diff --git a/src/mem/cache/prefetch/Prefetcher.py b/src/mem/cache/prefetch/Prefetcher.py index 7d7aeed321..c4b6b8845c 100644 --- a/src/mem/cache/prefetch/Prefetcher.py +++ b/src/mem/cache/prefetch/Prefetcher.py @@ -65,6 +65,8 @@ class BasePrefetcher(ClockedObject): "Only prefetch on read requests (write requests ignored)") on_prefetch = Param.Bool(True, "Let lower cache prefetcher train on prefetch requests") + inst_tagged = Param.Bool(True, + "Perform a tagged prefetch for instruction fetches always") sys = Param.System(Parent.any, "System this device belongs to") class GHBPrefetcher(BasePrefetcher): diff --git a/src/mem/cache/prefetch/stride.cc b/src/mem/cache/prefetch/stride.cc index a7abf48094..c4cf2023aa 100644 --- a/src/mem/cache/prefetch/stride.cc +++ b/src/mem/cache/prefetch/stride.cc @@ -66,6 +66,23 @@ StridePrefetcher::calculatePrefetch(PacketPtr &pkt, std::list &addresses, assert(master_id < Max_Contexts); std::list &tab = table[master_id]; + // Revert to simple N-block ahead prefetch for instruction fetches + if (instTagged && pkt->req->isInstFetch()) { + for (int d = 1; d <= degree; d++) { + Addr new_addr = data_addr + d * blkSize; + if (pageStop && !samePage(data_addr, new_addr)) { + // Spanned the page, so now stop + pfSpanPage += degree - d + 1; + return; + } + DPRINTF(HWPrefetch, "queuing prefetch to %x @ %d\n", + new_addr, latency); + addresses.push_back(new_addr); + delays.push_back(latency); + } + return; + } + /* Scan Table for instAddr Match */ std::list::iterator iter; for (iter = tab.begin(); iter != tab.end(); iter++) { diff --git a/src/mem/cache/prefetch/stride.hh b/src/mem/cache/prefetch/stride.hh index b02d97d569..0e31984f96 100644 --- a/src/mem/cache/prefetch/stride.hh +++ b/src/mem/cache/prefetch/stride.hh @@ -76,10 +76,12 @@ class StridePrefetcher : public BasePrefetcher std::list table[Max_Contexts]; + bool instTagged; + public: StridePrefetcher(const Params *p) - : BasePrefetcher(p) + : BasePrefetcher(p), instTagged(p->inst_tagged) { }