1 /* 2 * Copyright (c) 2012, 2018, 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 static org.graalvm.compiler.nodeinfo.InputType.Association; 28 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_0; 29 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_0; 30 31 import org.graalvm.compiler.graph.IterableNodeType; 32 import org.graalvm.compiler.graph.Node; 33 import org.graalvm.compiler.graph.NodeClass; 34 import org.graalvm.compiler.graph.iterators.NodeIterable; 35 import org.graalvm.compiler.graph.spi.Simplifiable; 36 import org.graalvm.compiler.graph.spi.SimplifierTool; 37 import org.graalvm.compiler.nodeinfo.NodeInfo; 38 39 @NodeInfo(allowedUsageTypes = {Association}, cycles = CYCLES_0, size = SIZE_0) 40 public final class LoopExitNode extends BeginStateSplitNode implements IterableNodeType, Simplifiable { 41 42 public static final NodeClass<LoopExitNode> TYPE = NodeClass.create(LoopExitNode.class); 43 44 /* 45 * The declared type of the field cannot be LoopBeginNode, because loop explosion during partial 46 * evaluation can temporarily assign a non-loop begin. This node will then be deleted shortly 47 * after - but we still must not have type system violations for that short amount of time. 48 */ 49 @Input(Association) AbstractBeginNode loopBegin; 50 51 public LoopExitNode(LoopBeginNode loop) { 52 super(TYPE); 53 assert loop != null; 54 loopBegin = loop; 55 } 56 57 public LoopBeginNode loopBegin() { 58 return (LoopBeginNode) loopBegin; 59 } 60 61 @Override 62 public NodeIterable<Node> anchored() { 63 return super.anchored().filter(n -> { 64 if (n instanceof ProxyNode) { 65 ProxyNode proxyNode = (ProxyNode) n; 66 return proxyNode.proxyPoint() != this; 67 } 68 return true; 69 }); 70 } 71 72 @Override 73 public void prepareDelete(FixedNode evacuateFrom) { 74 removeProxies(); 75 super.prepareDelete(evacuateFrom); 76 } 77 78 public void removeProxies() { 79 if (this.hasUsages()) { 80 outer: while (true) { 81 for (ProxyNode vpn : proxies().snapshot()) { 82 ValueNode value = vpn.value(); 83 vpn.replaceAtUsagesAndDelete(value); 84 if (value == this) { 85 // Guard proxy could have this input as value. 86 continue outer; 87 } 88 } 89 break; 90 } 91 } 92 } 93 94 @SuppressWarnings({"unchecked", "rawtypes"}) 95 public NodeIterable<ProxyNode> proxies() { 96 return (NodeIterable) usages().filter(n -> { 97 if (n instanceof ProxyNode) { 98 ProxyNode proxyNode = (ProxyNode) n; 99 return proxyNode.proxyPoint() == this; 100 } 101 return false; 102 }); 103 } 104 105 @Override 106 public void simplify(SimplifierTool tool) { 107 Node prev = this.predecessor(); 108 while (tool.allUsagesAvailable() && prev instanceof BeginNode && prev.hasNoUsages()) { 109 AbstractBeginNode begin = (AbstractBeginNode) prev; 110 this.setNodeSourcePosition(begin.getNodeSourcePosition()); 111 prev = prev.predecessor(); 112 graph().removeFixed(begin); 113 } 114 } 115 }