I need to scatter a 2D array with non-contiguous blocks in a Fortran 90 code. The code need to call MPI_TYPE_CREATE_RESIZED to change the bounds and extend of the new vector type before calling MPI_SCATTER. The compiler I use is Intel XE 12.1.
When using the Intel MPI, the code compiles well but with a warning message, which I don't think it should be there:
mpiifort -c test.f90
test.f90(21): warning #6075: The data type of the actual argument does not match the definition. [EXTENT]
call MPI_TYPE_CREATE_RESIZED(oldtype, 1, extent, newtype, ierr)
-----------------------------------------^
When using the OpenMPI, the compilation terminates with an error:
mpif90 -c test.f90
test.f90(21): error #6285: There is no matching specific subroutine for this generic subroutine call. [MPI_TYPE_CREATE_RESIZED]
call MPI_TYPE_CREATE_RESIZED(oldtype, 1, extent, newtype, ierr)
-----^
compilation aborted for test.f90 (code 1)
Is this a bug in OpenMPI? Does anybody know how to fix it? Thanks.
The test code is pasted below:
program test
!
USE MPI
implicit none
!
integer :: numprocs, ierr, status(MPI_STATUS_SIZE)
integer :: rows, cols
integer :: typesize, extent, oldtype, newtype
!=============================================================
!
call MPI_INIT( ierr )
call MPI_COMM_SIZE( MPI_COMM_WORLD, numprocs, ierr )
!
cols = 8
!
rows = cols
!
call MPI_TYPE_VECTOR(cols, rows/numprocs, rows, MPI_REAL8, oldtype, ierr)
call MPI_TYPE_SIZE(MPI_REAL8, typesize, ierr)
extent = rows/numprocs*typesize
call MPI_TYPE_CREATE_RESIZED(oldtype, 1, extent, newtype, ierr)
call MPI_TYPE_COMMIT(newtype, ierr)
!
call MPI_TYPE_FREE(oldtype, ierr)
call MPI_TYPE_FREE(newtype, ierr)
call MPI_FINALIZE(ierr)
stop
end
This is the compiler being picky about the types of arguments, which is a good thing; lower bound and extent here have to be integers of kind MPI_ADDRESS_KIND. So this works:
program test
!
USE MPI
implicit none
!
integer :: numprocs, ierr, status(MPI_STATUS_SIZE)
integer :: rows, cols, typesize
integer(kind=mpi_address_kind) :: lb, extent
integer :: oldtype, newtype
!=============================================================
!
call MPI_INIT( ierr )
call MPI_COMM_SIZE( MPI_COMM_WORLD, numprocs, ierr )
!
cols = 8
!
rows = cols
!
call MPI_TYPE_VECTOR(cols, rows/numprocs, rows, MPI_REAL8, oldtype, ierr)
call MPI_TYPE_SIZE(MPI_REAL8, typesize, ierr)
extent = rows/numprocs*typesize
lb = 1
call MPI_TYPE_CREATE_RESIZED(oldtype, lb, extent, newtype, ierr)
call MPI_TYPE_COMMIT(newtype, ierr)
!
call MPI_TYPE_FREE(oldtype, ierr)
call MPI_TYPE_FREE(newtype, ierr)
call MPI_FINALIZE(ierr)
stop
end