1 /* 2 * Copyright (c) 2011, 2011, 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.List; 26 27 import org.graalvm.compiler.nodes.AbstractBeginNode; 28 import org.graalvm.compiler.nodes.AbstractMergeNode; 29 import org.graalvm.compiler.nodes.ControlSplitNode; 30 import org.graalvm.compiler.nodes.LoopBeginNode; 31 import org.graalvm.compiler.nodes.LoopEndNode; 32 33 public abstract class MergeableState<T> { 34 35 @Override 36 public abstract T clone(); 37 38 /** 39 * This method is called on merge on the state of the first branch. The {@code withStates} list 40 * contains the states of the of the other branches in the order of the merge's end nodes. 41 * 42 * @param merge the merge node 43 * @param withStates the state at the the merge's end node except the first one. 44 */ 45 public abstract boolean merge(AbstractMergeNode merge, List<T> withStates); 46 47 /** 48 * This method is called before a loop is entered (before the {@link LoopBeginNode} is visited). 49 * 50 * @param loopBegin the begin node of the loop 51 */ 52 public void loopBegin(LoopBeginNode loopBegin) { 53 // empty default implementation 54 } 55 56 /** 57 * This method is called after all {@link LoopEndNode}s belonging to a loop have been visited. 58 * 59 * @param loopBegin the begin node of the loop 60 * @param loopEndStates the states at the loop ends, sorted according to 61 * {@link LoopBeginNode#orderedLoopEnds()} 62 */ 63 public void loopEnds(LoopBeginNode loopBegin, List<T> loopEndStates) { 64 // empty default implementation 65 } 66 67 /** 68 * This method is called before the successors of a {@link ControlSplitNode} are visited. 69 * 70 * @param node the successor of the control split that is about to be visited 71 */ 72 public void afterSplit(AbstractBeginNode node) { 73 // empty default implementation 74 } 75 }