1 /*
   2  * Copyright (c) 2014, 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 package org.graalvm.compiler.nodes.cfg;
  24 
  25 import org.graalvm.compiler.core.common.LocationIdentity;
  26 import org.graalvm.compiler.core.common.cfg.Loop;
  27 import org.graalvm.compiler.nodes.LoopBeginNode;
  28 
  29 public final class HIRLoop extends Loop<Block> {
  30 
  31     private LocationSet killLocations;
  32 
  33     protected HIRLoop(Loop<Block> parent, int index, Block header) {
  34         super(parent, index, header);
  35     }
  36 
  37     @Override
  38     public long numBackedges() {
  39         return ((LoopBeginNode) getHeader().getBeginNode()).loopEnds().count();
  40     }
  41 
  42     public LocationSet getKillLocations() {
  43         if (killLocations == null) {
  44             killLocations = new LocationSet();
  45             for (Block b : this.getBlocks()) {
  46                 if (b.getLoop() == this) {
  47                     killLocations.addAll(b.getKillLocations());
  48                     if (killLocations.isAny()) {
  49                         break;
  50                     }
  51                 }
  52             }
  53         }
  54         for (Loop<Block> child : this.getChildren()) {
  55             if (killLocations.isAny()) {
  56                 break;
  57             }
  58             killLocations.addAll(((HIRLoop) child).getKillLocations());
  59         }
  60         return killLocations;
  61     }
  62 
  63     public boolean canKill(LocationIdentity location) {
  64         return getKillLocations().contains(location);
  65     }
  66 
  67     @Override
  68     public String toString() {
  69         return super.toString() + " header:" + getHeader().getBeginNode();
  70     }
  71 }