Underscores could be the issue. My program is calling MPI functions in all caps with no underscoring, e.g. MPI_SEND . I tried adding -fno_underscoring to my LDFLAGS, but that didn't help. Are there any other flags can I try using?

Aaron Thompson

Vanderbilt University

Could your problem be Case or leading or trailing underscores?

Some code has:

MPI_Send
mpi_send
mpi_send_
_mpi_send_

The code and MPI libs need to have the same Case and underscore policy.

Regards,
joe Griffin

On Jul 9, 2007, at 1:20 PM, lam-request@lam-mpi.org wrote:

cp /usr/local/lammpi/include/mpif.h .

   $(MAKE) LD="/opt/ibmcmp/xlf/8.1/bin/xlf -o" \

   LDFLAGS="-I/usr/local/lammpi/include -L/usr/local/lammpi/lib

-llammpio -llamf77mpi -lmpi -llam -ldl" \

   FC="/opt/ibmcmp/xlf/8.1/bin/xlf" \

   FFLAGS="-c -ffast-math -qstrict -O3 -qarch=auto -

qmaxmem=32768 -I/usr/local/lammpi/include" \

   EX=$(EX) BINROOT=$(BINROOT) $(TYPE)

Here's the exact error I'm getting:

/usr/bin/ld: Undefined symbols:

_mpi_allreduce_

_mpi_barrier_

_mpi_comm_rank_

_mpi_comm_size_

_mpi_finalize_

_mpi_init_

_mpi_recv_

_mpi_send_

_mpi_irecv_

_mpi_wait_

Thank you!

Aaron Thompson

Vanderbilt University

aaron.p.thompson@vanderbilt.edu