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From: Rainer Keller (Keller_at_[hidden])
Date: 2005-09-17 13:28:29

Hello Brian,
On Friday 16 September 2005 18:41, Brian Barrett wrote:
> A quick question about MPI_Group_range_excl(). I notice that if for a
> given triplet, first_rank == last_rank, we error if stride is not 1. I
> notice we don't have that test in MPI_Group_range_incl(). Is there a
> reason that test should be there - the standard doesn't seem to imply
> that stride must be 1 if first_rank == last_rank.
As said in the other mail, the standard claims, that an MPI_Group_incl(i) /
MPI_Group_excl(i) is equivalent to an MPI_Group_range_incl /
MPI_Group_range_excl with (i,i,1) -- see p. 142 in the MPI-11 standard.
So, the test is just for correctness of the supplied data (or against lazyness
of the app.-programmer? ,-])

But then again, the std. is (as always) not too strict in specifying all those
marginal cases. So, I don't feel too strong about this test.

BTW: the intel-tests failing are in MPI_Group_range_excl3_c.c, right?


Dipl.-Inf. Rainer Keller             email: keller_at_[hidden]
  High Performance Computing         Tel: ++49 (0)711-685 5858
    Center Stuttgart (HLRS)          Fax: ++49 (0)711-678 7626
  Nobelstrasse 19,  R. O0.030
  70550 Stuttgart