From 1716749c8cec6f9c9f10a0aeaff981be759bb4e5 Mon Sep 17 00:00:00 2001 From: Mitch Hayenga Date: Wed, 3 Sep 2014 07:42:34 -0400 Subject: cpu: Fix o3 front-end pipeline interlock behavior The o3 pipeline interlock/stall logic is incorrect. o3 unnecessicarily stalled fetch and decode due to later stages in the pipeline. In general, a stage should usually only consider if it is stalled by the adjacent, downstream stage. Forcing stalls due to later stages creates and results in bubbles in the pipeline. Additionally, o3 stalled the entire frontend (fetch, decode, rename) on a branch mispredict while the ROB is being serially walked to update the RAT (robSquashing). Only should have stalled at rename. --- src/cpu/o3/comm.hh | 2 -- 1 file changed, 2 deletions(-) (limited to 'src/cpu/o3/comm.hh') diff --git a/src/cpu/o3/comm.hh b/src/cpu/o3/comm.hh index ab0a9ff42..a425484f5 100644 --- a/src/cpu/o3/comm.hh +++ b/src/cpu/o3/comm.hh @@ -229,8 +229,6 @@ struct TimeBufStruct { bool renameUnblock[Impl::MaxThreads]; bool iewBlock[Impl::MaxThreads]; bool iewUnblock[Impl::MaxThreads]; - bool commitBlock[Impl::MaxThreads]; - bool commitUnblock[Impl::MaxThreads]; }; #endif //__CPU_O3_COMM_HH__ -- cgit v1.2.3