From 283935a6f0a17afe4574cc3c50c043515c866dfa Mon Sep 17 00:00:00 2001 From: Mitch Hayenga Date: Wed, 3 Sep 2014 07:42:38 -0400 Subject: [PATCH] cpu: Fix o3 quiesce fetch bug O3 is supposed to stop fetching instructions once a quiesce is encountered. However due to a bug, it would continue fetching instructions from the current fetch buffer. This is because of a break statment that only broke out of the first of 2 nested loops. It should have broken out of both. --- src/cpu/o3/fetch_impl.hh | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/cpu/o3/fetch_impl.hh b/src/cpu/o3/fetch_impl.hh index d583ae7b6..e20d2970a 100644 --- a/src/cpu/o3/fetch_impl.hh +++ b/src/cpu/o3/fetch_impl.hh @@ -1236,6 +1236,9 @@ DefaultFetch::fetch(bool &status_change) // ended this fetch block. bool predictedBranch = false; + // Need to halt fetch if quiesce instruction detected + bool quiesce = false; + TheISA::MachInst *cacheInsts = reinterpret_cast(fetchBuffer[tid]); @@ -1246,7 +1249,7 @@ DefaultFetch::fetch(bool &status_change) // Keep issuing while fetchWidth is available and branch is not // predicted taken while (numInst < fetchWidth && fetchQueue[tid].size() < fetchQueueSize - && !predictedBranch) { + && !predictedBranch && !quiesce) { // We need to process more memory if we aren't going to get a // StaticInst from the rom, the current macroop, or what's already // in the decoder. @@ -1363,9 +1366,10 @@ DefaultFetch::fetch(bool &status_change) if (instruction->isQuiesce()) { DPRINTF(Fetch, - "Quiesce instruction encountered, halting fetch!"); + "Quiesce instruction encountered, halting fetch!\n"); fetchStatus[tid] = QuiescePending; status_change = true; + quiesce = true; break; } } while ((curMacroop || decoder[tid]->instReady()) && -- 2.30.2