fail/src/core/sal/Register.hpp

#ifndef __REGISTER_HPP__
  #define __REGISTER_HPP__

#include <vector>
#include <cstdlib>
#include <cassert>
#include <string>
#include <stdint.h>

#include "SALConfig.hpp"

namespace fail {

/**
 * \enum RegisterType
 *
 * Lists the different register types. You need to expand this enumeration
 * to provide more detailed types for your concrete derived register classes
 * specific to a simulator/architecture.
 */
enum RegisterType {
	RT_GP, //!< general purpose
	RT_FP, //!< floating point register
	RT_IP, //!< program counter / instruction pointer
	RT_ST  //!< status register
};

/**
 * \class Register
 *
 * Represents the basic generic register class. A set of registers is composed
 * of classes which had been derived from this class.
 */
class Register {
protected:
	RegisterType m_Type; //!< the type of this register
	regwidth_t m_Width; //!< the register width
	unsigned int m_Id; //!< the unique id of this register
	//! \c true if register has already been assigned, \c false otherwise
	bool m_Assigned;
	//! The index in it's register set if assigned (\c -1 otherwise)
	size_t m_Index;
	std::string m_Name; //!< The (optional) name, maybe empty
	friend class UniformRegisterSet;
public:
	/**
	 * Creates a new register.
	 * @param id the unique id of this register (simulator specific)
	 * @param t the type of the register to be constructed
	 * @param w the width of the register in bits
	 */
	Register(unsigned int id, RegisterType t, regwidth_t w)
		: m_Type(t), m_Width(w), m_Id(id), m_Assigned(false),
		  m_Index(static_cast<size_t>(-1)) { }
	/**
	 * Returns the (fixed) type of this register.
	 * @return the type of this register
	 */
	RegisterType getType() const { return m_Type; }
	/**
	 * Returns the (fixed) width of this register.
	 * @return the width in bits
	 */
	regwidth_t getWidth() const { return m_Width; }
	/**
	 * Sets the (optional) name of this register.
	 * @param name the textual register name, e.g. "EAX"
	 */
	void setName(const std::string& name) { m_Name = name; }
	/**
	 * Retrieves the register name.
	 * @return the textual register description
	 */
	const std::string& getName() const { return m_Name; }
	/**
	 * Retrieves the unique index within it's assigned register set.
	 * If the register has not been assigned, \c (size_t)-1 will be
	 * returned.
	 * @return the register index or -1 if not assigned
	 * @see isAssigned()
	 */
	size_t getIndex() const { return m_Index; }
	/**
	 * Checks whether this register has already been assigned. On
	 * creation the register isn't initially assigned.
	 * @return \c true if assigned, \c false otherwise
	 */
	bool isAssigned() const { return m_Assigned; }
	/**
	 * Returns the unique id of this register.
	 * @return the unique id
	 */
	unsigned int getId() const { return m_Id; }
};

/**
 * \class UniformRegisterSet
 *
 * Represents a (type-uniform) set of registers, e.g. all general purpose
 * registers. The granularity of the register type is determined by the
 * enumeration \c RegisterType. (All registers within this set must be of the
 * same register type.) The capacity of the set is managed automatically.
 */
class UniformRegisterSet {
private:
	std::vector< Register* > m_Regs; //!< the unique set of registers
	RegisterType m_Type; //!< the overall type of this container (set)
	void m_add(Register* preg);
	friend class CPUArchitecture;
public:
	/**
	 * The iterator of this class used to loop through the list of
	 * added registers. To retrieve an iterator to the first element, call
	 * begin(). end() returns the iterator, pointing after the last element.
	 * (This behaviour equals the STL iterator in C++.)
	 */
	typedef std::vector< Register* >::iterator iterator;
	/**
	 * Returns an iterator to the beginning of the internal data structure.
	 * \code
	 * [1|2| ... |n]
	 *  ^
	 * \endcode
	 */
	iterator begin() { return m_Regs.begin(); }
	/**
	 * Returns an iterator to the end of the interal data structure.
	 * \code
	 * [1|2| ... |n]X
	 *              ^
	 * \endcode
	 */
	iterator end() { return m_Regs.end(); }
	/**
	 * Constructs a new register set with type \a containerType.
	 * @param containerType the type of registers which should be stored
	 *        in this set
	 */
	UniformRegisterSet(RegisterType containerType)
		: m_Type(containerType) { }
	/**
	 * Returns the type of this set.
	 * @return the type
	 */
	RegisterType getType() const { return m_Type; }
	/**
	 * Gets the number of registers of this set.
	 * @return the number of registers
	 */
	size_t count() const { return m_Regs.size(); }
	/**
	 * Retrieves the \a i-th register within this set.
	 * @return a pointer to the \a i-th register; if \a i is invalid, an
	 *         assertion is thrown
	 */
	Register* getRegister(size_t i) const;
	/**
	 * Retrieves the first register within this set (syntactical sugar).
	 * @return a pointer to the first register (if existing -- otherwise an
	 *         assertion is thrown)
	 */
	virtual Register* first() const { return getRegister(0); }
};

} // end-of-namespace: fail

#endif // __REGISTER_HPP__