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Subject: Re: [OMPI users] Q regarding MPI_SHORT and MPI_Isend
From: George Bosilca (bosilca_at_[hidden])
Date: 2009-11-24 11:14:02


Each predefined MPI datatype is mapped to a standard type. The table
that defines this relation can be found in the MPI Standard (2.2) in
Annex A page 534.

   george.

On Nov 23, 2009, at 16:49 , Natarajan CS wrote:

> Oh okay that explains the behaviour of MPI_SHORT, guess sizeof is
> going to give me the same value no matter what MPI_Datatype I use?
> Thanks for the quick response!
>
> On Mon, Nov 23, 2009 at 2:33 PM, Edmund Sumbar <esumbar_at_[hidden]>
> wrote:
> On Mon, 23 Nov 2009, Natarajan CS wrote:
>
> [...]
>
> 1) When I use MPI_SHORT instead of short to count the number of data
> transferred I get an array that is half the size. (ie MPI_Isend
> (&data2[0][0][0], (int) (sizeof(data2)/sizeof(MPI_SHORT)),
> MPI_SHORT, rank, 123,
> cartcomm,&request[rank-1]);
>
> MPI_SHORT and the other data types are actually macros that resolve
> to MPI_Datatype which is a pointer to a struct.
>
> [...]
>
> --
> Edmund Sumbar
> AICT Research Support Group
> esumbar_at_[hidden]
> 780.492.9360
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