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Ship it! Ship It! - Anthony Gutierrez On Nov. 29, 2013, 4:36 p.m., Andreas Sandberg wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > http://reviews.gem5.org/r/2095/ > ----------------------------------------------------------- > > (Updated Nov. 29, 2013, 4:36 p.m.) > > > Review request for Default. > > > Repository: gem5 > > > Description > ------- > > Changeset 9991:ae26c5a9ba33 > --------------------------- > cpu: simple: Add support for using branch predictors > > This changesets adds branch predictor support to the > BaseSimpleCPU. The simple CPUs normally don't need a branch predictor, > however, there are at least two cases where it can be desirable: > > 1) A simple CPU can be used to warm the branch predictor of an O3 > CPU before switching to the slower O3 model. > > 2) The simple CPU can be used as a quick way of evaluating/debugging > new branch predictors since it exposes branch predictor > statistics. > > Limitations: > * Since the simple CPU doesn't speculate, only one instruction will > be active in the branch predictor at a time (i.e., the branch > predictor will never see speculative branches). > > * The outcome of a branch prediction does not affect the performance > of the simple CPU. > > > Diffs > ----- > > src/cpu/simple/BaseSimpleCPU.py 12a0efdde000 > src/cpu/simple/base.hh 12a0efdde000 > src/cpu/simple/base.cc 12a0efdde000 > > Diff: http://reviews.gem5.org/r/2095/diff/ > > > Testing > ------- > > X86/quick/(fs|se) pass (modulo the additional statistics). We have used it > for a long time to warm branch predictors in several SMARTS-like sampling > strategies with good results. > > > Thanks, > > Andreas Sandberg > > _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
