Hi Matt, Are you able to test `use mpi_f08` instead? We'll open an issue to track this for "use mpi". In the meantime, you may be able to bypass this issue by adding the `-fallow-argument-mismatch flag to mpifort​. Hui ________________________________ From: Thompson, Matt (GSFC-610.1)[SCIENCE SYSTEMS AND APPLICATIONS INC] via discuss <[email protected]> Sent: Friday, September 22, 2023 9:11 AM To: [email protected] <[email protected]> Cc: Thompson, Matt (GSFC-610.1)[SCIENCE SYSTEMS AND APPLICATIONS INC] <[email protected]> Subject: [mpich-discuss] MPI_alloc_mem call code compiles with Open MPI, not MPICH All, I'm sort of new to MPICH and I'm encountering one call that works with Open MPI but not MPICH. As such, I'm wondering if I built MPICH incorrectly or incompletely (always easy to miss a configure flag!). To wit, I have a code like: program main use mpi use iso_fortran_env, only: INT64 use iso_c_binding, only: C_PTR integer(kind=INT64) :: sz type (c_ptr) :: ptr call MPI_Alloc_mem(sz, MPI_INFO_NULL, ptr, ierror) end program main If I compile with GCC 12.1 + Open MPI 4.1.3, all is well: $ mpifort --showme:version mpifort: Open MPI 4.1.3 (Language: Fortran) mathomp4@discover23 ~/MPITests/CPtr master ?25 $ mpifort support_for_mpi_alloc_mem_cptr.F90 mathomp4@discover23 ~/MPITests/CPtr master ?25 $ echo $? 0 I'll also say Intel MPI builds this code as well. But with MPICH 4.1.2 I just built: $ mpifort support_for_mpi_alloc_mem_cptr.F90 support_for_mpi_alloc_mem_cptr.F90:9:53: 9 | call MPI_Alloc_mem(sz, MPI_INFO_NULL, ptr, ierror) | 1 Error: Type mismatch in argument 'baseptr' at (1); passed TYPE(c_ptr) to INTEGER(8) Now, my configure lines to Open MPI and MPICH are pretty boring, so the resulting mpiforts are as well: $ mpifort -show gfortran -I/discover/swdev/gmao_SIteam/MPI/openmpi/4.1.3/gcc-12.1.0/include -pthread -I/discover/swdev/gmao_SIteam/MPI/openmpi/4.1.3/gcc-12.1.0/lib -L/discover/swdev/gmao_SIteam/MPI/openmpi/4.1.3/gcc-12.1.0/lib -lmpi_usempif08 -lmpi_usempi_ignore_tkr -lmpi_mpifh -lmpi $ mpifort -show gfortran -I/discover/swdev/gmao_SIteam/MPI/mpich/4.1.2/gcc-12.1.0/include -I/discover/swdev/gmao_SIteam/MPI/mpich/4.1.2/gcc-12.1.0/include -L/discover/swdev/gmao_SIteam/MPI/mpich/4.1.2/gcc-12.1.0/lib -lmpifort -Wl,-rpath -Wl,/discover/swdev/gmao_SIteam/MPI/mpich/4.1.2/gcc-12.1.0/lib -Wl,--enable-new-dtags -lmpi But I see Open MPI has that "mpi_usempi_ignore_tkr", is it possible that's what is doing it? Perhaps we just need to recode the code (using transfer, etc?) Thanks for any help, Matt -- Matt Thompson, SSAI, Sr Scientific Programmer/Analyst NASA GSFC, Global Modeling and Assimilation Office Code 610.1, 8800 Greenbelt Rd, Greenbelt, MD 20771 Phone: 301-614-6712 Fax: 301-614-6246 http://science.gsfc.nasa.gov/sed/bio/matthew.thompson