[MPI3 Fortran] Proposing changes to Fortran 2008
alexander.supalov at intel.com
Thu Mar 27 16:15:30 CDT 2008
PPS. John apparently retired from the Rutherford Labs but remained
active. Please pass my best wishes to him next time you meet.
From: mpi3-fortran-bounces at lists.mpi-forum.org
[mailto:mpi3-fortran-bounces at lists.mpi-forum.org] On Behalf Of
Sent: Thursday, March 27, 2008 9:31 PM
To: MPI-3 Fortran working group
Subject: Re: [MPI3 Fortran] Proposing changes to Fortran 2008
MPI_ISend has many more issues than MPI_Send. Which one are we
For MPI_Send, I see no problem with copy in/out, in fact, I see it as
desirable because the compiler does the work of copying things like
of arrays into contig buffers. Is there a problem with copy in/out and
> The C_LOC functionality is not far away from this requirement
C_LOC exactly satisfies the requirement of no copy in/out and probably
be used for MPI_ISend. It requires TARGET, which should in fact be
if you are retaining a pointer to an array (even if this pointer is only
and not visible to the Fortran compiler).
> the ASYNCHRONOUS attribute also avoids any copying of the actual
In the case of MPI_ISend even with C_LOC, ASYNCHRONOUS (actually
be exact) is necessary on the array whose values are being modified
the compiler's back. This is independent of the issue of copying.
P.S. John Reid is still the head of the Fortran committee
Aleksandar Donev, Ph.D.
Lawrence Postdoctoral Fellow @ Lawrence Livermore National Laboratory
High Performance Computational Materials Science and Chemistry
E-mail: donev1 at llnl.gov
Phone: (925) 424-6816 Fax: (925) 423-0785
Address: P.O.Box 808, L-367, Livermore, CA 94551-9900
mpi3-fortran mailing list
mpi3-fortran at lists.mpi-forum.org
Dornacher Strasse 1
85622 Feldkirchen/Muenchen Germany
Sitz der Gesellschaft: Feldkirchen bei Muenchen
Geschaeftsfuehrer: Douglas Lusk, Peter Gleissner, Hannes Schwaderer
Registergericht: Muenchen HRB 47456 Ust.-IdNr.
VAT Registration No.: DE129385895
Citibank Frankfurt (BLZ 502 109 00) 600119052
This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.
More information about the mpiwg-fortran