The following is an issue found when testing with xlf-14.1, which is already known to have problems with the F08 stuff. So, I've configured with "FC=xlf90 --enable-mpi-fortran=usempi".
The problem is that mpifort is now a wrapper around xlf90 and thus is assuming F90 free-form input, independent of the file suffix. This results in errors building fixed-form (f77) codes: $ mpifort hello_mpifh.f "hello_mpifh.f", line 1.1: 1515-019 (S) Syntax is incorrect. "hello_mpifh.f", line 2.3: 1515-019 (S) Syntax is incorrect. "hello_mpifh.f", line 3.27: 1515-019 (S) Syntax is incorrect. "hello_mpifh.f", line 4.27: 1515-019 (S) Syntax is incorrect. "hello_mpifh.f", line 5.3: 1515-019 (S) Syntax is incorrect. "hello_mpifh.f", line 6.3: 1515-019 (S) Syntax is incorrect. "hello_mpifh.f", line 7.1: 1515-019 (S) Syntax is incorrect. "hello_mpifh.f", line 8.3: 1515-019 (S) Syntax is incorrect. "hello_mpifh.f", line 9.1: 1515-019 (S) Syntax is incorrect. "hello_mpifh.f", 1515-002 (S) END card is missing. One is assumed. ** _main === End of Compilation 1 === "hello_mpifh.f", line 22.19: 1515-019 (S) Syntax is incorrect. ** main === End of Compilation 2 === 1501-511 Compilation failed for file hello_mpifh.f. This can, fortunately, be worked around with "-qfixed": $ mpifort -qfixed hello_mpifh.f ** main === End of Compilation 1 === 1501-510 Compilation successful for file hello_mpifh.f. I *think* that I should have configured with FC=xlf (rather than xlf90) then it will determine language-level and format based on file suffix. I can (without re-configuring) confirm that xlf honors the extension by setting OMPI_FC=xlf: {hargrove@vestalac1 examples}$ OMPI_FC=xlf mpifort hello_mpifh.f ** main === End of Compilation 1 === 1501-510 Compilation successful for file hello_mpifh.f. {hargrove@vestalac1 examples}$ OMPI_FC=xlf mpifort hello_usempi.f90 ** main === End of Compilation 1 === 1501-510 Compilation successful for file hello_usempi.f90. The term "fortran compiler" in Open MPI's README is not (as far as I could see) clearly defined as "a fortran compiler which honors file suffixes to determine language dialect" My FC=xlf90 setting is "historical" from the testing scripts I've used since the 1.5 and 1.6 series. ADDITIONALLY, the Open MPI manpages STILL say FC is to be a fortran90 compiler and F77 is to be an fortran77 compiler. It looks like others might encounter the same problem I describe above just by reading the documentation too closely. I will follow up with specifics on what appears to be out-of-date in the manpages. -Paul -- Paul H. Hargrove phhargr...@lbl.gov Future Technologies Group Computer and Data Sciences Department Tel: +1-510-495-2352 Lawrence Berkeley National Laboratory Fax: +1-510-486-6900