dependenceflowedge.java

来自「一种将c高级语言转化给VHDL的编译器」· Java 代码 · 共 154 行

/*
 *
 LA-CC 05-135 Trident 0.7.1

Copyright Notice
Copyright 2006 (c) the Regents of the University of California.

This Software was produced under a U.S. Government contract
(W-7405-ENG-36) by Los Alamos National Laboratory, which is operated
by the University of California for the U.S. Department of Energy. The
U.S. Government is licensed to use, reproduce, and distribute this
Software. Permission is granted to the public to copy and use this
Software without charge, provided that this Notice and any statement
of authorship are reproduced on all copies. Neither the Government nor
the University makes any warranty, express or implied, or assumes any
liability or responsibility for the user of this Software.


 */


package fp.flowgraph;

import fp.graph.Edge;

/** 
 * A directed edge in a data-flow graph
 * 
 * @author Nathan Kitchen
 * copied and modified by Kris Peterson
 */
public class DependenceFlowEdge extends Edge {
  /** 
   * An object that identifies the condition for which this
   * transition is taken
   */
  Object _label;
  /** is this edge a data dependence edge?
   */
  boolean _isDataEdge;
   
  /** does this edge effect the next iteration of the loop, or the current?
   */
  boolean _isBackWardsPointing;
   
  /** 
   * Construct a new data-flow edge with no tag, no source, and no sink
   */
  public DependenceFlowEdge() {
    this(null);
  }
  
  /** 
   * Construct a new data-flow edge with the given tag, no source, and
   * no sink
   */
  public DependenceFlowEdge(Object tag) {
    super(tag);
    setDotAttribute("label", "");
    _isBackWardsPointing = false;
    _isDataEdge = false;
    if(_isDataEdge)       
      setLabel("Data Dependency Flow Edge: forwards pointing");
    else 
      setLabel("Control Dependency Flow Edge: forwards pointing");
  }
  
  /** 
   * Construct a new data-flow edge with no tag from <code>source</code>
   * to <code>sink</code>
   */
  public DependenceFlowEdge(DependenceFlowNode source, DependenceFlowNode sink){
    this(source, sink, null);
  }
  
  /** 
   * Construct a new data-flow edge with the given tag from
   * <code>source</code> to <code>sink</code>
   */
  public DependenceFlowEdge(DependenceFlowNode source, DependenceFlowNode sink, 
                            Object tag) {
    super(source, sink, tag);
    setDotAttribute("label", "");
    _isBackWardsPointing = false;
    _isDataEdge = false;
  }
   
  /** defines this edge as a Data Dependence Edge (as opposed to a Control 
   *  Dependence Edge--the default).
   */
  public void setIsDataEdge(){_isDataEdge = true;}
  /** return if this edge is a data dependence edge instead of a control 
   *  dependence edge
   * 
   * @return true if data dependence edge; false if control dependence edge
   */
  //public boolean getIsDataEdge(){return _isDataEdge;}
  public final boolean getIsDataEdge() {
    return this instanceof DependenceDataFlowEdge;
  }
  public final boolean getIsCntrlEdge() {
    return this instanceof DependenceCntrlFlowEdge;
  }
   
  /** save if this edge is a recursive edge going over the loop boundary.
   * 
   * @param b_boolean whether or not the edge is recursive
   */
  public void setisBackWardsPointing(boolean b_boolean) {
    _isBackWardsPointing = b_boolean;
     
    if(_isDataEdge) {
      setDotAttribute("color", "purple");
      if(b_boolean)
        setLabel("Data Dependency Flow Edge: backwards pointing");
    }
    else {
      setDotAttribute("color", "orange");
      if(b_boolean)
        setLabel("Control Dependency Flow Edge: backwards pointing");
    }
  }
  /** save if this edge is a recursive edge going over the loop boundary.
   * 
   * @param b_boolean whether or not the edge is recursive
   */
  public void setBackWardsPointing() {
    _isBackWardsPointing = true;
     
    if(_isDataEdge) {
      setDotAttribute("color", "purple");
      setLabel("Data Dependency Flow Edge: backwards pointing");
    }
    else {
      setDotAttribute("color", "orange");
      setLabel("Control Dependency Flow Edge: backwards pointing");
    }
  }
  /** return if this edge is a recursive edge going over the loop boundary.
   * 
   * @return true if edge is recursive; false if not
   */
  public boolean getisBackWardsPointing(){return _isBackWardsPointing;}
  
  /** 
   * Assigns the object that identifies the condition for which this
   * transition is taken
   */
  public void setLabel(Object label) {
    _label = label;
    setDotAttribute("label", label == null ? "" : label.toString());
  }
}