Ricardo,
I can't reproduce your problem with the latest version (trunk r21734).
If I run the provided program on two nodes I get the following answer.
[***]$ mpif77 inplace.f -o inplace -g
[***]$ mpirun -bynode -np 2 ./inplace
Result:
3.0000000 3.0000000 3.0000000 3.0000000
This seems correct and in sync with the C answer.
george.
On Jul 27, 2009, at 09:42 , Ricardo Fonseca wrote:
program inplace
use mpi
implicit none
integer :: ierr, rank, rsize, bsize
real, dimension( 2, 2 ) :: buffer, out
integer :: rc
call MPI_INIT(ierr)
call MPI_COMM_RANK(MPI_COMM_WORLD, rank, ierr)
call MPI_COMM_SIZE(MPI_COMM_WORLD, rsize, ierr)
buffer = rank + 1
bsize = size(buffer,1) * size(buffer,2)
if ( rank == 0 ) then
call mpi_reduce( MPI_IN_PLACE, buffer, bsize, MPI_REAL, MPI_SUM,
0, MPI_COMM_WORLD, ierr )
else
call mpi_reduce( buffer, 0, bsize, MPI_REAL, MPI_SUM,
0, MPI_COMM_WORLD, ierr )
endif
! use allreduce instead
! call mpi_allreduce( MPI_IN_PLACE, buffer, bsize, MPI_REAL,
MPI_SUM, MPI_COMM_WORLD, ierr )
if ( rank == 0 ) then
print *, 'Result:'
print *, buffer
endif
rc = 0
call mpi_finalize( rc )
end program
