On Fri, Jun 14, 2019 at 1:44 PM lejeczek via R-devel <r-devel@r-project.org> wrote:
> On 13/06/2019 16:14, Dirk Eddelbuettel wrote: > > On 13 June 2019 at 16:05, lejeczek via R-devel wrote: > > | I'd like to ask, and I believe this place here should be best as who > can > > | know better, if building R with different compilers and opt flags is > > | something worth investing time into? > > | > > | Or maybe this a subject that somebody has already investigated. If yes > > | what then are the conclusion? > It is worth spending sometime,but all in all, you may end disapointed. There are other things you may try: new Intel Linux distro (optimized for Intelprocessors); build with Clang compiler instead of GCC; use optimized BLAS (that's indeed a very good idea,look for openblas). I have build R with Intel MKL.The libraries are free for one year (maybe did it change). The build is far from being trivial. Please find on my github[0] some details > | > > | Reason I ask is such that, on Centos 7.6 with different compilers from > > | stock repo but also from so called software collections, do not > > | render(with flags for performance) an R binaries which would perform > any > > | better, according to R-benchmark-25 at least, then "vanilla" packages > > | shipped from distro. > > | > > | And that makes me curious - is it because R is such a case which is > > | prone to any compiler performance optimizations? > > | > > | Maybe there is more structured and organized way to conduct such > > | different-compilers-optimizations benchmarks/test? > > | > > | What do devel can say and advise with regards to > compile-for-performance > > | subject? > > > > Of course you do that, and add those switches to ~/.R/Makeconf. The > > resulting binaries may become non-portable. > > > > E.g. "at work" we use -march=native quite a bit but it means can't share > > libraries from a beefier dev box with skinnier deployment boxen as they > don't > > have the same chipset even thought the are both x86_64 and use the same > Linux > > distro. > > > > As for which switches help in which way on different compiler: that is > > probably best seen as a black box. Time and profile locally, I no > longer try > > to generalize. The newer 'link-time-optimizations' can help too, they > > certainly make builds longer ... > > > > Dirk > > > I've tried the "usual" tweaks and what puzzles me is the fact, that > -march=native and -lto(s) + Os/3 do not help much, make almost invisible > improvements (again, judging by results from R-benchmark-25) with gcc >= > 7 as compared to distro's package which is built with -O2 -mtune=generic > and no ltos. > > Would there be other(better) way to test core R? > > What king of R perf increases do you guys see with compiler's opt flags, > if any? > > regards, L. > > [0] https://github.com/gabx/R-project/tree/master/R-mkl > > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel