In my understanding, almost all of the speed up comes from using an optimized BLAS. Optimizing LAPACK tend to have negligible impact on performance. At least that is my impression, although I won't say I'm an expert.
Best, Kasper On Tue, Sep 29, 2020 at 9:53 AM roy <rollinfor...@gmail.com> wrote: > Hi Simon, > Thanks for the info. I was totally unaware of ABI, vecLib, etc and that > Apple has blas, lapack, etc. But after reading up on this and re-reading > your email, I'm beginning to understand more about this. > > So, I would like to first checkout vecLib. From what you say, would I have > to do something like the following? > > ./configure --enable-BLAS-shlib --with-blas="-lBLAS" ... > > Is this also possible with LAPACK? > > tx again. > cheers, roy > > > On Mon, Sep 28, 2020 at 3:01 PM Simon Urbanek <simon.urba...@r-project.org > > > wrote: > > > Rollin, > > > > it has been several years since I last tested MKL, so take it with a > grain > > of salt, but in general you don't necessarily have to build R with MKL in > > order to use it - you only need to use --enable-BLAS-shlib and link to > any > > ABI-compatible BLAS which can be vecLib as well. Then you can change the > > link from vecLib to MKL in the BLAS stub. Note that we only need the C > ABI, > > there are wrappers vecLibg95f.* which re-map the F entry points to C > entry > > points as to avoid Fortran ABI issues thus you don't care about the > > Fortran. However, historically, MKL has not been much more performant > than > > vecLib so it's unclear if it is worth the hassle. As with any accelerated > > BLAS, note that this may have effects on results in R. > > > > Cheers, > > Simon > > > > > > > > > On 28/09/2020, at 7:07 PM, rollin <rollinfor...@gmail.com> wrote: > > > > > > I wanted to build R from source on macos (10.15.5) so I could include > > > Intel's MKL. So I first looked at building R from source without MKL. > > > > > > From the installation doc, I modified config.site to have the > following: > > > > > > CC=clang > > > OBJC=$CC > > > FC=/usr/local/bin/gfortran > > > CXX=clang++ > > > > > > > > > I then ran configuration via the command: > > > > > > ./configure -C --enable-R-shlib --enable-memory-profiling > > > --x-includes=/opt/X11/include --x-libraries=/opt/X11/lib > > > > > > PKG_CONFIG_PATH=/opt/X11/lib/pkgconfig:/usr/local/lib/pkgconfig:/usr/lib/pkgconfig > > > > > > > > > And received the following information and error: > > > > > > checking if bzip2 version >= 1.0.6... no > > > checking whether bzip2 support suffices... configure: error: bzip2 > > library > > > and headers are required > > > > > > > > > By looking at the log, I saw a compiler error due to an implicit > > function. > > > I then made the following change in config.site: > > > > > > CFLAGS='-Wno-implicit-function-declaration -g -O2'' > > > > > > > > > And configure now ran without errors. > > > > > > However, when I looked at configuring to use MKL, I discovered that MKL > > on > > > macos does not support gnu fortran so, unless I purchase Intel's > Fortran > > > compiler, it looks like I'm sol. > > > > > > Has anyone built R with MKL on macos (10.15)? In any event, I wanted > to > > at > > > least note the issue and work around I encountered when building R on > > > macos with clang/xcode. > > > > > > [[alternative HTML version deleted]] > > > > > > _______________________________________________ > > > R-SIG-Mac mailing list > > > R-SIG-Mac@r-project.org > > > https://stat.ethz.ch/mailman/listinfo/r-sig-mac > > > > > > [[alternative HTML version deleted]] > > _______________________________________________ > R-SIG-Mac mailing list > R-SIG-Mac@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-mac > -- Best, Kasper [[alternative HTML version deleted]] _______________________________________________ R-SIG-Mac mailing list R-SIG-Mac@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-mac
