/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
/*
 *  (C) 2010 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */

#include "mpiimpl.h"

/*
=== BEGIN_MPI_T_CVAR_INFO_BLOCK ===

cvars:
    - name        : MPIR_CVAR_IREDUCE_INTRA_ALGORITHM
      category    : COLLECTIVE
      type        : string
      default     : auto
      class       : device
      verbosity   : MPI_T_VERBOSITY_USER_BASIC
      scope       : MPI_T_SCOPE_ALL_EQ
      description : |-
        Variable to select ireduce algorithm
        auto                  - Internal algorithm selection
        binomial              - Force binomial algorithm
        reduce_scatter_gather - Force reduce scatter gather algorithm

    - name        : MPIR_CVAR_IREDUCE_INTER_ALGORITHM
      category    : COLLECTIVE
      type        : string
      default     : auto
      class       : device
      verbosity   : MPI_T_VERBOSITY_USER_BASIC
      scope       : MPI_T_SCOPE_ALL_EQ
      description : |-
        Variable to select ireduce algorithm
        auto                     - Internal algorithm selection
        local_reduce_remote_send - Force local-reduce-remote-send algorithm

    - name        : MPIR_CVAR_IREDUCE_DEVICE_COLLECTIVE
      category    : COLLECTIVE
      type        : boolean
      default     : true
      class       : device
      verbosity   : MPI_T_VERBOSITY_USER_BASIC
      scope       : MPI_T_SCOPE_ALL_EQ
      description : >-
        If set to true, MPI_Ireduce will allow the device to override the
        MPIR-level collective algorithms. The device still has the
        option to call the MPIR-level algorithms manually.
        If set to false, the device-level ireduce function will not be
        called.

=== END_MPI_T_CVAR_INFO_BLOCK ===
*/

/* -- Begin Profiling Symbol Block for routine MPI_Ireduce */
#if defined(HAVE_PRAGMA_WEAK)
#pragma weak MPI_Ireduce = PMPI_Ireduce
#elif defined(HAVE_PRAGMA_HP_SEC_DEF)
#pragma _HP_SECONDARY_DEF PMPI_Ireduce  MPI_Ireduce
#elif defined(HAVE_PRAGMA_CRI_DUP)
#pragma _CRI duplicate MPI_Ireduce as PMPI_Ireduce
#elif defined(HAVE_WEAK_ATTRIBUTE)
int MPI_Ireduce(const void *sendbuf, void *recvbuf, int count, MPI_Datatype datatype,
                MPI_Op op, int root, MPI_Comm comm, MPI_Request * request)
    __attribute__ ((weak, alias("PMPI_Ireduce")));
#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_Ireduce
#define MPI_Ireduce PMPI_Ireduce

#undef FUNCNAME
#define FUNCNAME MPIR_Ireduce_sched_intra_auto
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Ireduce_sched_intra_auto(const void *sendbuf, void *recvbuf, int count,
                                  MPI_Datatype datatype, MPI_Op op, int root, MPIR_Comm * comm_ptr,
                                  MPIR_Sched_t s)
{
    int mpi_errno = MPI_SUCCESS;
    int pof2, type_size;

    MPIR_Assert(comm_ptr->comm_kind == MPIR_COMM_KIND__INTRACOMM);

    MPIR_Datatype_get_size_macro(datatype, type_size);

    /* get nearest power-of-two less than or equal to number of ranks in the communicator */
    pof2 = comm_ptr->pof2;

    if ((count * type_size > MPIR_CVAR_REDUCE_SHORT_MSG_SIZE) &&
        (HANDLE_GET_KIND(op) == HANDLE_KIND_BUILTIN) && (count >= pof2)) {
        /* do a reduce-scatter followed by gather to root. */
        mpi_errno =
            MPIR_Ireduce_sched_intra_reduce_scatter_gather(sendbuf, recvbuf, count, datatype, op,
                                                           root, comm_ptr, s);
        if (mpi_errno)
            MPIR_ERR_POP(mpi_errno);
    } else {
        /* use a binomial tree algorithm */
        mpi_errno =
            MPIR_Ireduce_sched_intra_binomial(sendbuf, recvbuf, count, datatype, op, root, comm_ptr,
                                              s);
        if (mpi_errno)
            MPIR_ERR_POP(mpi_errno);
    }

