summaryrefslogtreecommitdiff
path: root/lib/Transforms
diff options
context:
space:
mode:
authorHal Finkel <hfinkel@anl.gov>2013-11-30 20:55:12 +0000
committerHal Finkel <hfinkel@anl.gov>2013-11-30 20:55:12 +0000
commit15c773b6f276edfd57712cb9c2dd1738ef79efbd (patch)
tree6ef03c2c6f6ced5a3eb510a7e174f54fa35d1da5 /lib/Transforms
parentbc0bdb26da10037e182d83707aeb51b49ae35d8a (diff)
downloadllvm-15c773b6f276edfd57712cb9c2dd1738ef79efbd.tar.gz
llvm-15c773b6f276edfd57712cb9c2dd1738ef79efbd.tar.bz2
llvm-15c773b6f276edfd57712cb9c2dd1738ef79efbd.tar.xz
Add a scheduling model (with itinerary) for the PPC POWER7
This adds a scheduling model for the POWER7 (P7) core, and enables the machine-instruction scheduler when targeting the P7. Scheduling for the P7, like earlier ooo PPC cores, requires considering both dispatch group hazards, and functional unit resources and latencies. These are both modeled in a combined itinerary. Dispatch group formation is still handled by the post-RA scheduler (which still needs to be updated for the P7, but nevertheless does a pretty good job). One interesting aspect of this change is that I've also enabled to use of AA duing CodeGen for the P7 (just as it is for the embedded cores). The benchmark results seem to support this decision (see below), and while this is normally useful for in-order cores, and not for ooo cores like the P7, I think that the dispatch slot hazards are enough like in-order resources to make the AA useful. Test suite significant performance differences (where negative is a speedup, and positive is a regression) vs. the current situation: MultiSource/Benchmarks/BitBench/drop3/drop3 with AA: N/A without AA: -28.7614% +/- 19.8356% (significantly against AA) MultiSource/Benchmarks/FreeBench/neural/neural with AA: -17.7406% +/- 11.2712% without AA: N/A (significantly in favor of AA) MultiSource/Benchmarks/SciMark2-C/scimark2 with AA: -11.2079% +/- 1.80543% without AA: -11.3263% +/- 2.79651% MultiSource/Benchmarks/TSVC/Symbolics-flt/Symbolics-flt with AA: -41.8649% +/- 17.0053% without AA: -34.5256% +/- 23.7072% MultiSource/Benchmarks/mafft/pairlocalalign with AA: 25.3016% +/- 17.8614% without AA: 38.6629% +/- 14.9391% (significantly in favor of AA) MultiSource/Benchmarks/sim/sim with AA: N/A without AA: 13.4844% +/- 7.18195% (significantly in favor of AA) SingleSource/Benchmarks/BenchmarkGame/Large/fasta with AA: 15.0664% +/- 6.70216% without AA: 12.7747% +/- 8.43043% SingleSource/Benchmarks/BenchmarkGame/puzzle with AA: 82.2713% +/- 26.3567% without AA: 75.7525% +/- 41.1842% SingleSource/Benchmarks/Misc/flops-2 with AA: -37.1621% +/- 20.7964% without AA: -35.2342% +/- 20.2999% (significantly in favor of AA) These are 99.5% confidence intervals from 5 runs per configuration. Regarding the choice to turn on AA during CodeGen, of these results, four seem significantly in favor of using AA, and one seems significantly against. I'm not making this decision based on these numbers alone, but these results seem consistent with results I have from other tests, and so I think that, on balance, using AA is a win. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195981 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms')
0 files changed, 0 insertions, 0 deletions