[mpich-devel] when is MPICH going to be count-safe?

[Rob Latham]

On Mon, Oct 14, 2013 at 02:25:49PM -0500, Rob Latham wrote:
> er, maybe I should say "qualified to review, once I pass your tests":
> 
> % ./test_type_contig.x 15
> count = 32768 
> ocount = 32768 
> % ./test_type_contig.x 25
> count = 33554432 
> ocount = 33554432 
> % ./test_type_contig.x 30
> count = 1073741824 
> ocount = 1073741824 
> % ./test_type_contig.x 31
> count = 2147483648 
> ocount = -2147483648 
> 
> Heh.  silent error vs violent explosion.  I'll let you consider which
> mode is preferable while I go fix my branch.

good news is that I think everything "important" is happening
correctly.  It's just that when the status object is updated it's
picking up an overflowed integer.  status.count is MPI_Count big, so
that's not the source of the overflow.  will look once more at my
mountain of clang -Wshorten-64-to-32 related warnings in the morning.

==rob

-- 
Rob Latham
Mathematics and Computer Science Division
Argonne National Lab, IL USA