--- /dev/null
+/* -*- Mode: C; c-basic-offset:4 ; -*- */
+/*
+ * (C) 2001 by Argonne National Laboratory.
+ * See COPYRIGHT in top-level directory.
+ */
+#include "mpi.h"
+#include <string.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+
+/*
+ This program tests MPI_Alltoallv by having processor i send different
+ amounts of data to each processor.
+
+ Because there are separate send and receive types to alltoallv,
+ there need to be tests to rearrange data on the fly. Not done yet.
+
+ The first test sends i items to processor i from all processors.
+
+ Currently, the test uses only MPI_INT; this is adequate for testing systems
+ that use point-to-point operations
+ */
+
+
+/* example values:
+ * For 3 processes:
+ * <0> sbuf: (#9): [0][1][2][3][4][5][6][7][8]
+ <0> scount: (#3): [0][1][2]
+ <0> rcount: (#3): [0][0][0]
+ <0> sdisp: (#3): [0][1][3]
+ <0> rdisp: (#3): [0][0][0]
+
+ <1> sbuf: (#9): [100][101][102][103][104][105][106][107][108]
+ <1> scount: (#3): [0][1][2]
+ <1> rcount: (#3): [1][1][1]
+ <1> sdisp: (#3): [0][1][3]
+ <1> rdisp: (#3): [0][1][2]
+
+ <2> sbuf: (#9): [200][201][202][203][204][205][206][207][208]
+ <2> scount: (#3): [0][1][2]
+ <2> rcount: (#3): [2][2][2]
+ <2> sdisp: (#3): [0][1][3]
+ <2> rdisp: (#3): [0][2][4]
+
+ after MPI_Alltoallv :
+ <0> rbuf: (#9): [0][-1][-2][-3][-4][-5][-6][-7][-8]
+ <1> rbuf: (#9): [1][101][201][-3][-4][-5][-6][-7][-8]
+ <2> rbuf: (#9): [3][4][103][104][203][204][-6][-7][-8]
+*/
+
+
+static void print_buffer_int(void *buf, int len, char *msg, int rank)
+{
+ int tmp, *v;
+ printf("**<%d> %s (#%d): ", rank, msg, len);
+ for (tmp = 0; tmp < len; tmp++) {
+ v = buf;
+ printf("[%d]", v[tmp]);
+ }
+ printf("\n");
+ free(msg);
+}
+
+
+int main(int argc, char **argv)
+{
+
+ MPI_Comm comm;
+ int *sbuf, *rbuf, *erbuf;
+ int rank, size;
+ int *sendcounts, *recvcounts, *rdispls, *sdispls;
+ int i, j, *p, err;
+
+ MPI_Init(&argc, &argv);
+ err = 0;
+
+ comm = MPI_COMM_WORLD;
+
+ /* Create the buffer */
+ MPI_Comm_size(comm, &size);
+ MPI_Comm_rank(comm, &rank);
+ sbuf = (int *) malloc(size * size * sizeof(int));
+ rbuf = (int *) malloc(size * size * sizeof(int));
+ erbuf = (int *) malloc(size * size * sizeof(int)); // expected
+ if (!sbuf || !rbuf) {
+ fprintf(stderr, "Could not allocated buffers!\n");
+ MPI_Abort(comm, 1);
+ }
+
+ /* Load up the buffers */
+ for (i = 0; i < size * size; i++) {
+ sbuf[i] = i + 100 * rank;
+ rbuf[i] = -i;
+ erbuf[i] = -i;
+ }
+
+ /* Create and load the arguments to alltoallv */
+ sendcounts = (int *) malloc(size * sizeof(int));
+ recvcounts = (int *) malloc(size * sizeof(int));
+ rdispls = (int *) malloc(size * sizeof(int));
+ sdispls = (int *) malloc(size * sizeof(int));
+ if (!sendcounts || !recvcounts || !rdispls || !sdispls) {
+ fprintf(stderr, "Could not allocate arg items!\n");
+ MPI_Abort(comm, 1);
+ }
+ for (i = 0; i < size; i++) {
+ sendcounts[i] = i;
+ recvcounts[i] = rank;
+ rdispls[i] = i * rank;
+ sdispls[i] = (i * (i + 1)) / 2;
+ }
+
+ /* debug */
+ /*
+ print_buffer_int( sbuf, size*size, strdup("sbuf:"),rank);
+ print_buffer_int( sendcounts, size, strdup("scount:"),rank);
+ print_buffer_int( recvcounts, size, strdup("rcount:"),rank);
+ print_buffer_int( sdispls, size, strdup("sdisp:"),rank);
+ print_buffer_int( rdispls, size, strdup("rdisp:"),rank);
+ */
+
+
+ /* debug : erbuf */
+ /* debug
+ for (i=0; i<size; i++) {
+ for (j=0; j<rank; j++) {
+ *(erbuf+j+ rdispls[i]) = i * 100 + (rank*(rank+1))/2 + j;
+ }
+ }
+ */
+
+
+ //print_buffer_int( erbuf, size*size, strdup("erbuf:"),rank);
+
+ MPI_Alltoallv(sbuf, sendcounts, sdispls, MPI_INT,
+ rbuf, recvcounts, rdispls, MPI_INT, comm);
+
+ // debug: print_buffer_int( rbuf, size*size, strdup("rbuf:"),rank);
+
+
+ /* Check rbuf */
+ for (i = 0; i < size; i++) {
+ p = rbuf + rdispls[i];
+ for (j = 0; j < rank; j++) {
+ if (p[j] != i * 100 + (rank * (rank + 1)) / 2 + j) {
+ fprintf(stderr, "** Error: <%d> got %d expected %d for %dth\n",
+ rank, p[j], (i * (i + 1)) / 2 + j, j);
+ err++;
+ }
+ }
+ }
+
+ /* Summary */
+ if (err > 0) {
+ printf("<%d> Alltoallv test: failure (%d errors).\n", rank, err);
+ }
+ if (0 == rank) {
+ printf("* Alltoallv TEST COMPLETE.\n");
+ }
+ free(sdispls);
+ free(rdispls);
+ free(recvcounts);
+ free(sendcounts);
+ free(rbuf);
+ free(sbuf);
+
+ MPI_Barrier(MPI_COMM_WORLD);
+ MPI_Finalize();
+ return 0;
+}
