/*
 * Copyright (C) by Argonne National Laboratory
 *     See COPYRIGHT in top-level directory
 */

#include "mpiimpl.h"

/* -- Begin Profiling Symbol Block for routine MPI_Type_create_subarray */
#if defined(HAVE_PRAGMA_WEAK)
#pragma weak MPI_Type_create_subarray = PMPI_Type_create_subarray
#elif defined(HAVE_PRAGMA_HP_SEC_DEF)
#pragma _HP_SECONDARY_DEF PMPI_Type_create_subarray  MPI_Type_create_subarray
#elif defined(HAVE_PRAGMA_CRI_DUP)
#pragma _CRI duplicate MPI_Type_create_subarray as PMPI_Type_create_subarray
#elif defined(HAVE_WEAK_ATTRIBUTE)
int MPI_Type_create_subarray(int ndims, const int array_of_sizes[],
                             const int array_of_subsizes[], const int array_of_starts[],
                             int order, MPI_Datatype oldtype, MPI_Datatype * newtype)
    __attribute__ ((weak, alias("PMPI_Type_create_subarray")));
#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_Type_create_subarray
#define MPI_Type_create_subarray PMPI_Type_create_subarray

#endif

/*@
   MPI_Type_create_subarray - Create a datatype for a subarray of a regular,
    multidimensional array

Input Parameters:
+ ndims - number of array dimensions (positive integer)
. array_of_sizes - number of elements of type oldtype in each dimension of the
  full array (array of positive integers)
. array_of_subsizes - number of elements of type oldtype in each dimension of
  the subarray (array of positive integers)
. array_of_starts - starting coordinates of the subarray in each dimension
  (array of nonnegative integers)
. order - array storage order flag (state)
- oldtype - array element datatype (handle)

Output Parameters:
. newtype - new datatype (handle)

.N ThreadSafe

.N Fortran

.N Errors
.N MPI_SUCCESS
.N MPI_ERR_TYPE
.N MPI_ERR_ARG
@*/
int MPI_Type_create_subarray(int ndims,
                             const int array_of_sizes[],
                             const int array_of_subsizes[],
                             const int array_of_starts[],
                             int order, MPI_Datatype oldtype, MPI_Datatype * newtype)
{
    int mpi_errno = MPI_SUCCESS, i;
    MPI_Datatype new_handle;

    /* these variables are from the original version in ROMIO */
    MPI_Aint size, extent, disps[3];
    MPI_Datatype tmp1, tmp2;

#ifdef HAVE_ERROR_CHECKING
    MPI_Aint size_with_aint;
    MPI_Offset size_with_offset;
#endif

    /* for saving contents */
    int *ints;
    MPIR_Datatype *new_dtp;

    MPIR_CHKLMEM_DECL(1);
    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPI_TYPE_CREATE_SUBARRAY);

    MPIR_ERRTEST_INITIALIZED_ORDIE();

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

#ifdef HAVE_ERROR_CHECKING
    {
        MPID_BEGIN_ERROR_CHECKS;
        {
            MPIR_Datatype *datatype_ptr = NULL;

