Hi, For what it's worth, it looks like it is still possible to use OpenMP on macOS with the system toolchain. Using the example file here:
https://computing.llnl.gov/tutorials/openMP/samples/C/omp_hello.c I can compile + link + run this on macOS 10.15.4 and with: $ /usr/bin/clang -Xpreprocessor -fopenmp -I/usr/local/opt/libomp/include -L/usr/local/opt/libomp/lib -lomp omp_hello.c As for whether this is 'safe', or whether R could conceivably bundle and use its own copy of libomp is a separate question I cannot answer. But at least this is a mechanism for enterprising users to enable OpenMP in packages built from source if they so desire. Best, Kevin On Thu, Apr 2, 2020 at 6:01 AM BATES Timothy <tim.ba...@ed.ac.uk> wrote: > > Moving to a compiler that drops support for OpenMP seems a sad choice, > especially now we’ve all climbed the learning curve of the non-Apple compiler > (the real barrier was lack of a pkg installer and that’s done now). > > Losing OpenMP for the CRAN version of OpenMx/umx (our SEM packages) would be > a big loss for users (for whom the CRAN version now supports OpenMP giving > them a 2-12x speed up). In general, R on Mac is made more viable by having > OpenMP > > Re Brian’s points, I’d say that the distribution problem is crucial: Packages > not on CRAN have dramatically diminished accessibility/useage. > > Second, a great range of compute-intensive problems are amenable to division > amongst cores, including nearly all models that take more than a nominal > amount of time to run: So simulations, CIs, bootstrapping, nearly everything > in genetics all speeds up. > > I’d say especially on desktop/laptop. The big advantage of multi blade > systems requires snowfall-type solutions, but desktops profit automatically > from their multi-core structure and don;’t have multiple processors (except > graphics, which no-one seems to be exploiting on CRAN-style R), so OpenMP is > their one trick. I’d hope not to lose it. > > Best, t > > > > On 2 Apr 2020, at 05:18, Prof Brian Ripley <rip...@stats.ox.ac.uk> wrote: > > > > On 01/04/2020 22:02, Simon Urbanek wrote: > >> JJB, > >> 1. correct, there was too much trouble in this. But please feel free to > >> start a new thread about this here if you have strong opinions. > > > > Also note that it is possible (and not hard) to install packages from > > source with an OpenMP-supporting compiler, and how to do so is in the > > R-admin manual. The problems come in distributing them. > > > > The benefits of OpenMP are often overestimated, especially on > > desktop/laptop level hardware. But it is available for the small (tiny?) > > proportion of users who need it. > The University of Edinburgh is a charitable body, registered in Scotland, > with registration number SC005336. > _______________________________________________ > R-SIG-Mac mailing list > R-SIG-Mac@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-mac _______________________________________________ R-SIG-Mac mailing list R-SIG-Mac@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-mac
