xref: /gem5/src/cpu/o3/free_list.cc

/*
 * Copyright (c) 2004-2005 The Regents of The University of Michigan
 * 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 copyright holders 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 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Kevin Lim
 */

#include "base/trace.hh"

#include "cpu/o3/free_list.hh"

SimpleFreeList::SimpleFreeList(unsigned _numLogicalIntRegs,
                               unsigned _numPhysicalIntRegs,
                               unsigned _numLogicalFloatRegs,
                               unsigned _numPhysicalFloatRegs)
    : numLogicalIntRegs(_numLogicalIntRegs),
      numPhysicalIntRegs(_numPhysicalIntRegs),
      numLogicalFloatRegs(_numLogicalFloatRegs),
      numPhysicalFloatRegs(_numPhysicalFloatRegs),
      numPhysicalRegs(numPhysicalIntRegs + numPhysicalFloatRegs)
{
    DPRINTF(FreeList, "FreeList: Creating new free list object.\n");

    // DEBUG stuff.
    freeIntRegsScoreboard.resize(numPhysicalIntRegs);

    freeFloatRegsScoreboard.resize(numPhysicalRegs);

    for (PhysRegIndex i = 0; i < numLogicalIntRegs; ++i) {
        freeIntRegsScoreboard[i] = 0;
    }

    // Put all of the extra physical registers onto the free list.  This
    // means excluding all of the base logical registers.
    for (PhysRegIndex i = numLogicalIntRegs;
         i < numPhysicalIntRegs; ++i)
    {
        freeIntRegs.push(i);

        freeIntRegsScoreboard[i] = 1;
    }

    for (PhysRegIndex i = 0; i < numPhysicalIntRegs + numLogicalFloatRegs;
         ++i)
    {
        freeFloatRegsScoreboard[i] = 0;
    }

    // Put all of the extra physical registers onto the free list.  This
    // means excluding all of the base logical registers.  Because the
    // float registers' indices start where the physical registers end,
    // some math must be done to determine where the free registers start.
    for (PhysRegIndex i = numPhysicalIntRegs + numLogicalFloatRegs;
         i < numPhysicalRegs; ++i)
    {
        freeFloatRegs.push(i);

        freeFloatRegsScoreboard[i] = 1;
    }
}