1 /* 2 * Copyright (c) 2013, 2013, 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.phases.graph; 24 25 import java.util.ListIterator; 26 27 import org.graalvm.compiler.graph.Node; 28 import org.graalvm.compiler.nodes.FixedNode; 29 import org.graalvm.compiler.nodes.FixedWithNextNode; 30 import org.graalvm.compiler.nodes.StructuredGraph.ScheduleResult; 31 import org.graalvm.compiler.nodes.cfg.Block; 32 33 /** 34 * Iterates over a list of nodes, which usually comes from 35 * {@link ScheduleResult#getBlockToNodesMap()}. 36 * 37 * While iterating, it is possible to {@link #insert(FixedNode, FixedWithNextNode) insert} and 38 * {@link #replaceCurrent(FixedWithNextNode) replace} nodes. 39 */ 40 public abstract class ScheduledNodeIterator { 41 42 private FixedWithNextNode lastFixed; 43 private FixedWithNextNode reconnect; 44 private ListIterator<Node> iterator; 45 46 public void processNodes(Block block, ScheduleResult schedule) { 47 lastFixed = block.getBeginNode(); 48 assert lastFixed != null; 49 reconnect = null; 50 iterator = schedule.nodesFor(block).listIterator(); 51 52 while (iterator.hasNext()) { 53 Node node = iterator.next(); 54 if (!node.isAlive()) { 55 continue; 56 } 57 if (reconnect != null && node instanceof FixedNode) { 58 reconnect.setNext((FixedNode) node); 59 reconnect = null; 60 } 61 if (node instanceof FixedWithNextNode) { 62 lastFixed = (FixedWithNextNode) node; 63 } 64 processNode(node); 65 } 66 if (reconnect != null) { 67 assert block.getSuccessorCount() == 1; 68 reconnect.setNext(block.getFirstSuccessor().getBeginNode()); 69 } 70 } 71 72 protected void insert(FixedNode start, FixedWithNextNode end) { 73 this.lastFixed.setNext(start); 74 this.lastFixed = end; 75 this.reconnect = end; 76 } 77 78 protected void replaceCurrent(FixedWithNextNode newNode) { 79 Node current = iterator.previous(); 80 iterator.next(); // needed because of the previous() call 81 current.replaceAndDelete(newNode); 82 insert(newNode, newNode); 83 iterator.set(newNode); 84 } 85 86 protected abstract void processNode(Node node); 87 }