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/*
* Copyright (C) by Argonne National Laboratory
* See COPYRIGHT in top-level directory
*/
/*
* Test of reduce scatter with large data on an intercommunicator
* (needed in MPICH to trigger the long-data algorithm)
*
* Each processor contributes its rank + the index to the reduction,
* then receives the ith sum
*
* Can be called with any number of processors.
*/
#include "mpi.h"
#include <stdio.h>
#include <stdlib.h>
#include "mpitest.h"
#include "mpicolltest.h"
int main(int argc, char **argv)
{
int errs = 0;
int *recvcounts;
int size, rsize, rank, i;
int recvcount, /* Each process receives this much data */
sendcount, /* Each process contributes this much data */
basecount; /* Unit of elements - basecount *rsize is recvcount,
* etc. */
int isLeftGroup;
long long *sendbuf, *recvbuf;
long long sumval;
MPI_Comm comm;
MTest_Init(&argc, &argv);
comm = MPI_COMM_WORLD;
basecount = 1024;
while (MTestGetIntercomm(&comm, &isLeftGroup, 2)) {
if (comm == MPI_COMM_NULL)
continue;
MPI_Comm_remote_size(comm, &rsize);
MPI_Comm_size(comm, &size);
MPI_Comm_rank(comm, &rank);
if (0) {
printf("[%d] %s (%d,%d) remote %d\n", rank, isLeftGroup ? "L" : "R", rank, size, rsize);
}
recvcount = basecount * rsize;
sendcount = basecount * rsize * size;
recvcounts = (int *) malloc(size * sizeof(int));
if (!recvcounts) {
fprintf(stderr, "Could not allocate %d int for recvcounts\n", size);
MPI_Abort(MPI_COMM_WORLD, 1);
}
for (i = 0; i < size; i++)
recvcounts[i] = recvcount;
sendbuf = (long long *) malloc(sendcount * sizeof(long long));
if (!sendbuf) {
fprintf(stderr, "Could not allocate %d ints for sendbuf\n", sendcount);
MPI_Abort(MPI_COMM_WORLD, 1);
}
for (i = 0; i < sendcount; i++) {
sendbuf[i] = (long long) rank *sendcount + i;
}
recvbuf = (long long *) malloc(recvcount * sizeof(long long));
if (!recvbuf) {
fprintf(stderr, "Could not allocate %d ints for recvbuf\n", recvcount);
MPI_Abort(MPI_COMM_WORLD, 1);
}
for (i = 0; i < recvcount; i++) {
recvbuf[i] = (long long) (-i);
}
MTest_Reduce_scatter(sendbuf, recvbuf, recvcounts, MPI_LONG_LONG, MPI_SUM, comm);
/* Check received data */
for (i = 0; i < recvcount; i++) {
sumval = (long long) (sendcount) * (long long) ((rsize * (rsize - 1)) / 2) +
(long long) (i + rank * rsize * basecount) * (long long) rsize;
if (recvbuf[i] != sumval) {
errs++;
if (errs < 4) {
fprintf(stdout, "Did not get expected value for reduce scatter\n");
fprintf(stdout, "[%d] %s recvbuf[%d] = %lld, expected %lld\n",
rank, isLeftGroup ? "L" : "R", i, recvbuf[i], sumval);
}
}
}
free(sendbuf);
free(recvbuf);
free(recvcounts);
MTestFreeComm(&comm);
}
MTest_Finalize(errs);
return MTestReturnValue(errs);
}
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