/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */

/*

 *

 *  (C) 2001 by Argonne National Laboratory.

 *      See COPYRIGHT in top-level directory.

 */

#include "mpiimpl.h"

#include "group.h"

/* -- Begin Profiling Symbol Block for routine MPI_Group_range_excl */

#if defined(HAVE_PRAGMA_WEAK)

#pragma weak MPI_Group_range_excl = PMPI_Group_range_excl

#elif defined(HAVE_PRAGMA_HP_SEC_DEF)

#pragma _HP_SECONDARY_DEF PMPI_Group_range_excl  MPI_Group_range_excl

#elif defined(HAVE_PRAGMA_CRI_DUP)

#pragma _CRI duplicate MPI_Group_range_excl as PMPI_Group_range_excl

#elif defined(HAVE_WEAK_ATTRIBUTE)

int MPI_Group_range_excl(MPI_Group group, int n, int ranges[][3], MPI_Group * newgroup)

    __attribute__ ((weak, alias("PMPI_Group_range_excl")));

#endif

/* -- End Profiling Symbol Block */

/* Define MPICH_MPI_FROM_PMPI if weak symbols are not supported to build

   the MPI routines */

#ifndef MPICH_MPI_FROM_PMPI

#undef MPI_Group_range_excl

#define MPI_Group_range_excl PMPI_Group_range_excl

#undef FUNCNAME

#define FUNCNAME MPIR_Group_range_excl_impl

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

int MPIR_Group_range_excl_impl(MPIR_Group * group_ptr, int n, int ranges[][3],

                               MPIR_Group ** new_group_ptr)

{

    int mpi_errno = MPI_SUCCESS;

    int size, i, j, k, nnew, first, last, stride;

    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPIR_GROUP_RANGE_EXCL_IMPL);

    MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPIR_GROUP_RANGE_EXCL_IMPL);

    /* Compute size, assuming that included ranks are valid (and distinct) */

    size = group_ptr->size;

    nnew = 0;

    for (i = 0; i < n; i++) {

        first = ranges[i][0];

        last = ranges[i][1];

        stride = ranges[i][2];

        /* works for stride of either sign.  Error checking above

         * has already guaranteed stride != 0 */

        nnew += 1 + (last - first) / stride;

    }

    nnew = size - nnew;

    if (nnew == 0) {

        *new_group_ptr = MPIR_Group_empty;

        goto fn_exit;

    }

    /* Allocate a new group and lrank_to_lpid array */

    mpi_errno = MPIR_Group_create(nnew, new_group_ptr);

    /* --BEGIN ERROR HANDLING-- */

    if (mpi_errno) {

        goto fn_fail;

    }

    /* --END ERROR HANDLING-- */

    (*new_group_ptr)->rank = MPI_UNDEFINED;

    /* Group members are taken in rank order from the original group,

     * with the specified members removed. Use the flag array for that

     * purpose.  If this was a critical routine, we could use the

     * flag values set in the error checking part, if the error checking

     * was enabled *and* we are not MPI_THREAD_MULTIPLE, but since this

     * is a low-usage routine, we haven't taken that optimization.  */

    /* First, mark the members to exclude */

    for (i = 0; i < size; i++)

        group_ptr->lrank_to_lpid[i].flag = 0;

    for (i = 0; i < n; i++) {

        first = ranges[i][0];

        last = ranges[i][1];

        stride = ranges[i][2];

        if (stride > 0) {

            for (j = first; j <= last; j += stride) {

                group_ptr->lrank_to_lpid[j].flag = 1;

            }

        } else {

            for (j = first; j >= last; j += stride) {

                group_ptr->lrank_to_lpid[j].flag = 1;

            }

        }

    }

    /* Now, run through the group and pick up the members that were

     * not excluded */

    k = 0;

    for (i = 0; i < size; i++) {

        if (!group_ptr->lrank_to_lpid[i].flag) {

            (*new_group_ptr)->lrank_to_lpid[k].lpid = group_ptr->lrank_to_lpid[i].lpid;

            if (group_ptr->rank == i) {

                (*new_group_ptr)->rank = k;

            }

            k++;

        }

    }

    /* TODO calculate is_local_dense_monotonic */

  fn_exit:

    MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPIR_GROUP_RANGE_EXCL_IMPL);

    return mpi_errno;

  fn_fail:

    goto fn_exit;

}

#endif

#undef FUNCNAME

#define FUNCNAME MPI_Group_range_excl

#undef FCNAME

#define FCNAME MPL_QUOTE(FUNCNAME)

/*@

MPI_Group_range_excl - Produces a group by excluding ranges of processes from

       an existing group

Input Parameters:

+ group - group (handle)

. n - number of elements in array 'ranks' (integer)

- ranges - a one-dimensional array of integer triplets of the

form (first rank, last rank, stride), indicating the ranks in

'group'  of processes to be excluded from the output group 'newgroup' .

Output Parameters:

. newgroup - new group derived from above, preserving the

order in 'group'  (handle)

Note:

The MPI standard requires that each of the ranks to be excluded must be

a valid rank in the group and all elements must be distinct or the

function is erroneous.

.N ThreadSafe

.N Fortran

.N Errors

.N MPI_SUCCESS

.N MPI_ERR_GROUP

.N MPI_ERR_EXHAUSTED

.N MPI_ERR_RANK

.N MPI_ERR_ARG

.seealso: MPI_Group_free

@*/

int MPI_Group_range_excl(MPI_Group group, int n, int ranges[][3], MPI_Group * newgroup)

{

    int mpi_errno = MPI_SUCCESS;

    MPIR_Group *group_ptr = NULL, *new_group_ptr;

    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPI_GROUP_RANGE_EXCL);

    MPIR_ERRTEST_INITIALIZED_ORDIE();

    MPID_THREAD_CS_ENTER(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);

    MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPI_GROUP_RANGE_EXCL);

    /* Validate parameters, especially handles needing to be converted */

#ifdef HAVE_ERROR_CHECKING

    {

        MPID_BEGIN_ERROR_CHECKS;

        {

            MPIR_ERRTEST_GROUP(group, mpi_errno);

        }

        MPID_END_ERROR_CHECKS;

    }

#endif

    /* Convert MPI object handles to object pointers */

    MPIR_Group_get_ptr(group, group_ptr);

    /* Validate parameters and objects (post conversion) */

#ifdef HAVE_ERROR_CHECKING

    {

        MPID_BEGIN_ERROR_CHECKS;

        {

            /* Validate group_ptr */

            MPIR_Group_valid_ptr(group_ptr, mpi_errno);

            /* If group_ptr is not valid, it will be reset to null */

            /* Check the exclusion array.  Ensure that all ranges are

             * valid and that the specified exclusions are unique */

            if (group_ptr) {

                mpi_errno = MPIR_Group_check_valid_ranges(group_ptr, ranges, n);

            }

            if (mpi_errno)

                goto fn_fail;

            MPIR_ERRTEST_ARGNULL(newgroup, "newgroup", mpi_errno);

        }

        MPID_END_ERROR_CHECKS;

    }

#endif /* HAVE_ERROR_CHECKING */

    /* ... body of routine ...  */

    mpi_errno = MPIR_Group_range_excl_impl(group_ptr, n, ranges, &new_group_ptr);

    if (mpi_errno)

        goto fn_fail;

    MPIR_OBJ_PUBLISH_HANDLE(*newgroup, new_group_ptr->handle);

    /* ... end of body of routine ... */

  fn_exit:

    MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPI_GROUP_RANGE_EXCL);

    MPID_THREAD_CS_EXIT(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);

    return mpi_errno;

  fn_fail:

    /* --BEGIN ERROR HANDLING-- */

#ifdef HAVE_ERROR_CHECKING

    {

        mpi_errno =

            MPIR_Err_create_code(mpi_errno, MPIR_ERR_RECOVERABLE, FCNAME, __LINE__, MPI_ERR_OTHER,

                                 "**mpi_group_range_excl", "**mpi_group_range_excl %G %d %p %p",

                                 group, n, ranges, newgroup);

    }

#endif

    mpi_errno = MPIR_Err_return_comm(NULL, FCNAME, mpi_errno);

    goto fn_exit;

    /* --END ERROR HANDLING-- */

}