (constant != null) { return ConstantNode.forConstant(constant, tool.getMetaAccess()); } } } return this; } }