1 /* 2 * Copyright (c) 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 24 25 package org.graalvm.compiler.nodes; 26 27 import java.util.Iterator; 28 import java.util.NoSuchElementException; 29 30 import org.graalvm.compiler.core.common.type.Stamp; 31 import org.graalvm.compiler.core.common.type.StampFactory; 32 import org.graalvm.compiler.graph.IterableNodeType; 33 import org.graalvm.compiler.graph.Node; 34 import org.graalvm.compiler.graph.NodeClass; 35 import org.graalvm.compiler.graph.iterators.NodeIterable; 36 import org.graalvm.compiler.nodeinfo.InputType; 37 import org.graalvm.compiler.nodeinfo.NodeInfo; 38 import org.graalvm.compiler.nodes.extended.AnchoringNode; 39 import org.graalvm.compiler.nodes.extended.GuardingNode; 40 import org.graalvm.compiler.nodes.spi.LIRLowerable; 41 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool; 42 43 @NodeInfo(allowedUsageTypes = {InputType.Guard, InputType.Anchor}) 44 public abstract class AbstractBeginNode extends FixedWithNextNode implements LIRLowerable, GuardingNode, AnchoringNode, IterableNodeType { 45 46 public static final NodeClass<AbstractBeginNode> TYPE = NodeClass.create(AbstractBeginNode.class); 47 48 protected AbstractBeginNode(NodeClass<? extends AbstractBeginNode> c) { 49 this(c, StampFactory.forVoid()); 50 } 51 52 protected AbstractBeginNode(NodeClass<? extends AbstractBeginNode> c, Stamp stamp) { 53 super(c, stamp); 54 } 55 56 public static AbstractBeginNode prevBegin(FixedNode from) { 57 Node next = from; 58 while (next != null) { 59 if (next instanceof AbstractBeginNode) { 60 AbstractBeginNode begin = (AbstractBeginNode) next; 61 return begin; 62 } 63 next = next.predecessor(); 64 } 65 return null; 66 } 67 68 private void evacuateGuards(FixedNode evacuateFrom) { 69 if (!hasNoUsages()) { 70 AbstractBeginNode prevBegin = prevBegin(evacuateFrom); 71 assert prevBegin != null; 72 for (Node anchored : anchored().snapshot()) { 73 anchored.replaceFirstInput(this, prevBegin); 74 } 75 } 76 } 77 78 public void prepareDelete() { 79 prepareDelete((FixedNode) predecessor()); 80 } 81 82 public void prepareDelete(FixedNode evacuateFrom) { 83 evacuateGuards(evacuateFrom); 84 } 85 86 @Override 87 public boolean verify() { 88 assertTrue(predecessor() != null || this == graph().start() || this instanceof AbstractMergeNode, "begin nodes must be connected"); 89 return super.verify(); 90 } 91 92 @Override 93 public void generate(NodeLIRBuilderTool gen) { 94 // nop 95 } 96 97 public NodeIterable<GuardNode> guards() { 98 return usages().filter(GuardNode.class); 99 } 100 101 public NodeIterable<Node> anchored() { 102 return usages(); 103 } 104 105 public NodeIterable<FixedNode> getBlockNodes() { 106 return new NodeIterable<FixedNode>() { 107 108 @Override 109 public Iterator<FixedNode> iterator() { 110 return new BlockNodeIterator(AbstractBeginNode.this); 111 } 112 }; 113 } 114 115 private static class BlockNodeIterator implements Iterator<FixedNode> { 116 117 private FixedNode current; 118 119 BlockNodeIterator(FixedNode next) { 120 this.current = next; 121 } 122 123 @Override 124 public boolean hasNext() { 125 return current != null; 126 } 127 128 @Override 129 public FixedNode next() { 130 FixedNode ret = current; 131 if (ret == null) { 132 throw new NoSuchElementException(); 133 } 134 if (current instanceof FixedWithNextNode) { 135 current = ((FixedWithNextNode) current).next(); 136 if (current instanceof AbstractBeginNode) { 137 current = null; 138 } 139 } else { 140 current = null; 141 } 142 return ret; 143 } 144 145 @Override 146 public void remove() { 147 throw new UnsupportedOperationException(); 148 } 149 } 150 }