My concern is how do the C side know fortran integer using 8 bytes?
My valgrind check show something like:

==8482== Invalid read of size 8
==8482== at 0x5F4A50E: ompi_op_base_minloc_2integer (op_base_functions.c:631)
==8482== by 0xBF70DD1: ompi_coll_tuned_allreduce_intra_recursivedoubling (op.h:498)
==8482== by 0x5F031CB: PMPI_Allreduce (pallreduce.c:105)
==8482== by 0x62E2F22: PMPI_ALLREDUCE (pallreduce_f.c:77)
==8482== by 0x5C8934: mumps_276_ (mumps_part9.F:4667)
==8482== by 0x54D89A: dmumps_ (dmumps_part1.F:157)
==8482== by 0x43D358: dmumps_f77_ (dmumps_part3.F:6651)
==8482== by 0x41420C: dmumps_c (mumps_c.c:422)
==8482== by 0x412CB4: main (my_cExample_client.c:80)
==8482== Address 0x7369608 is 0 bytes after a block of size 8 alloc'd
==8482== at 0x4A0610C: malloc (vg_replace_malloc.c:195)
==8482== by 0xBF709B9: ompi_coll_tuned_allreduce_intra_recursivedoubling (coll_tuned_allreduce.c:158)
==8482== by 0x5F031CB: PMPI_Allreduce (pallreduce.c:105)
==8482== by 0x62E2F22: PMPI_ALLREDUCE (pallreduce_f.c:77)
==8482== by 0x5C8934: mumps_276_ (mumps_part9.F:4667)
==8482== by 0x54D89A: dmumps_ (dmumps_part1.F:157)
==8482== by 0x43D358: dmumps_f77_ (dmumps_part3.F:6651)
==8482== by 0x41420C: dmumps_c (mumps_c.c:422)
==8482== by 0x412CB4: main (my_cExample_client.c:80)


The fortran side:

INTEGER IN( 2 ), OUT( 2 )

CALL MPI_ALLREDUCE( IN, OUT, 1, MPI_2INTEGER, MPI_MINLOC,
& COMM, IERR)

The compiler options will take care of IN be INTEGER*8, but will
it do the same for MPI_2INTEGER in the C side

Thanks.

Regards,

William



Date: Fri, 29 Jun 2012 07:03:18 -0400
From: Jeff Squyres <jsquyres@cisco.com>
Subject: Re: [OMPI users] fortran program with integer kind=8 using
openmpi
To: <warren@atmos.washington.edu>, Open MPI Users <users@open-mpi.org>
Message-ID: <6FFEA644-3F39-4B6E-ADD6-3721F485525F@cisco.com>
Content-Type: text/plain; charset=iso-8859-1

On Jun 28, 2012, at 8:37 PM, David Warren wrote:

> You should not have to recompile openmpi, but you do have to use the correct type. You can check the size of integers in your fortrana nd use MPI_INTEGER4 or MPI_INTEGER8 depending on what you get.

If you configure ompi with -fdefault-integer-8, then OMPI will assume that Fortran integers are always 8 bytes, so be sure to also compile all of your MPI applications the same way. Indeed, you may want to configure OMPI with something like:

./configure FCFLAGS=-fdefault-integer-8 FFLAGS=-fdefault-integer-8 \
--with-wrapper-fflags=-fdefault-integer-8 \
--with-wrapper-fcflags=-fdefault-integer-8

This will add -fdefault-integer-8 to the mpif77 and mpif90 command lines automatically so that you *can't* compile without that flag.

Be aware that 8-byte Fortran integers *should work* in Open MPI, but it is probably not well tested. You may well run into some issues; be sure to let us know if you run into bugs. Sending small test programs that show the problem are usually the best way to help us identify/fix the precise problem.

> in gfortran use
> integer i
> if(sizeof(i) .eq. 8) then
> mpi_int_type=MPI_INTEGER8
> else
> mpi_int_type=MPI_INTEGER4
> endif

I don't think that this should be necessary -- as long as you configured OMPI with the 8-byte-integer setting, then MPI_INTEGER should represent an 8 byte integer.

--
Jeff Squyres
jsquyres@cisco.com
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