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Subject: [OMPI devel] Wrong Endianness in Open MPI for external32 representation
From: Christoph Niethammer (niethammer_at_[hidden])
Date: 2014-04-29 08:03:41


It seems for me that the endianness is wrong in Open MPI's I/O for the external32 data representation. :O

Find attached my test programs which write the integer -30 and the double 16.25 into a file.
Here the output on my Linux system:

mpicc c-xdr.c -o c-xdr
mpicc mpi-io-external32.c -o mpi-io-external32
Output file: c-xdr.dat
hexdump c-xdr.dat
0000000 ffff e2ff 3040 0040 0000 0000
Output file: mpi-io-external32.dat
hexdump mpi-io-external32.dat
0000000 ffe2 ffff 0000 0000 4000 4030

Best regards
Christoph Niethammer

Christoph Niethammer
High Performance Computing Center Stuttgart (HLRS)
Nobelstrasse 19
70569 Stuttgart
Tel: ++49(0)711-685-87203
email: niethammer_at_[hidden]