> On 2010-07-10 14:50:15, Korey Sewell wrote: > > src/cpu/pred/bpred_unit_impl.hh, line 191 > > <http://reviews.m5sim.org/r/47/diff/1/?file=725#file725line191> > > > > Shouldnt this *not* be hardcoded to 16, but instead the true RAS size? > > > > > >
Seems reasonable to me, I'll fix this. > On 2010-07-10 14:50:15, Korey Sewell wrote: > > src/cpu/pred/bpred_unit_impl.hh, line 207 > > <http://reviews.m5sim.org/r/47/diff/1/?file=725#file725line207> > > > > What happens if the RAS is full? is it right to just overwrite the next > > entry? Presumably that's what a real processor would do, otherwise the depth of the call stack would be limited? > On 2010-07-10 14:50:15, Korey Sewell wrote: > > src/cpu/pred/bpred_unit_impl.hh, line 231 > > <http://reviews.m5sim.org/r/47/diff/1/?file=725#file725line231> > > > > If you miss on a BTB lookup and you've predicted taken, should you not > > instead stall (or have the option to stall) the CPU until branch > > resolution??? > > > > (I've got a patch for this option in another tree if people think > > that's useful) It would be a good thing to have the option of doing that, in my opinion. > On 2010-07-10 14:50:15, Korey Sewell wrote: > > src/cpu/pred/bpred_unit_impl.hh, line 395 > > <http://reviews.m5sim.org/r/47/diff/1/?file=725#file725line395> > > > > I'm not a fan of this localBP vs tournamentBP comparison we do > > everytime we need to lookup or update the predictor... > > > > Why isnt there a base predictor class that the localBP and the > > tournamentBP derive from? > > > > Eventually if someone wanted to substitute the predictor or implement > > something else (e.g. no predictor at all and always predict false), all you > > would need to do is pass that as a SimObject(?) to the branch prediction > > unit and it would be plug-n-play. I agree, and I can have a go at making the branch predictor like that, if you like? - Timothy ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: http://reviews.m5sim.org/r/47/#review69 ----------------------------------------------------------- On 2010-07-09 18:08:18, Timothy Jones wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > http://reviews.m5sim.org/r/47/ > ----------------------------------------------------------- > > (Updated 2010-07-09 18:08:18) > > > Review request for Default. > > > Summary > ------- > > BranchPred: Take the branch predictor out of O3CPU and make it a stand-alone > SimObject. This then allows the same branch predictor to be shared amongst > several CPUs. > > This patch is unfinished. I would like to take the branch predictor out of > the inorder CPU as well, but want comments on whether this is the best > approach to take first. > > > Diffs > ----- > > src/cpu/o3/O3CPU.py 249f174e6f37 > src/cpu/o3/SConscript 249f174e6f37 > src/cpu/o3/bpred_unit.hh 249f174e6f37 > src/cpu/o3/bpred_unit.cc 249f174e6f37 > src/cpu/o3/bpred_unit_impl.hh 249f174e6f37 > src/cpu/o3/cpu_builder.cc 249f174e6f37 > src/cpu/o3/cpu_policy.hh 249f174e6f37 > src/cpu/o3/fetch.hh 249f174e6f37 > src/cpu/o3/fetch_impl.hh 249f174e6f37 > src/cpu/pred/BaseBPredUnit.py PRE-CREATION > src/cpu/pred/SConscript 249f174e6f37 > src/cpu/pred/base.hh PRE-CREATION > src/cpu/pred/base.cc PRE-CREATION > src/cpu/pred/bpred_unit.hh PRE-CREATION > src/cpu/pred/bpred_unit.cc PRE-CREATION > src/cpu/pred/bpred_unit_impl.hh PRE-CREATION > src/cpu/pred/builder.cc PRE-CREATION > > Diff: http://reviews.m5sim.org/r/47/diff > > > Testing > ------- > > > Thanks, > > Timothy > > _______________________________________________ m5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/m5-dev