  fn_exit:
    return mpi_errno;
  fn_fail:
    goto fn_exit;
}

#undef FUNCNAME
#define FUNCNAME MPIR_Ireduce_sched_inter_auto
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Ireduce_sched_inter_auto(const void *sendbuf, void *recvbuf,
                                  int count, MPI_Datatype datatype, MPI_Op op, int root,
                                  MPIR_Comm * comm_ptr, MPIR_Sched_t s)
{
    int mpi_errno = MPI_SUCCESS;

    mpi_errno = MPIR_Ireduce_sched_inter_local_reduce_remote_send(sendbuf, recvbuf, count,
                                                                  datatype, op, root, comm_ptr, s);

    return mpi_errno;
}

#undef FUNCNAME
#define FUNCNAME MPIR_Ireduce_sched_impl
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Ireduce_sched_impl(const void *sendbuf, void *recvbuf, int count, MPI_Datatype datatype,
                            MPI_Op op, int root, MPIR_Comm * comm_ptr, MPIR_Sched_t s)
{
    int mpi_errno = MPI_SUCCESS;

    if (comm_ptr->comm_kind == MPIR_COMM_KIND__INTRACOMM) {
        if (comm_ptr->hierarchy_kind == MPIR_COMM_HIERARCHY_KIND__PARENT &&
            MPIR_CVAR_ENABLE_SMP_COLLECTIVES && MPIR_CVAR_ENABLE_SMP_REDUCE) {
            mpi_errno = MPIR_Ireduce_sched_intra_smp(sendbuf, recvbuf, count,
                                                     datatype, op, root, comm_ptr, s);
        } else {
            /* intracommunicator */
            switch (MPIR_Ireduce_intra_algo_choice) {
                case MPIR_IREDUCE_INTRA_ALGO_BINOMIAL:
                    mpi_errno = MPIR_Ireduce_sched_intra_binomial(sendbuf, recvbuf, count,
                                                                  datatype, op, root, comm_ptr, s);
                    break;
                case MPIR_IREDUCE_INTRA_ALGO_REDUCE_SCATTER_GATHER:
                    mpi_errno =
                        MPIR_Ireduce_sched_intra_reduce_scatter_gather(sendbuf, recvbuf, count,
                                                                       datatype, op, root, comm_ptr,
                                                                       s);
                    break;
                case MPIR_IREDUCE_INTRA_ALGO_AUTO:
                    MPL_FALLTHROUGH;
                default:
                    mpi_errno = MPIR_Ireduce_sched_intra_auto(sendbuf, recvbuf, count,
                                                              datatype, op, root, comm_ptr, s);
                    break;
            }
        }
    } else {
        /* intercommunicator */
        switch (MPIR_Ireduce_inter_algo_choice) {
            case MPIR_IREDUCE_INTER_ALGO_LOCAL_REDUCE_REMOTE_SEND:
                mpi_errno =
                    MPIR_Ireduce_sched_inter_local_reduce_remote_send(sendbuf, recvbuf, count,
                                                                      datatype, op, root, comm_ptr,
                                                                      s);
                break;
            case MPIR_IREDUCE_INTER_ALGO_AUTO:
                MPL_FALLTHROUGH;
            default:
                mpi_errno = MPIR_Ireduce_sched_inter_auto(sendbuf, recvbuf, count,
                                                          datatype, op, root, comm_ptr, s);
                break;
        }
    }

    return mpi_errno;
}

#undef FUNCNAME
#define FUNCNAME MPIR_Ireduce_sched
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Ireduce_sched(const void *sendbuf, void *recvbuf, int count, MPI_Datatype datatype,
                       MPI_Op op, int root, MPIR_Comm * comm_ptr, MPIR_Sched_t s)
{
    int mpi_errno = MPI_SUCCESS;

