fu_pool.cc

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」· CC 代码 · 共 283 行

/*
 * Copyright (c) 2006
 * 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
 */

#include <sstream>

#include "cpu/o3/fu_pool.hh"
#include "cpu/func_unit.hh"

using namespace std;

////////////////////////////////////////////////////////////////////////////
//
//  A pool of function units
//

inline void
FUPool::FUIdxQueue::addFU(int fu_idx)
{
    funcUnitsIdx.push_back(fu_idx);
    ++size;
}

inline int
FUPool::FUIdxQueue::getFU()
{
    int retval = funcUnitsIdx[idx++];

    if (idx == size)
        idx = 0;

    return retval;
}

FUPool::~FUPool()
{
    fuListIterator i = funcUnits.begin();
    fuListIterator end = funcUnits.end();
    for (; i != end; ++i)
        delete *i;
}


// Constructor
FUPool::FUPool(const Params *p)
    : SimObject(p)
{
    numFU = 0;

    funcUnits.clear();

    for (int i = 0; i < Num_OpClasses; ++i) {
        maxOpLatencies[i] = 0;
        maxIssueLatencies[i] = 0;
    }

    //
    //  Iterate through the list of FUDescData structures
    //
    const vector<FUDesc *> &paramList =  p->FUList;
    for (FUDDiterator i = paramList.begin(); i != paramList.end(); ++i) {

        //
        //  Don't bother with this if we're not going to create any FU's
        //
        if ((*i)->number) {
            //
            //  Create the FuncUnit object from this structure
            //   - add the capabilities listed in the FU's operation
            //     description
            //
            //  We create the first unit, then duplicate it as needed
            //
            FuncUnit *fu = new FuncUnit;

            OPDDiterator j = (*i)->opDescList.begin();
            OPDDiterator end = (*i)->opDescList.end();
            for (; j != end; ++j) {
                // indicate that this pool has this capability
                capabilityList.set((*j)->opClass);

                // Add each of the FU's that will have this capability to the
                // appropriate queue.
                for (int k = 0; k < (*i)->number; ++k)
                    fuPerCapList[(*j)->opClass].addFU(numFU + k);

                // indicate that this FU has the capability
                fu->addCapability((*j)->opClass, (*j)->opLat, (*j)->issueLat);

                if ((*j)->opLat > maxOpLatencies[(*j)->opClass])
                    maxOpLatencies[(*j)->opClass] = (*j)->opLat;

                if ((*j)->issueLat > maxIssueLatencies[(*j)->opClass])
                    maxIssueLatencies[(*j)->opClass] = (*j)->issueLat;
            }

            numFU++;

            //  Add the appropriate number of copies of this FU to the list
            ostringstream s;

            s << (*i)->name() << "(0)";
            fu->name = s.str();
            funcUnits.push_back(fu);

            for (int c = 1; c < (*i)->number; ++c) {
                ostringstream s;
                numFU++;
                FuncUnit *fu2 = new FuncUnit(*fu);

                s << (*i)->name() << "(" << c << ")";
                fu2->name = s.str();
                funcUnits.push_back(fu2);
            }
        }
    }

    unitBusy.resize(numFU);

    for (int i = 0; i < numFU; i++) {
        unitBusy[i] = false;
    }
}

void
FUPool::annotateMemoryUnits(unsigned hit_latency)
{
    maxOpLatencies[MemReadOp] = hit_latency;

    fuListIterator i = funcUnits.begin();
    fuListIterator iend = funcUnits.end();
    for (; i != iend; ++i) {
        if ((*i)->provides(MemReadOp))
            (*i)->opLatency(MemReadOp) = hit_latency;

        if ((*i)->provides(MemWriteOp))
            (*i)->opLatency(MemWriteOp) = hit_latency;
    }
}

int
FUPool::getUnit(OpClass capability)
{
    //  If this pool doesn't have the specified capability,
    //  return this information to the caller
    if (!capabilityList[capability])
        return -2;

    int fu_idx = fuPerCapList[capability].getFU();
    int start_idx = fu_idx;

    // Iterate through the circular queue if needed, stopping if we've reached
    // the first element again.
    while (unitBusy[fu_idx]) {
        fu_idx = fuPerCapList[capability].getFU();
        if (fu_idx == start_idx) {
            // No FU available
            return -1;
        }
    }

    assert(fu_idx < numFU);

    unitBusy[fu_idx] = true;

    return fu_idx;
}

void
FUPool::freeUnitNextCycle(int fu_idx)
{
    assert(unitBusy[fu_idx]);
    unitsToBeFreed.push_back(fu_idx);
}

void
FUPool::processFreeUnits()
{
    while (!unitsToBeFreed.empty()) {
        int fu_idx = unitsToBeFreed.back();
        unitsToBeFreed.pop_back();

        assert(unitBusy[fu_idx]);

        unitBusy[fu_idx] = false;
    }
}

void
FUPool::dump()
{
    cout << "Function Unit Pool (" << name() << ")\n";
    cout << "======================================\n";
    cout << "Free List:\n";

    for (int i = 0; i < numFU; ++i) {
        if (unitBusy[i]) {
            continue;
        }

        cout << "  [" << i << "] : ";

        cout << funcUnits[i]->name << " ";

        cout << "\n";
    }

    cout << "======================================\n";
    cout << "Busy List:\n";
    for (int i = 0; i < numFU; ++i) {
        if (!unitBusy[i]) {
            continue;
        }

        cout << "  [" << i << "] : ";

        cout << funcUnits[i]->name << " ";

        cout << "\n";
    }
}

void
FUPool::switchOut()
{
}

void
FUPool::takeOverFrom()
{
    for (int i = 0; i < numFU; i++) {
        unitBusy[i] = false;
    }
    unitsToBeFreed.clear();
}

//

////////////////////////////////////////////////////////////////////////////
//
//  The SimObjects we use to get the FU information into the simulator
//
////////////////////////////////////////////////////////////////////////////

//
//    FUPool - Contails a list of FUDesc objects to make available
//

//
//  The FuPool object
//
FUPool *
FUPoolParams::create()
{
    return new FUPool(this);
}