[MPICH] Problem with MPI_Gather

[Jonathan Patterson]

>Hello, Jonathan!
>I have tested your example with mpich2 1.0.6 the previous stable release of 
mpich2 and
>found the example work correctly. I have compiled your program with 
mpich2-1.0.6p1 with
>gather.c taken from src/mpi/coll of mpich2-1.0.6 distribution and found the 
example to work
>as well. The problem with 1.0.6p1 seems to show only with messages of size 
greater than the
>value of MPIR_GATHER_VSMALL_MSG set in mpiimpl.h . Currently this constant is 
set to
>1024 bytes which explains why reducing DATASIZE to less than 256 removes the 
bug on
>32 bit machines. I hope someone from the developers will come up with a fix 
soon, since
>the algorithm seems to have been slightly modified in 1.0.6p1.

	Thanks a lot for your very helpful reply. I'll submit it as a bug.