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