1 /* 2 * Copyright (c) 2009, 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 */ 23 package org.graalvm.compiler.nodes; 24 25 import org.graalvm.compiler.graph.NodeClass; 26 import org.graalvm.compiler.nodeinfo.NodeInfo; 27 28 /** 29 * Denotes the merging of multiple control-flow paths. 30 */ 31 @NodeInfo 32 public final class MergeNode extends AbstractMergeNode { 33 34 public static final NodeClass<MergeNode> TYPE = NodeClass.create(MergeNode.class); 35 36 public MergeNode() { 37 super(TYPE); 38 } 39 40 public static void removeMergeIfDegenerated(MergeNode node) { 41 if (node.forwardEndCount() == 1 && node.hasNoUsages()) { 42 FixedNode currentNext = node.next(); 43 node.setNext(null); 44 EndNode forwardEnd = node.forwardEndAt(0); 45 forwardEnd.replaceAtPredecessor(currentNext); 46 node.markDeleted(); 47 forwardEnd.markDeleted(); 48 } 49 } 50 51 @Override 52 public boolean verify() { 53 assertTrue(this.forwardEndCount() > 1, "Must merge more than one end."); 54 return true; 55 } 56 }