ras.cc

来自「linux下基于c++的处理器仿真平台。具有处理器流水线」· CC 代码 · 共 77 行

/*
 * Copyright (c) 2004, 2005
 * The Regents of The University of Michigan
 * All Rights Reserved
 *
 * This code is part of the M5 simulator, developed by Nathan Binkert,
 * Erik Hallnor, Steve Raasch, and Steve Reinhardt, with contributions
 * from Ron Dreslinski, Dave Greene, Lisa Hsu, Kevin Lim, Ali Saidi, 
 * and Andrew Schultz.
 *
 * 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.
 */

#include "cpu/o3/ras.hh"

ReturnAddrStack::ReturnAddrStack(unsigned _numEntries)
    : numEntries(_numEntries), usedEntries(0),
      tos(0)
{
    addrStack = new Addr[numEntries];

    for (int i = 0; i < numEntries; ++i)
        addrStack[i] = 0;
}

void 
ReturnAddrStack::push(const Addr &return_addr)
{
    incrTos();

    addrStack[tos] = return_addr;

    if (usedEntries != numEntries) {
        ++usedEntries;
    }
}

void 
ReturnAddrStack::pop()
{
    // Not sure it's possible to really track usedEntries properly.
//    assert(usedEntries > 0);

    if (usedEntries > 0) {
        --usedEntries;
    }

    decrTos();
}

void 
ReturnAddrStack::restore(unsigned top_entry_idx, 
                         const Addr &restored_target)
{
    tos = top_entry_idx;

    addrStack[tos] = restored_target;
}