1 /* 2 * Copyright (c) 2017, 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.phases.common; 26 27 import jdk.internal.vm.compiler.collections.EconomicMap; 28 import jdk.internal.vm.compiler.collections.EconomicSet; 29 import jdk.internal.vm.compiler.collections.MapCursor; 30 import org.graalvm.compiler.graph.NodeStack; 31 import org.graalvm.compiler.nodes.AbstractBeginNode; 32 import org.graalvm.compiler.nodes.AbstractDeoptimizeNode; 33 import org.graalvm.compiler.nodes.AbstractEndNode; 34 import org.graalvm.compiler.nodes.AbstractMergeNode; 35 import org.graalvm.compiler.nodes.ControlSplitNode; 36 import org.graalvm.compiler.nodes.FixedNode; 37 import org.graalvm.compiler.nodes.StructuredGraph; 38 import org.graalvm.compiler.nodes.spi.CoreProviders; 39 import org.graalvm.compiler.phases.BasePhase; 40 41 /** 42 * This phase will make sure that the branch leading towards this deopt has 0.0 probability. 43 * 44 */ 45 public class PropagateDeoptimizeProbabilityPhase extends BasePhase<CoreProviders> { 46 47 @Override 48 @SuppressWarnings("try") 49 protected void run(final StructuredGraph graph, CoreProviders context) { 50 assert !graph.hasValueProxies() : "ConvertDeoptimizeToGuardPhase always creates proxies"; 51 52 if (graph.hasNode(AbstractDeoptimizeNode.TYPE)) { 53 54 NodeStack stack = new NodeStack(); 55 EconomicMap<ControlSplitNode, EconomicSet<AbstractBeginNode>> reachableSplits = EconomicMap.create(); 56 57 // Mark all control flow nodes that are post-dominated by a deoptimization. 58 for (AbstractDeoptimizeNode d : graph.getNodes(AbstractDeoptimizeNode.TYPE)) { 59 stack.push(AbstractBeginNode.prevBegin(d)); 60 while (!stack.isEmpty()) { 61 AbstractBeginNode beginNode = (AbstractBeginNode) stack.pop(); 62 FixedNode fixedNode = (FixedNode) beginNode.predecessor(); 63 64 if (fixedNode == null) { 65 // Can happen for start node. 66 } else if (fixedNode instanceof AbstractMergeNode) { 67 AbstractMergeNode mergeNode = (AbstractMergeNode) fixedNode; 68 for (AbstractEndNode end : mergeNode.forwardEnds()) { 69 AbstractBeginNode newBeginNode = AbstractBeginNode.prevBegin(end); 70 stack.push(newBeginNode); 71 } 72 } else if (fixedNode instanceof ControlSplitNode) { 73 ControlSplitNode controlSplitNode = (ControlSplitNode) fixedNode; 74 EconomicSet<AbstractBeginNode> reachableSuccessors = reachableSplits.get(controlSplitNode); 75 if (reachableSuccessors == null) { 76 reachableSuccessors = EconomicSet.create(); 77 reachableSplits.put(controlSplitNode, reachableSuccessors); 78 } 79 80 if (controlSplitNode.getSuccessorCount() == reachableSuccessors.size() - 1) { 81 // All successors of this split lead to deopt, propagate reachability 82 // further upwards. 83 reachableSplits.removeKey(controlSplitNode); 84 stack.push(AbstractBeginNode.prevBegin((FixedNode) controlSplitNode.predecessor())); 85 } else { 86 reachableSuccessors.add(beginNode); 87 } 88 } else { 89 stack.push(AbstractBeginNode.prevBegin(fixedNode)); 90 } 91 } 92 } 93 94 // Make sure the probability on the path towards the deoptimization is 0.0. 95 MapCursor<ControlSplitNode, EconomicSet<AbstractBeginNode>> entries = reachableSplits.getEntries(); 96 while (entries.advance()) { 97 ControlSplitNode controlSplitNode = entries.getKey(); 98 EconomicSet<AbstractBeginNode> value = entries.getValue(); 99 for (AbstractBeginNode begin : value) { 100 double probability = controlSplitNode.probability(begin); 101 if (probability != 0.0) { 102 controlSplitNode.setProbability(begin, 0.0); 103 } 104 } 105 } 106 } 107 } 108 }