1 /* 2 * Copyright (c) 2012, 2015, 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 static org.graalvm.compiler.nodeinfo.InputType.Association; 26 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_0; 27 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_0; 28 29 import org.graalvm.compiler.graph.IterableNodeType; 30 import org.graalvm.compiler.graph.Node; 31 import org.graalvm.compiler.graph.NodeClass; 32 import org.graalvm.compiler.graph.iterators.NodeIterable; 33 import org.graalvm.compiler.graph.spi.Simplifiable; 34 import org.graalvm.compiler.graph.spi.SimplifierTool; 35 import org.graalvm.compiler.nodeinfo.NodeInfo; 36 37 @NodeInfo(allowedUsageTypes = {Association}, cycles = CYCLES_0, size = SIZE_0) 38 public final class LoopExitNode extends BeginStateSplitNode implements IterableNodeType, Simplifiable { 39 40 public static final NodeClass<LoopExitNode> TYPE = NodeClass.create(LoopExitNode.class); 41 42 /* 43 * The declared type of the field cannot be LoopBeginNode, because loop explosion during partial 44 * evaluation can temporarily assign a non-loop begin. This node will then be deleted shortly 45 * after - but we still must not have type system violations for that short amount of time. 46 */ 47 @Input(Association) AbstractBeginNode loopBegin; 48 49 public LoopExitNode(LoopBeginNode loop) { 50 super(TYPE); 51 assert loop != null; 52 loopBegin = loop; 53 } 54 55 public LoopBeginNode loopBegin() { 56 return (LoopBeginNode) loopBegin; 57 } 58 59 @Override 60 public NodeIterable<Node> anchored() { 61 return super.anchored().filter(n -> { 62 if (n instanceof ProxyNode) { 63 ProxyNode proxyNode = (ProxyNode) n; 64 return proxyNode.proxyPoint() != this; 65 } 66 return true; 67 }); 68 } 69 70 @Override 71 public void prepareDelete(FixedNode evacuateFrom) { 72 removeProxies(); 73 super.prepareDelete(evacuateFrom); 74 } 75 76 public void removeProxies() { 77 if (this.hasUsages()) { 78 outer: while (true) { 79 for (ProxyNode vpn : proxies().snapshot()) { 80 ValueNode value = vpn.value(); 81 vpn.replaceAtUsagesAndDelete(value); 82 if (value == this) { 83 // Guard proxy could have this input as value. 84 continue outer; 85 } 86 } 87 break; 88 } 89 } 90 } 91 92 @SuppressWarnings({"unchecked", "rawtypes"}) 93 public NodeIterable<ProxyNode> proxies() { 94 return (NodeIterable) usages().filter(n -> { 95 if (n instanceof ProxyNode) { 96 ProxyNode proxyNode = (ProxyNode) n; 97 return proxyNode.proxyPoint() == this; 98 } 99 return false; 100 }); 101 } 102 103 @Override 104 public void simplify(SimplifierTool tool) { 105 Node prev = this.predecessor(); 106 while (tool.allUsagesAvailable() && prev instanceof BeginNode && prev.hasNoUsages()) { 107 AbstractBeginNode begin = (AbstractBeginNode) prev; 108 prev = prev.predecessor(); 109 graph().removeFixed(begin); 110 } 111 } 112 }