--- /dev/null 2017-01-22 10:16:57.869617664 -0800 +++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.nodes/src/org/graalvm/compiler/nodes/debug/WeakCounterNode.java 2017-02-15 17:07:14.561205032 -0800 @@ -0,0 +1,75 @@ +/* + * 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.nodes.debug; + +import org.graalvm.compiler.graph.NodeClass; +import org.graalvm.compiler.graph.spi.Simplifiable; +import org.graalvm.compiler.graph.spi.SimplifierTool; +import org.graalvm.compiler.nodeinfo.NodeInfo; +import org.graalvm.compiler.nodes.ConstantNode; +import org.graalvm.compiler.nodes.FixedNode; +import org.graalvm.compiler.nodes.StructuredGraph; +import org.graalvm.compiler.nodes.ValueNode; +import org.graalvm.compiler.nodes.calc.FloatingNode; +import org.graalvm.compiler.nodes.spi.Virtualizable; +import org.graalvm.compiler.nodes.spi.VirtualizerTool; +import org.graalvm.compiler.nodes.virtual.VirtualObjectNode; + +/** + * This is a special version of the dynamic counter node that removes itself as soon as it's the + * only usage of the associated node. This way it only increments the counter if the node is + * actually executed. + */ +@NodeInfo +public final class WeakCounterNode extends DynamicCounterNode implements Simplifiable, Virtualizable { + + public static final NodeClass TYPE = NodeClass.create(WeakCounterNode.class); + @Input ValueNode checkedValue; + + public WeakCounterNode(String group, String name, ValueNode increment, boolean addContext, ValueNode checkedValue) { + super(TYPE, group, name, increment, addContext); + this.checkedValue = checkedValue; + } + + @Override + public void simplify(SimplifierTool tool) { + if (checkedValue instanceof FloatingNode && checkedValue.getUsageCount() == 1) { + tool.addToWorkList(checkedValue); + graph().removeFixed(this); + } + } + + @Override + public void virtualize(VirtualizerTool tool) { + ValueNode alias = tool.getAlias(checkedValue); + if (alias instanceof VirtualObjectNode) { + tool.delete(); + } + } + + public static void addCounterBefore(String group, String name, long increment, boolean addContext, ValueNode checkedValue, FixedNode position) { + StructuredGraph graph = position.graph(); + WeakCounterNode counter = graph.add(new WeakCounterNode(name, group, ConstantNode.forLong(increment, graph), addContext, checkedValue)); + graph.addBeforeFixed(position, counter); + } +}