1 /*
   2  * Copyright (c) 2012, 2016, 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.loop.phases;
  26 
  27 import jdk.internal.vm.compiler.collections.EconomicMap;
  28 import jdk.internal.vm.compiler.collections.Equivalence;
  29 import org.graalvm.compiler.graph.Graph;
  30 import org.graalvm.compiler.loop.LoopEx;
  31 import org.graalvm.compiler.loop.LoopPolicies;
  32 import org.graalvm.compiler.loop.LoopsData;
  33 import org.graalvm.compiler.nodes.LoopBeginNode;
  34 import org.graalvm.compiler.nodes.StructuredGraph;
  35 import org.graalvm.compiler.nodes.extended.OpaqueNode;
  36 import org.graalvm.compiler.phases.common.CanonicalizerPhase;
  37 import org.graalvm.compiler.phases.common.util.EconomicSetNodeEventListener;
  38 import org.graalvm.compiler.phases.tiers.PhaseContext;
  39 
  40 public class LoopPartialUnrollPhase extends LoopPhase<LoopPolicies> {
  41 
  42     private final CanonicalizerPhase canonicalizer;
  43 
  44     public LoopPartialUnrollPhase(LoopPolicies policies, CanonicalizerPhase canonicalizer) {
  45         super(policies);
  46         this.canonicalizer = canonicalizer;
  47     }
  48 
  49     @Override
  50     @SuppressWarnings("try")
  51     protected void run(StructuredGraph graph, PhaseContext context) {
  52         if (graph.hasLoops()) {
  53             EconomicSetNodeEventListener listener = new EconomicSetNodeEventListener();
  54             boolean changed = true;
  55             EconomicMap<LoopBeginNode, OpaqueNode> opaqueUnrolledStrides = null;
  56             while (changed) {
  57                 changed = false;
  58                 try (Graph.NodeEventScope nes = graph.trackNodeEvents(listener)) {
  59                     LoopsData dataCounted = new LoopsData(graph);
  60                     dataCounted.detectedCountedLoops();
  61                     Graph.Mark mark = graph.getMark();
  62                     boolean prePostInserted = false;
  63                     for (LoopEx loop : dataCounted.countedLoops()) {
  64                         if (!LoopTransformations.isUnrollableLoop(loop)) {
  65                             continue;
  66                         }
  67                         if (getPolicies().shouldPartiallyUnroll(loop)) {
  68                             if (loop.loopBegin().isSimpleLoop()) {
  69                                 // First perform the pre/post transformation and do the partial
  70                                 // unroll when we come around again.
  71                                 LoopTransformations.insertPrePostLoops(loop);
  72                                 prePostInserted = true;
  73                             } else {
  74                                 if (opaqueUnrolledStrides == null) {
  75                                     opaqueUnrolledStrides = EconomicMap.create(Equivalence.IDENTITY);
  76                                 }
  77                                 LoopTransformations.partialUnroll(loop, opaqueUnrolledStrides);
  78                             }
  79                             changed = true;
  80                         }
  81                     }
  82                     dataCounted.deleteUnusedNodes();
  83 
  84                     if (!listener.getNodes().isEmpty()) {
  85                         canonicalizer.applyIncremental(graph, context, listener.getNodes());
  86                         listener.getNodes().clear();
  87                     }
  88 
  89                     assert !prePostInserted || checkCounted(graph, mark);
  90                 }
  91             }
  92             if (opaqueUnrolledStrides != null) {
  93                 try (Graph.NodeEventScope nes = graph.trackNodeEvents(listener)) {
  94                     for (OpaqueNode opaque : opaqueUnrolledStrides.getValues()) {
  95                         opaque.remove();
  96                     }
  97                     if (!listener.getNodes().isEmpty()) {
  98                         canonicalizer.applyIncremental(graph, context, listener.getNodes());
  99                     }
 100                 }
 101             }
 102         }
 103     }
 104 
 105     private static boolean checkCounted(StructuredGraph graph, Graph.Mark mark) {
 106         LoopsData dataCounted;
 107         dataCounted = new LoopsData(graph);
 108         dataCounted.detectedCountedLoops();
 109         for (LoopEx anyLoop : dataCounted.loops()) {
 110             if (graph.isNew(mark, anyLoop.loopBegin())) {
 111                 assert anyLoop.isCounted() : "pre/post transformation loses counted loop " + anyLoop.loopBegin();
 112             }
 113         }
 114         return true;
 115     }
 116 
 117     @Override
 118     public boolean checkContract() {
 119         return false;
 120     }
 121 }