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src/cpu/pred/bpred_unit_impl.hh <http://reviews.m5sim.org/r/47/#comment222> What if there is no valid entry at the top here? (the call stack is greater than RAS size)... In the later comment, I discuss options for this... src/cpu/pred/bpred_unit_impl.hh <http://reviews.m5sim.org/r/47/#comment221> But isnt the depth of a stack limited by the size of the RAS anyway? Say we have 16 entries, then the call stack is limited by 16 no? I have 2 concerns here (and for surrounding RAS code): (1) If the RAS does overflow and we want to just keep overwriting, then are we always overwriting the to the right entry? (2) If there is no valid RAS entry (in the case of the call stack being greater than the RAS size), then the branch prediction needs to either return false or simply stall until resolution (similar to the BTB concern I had) - Korey 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
