The ompi_datatype_get_single_predefined_type_from_args() recurses down
into a constructed type to identify what base datatype it's built from
if it's built from a single type. But if the type has MPI_LB/MPI_UB,
for example
lens[0] = 1;
lens[1] = 1;
disps[0] = 0;
disps[1] = 0;
types[0] = MPI_LB;
types[1] = MPI_INT;
MPI_Type_create_struct(2, lens, disps, types, &mydt);
then this function will see the base type MPI_LB as differing from MPI_INT
and will identify mydt as not being constructed from a single base type, so
the type will be rejected for calls like MPI_Accumulate.
I think those "meta data" types shouldn't result in rejection like that, and
the above mydt should still be identified as having a single base type
of MPI_INT.
Addition: boslica wanted another change discussed here
https://github.com/open-mpi/ompi/pull/3609
relating to the calculation for "count" after identifying the
predefined_type that was being used.
Signed-off-by: Mark Allen <markalle@us.ibm.com>
e24d5ccb7e