/* -*- Mode: C; c-basic-offset:4 ; -*- */
/*
 *
 *  (C) 2003 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */
#include "mpi.h"
#include <stdio.h>
#include <stdlib.h>
#include "mpitest.h"

static char MTEST_Descrip[] = "Simple intercomm allgather test";

int main( int argc, char *argv[] )
{
    int errs = 0, err;
    int *rbuf = 0, *sbuf = 0;
    int leftGroup, i, count, rank, rsize;
    MPI_Comm comm;
    MPI_Datatype datatype;

    MTest_Init( &argc, &argv );

    datatype = MPI_INT;
    /* Get an intercommunicator */
    while (MTestGetIntercomm( &comm, &leftGroup, 4 )) {
	if (comm == MPI_COMM_NULL) continue;
	MPI_Comm_rank( comm, &rank );
	MPI_Comm_remote_size( comm, &rsize );

	/* To improve reporting of problems about operations, we
	   change the error handler to errors return */
	MPI_Errhandler_set( comm, MPI_ERRORS_RETURN );

	for (count = 1; count < 65000; count = 2 * count) {
	    /* The left group will send rank to the right group;
	       The right group will send -rank to the left group */
	    rbuf = (int *)malloc( count * rsize * sizeof(int) );
	    sbuf = (int *)malloc( count * sizeof(int) );
	    for (i=0; i<count*rsize; i++) rbuf[i] = -1;
	    if (leftGroup) {
		for (i=0; i<count; i++)       sbuf[i] = i + rank*count;
	    }
	    else {
		for (i=0; i<count; i++)       sbuf[i] = -(i + rank*count);
	    }
	    err = MPI_Allgather( sbuf, count, datatype,
				 rbuf, count, datatype, comm );
	    if (err) {
		errs++;
		MTestPrintError( err );
	    }
	    if (leftGroup) {
		for (i=0; i<count*rsize; i++) {
		    if (rbuf[i] != -i) {
			errs++;
		    }
		}
	    }
	    else {
		for (i=0; i<count*rsize; i++) {
		    if (rbuf[i] != i) {
			errs++;
		    }
		}
	    }

	    /* Use Allgather in a unidirectional way */
	    for (i=0; i<count*rsize; i++) rbuf[i] = -1;
	    if (leftGroup) {
		err = MPI_Allgather( sbuf, 0, datatype,
				     rbuf, count, datatype, comm );
		if (err) {
		    errs++;
		    MTestPrintError( err );
		}
		for (i=0; i<count*rsize; i++) {
		    if (rbuf[i] != -i) {
			errs++;
		    }
		}
	    }
	    else {
		err = MPI_Allgather( sbuf, count, datatype,
				     rbuf, 0, datatype, comm );
		if (err) {
		    errs++;
		    MTestPrintError( err );
		}
		for (i=0; i<count*rsize; i++) {
		    if (rbuf[i] != -1) {
			errs++;
		    }
		}
	    }
	    free( rbuf );
	    free( sbuf );
	}
	MTestFreeComm( &comm );
    }

    MTest_Finalize( errs );
    MPI_Finalize();
    return 0;
}
