rename_map.hh

来自「M5,一个功能强大的多处理器系统模拟器.很多针对处理器架构,性能的研究都使用它作」· HH 代码 · 共 168 行

/*
 * Copyright (c) 2004, 2005
 * The Regents of The University of Michigan
 * All Rights Reserved
 *
 * This code is part of the M5 simulator.
 *
 * Permission is granted to use, copy, create derivative works and
 * redistribute this software and such derivative works for any
 * purpose, so long as the copyright notice above, this grant of
 * permission, and the disclaimer below appear in all copies made; and
 * so long as the name of The University of Michigan is not used in
 * any advertising or publicity pertaining to the use or distribution
 * of this software without specific, written prior authorization.
 *
 * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION FROM THE
 * UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY PURPOSE, AND
 * WITHOUT WARRANTY BY THE UNIVERSITY OF MICHIGAN OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE. THE REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE
 * LIABLE FOR ANY DAMAGES, INCLUDING DIRECT, SPECIAL, INDIRECT,
 * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM
 * ARISING OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
 * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGES.
 *
 * Authors: Kevin T. Lim
 */

// Todo:  Create destructor.
// Have it so that there's a more meaningful name given to the variable
// that marks the beginning of the FP registers.

#ifndef __CPU_O3_RENAME_MAP_HH__
#define __CPU_O3_RENAME_MAP_HH__

#include <iostream>
#include <utility>
#include <vector>

#include "cpu/o3/free_list.hh"
#include "arch/types.hh"

class SimpleRenameMap
{
  protected:
    typedef TheISA::RegIndex RegIndex;
  public:
    /**
     * Pair of a logical register and a physical register.  Tells the
     * previous mapping of a logical register to a physical register.
     * Used to roll back the rename map to a previous state.
     */
    typedef std::pair<RegIndex, PhysRegIndex> UnmapInfo;

    /**
     * Pair of a physical register and a physical register.  Used to
     * return the physical register that a logical register has been
     * renamed to, and the previous physical register that the same
     * logical register was previously mapped to.
     */
    typedef std::pair<PhysRegIndex, PhysRegIndex> RenameInfo;

  public:
    /** Default constructor.  init() must be called prior to use. */
    SimpleRenameMap() {};

    /** Destructor. */
    ~SimpleRenameMap();

    /** Initializes rename map with given parameters. */
    void init(unsigned _numLogicalIntRegs,
              unsigned _numPhysicalIntRegs,
              PhysRegIndex &_int_reg_start,

              unsigned _numLogicalFloatRegs,
              unsigned _numPhysicalFloatRegs,
              PhysRegIndex &_float_reg_start,

              unsigned _numMiscRegs,

              RegIndex _intZeroReg,
              RegIndex _floatZeroReg,

              int id,
              bool bindRegs);

    /** Sets the free list used with this rename map. */
    void setFreeList(SimpleFreeList *fl_ptr);

    //Tell rename map to get a free physical register for a given
    //architected register.  Not sure it should have a return value,
    //but perhaps it should have some sort of fault in case there are
    //no free registers.
    RenameInfo rename(RegIndex arch_reg);

    PhysRegIndex lookup(RegIndex phys_reg);

    /**
     * Marks the given register as ready, meaning that its value has been
     * calculated and written to the register file.
     * @param ready_reg The index of the physical register that is now ready.
     */
    void setEntry(RegIndex arch_reg, PhysRegIndex renamed_reg);

    int numFreeEntries();

  private:
    /** Rename Map ID  */
    int id;

    /** Number of logical integer registers. */
    int numLogicalIntRegs;

    /** Number of physical integer registers. */
    int numPhysicalIntRegs;

    /** Number of logical floating point registers. */
    int numLogicalFloatRegs;

    /** Number of physical floating point registers. */
    int numPhysicalFloatRegs;

    /** Number of miscellaneous registers. */
    int numMiscRegs;

    /** Number of logical integer + float registers. */
    int numLogicalRegs;

    /** Number of physical integer + float registers. */
    int numPhysicalRegs;

    /** The integer zero register.  This implementation assumes it is always
     *  zero and never can be anything else.
     */
    RegIndex intZeroReg;

    /** The floating point zero register.  This implementation assumes it is
     *  always zero and never can be anything else.
     */
    RegIndex floatZeroReg;

    class RenameEntry
    {
      public:
        PhysRegIndex physical_reg;
        bool valid;

        RenameEntry()
            : physical_reg(0), valid(false)
        { }
    };

  private:
    /** Integer rename map. */
    std::vector<RenameEntry> intRenameMap;

    /** Floating point rename map. */
    std::vector<RenameEntry> floatRenameMap;

  private:
    /** Free list interface. */
    SimpleFreeList *freeList;
};

#endif //__CPU_O3_RENAME_MAP_HH__