            /* Check parameters */
            MPIR_ERRTEST_ARGNONPOS(ndims, "ndims", mpi_errno, MPI_ERR_DIMS);
            MPIR_ERRTEST_ARGNULL(array_of_sizes, "array_of_sizes", mpi_errno);
            MPIR_ERRTEST_ARGNULL(array_of_subsizes, "array_of_subsizes", mpi_errno);
            MPIR_ERRTEST_ARGNULL(array_of_starts, "array_of_starts", mpi_errno);
            for (i = 0; mpi_errno == MPI_SUCCESS && i < ndims; i++) {
                MPIR_ERRTEST_ARGNONPOS(array_of_sizes[i], "size", mpi_errno, MPI_ERR_ARG);
                MPIR_ERRTEST_ARGNONPOS(array_of_subsizes[i], "subsize", mpi_errno, MPI_ERR_ARG);
                MPIR_ERRTEST_ARGNEG(array_of_starts[i], "start", mpi_errno);
                if (array_of_subsizes[i] > array_of_sizes[i]) {
                    mpi_errno = MPIR_Err_create_code(MPI_SUCCESS,
                                                     MPIR_ERR_RECOVERABLE,
                                                     __func__,
                                                     __LINE__,
                                                     MPI_ERR_ARG,
                                                     "**argrange",
                                                     "**argrange %s %d %d",
                                                     "array_of_subsizes",
                                                     array_of_subsizes[i], array_of_sizes[i]);
                    goto fn_fail;
                }
                if (array_of_starts[i] > (array_of_sizes[i] - array_of_subsizes[i])) {
                    mpi_errno = MPIR_Err_create_code(MPI_SUCCESS,
                                                     MPIR_ERR_RECOVERABLE,
                                                     __func__,
                                                     __LINE__,
                                                     MPI_ERR_ARG,
                                                     "**argrange",
                                                     "**argrange %s %d %d",
                                                     "array_of_starts",
                                                     array_of_starts[i],
                                                     array_of_sizes[i] - array_of_subsizes[i]);
                    goto fn_fail;
                }
            }
            if (order != MPI_ORDER_FORTRAN && order != MPI_ORDER_C) {
                mpi_errno = MPIR_Err_create_code(MPI_SUCCESS,
                                                 MPIR_ERR_RECOVERABLE,
                                                 __func__,
                                                 __LINE__,
                                                 MPI_ERR_ARG, "**arg", "**arg %s", "order");
                goto fn_fail;
            }

            MPIR_Datatype_get_extent_macro(oldtype, extent);

            /* check if MPI_Aint is large enough for size of global array.
             * if not, complain. */

            size_with_aint = extent;
            for (i = 0; i < ndims; i++)
                size_with_aint *= array_of_sizes[i];
            size_with_offset = extent;
            for (i = 0; i < ndims; i++)
                size_with_offset *= array_of_sizes[i];
            if (size_with_aint != size_with_offset) {
                mpi_errno = MPIR_Err_create_code(MPI_SUCCESS,
                                                 MPIR_ERR_FATAL,
                                                 __func__,
                                                 __LINE__,
                                                 MPI_ERR_ARG,
                                                 "**subarrayoflow",
                                                 "**subarrayoflow %L", size_with_offset);
                goto fn_fail;
            }

            /* Get handles to MPI objects. */
            MPIR_Datatype_get_ptr(oldtype, datatype_ptr);

            /* Validate datatype_ptr */
            MPIR_Datatype_valid_ptr(datatype_ptr, mpi_errno);
            /* If datatype_ptr is not valid, it will be reset to null */
            if (mpi_errno != MPI_SUCCESS)
                goto fn_fail;
        }
        MPID_END_ERROR_CHECKS;
    }
#endif /* HAVE_ERROR_CHECKING */

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

    /* TODO: CHECK THE ERROR RETURNS FROM ALL THESE!!! */

    /* TODO: GRAB EXTENT WITH A MACRO OR SOMETHING FASTER */
    MPIR_Datatype_get_extent_macro(oldtype, extent);

    if (order == MPI_ORDER_FORTRAN) {
        if (ndims == 1)
            mpi_errno = MPIR_Type_contiguous(array_of_subsizes[0], oldtype, &tmp1);
        else {
            mpi_errno = MPIR_Type_vector(array_of_subsizes[1], array_of_subsizes[0], (MPI_Aint) (array_of_sizes[0]), 0, /* stride in types */
                                         oldtype, &tmp1);
            MPIR_ERR_CHECK(mpi_errno);

            size = ((MPI_Aint) (array_of_sizes[0])) * extent;
            for (i = 2; i < ndims; i++) {
                size *= (MPI_Aint) (array_of_sizes[i - 1]);
                mpi_errno = MPIR_Type_vector(array_of_subsizes[i], 1, size, 1,  /* stride in bytes */
                                             tmp1, &tmp2);
                MPIR_ERR_CHECK(mpi_errno);
                MPIR_Type_free_impl(&tmp1);
                tmp1 = tmp2;
            }
        }
        MPIR_ERR_CHECK(mpi_errno);

