Plans for usage of LLVM's linker were just discussed on BSDNow (from toolchain mailing list):
http://www.bsdnow.tv/episodes/2016_08_24-the_fresh_bsd_experience https://lists.freebsd.org/pipermail/freebsd-toolchain/2016-August/002240.html - Eric On Wednesday, August 31, 2016, Fernando Herrero Carrón <elfe...@gmail.com> wrote: > That's great news! Thanks a lot! > > Excuse me if I drift off-topic, how about -flto? LTO requires both > compiler and linker support, however clang3? from ports still calls the > system linker 'ld'. LLVM has its own linker, 'lld', but it is not > straightforward, AFAIK, to make clang3? call it. > > My trick up to now is to create a symbolic link in the current directory > and have '.' in the PATH before anything else. > > ln -s /usr/local/llvm37/bin/lld ./ld > clang37 -flto ... > > Am I missing something or is there a chance for improvement here? > > 2016-08-31 3:17 GMT+02:00 K. Macy <km...@freebsd.org > <javascript:_e(%7B%7D,'cvml','km...@freebsd.org');>>: > >> On Tue, Aug 30, 2016 at 10:39 AM, Eric A. Borisch <ebori...@gmail.com >> <javascript:_e(%7B%7D,'cvml','ebori...@gmail.com');>> wrote: >> > FWIW, in MacPorts, we patch clang such that it can find the (MacPorts >> > provided) libomp headers and library. This lets -fopenmp "just work," >> > and configure scripts can do their job. The libomp headers and lib in >> > dedicated sub-directories to minimize the impact of -fopenmp adding >> > them to the include and link paths. >> > >> > It is a fairly minor patch, and shouldn't (tm) have any impact on >> > clang executions without an openmp flag: >> > https://trac.macports.org/browser/trunk/dports/lang/llvm-3. >> 8/files/openmp-locations.patch >> > >> > To get a simple OpenMP test script to compile on FreeBSD, I currently >> > need to pass (note I'm not the one using -lm): >> > >> > clang38 -fopenmp -o test test.c -L /usr/local/llvm38/lib -lm >> > >> > instead of (~ what configure will try) >> > >> > clang38 -fopenmp -o test test.c >> > >> > (11.0RC2 w/ llvm38 installed via pkg) >> > >> > I'd love to see base include llvm's OpenMP support, but failing that, >> > the one from ports should be made to work as configure scripts expect. >> > >> > And who knows, if it is there, maybe some items in base will start to >> > use it. We've got a chicken-and-egg problem right now. >> >> Thanks for the patch. Johannes Dieterich hacked the llvm38 port in my >> graphics branch and: >> >> >> mmacy@armageddon [~|18:13|81] clang++ omp.cpp -fopenmp >> mmacy@armageddon [~|18:13|81] cat omp.cpp >> #include <string> >> #include <iostream> >> using namespace std; >> int main(int argc, char** argv) { >> >> >> #pragma omp parallel for default(shared) >> for(int i = 0; i < 100; ++i){ >> #ifdef _OPENMP >> cout << "WITH OPENMP " << i << endl; >> #else >> cout << "WITHOUT OPENMP " << i << endl; >> #endif >> } >> return 0; >> } >> mmacy@armageddon [~|18:13|82] clang++38 omp.cpp -fopenmp >> mmacy@armageddon [~|18:13|83] ./a.out| head -5 >> WITH OPENMP WITH OPENMP 84WITH OPENMP 92WITH OPENMP >> 44 >> WITH OPENMP WITH OPENMP 9352WITH OPENMP >> 76WITH OPENMP WITH OPENMP 0 >> WITH OPENMP >> >> >> >> Fingers crossed that this can get propagated to master and the >> defaults for openblas, FFTW, and others can be made more sensible. >> >> -M >> _______________________________________________ >> freebsd-stable@freebsd.org >> <javascript:_e(%7B%7D,'cvml','freebsd-stable@freebsd.org');> mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-stable >> To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org >> <javascript:_e(%7B%7D,'cvml','freebsd-stable-unsubscr...@freebsd.org');>" >> > > _______________________________________________ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
