Archives


- Beowulf
- Beowulf Announce
- Scyld-users
- Beowulf on Debian

Fortran 90 and BeoMPI

Many of your questions may have already been answered in earlier discussions or in the FAQ. The search results page will indicate current discussions as well as past list serves, articles, and papers.

Search

Robert G. Brown rgb at phy.duke.edu
Wed Mar 14 11:08:26 PST 2001


On Wed, 14 Mar 2001, Martin Siegert wrote:

> The problem is g77 and libraries built to work with g77:
> g77 has the "unfortunate" (to put it mildly) property to append two
> underscores to a function name, if the function name already contains
> an underscore. E.g., if your fortran program calls MPI_Comm_rank g77
> calls mpi_comm_rank__ and looks for that reference in the MPI library.
> Hence a library built to work with g77 contains mpi_comm_rank__ and not
> mpi_comm_rank_. Sigh. All other compilers I have worked with so far
> just append a single underscore (e.g., mpi_comm_rank_) regardless of
> whether the function name already contains an underscore.
> Solution? As a workaround you could call mpi_comm_rank_ from your program...
> Which makes your program non portable, etc. Very ugly.
> Otherwise you need a new library. I wish that all libraries that support
> fortran would be built by appending a single underscore to function
> names by default (and thus breaking compatability with g77). Only if
> support for g77 is explicitely required should a wrapper for g77 be
> included as well. Performance wise that should be irrelevant: g77 is
> the slowest compiler around anyway so an additional wrapper doesn't
> matter much.

Thanks!  This explains something that puzzled the hell out of me when I
sought (unsuccessfully) to integrate a single timer object module with
both the C and Fortran version of stream on the dual athlon tests.
my_second() wasn't such a great name, then.

I just don't use Fortran (if I can possibly help it, and I nearly
always can:-) these days...

  rgb

-- 
Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu







More information about the Beowulf mailing list