I have now created a page about this: http://mac.r-project.org/openmp
which also provides libomp binaries for all recent versions of Xcode (and more). Important note: this is about Xcode - it is NOT about using Homebrew tools nor the custom compilers we used before R 4.0.0. Both of the latter are not suitable for use with R 4.0.0 binaries. Please give it a shot. Thanks for those participating in the discussion. Cheers, Simon > On 1/05/2020, at 2:23 AM, Wright, Erik Scott <eswri...@pitt.edu> wrote: > > Hi Kevin et al., > > The setup you suggested did not work for me, but I was able to get OpenMP to > work on Mac (10.13) with R v4.0 packages. Here's what I did: > > (1) After installing Homebrew, ran > brew install libomp > # Note it is also possible to install from OpenMP Source code: > https://releases.llvm.org/download.html#10.0.0 > (2) Determined the install path with > brew --prefix libomp > # In my case /usr/local/opt/libomp > (3) Added lines to ~/.R/Makevars > CC=/usr/local/clang4/bin/clang -fopenmp -I/usr/local/opt/libomp/include > LDFLAGS=-L/usr/local/opt/libomp/lib > > I imagine the process is similar for C++ code by setting CXX. Now > parallelization for C code with OpenMP is working again on Mac. > > As always, I am thankful to the R community for helping problem solve. > > I wish more direction along these lines could be added to mac.r-project.org > > Erik > > >> On Apr 29, 2020, at 1:51 AM, Dmitriy Selivanov <selivanov.dmit...@gmail.com> >> wrote: >> >> Thanks, Kevin, I can confirm suggested setup works fine so far. Thank you! >> >> I understand it, is that there's >> no guarantee that this will work properly (or continue to work >> properly) as the Apple toolchain continues to be updated -- e.g. a new >> version of macOS / Xcode could install a version of Apple Clang that >> is then incompatible with the version of libomp currently in use. In >> such a case, I suspect one would need to find and reinstall libomp. >> >> Thats understandable. >> >> On Sat, Apr 25, 2020 at 8:09 PM Kevin Ushey <kevinus...@gmail.com> wrote: >> The following works for me on macOS 10.15.4 using Apple Clang + libomp >> from LLVM 10 (via Homebrew). >> >> Install libomp from Homebrew with: >> >> brew install libomp >> >> Then, put the following in ~/.R/Makevars >> >> CPPFLAGS += -I/usr/local/opt/libomp/include -Xclang -fopenmp >> LDFLAGS += -L/usr/local/opt/libomp/lib -lomp >> >> Then R will automatically enable + use OpenMP as appropriate when >> installing packages from sources. >> >> The main danger of this approach, as I understand it, is that there's >> no guarantee that this will work properly (or continue to work >> properly) as the Apple toolchain continues to be updated -- e.g. a new >> version of macOS / Xcode could install a version of Apple Clang that >> is then incompatible with the version of libomp currently in use. In >> such a case, I suspect one would need to find and reinstall libomp. >> >> In theory, this could be alleviated by ensuring all users download and >> use the same version of Xcode as is being used by the macOS build >> machine (Xcode 10.1), but in practice users will likely just be using >> the "default" set of command line tools that comes with their version >> of macOS. >> >> Cunningham's law will hopefully ensure someone else will chime in if >> I've got something wrong :-) >> >> Best, >> Kevin >> >> On Sat, Apr 25, 2020 at 8:29 AM Wright, Erik Scott <eswri...@pitt.edu> wrote: >> > >> > I second this request. Dropping OpenMP support in R v4.0 on Mac is >> > unfortunate. My R package is highly parallelized via OpenMP, and many of >> > my end-users take advantage of the excellent speedups. It would be much >> > appreciated if user-level instructions could be provided for how to enable >> > OpenMP support on the Mac. >> > >> > Thanks, >> > Erik >> > >> > >> > > On Apr 23, 2020, at 7:08 AM, Dmitriy Selivanov >> > > <selivanov.dmit...@gmail.com> wrote: >> > > >> > > Hi Simon, >> > > >> > > Just wanted follow up on this topic. >> > > >> > > It would be very helpful if you can provide some guide on >> > > https://nam05.safelinks.protection.outlook.com/?url=https%3A%2F%2Fmac.r-project.org%2F&data=02%7C01%7Ceswright%40pitt.edu%7C65097590dea4453ab8cf08d7e776b868%7C9ef9f489e0a04eeb87cc3a526112fd0d%7C1%7C0%7C637232369415901734&sdata=qlhXuEubgD6PNmkbD%2BWQy5OI9X%2BGjxSYHMNjA%2BQHZzI%3D&reserved=0<https://nam05.safelinks.protection.outlook.com/?url=https%3A%2F%2Fmac.r-project.org%2F&data=02%7C01%7Ceswright%40pitt.edu%7C65097590dea4453ab8cf08d7e776b868%7C9ef9f489e0a04eeb87cc3a526112fd0d%7C1%7C0%7C637232369415911728&sdata=5XR5LJuAKu4%2B3%2FUHsWVPMlyXTLY87P6OF%2FP%2FTZt1W8Y%3D&reserved=0> >> > > for those users >> > > (advanced?) and developers who wants to be able to use OpenMP on mac. >> > > From >> > > what I've understood from this mail thread the easiest way is to install >> > > R >> > > from homebrew as it is built with non-standard Apple toolchain. >> > > Apart from that you've mentioned you may consider to bundle binary iomp >> > > with R installation, but "it would be on the package author to make sure >> > > that the way the package operates is compatible with that binary". Could >> > > you please elaborate on that? >> > > >> > > I believe I'm not alone who would like to be able to use OpenMP on mac >> > > and >> > > "official" guidance would be very helpful. >> > > >> > > -- >> > > Regards >> > > Dmitriy Selivanov >> > > >> > > [[alternative HTML version deleted]] >> > > >> > > _______________________________________________ >> > > R-SIG-Mac mailing list >> > > R-SIG-Mac@r-project.org >> > > https://nam05.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstat.ethz.ch%2Fmailman%2Flistinfo%2Fr-sig-mac&data=02%7C01%7Ceswright%40pitt.edu%7C65097590dea4453ab8cf08d7e776b868%7C9ef9f489e0a04eeb87cc3a526112fd0d%7C1%7C0%7C637232369415911728&sdata=yAu4MKX2Ka5yEaoq51byWJSkbL%2FpO1HvtUsI%2BQXmtJQ%3D&reserved=0 >> > >> > _______________________________________________ >> > R-SIG-Mac mailing list >> > R-SIG-Mac@r-project.org >> > https://stat.ethz.ch/mailman/listinfo/r-sig-mac >> >> >> -- >> Regards >> Dmitriy Selivanov > _______________________________________________ R-SIG-Mac mailing list R-SIG-Mac@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-mac
