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Vadim Yanitskiy axilirator at gmail.comHi Tom, Thank you for explainations! > Potential Viterbi optimization using SIMD methods is substantial as I > demonstrated many years ago. The implementation does require > separation of puncturing and Viterbi. Unfortunately, the has code > experienced code rot since then. Admittedly, I accept much of that > blame. I think it would be really good to have/use your Viterbi implementation inside the libosmocoding. Regarding to some remarks to your code, I am ready to fix them (such as malloc -> talloc). Moreover, recently I had a conversation with Alexander Chemeris. He also mentioned your implementation, which would be better to use in embedded platforms (such as UmSITE) due to performance reasons. > In summary, my concern is about the implementation and not the API. > Perhaps we could pull the puncturing into the library as Max suggests. > Then, separately, consider performance changes to the internal > puncturing and Viterbi implementations. So, my suggestion is to: 1) Extend your code with encoding capabilities. 2) Merge Viterbi transcoder with the libosmocoding. 3) Merge libosmocoding into libosmocore as a sub-library or spawn a separate repository. Any opinions? With best regards, Vadim Yanitskiy. 2016-10-13 1:54 GMT+07:00 Tom Tsou <tom at tsou.cc>: > On Wed, Oct 12, 2016 at 10:58 AM, Max <msuraev at sysmocom.de> wrote: > > Is there some microbenchmark available? Perhaps we can use it to improve > > generated code? > > Potential Viterbi optimization using SIMD methods is substantial as I > demonstrated many years ago. The implementation does require > separation of puncturing and Viterbi. Unfortunately, the has code > experienced code rot since then. Admittedly, I accept much of that > blame. > > ================================================= > [+] Testing: GSM TCH/AFS 6.7 > [.] Specs: (N=4, K=5, recursive, flushed, punctured) > [.] Input length : ret = 140 exp = 140 -> OK > [.] Output length : ret = 448 exp = 448 -> OK > > [.] Performance benchmark: > [..] Encoding / Decoding 800000 bursts on 8 thread(s): > [..] Testing base: > [..] Elapsed time....................... 4.320001 secs > [..] Rate............................... 25.925920 Mbps > [..] Testing SIMD: > [..] Elapsed time....................... 0.458272 secs > [..] Rate............................... 244.396341 Mbps > [..] Speedup............................ 9.426718 > > http://lists.osmocom.org/pipermail/openbsc/2014-April/007365.html > > -TT > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.osmocom.org/pipermail/openbsc/attachments/20161014/4e71d813/attachment.htm>