split and simplify reduce and reduce-scatter

[simgrid.git] / teshsuite / smpi / coll-reduce-scatter / coll-reduce-scatter.c

diff --git a/teshsuite/smpi/coll-reduce-scatter/coll-reduce-scatter.c b/teshsuite/smpi/coll-reduce-scatter/coll-reduce-scatter.c
new file mode 100644 (file)
index 0000000..3bf3d91
--- /dev/null
+++ b/teshsuite/smpi/coll-reduce-scatter/coll-reduce-scatter.c
@@ -0,0 +1,56 @@
+/* Copyright (c) 2013-2014. The SimGrid Team.
+ * All rights reserved.                                                     */
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the license (GNU LGPL) which comes with this package. */
+
+/* 
+ * Test of reduce scatter.
+ * 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>
+
+int main( int argc, char **argv )
+{
+    int      err = 0, toterr;
+    int      *sendbuf, *recvbuf, *recvcounts;
+    int      size, rank, i, sumval;
+    MPI_Comm comm;
+
+    MPI_Init( &argc, &argv );
+    comm = MPI_COMM_WORLD;
+
+    MPI_Comm_size( comm, &size );
+    MPI_Comm_rank( comm, &rank );
+    sendbuf = (int *) malloc( size * sizeof(int) );
+    for (i=0; i<size; i++) 
+      sendbuf[i] = rank + i;
+    recvcounts = (int *)malloc( size * sizeof(int) );
+    recvbuf = (int *)malloc( size * sizeof(int) );
+    for (i=0; i<size; i++) 
+      recvcounts[i] = 1;
+    MPI_Reduce_scatter( sendbuf, recvbuf, recvcounts, MPI_INT, MPI_SUM, comm );
+    sumval = size * rank + ((size - 1) * size)/2;
+    /* recvbuf should be size * (rank + i) */
+    if (recvbuf[0] != sumval) {
+      err++;
+      fprintf( stdout, "Did not get expected value for reduce scatter\n" );
+      fprintf( stdout, "[%d] Got %d expected %d\n", rank, recvbuf[0], sumval );
+    }
+
+    MPI_Allreduce( &err, &toterr, 1, MPI_INT, MPI_SUM, MPI_COMM_WORLD );
+    if (rank == 0 && toterr == 0) {
+      printf( " No Errors\n" );
+    }
+    free(sendbuf);
+    free(recvcounts);
+    free(recvbuf);
+
+    MPI_Finalize();
+
+    return toterr;
+}