Hi, and welcome to the GCC / gfortran community.
On 23.02.23 14:15, varma datla via Fortran wrote:
I am willing to contribute to the project idea "Fortran – DO CONCURRENT".
I hope the following helps a bit – it is admittedly a bit chaotic, but I try to write something cleaner later. But to have something to think of and to startwith, it should be sufficient: I think there are two parts to it: First, to add the changes of newer Fortran to gfortran and then to actually use them to generate concurrently running code. (Internally, gfortran currently handles 'do concurrent' to run mostly like a normal loop – except that it annotates the loops are independent. – Real parallelization would be useful, however.) If you want to see examples, see do_concurrent_1.f90 to do_concurrent_6.f90 in gfortran's testsuite, i.e. gcc/testsuite/gfortran.dg/ in the GCC sources. That's at https://gcc.gnu.org/git/?p=gcc.git;a=tree;f=gcc/testsuite/gfortran.dg;hb=refs/heads/master / But it is best to download GCC yourself via Git as described at https://gcc.gnu.org/git.html I want to note that the DO CONCURRENT syntax also permits a mask argument, like in 'do concurrent (i=1:5, j=1:5, (i/=j))' where the last argument selects a subset. For the Fortran standard, see https://gcc.gnu.org/wiki/GFortranStandards Fortran 2018 (= 18-007r1) adds for locality specifiers: LOCAL, LOCAL_INIT, SHARED and DEFAULT(NONE). Fortran 202x alias 2023 adds 'reduce' as in 'do concurrent (i = 1, n) reduce(+:a, b, c) reduce(max:d, e, f)' I think the first step is to add parsing support for those new features, i.e. store them, check for issues (diagnostic) and then fail with a 'sorry not yet implemented'. The next step would be to implement LOCAL/LOCAL_INIT for running on the host. And then, finally, would be to translate into code which can then be run concurrently. I was thinking of mapping it internally to OpenMP or OpenACC, to be toggled via a commandline option like -fdo-concurrent=<openmp,openmp-target,openacc,...>. * * * I think the first step would be to download GCC and build it. Something like "git clone" as described above, then "mkdir build" (some directory); "cd build" and then "../configure --prefix=where-to-install" followed by "make -j12" and "make install". The "-j12" runs 12 build jobs in parallel. How much to use depends on your system. You probably need to install some development versions of libraries such as ISL, gmp, mpfr and mpc. If you don't have them readily, an option is to run ./contrib/download_prerequisites to download those and build them automatically alongside GCC. So far for now. If you have questions, please ask. — And I will try to write something more structured later. Tobias -- Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955 ----------------- Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955
