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<div>MPI 3.1 Chapter 5.9.3 reads "MPI_CHAR, MPI_WCHAR, and MPI_CHARACTER (which represent printable characters) cannot be used in reduction operations". But the following code with MPICH does not abort.<br>
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<div>#include <mpi.h></div>
<div>#include <stdlib.h></div>
<div>int main(int argc, char* argv[])</div>
<div>{</div>
<div> char a ='A',b;</div>
<div> MPI_Init(&argc,&argv);</div>
<div> if(MPI_Allreduce(&a,&b,1,MPI_CHAR,MPI_SUM,MPI_COMM_WORLD)) abort();</div>
<div> MPI_Finalize();</div>
<div>}</div>
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<div dir="ltr">--Junchao Zhang</div>
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