    if (MPIR_CVAR_IREDUCE_DEVICE_COLLECTIVE && MPIR_CVAR_DEVICE_COLLECTIVES) {
        mpi_errno = MPID_Ireduce_sched(sendbuf, recvbuf, count, datatype, op, root, comm_ptr, s);
    } else {
        mpi_errno = MPIR_Ireduce_sched_impl(sendbuf, recvbuf, count, datatype, op, root, comm_ptr,
                                            s);
    }

    return mpi_errno;
}

#undef FUNCNAME
#define FUNCNAME MPIR_Ireduce_impl
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Ireduce_impl(const void *sendbuf, void *recvbuf, int count,
                      MPI_Datatype datatype, MPI_Op op, int root,
                      MPIR_Comm * comm_ptr, MPIR_Request ** request)
{
    int mpi_errno = MPI_SUCCESS;
    int tag = -1;
    MPIR_Sched_t s = MPIR_SCHED_NULL;

    *request = NULL;

    mpi_errno = MPIR_Sched_next_tag(comm_ptr, &tag);
    if (mpi_errno)
        MPIR_ERR_POP(mpi_errno);
    mpi_errno = MPIR_Sched_create(&s);
    if (mpi_errno)
        MPIR_ERR_POP(mpi_errno);

    mpi_errno = MPIR_Ireduce_sched(sendbuf, recvbuf, count, datatype, op, root, comm_ptr, s);
    if (mpi_errno)
        MPIR_ERR_POP(mpi_errno);

    mpi_errno = MPIR_Sched_start(&s, comm_ptr, tag, request);
    if (mpi_errno)
        MPIR_ERR_POP(mpi_errno);

  fn_exit:
    return mpi_errno;
  fn_fail:
    goto fn_exit;
}

#undef FUNCNAME
#define FUNCNAME MPIR_Ireduce
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
int MPIR_Ireduce(const void *sendbuf, void *recvbuf, int count,
                 MPI_Datatype datatype, MPI_Op op, int root,
                 MPIR_Comm * comm_ptr, MPIR_Request ** request)
{
    int mpi_errno = MPI_SUCCESS;

    if (MPIR_CVAR_IREDUCE_DEVICE_COLLECTIVE && MPIR_CVAR_DEVICE_COLLECTIVES) {
        mpi_errno = MPID_Ireduce(sendbuf, recvbuf, count, datatype, op, root, comm_ptr, request);
    } else {
        mpi_errno = MPIR_Ireduce_impl(sendbuf, recvbuf, count, datatype, op, root, comm_ptr,
                                      request);
    }

    return mpi_errno;
}

#endif /* MPICH_MPI_FROM_PMPI */

#undef FUNCNAME
#define FUNCNAME MPI_Ireduce
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
/*@
MPI_Ireduce - Reduces values on all processes to a single value
              in a nonblocking way

Input Parameters:
+ sendbuf - address of the send buffer (choice)
. count - number of elements in send buffer (non-negative integer)
. datatype - data type of elements of send buffer (handle)
. op - reduce operation (handle)
. root - rank of root process (integer)
- comm - communicator (handle)

Output Parameters:
+ recvbuf - address of the receive buffer (significant only at root) (choice)
- request - communication request (handle)

.N ThreadSafe

.N Fortran

.N Errors
@*/
int MPI_Ireduce(const void *sendbuf, void *recvbuf, int count, MPI_Datatype datatype,
                MPI_Op op, int root, MPI_Comm comm, MPI_Request * request)
{
    int mpi_errno = MPI_SUCCESS;
    MPIR_Comm *comm_ptr = NULL;
    MPIR_Request *request_ptr = NULL;
    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPI_IREDUCE);

    MPID_THREAD_CS_ENTER(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);
    MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPI_IREDUCE);

