datatype decoding

Rajeev Thakur (thakur@mcs.anl.gov)
Fri, 18 Apr 1997 10:09:48 -0500

What is the defined behavior of the datatype decoding functions in the
context of the MPI_Type_resize function in the misc. chapter?
For example, if I pass an MPI_INT to MPI_Type_resize, and lb=-4,
extent=12, the newtype would be {(lb,-4), (int,0), (ub,8)}.
If this newtype is passed to the datatype decoding functions, what
will be returned?

I think a new combiner, MPI_RESIZED, is needed for
MPI_Type_get_envelope. And when such a resized datatype is passed to
MPI_Type_get_contents, it should return the oldtype in
array_datatypes[0] and lb and extent in array_addresses[0] and
array_addresses[1].

Rajeev