1 /*
   2  * Copyright (c) 2009, 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.nodes;
  26 
  27 import org.graalvm.compiler.core.common.type.Stamp;
  28 import org.graalvm.compiler.graph.IterableNodeType;
  29 import org.graalvm.compiler.graph.NodeClass;
  30 import org.graalvm.compiler.nodeinfo.NodeInfo;
  31 
  32 /**
  33  * The {@code ControlSplitNode} is a base class for all instructions that split the control flow
  34  * (ie. have more than one successor).
  35  */
  36 @NodeInfo
  37 public abstract class ControlSplitNode extends FixedNode implements IterableNodeType {
  38     public static final NodeClass<ControlSplitNode> TYPE = NodeClass.create(ControlSplitNode.class);
  39 
  40     protected ControlSplitNode(NodeClass<? extends ControlSplitNode> c, Stamp stamp) {
  41         super(c, stamp);
  42     }
  43 
  44     public abstract double probability(AbstractBeginNode successor);
  45 
  46     /**
  47      * Attempts to set the probability for the given successor to the passed value (which has to be
  48      * in the range of 0.0 and 1.0). Returns whether setting the probability was successful.
  49      */
  50     public abstract boolean setProbability(AbstractBeginNode successor, double value);
  51 
  52     /**
  53      * Primary successor of the control split. Data dependencies on the node have to be scheduled in
  54      * the primary successor. Returns null if data dependencies are not expected.
  55      *
  56      * @return the primary successor
  57      */
  58     public abstract AbstractBeginNode getPrimarySuccessor();
  59 
  60     /**
  61      * Returns the number of successors.
  62      */
  63     public abstract int getSuccessorCount();
  64 }