    /* Validate parameters, especially handles needing to be converted */
#ifdef HAVE_ERROR_CHECKING
    {
        MPID_BEGIN_ERROR_CHECKS;
        {
            MPIR_ERRTEST_COUNT(count, mpi_errno);
            MPIR_ERRTEST_DATATYPE(datatype, "datatype", mpi_errno);
            MPIR_ERRTEST_OP(op, mpi_errno);
            MPIR_ERRTEST_COMM(comm, mpi_errno);

            /* TODO more checks may be appropriate */
        }
        MPID_END_ERROR_CHECKS;
    }
#endif /* HAVE_ERROR_CHECKING */

    /* Convert MPI object handles to object pointers */
    MPIR_Comm_get_ptr(comm, comm_ptr);

    /* Validate parameters and objects (post conversion) */
#ifdef HAVE_ERROR_CHECKING
    {
        MPID_BEGIN_ERROR_CHECKS;
        {
            int rank;

            MPIR_Comm_valid_ptr(comm_ptr, mpi_errno, FALSE);
            if (HANDLE_GET_KIND(datatype) != HANDLE_KIND_BUILTIN) {
                MPIR_Datatype *datatype_ptr = NULL;
                MPIR_Datatype_get_ptr(datatype, datatype_ptr);
                MPIR_Datatype_valid_ptr(datatype_ptr, mpi_errno);
                if (mpi_errno != MPI_SUCCESS)
                    goto fn_fail;
                MPIR_Datatype_committed_ptr(datatype_ptr, mpi_errno);
                if (mpi_errno != MPI_SUCCESS)
                    goto fn_fail;
            }

            if (HANDLE_GET_KIND(op) != HANDLE_KIND_BUILTIN) {
                MPIR_Op *op_ptr = NULL;
                MPIR_Op_get_ptr(op, op_ptr);
                MPIR_Op_valid_ptr(op_ptr, mpi_errno);
            } else if (HANDLE_GET_KIND(op) == HANDLE_KIND_BUILTIN) {
                mpi_errno = (*MPIR_OP_HDL_TO_DTYPE_FN(op)) (datatype);
            }
            if (mpi_errno != MPI_SUCCESS)
                goto fn_fail;

            MPIR_ERRTEST_ARGNULL(request, "request", mpi_errno);

            if (comm_ptr->comm_kind == MPIR_COMM_KIND__INTRACOMM) {
                if (sendbuf != MPI_IN_PLACE)
                    MPIR_ERRTEST_USERBUFFER(sendbuf, count, datatype, mpi_errno);

                rank = comm_ptr->rank;
                if (rank == root) {
                    MPIR_ERRTEST_RECVBUF_INPLACE(recvbuf, count, mpi_errno);
                    MPIR_ERRTEST_USERBUFFER(recvbuf, count, datatype, mpi_errno);
                    if (count != 0 && sendbuf != MPI_IN_PLACE) {
                        MPIR_ERRTEST_ALIAS_COLL(sendbuf, recvbuf, mpi_errno);
                    }
                } else
                    MPIR_ERRTEST_SENDBUF_INPLACE(sendbuf, count, mpi_errno);
            }

            /* TODO more checks may be appropriate (counts, in_place, etc) */
        }
        MPID_END_ERROR_CHECKS;
    }
#endif /* HAVE_ERROR_CHECKING */

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

    mpi_errno = MPIR_Ireduce(sendbuf, recvbuf, count, datatype, op, root, comm_ptr, &request_ptr);
    if (mpi_errno)
        MPIR_ERR_POP(mpi_errno);

    /* return the handle of the request to the user */
    if (request_ptr)
        *request = request_ptr->handle;
    else
        *request = MPI_REQUEST_NULL;

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

  fn_exit:
    MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPI_IREDUCE);
    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_ireduce", "**mpi_ireduce %p %p %d %D %O %d %C %p", sendbuf,
                                 recvbuf, count, datatype, op, root, comm, request);
    }
#endif
    mpi_errno = MPIR_Err_return_comm(comm_ptr, FCNAME, mpi_errno);
    goto fn_exit;
    /* --END ERROR HANDLING-- */
}
