1/* 2 * Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23package org.graalvm.compiler.nodes.debug; 24 25import org.graalvm.compiler.graph.NodeClass; 26import org.graalvm.compiler.graph.spi.Simplifiable; 27import org.graalvm.compiler.graph.spi.SimplifierTool; 28import org.graalvm.compiler.nodeinfo.NodeInfo; 29import org.graalvm.compiler.nodes.ConstantNode; 30import org.graalvm.compiler.nodes.FixedNode; 31import org.graalvm.compiler.nodes.StructuredGraph; 32import org.graalvm.compiler.nodes.ValueNode; 33import org.graalvm.compiler.nodes.calc.FloatingNode; 34import org.graalvm.compiler.nodes.spi.Virtualizable; 35import org.graalvm.compiler.nodes.spi.VirtualizerTool; 36import org.graalvm.compiler.nodes.virtual.VirtualObjectNode; 37 38/** 39 * This is a special version of the dynamic counter node that removes itself as soon as it's the 40 * only usage of the associated node. This way it only increments the counter if the node is 41 * actually executed. 42 */ 43@NodeInfo 44public final class WeakCounterNode extends DynamicCounterNode implements Simplifiable, Virtualizable { 45 46 public static final NodeClass<WeakCounterNode> TYPE = NodeClass.create(WeakCounterNode.class); 47 @Input ValueNode checkedValue; 48 49 public WeakCounterNode(String group, String name, ValueNode increment, boolean addContext, ValueNode checkedValue) { 50 super(TYPE, group, name, increment, addContext); 51 this.checkedValue = checkedValue; 52 } 53 54 @Override 55 public void simplify(SimplifierTool tool) { 56 if (checkedValue instanceof FloatingNode && checkedValue.getUsageCount() == 1) { 57 tool.addToWorkList(checkedValue); 58 graph().removeFixed(this); 59 } 60 } 61 62 @Override 63 public void virtualize(VirtualizerTool tool) { 64 ValueNode alias = tool.getAlias(checkedValue); 65 if (alias instanceof VirtualObjectNode) { 66 tool.delete(); 67 } 68 } 69 70 public static void addCounterBefore(String group, String name, long increment, boolean addContext, ValueNode checkedValue, FixedNode position) { 71 StructuredGraph graph = position.graph(); 72 WeakCounterNode counter = graph.add(new WeakCounterNode(name, group, ConstantNode.forLong(increment, graph), addContext, checkedValue)); 73 graph.addBeforeFixed(position, counter); 74 } 75} 76