Open MPI logo

Open MPI Development Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Development mailing list

Subject: Re: [OMPI devel] RFC: add support for large counts using derived datatypes
From: Jeff Squyres (jsquyres) (jsquyres_at_[hidden])
Date: 2013-07-16 16:29:40

On Jul 16, 2013, at 4:22 PM, George Bosilca <bosilca_at_[hidden]> wrote:

> Btw, I have a question to you fellow MPI Forum attendees. I just can't remember why the MPI forum felt there was a need for the MPI_Type_get[_true]_extent_x? MPI_Count can't be bigger than MPI_Aint,

Yes, it can -- it has to be the largest integer type (i.e., it even has to be able to handle an MPI_Offset).

> so I don't see what is the benefit of extending the MPI_Type_get_true_extent(MPI_Datatype, MPI_Aint*, MPI_Aint*) and MPI_Type_get_extent(MPI_Datatype, MPI_Aint*, MPI_Aint*) with the corresponding _X versions?

Jeff Squyres
For corporate legal information go to: