/* }}} */
Time_t StridePrefetcher::nextInvalidateSlot( const MemRequest *mreq)
/* calculate next free time {{{1 */
{
if (nextBuffSlot() > nextTableSlot())
return nextBuffSlot();
return nextTableSlot();
}
/* }}} */
Time_t StridePrefetcher::nextBusReadSlot( const MemRequest *mreq)
/* calculate next free time {{{1 */
{
return globalClock;
if (nextBuffSlot() > nextTableSlot())
return nextBuffSlot();
return nextTableSlot();
}
void MarkovPrefetcher::insertTable(PAddr addr){
uint32_t tag = table->calcTag(addr);
Time_t lat = 0;
if(tag){
tEntry = table->readLine(addr);
if(tEntry){
lat = nextTableSlot() - globalClock;
prefetch(tEntry->predAddr1,lat);
lat = nextTableSlot() - globalClock;
prefetch(tEntry->predAddr2,lat);
lat = nextTableSlot() - globalClock;
prefetch(tEntry->predAddr3,lat);
lat = nextTableSlot() - globalClock;
prefetch(tEntry->predAddr4,lat);
//LOG("Prefetch %d", tEntry->predAddr1);
//LOG("Prefetch %d", tEntry->predAddr2);
}else{
tEntry = table->fillLine(addr);
}
LOG("last Addr %d", lastAddr);
tEntry = table->readLine(lastAddr);
//update last entry
tEntry->predAddr4 = tEntry->predAddr3;
tEntry->predAddr3 = tEntry->predAddr2;
tEntry->predAddr2 = tEntry->predAddr1;
tEntry->predAddr1 = addr;
lastAddr = addr;
}
}
void AlwaysPrefetch::read(MemRequest *mreq)
{
uint32_t paddr = mreq->getPAddr() & defaultMask;
bLine *l = buff->readLine(paddr);
if(l) { //hit
LOG("NLAP: hit on [%08lx]", (long unsigned int) paddr);
hit.inc();
mreq->goUpAbs(nextBuffSlot());
return;
}
penFetchSet::iterator it = pendingFetches.find(paddr);
if(it != pendingFetches.end()) { // half-miss
LOG("NLAP: half-miss on %08lx",(long unsigned int) paddr);
penReqMapper::iterator itR = pendingRequests.find(paddr);
halfMiss.inc();
if (itR == pendingRequests.end()) {
pendingRequests[paddr] = activeMemReqPool.out();
itR = pendingRequests.find(paddr);
}
I(itR != pendingRequests.end());
(*itR).second->push(mreq);
//prefetch(paddr+lineSize, 0);
//prefetch( paddr + buff->getLineSize(), 0 );
return;
}
LOG("NLAP: miss on [%08lx]", (long unsigned int) paddr);
miss.inc();
Time_t lat = nextTableSlot() - globalClock;
prefetch(paddr+(buff->getLineSize()), lat);
lat = nextTableSlot() - globalClock;
prefetch(paddr+(2*buff->getLineSize()), lat);
mreq->goDown(0, lowerLevel[0]);
}
void StridePrefetcher::learnHit(PAddr addr)
{
uint paddr = addr & defaultMask;
pEntry *pe = table->readLine(paddr);
Time_t lat = nextTableSlot() - globalClock;
if(pe == 0) // this hit in the buffer came from data
return; // from a no longer active stream
prefetch(pe, lat + learnHitDelay);
pe->setTag(table->calcTag(pe->nextAddr(table)));
LOG("SP:prefetching more: addr=%08lx", paddr + pe->stride);
}
void StridePrefetcher::learnMiss(AddrType addr) {
AddrType paddr = addr & defaultMask;
Time_t lat = nextTableSlot() - globalClock;
bool foundUnitStride = false;
uint32_t newStride = 0;
uint32_t minDelta = (uint32_t) -1;
bool goingUp = true;
if(lastMissesQ.empty()) {
lastMissesQ.push_back(paddr);
return;
}
// man, this is baad. i have to do a better search here
std::deque<AddrType>::iterator it = lastMissesQ.begin();
while(it != lastMissesQ.end()) {
uint32_t delta;
if(paddr < (*it)) {
goingUp = false;
delta = (*it) - paddr;
} else {
goingUp = true;
delta = paddr - (*it);
}
minDelta = (delta < minDelta ? delta : minDelta);
if((*it) == paddr - buff->getLineSize() || (*it) == paddr + buff->getLineSize()) {
foundUnitStride = true;
break;
}
it++;
}
// putting the new miss in the queue after we computed the stride
lastMissesQ.push_back(paddr);
if(lastMissesQ.size() > missWindow)
lastMissesQ.pop_front();
if(foundUnitStride) {
unitStrideStreams.inc();
newStride = buff->getLineSize();
} else {
nonUnitStrideStreams.inc();
newStride = minDelta;
}
if(newStride == 0 || newStride == (uint32_t) -1 || newStride > maxStride) {
ignoredStreams.inc();
return;
}
AddrType nextAddr = goingUp ? paddr + newStride : paddr - newStride;
if(!table->readLine(nextAddr) && !table->readLine(paddr)) {
pEntry *pe = table->fillLine(paddr);
pe->stride = newStride;
pe->goingUp = goingUp;
}
if (pendingRequests> MaxPendingRequests) {
// FIXME: fetch the depth following addresses
AddrType paddr = nextAddr & defaultMask;
bLine *l = buff->readLine(paddr);
if (l==0) {
MemRequest *mreq = MemRequest::createRead(this, nextAddr, 0);
router->fwdBusRead(mreq, missDelay);
}
}
}
void StridePrefetcher::learnMiss(PAddr addr)
{
uint paddr = addr & defaultMask;
Time_t lat = nextTableSlot() - globalClock;
bool foundUnitStride = false;
uint newStride = 0;
uint minDelta = (uint) -1;
bool goingUp = true;
if(lastMissesQ.empty()) {
lastMissesQ.push_back(paddr);
return;
}
// man, this is baad. i have to do a better search here
std::deque<PAddr>::iterator it = lastMissesQ.begin();
while(it != lastMissesQ.end()) {
uint delta;
if(paddr < (*it)) {
goingUp = false;
delta = (*it) - paddr;
} else {
goingUp = true;
delta = paddr - (*it);
}
minDelta = (delta < minDelta ? delta : minDelta);
if((*it) == paddr - buff->getLineSize() || (*it) == paddr + buff->getLineSize()) {
foundUnitStride = true;
break;
}
it++;
}
// putting the new miss in the queue after we computed the stride
lastMissesQ.push_back(paddr);
if(lastMissesQ.size() > missWindow)
lastMissesQ.pop_front();
if(foundUnitStride) {
unitStrideStreams.inc();
newStride = buff->getLineSize();
} else {
nonUnitStrideStreams.inc();
newStride = minDelta;
}
LOG("minDelta = %ld", minDelta);
if(newStride == 0 || newStride == (uint) -1 || newStride > maxStride) {
ignoredStreams.inc();
return;
}
PAddr nextAddr = goingUp ? paddr + newStride : paddr - newStride;
// TODO: do a better check if there is an overlapping stream
if(!table->readLine(nextAddr) && !table->readLine(paddr)) {
pEntry *pe = table->fillLine(paddr);
pe->stride = newStride;
pe->goingUp = goingUp;
LOG("SP: new stream. stride=%d paddr=%08lx nextAddr=%08lx %s", (int) newStride, paddr, nextAddr, goingUp ? "UP" : "DOWN");
prefetch(pe, lat + learnMissDelay);
pe->setTag(table->calcTag(pe->nextAddr(table)));
}
}
