/*
 * Copyright (c) 2009-2011, IETR/INSA of Rennes
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *   * Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *   * Neither the name of the IETR/INSA of Rennes nor the names of its
 *     contributors may be used to endorse or promote products derived from this
 *     software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 */
package net.sf.orcc.ir;

import org.eclipse.emf.common.util.EList;

/**
 * This interface defines an assignment of the result of a <code>phi</code>
 * function to a target local variable.
 * 
 * @author Matthieu Wipliez
 * @model extends="net.sf.orcc.ir.Instruction"
 */
public interface InstPhi extends Instruction {

	/**
	 * Returns the "old" variable of this phi. Only used when translating to SSA
	 * form.
	 * 
	 * @return the "old" variable of this phi
	 * @model
	 */
	Var getOldVariable();

	/**
	 * Returns the target of this call (may be <code>null</code>).
	 * 
	 * @return the target of this phi assignment (may be <code>null</code>)
	 * @model containment="true"
	 */
	Def getTarget();

	/**
	 * Returns the values of this phi instruction.
	 * 
	 * @return the values of this phi instruction
	 * @model containment="true"
	 */
	EList<Expression> getValues();

	/**
	 * Sets the "old" variable to be remembered when examining the "else" branch
	 * of an if. Only used when translating to SSA form.
	 * 
	 * @param old
	 *            an "old" variable
	 */
	void setOldVariable(Var old);

	/**
	 * Sets the target of this phi assignment.
	 * 
	 * @param target
	 *            a local variable
	 */
	void setTarget(Def target);

}