1 /* 2 * Copyright (c) 2012, 2012, 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.loop.phases; 24 25 import java.util.Iterator; 26 import java.util.List; 27 28 import org.graalvm.compiler.debug.Debug; 29 import org.graalvm.compiler.debug.DebugCounter; 30 import org.graalvm.compiler.graph.Node; 31 import org.graalvm.compiler.loop.LoopEx; 32 import org.graalvm.compiler.loop.LoopPolicies; 33 import org.graalvm.compiler.loop.LoopsData; 34 import org.graalvm.compiler.nodes.AbstractBeginNode; 35 import org.graalvm.compiler.nodes.ControlSplitNode; 36 import org.graalvm.compiler.nodes.StructuredGraph; 37 38 public class LoopUnswitchingPhase extends ContextlessLoopPhase<LoopPolicies> { 39 private static final DebugCounter UNSWITCHED = Debug.counter("Unswitched"); 40 private static final DebugCounter UNSWITCH_CANDIDATES = Debug.counter("UnswitchCandidates"); 41 private static final DebugCounter UNSWITCH_EARLY_REJECTS = Debug.counter("UnswitchEarlyRejects"); 42 43 public LoopUnswitchingPhase(LoopPolicies policies) { 44 super(policies); 45 } 46 47 @Override 48 protected void run(StructuredGraph graph) { 49 if (graph.hasLoops()) { 50 boolean unswitched; 51 do { 52 unswitched = false; 53 final LoopsData dataUnswitch = new LoopsData(graph); 54 for (LoopEx loop : dataUnswitch.outerFirst()) { 55 if (getPolicies().shouldTryUnswitch(loop)) { 56 List<ControlSplitNode> controlSplits = LoopTransformations.findUnswitchable(loop); 57 if (controlSplits != null) { 58 UNSWITCH_CANDIDATES.increment(); 59 if (getPolicies().shouldUnswitch(loop, controlSplits)) { 60 if (Debug.isLogEnabled()) { 61 logUnswitch(loop, controlSplits); 62 } 63 LoopTransformations.unswitch(loop, controlSplits); 64 Debug.dump(Debug.INFO_LOG_LEVEL, graph, "After unswitch %s", controlSplits); 65 UNSWITCHED.increment(); 66 unswitched = true; 67 break; 68 } 69 } 70 } else { 71 UNSWITCH_EARLY_REJECTS.increment(); 72 } 73 } 74 } while (unswitched); 75 } 76 } 77 78 private static void logUnswitch(LoopEx loop, List<ControlSplitNode> controlSplits) { 79 StringBuilder sb = new StringBuilder("Unswitching "); 80 sb.append(loop).append(" at "); 81 for (ControlSplitNode controlSplit : controlSplits) { 82 sb.append(controlSplit).append(" ["); 83 Iterator<Node> it = controlSplit.successors().iterator(); 84 while (it.hasNext()) { 85 sb.append(controlSplit.probability((AbstractBeginNode) it.next())); 86 if (it.hasNext()) { 87 sb.append(", "); 88 } 89 } 90 sb.append("]"); 91 } 92 Debug.log("%s", sb); 93 } 94 95 @Override 96 public float codeSizeIncrease() { 97 return 10.0f; 98 } 99 }