        /* add displacement and UB */

        disps[1] = (MPI_Aint) (array_of_starts[0]);
        size = 1;
        for (i = 1; i < ndims; i++) {
            size *= (MPI_Aint) (array_of_sizes[i - 1]);
            disps[1] += size * (MPI_Aint) (array_of_starts[i]);
        }
        /* rest done below for both Fortran and C order */
    } else {    /* MPI_ORDER_C */

        /* dimension ndims-1 changes fastest */
        if (ndims == 1) {
            mpi_errno = MPIR_Type_contiguous(array_of_subsizes[0], oldtype, &tmp1);
            MPIR_ERR_CHECK(mpi_errno);

        } else {
            mpi_errno = MPIR_Type_vector(array_of_subsizes[ndims - 2], array_of_subsizes[ndims - 1], (MPI_Aint) (array_of_sizes[ndims - 1]), 0, /* stride in types */
                                         oldtype, &tmp1);
            MPIR_ERR_CHECK(mpi_errno);

            size = (MPI_Aint) (array_of_sizes[ndims - 1]) * extent;
            for (i = ndims - 3; i >= 0; i--) {
                size *= (MPI_Aint) (array_of_sizes[i + 1]);
                mpi_errno = MPIR_Type_vector(array_of_subsizes[i], 1,   /* blocklen */
                                             size,      /* stride */
                                             1, /* stride in bytes */
                                             tmp1,      /* old type */
                                             &tmp2);
                MPIR_ERR_CHECK(mpi_errno);

                MPIR_Type_free_impl(&tmp1);
                tmp1 = tmp2;
            }
        }

        /* add displacement and UB */

        disps[1] = (MPI_Aint) (array_of_starts[ndims - 1]);
        size = 1;
        for (i = ndims - 2; i >= 0; i--) {
            size *= (MPI_Aint) (array_of_sizes[i + 1]);
            disps[1] += size * (MPI_Aint) (array_of_starts[i]);
        }
    }

    disps[1] *= extent;

    disps[2] = extent;
    for (i = 0; i < ndims; i++)
        disps[2] *= (MPI_Aint) (array_of_sizes[i]);

    disps[0] = 0;

    mpi_errno = MPIR_Type_blockindexed(1, 1, &disps[1], 1,      /* 1 means disp is in bytes */
                                       tmp1, &tmp2);
    MPIR_ERR_CHECK(mpi_errno);

    mpi_errno = MPIR_Type_create_resized(tmp2, 0, disps[2], &new_handle);
    MPIR_ERR_CHECK(mpi_errno);

    MPIR_Type_free_impl(&tmp1);
    MPIR_Type_free_impl(&tmp2);

    /* at this point we have the new type, and we've cleaned up any
     * intermediate types created in the process.  we just need to save
     * all our contents/envelope information.
     */

    /* Save contents */
    MPIR_CHKLMEM_MALLOC_ORJUMP(ints, int *, (3 * ndims + 2) * sizeof(int), mpi_errno,
                               "content description", MPL_MEM_BUFFER);

    ints[0] = ndims;
    for (i = 0; i < ndims; i++) {
        ints[i + 1] = array_of_sizes[i];
    }
    for (i = 0; i < ndims; i++) {
        ints[i + ndims + 1] = array_of_subsizes[i];
    }
    for (i = 0; i < ndims; i++) {
        ints[i + 2 * ndims + 1] = array_of_starts[i];
    }
    ints[3 * ndims + 1] = order;

    MPIR_Datatype_get_ptr(new_handle, new_dtp);
    mpi_errno = MPIR_Datatype_set_contents(new_dtp, MPI_COMBINER_SUBARRAY, 3 * ndims + 2,       /* ints */
                                           0,   /* aints */
                                           1,   /* types */
                                           ints, NULL, &oldtype);
    MPIR_ERR_CHECK(mpi_errno);

    mpi_errno = MPIR_Typerep_create_subarray(ndims, array_of_sizes, array_of_subsizes,
                                             array_of_starts, order, oldtype, new_dtp);
    MPIR_ERR_CHECK(mpi_errno);

    MPIR_OBJ_PUBLISH_HANDLE(*newtype, new_handle);
    /* ... end of body of routine ... */

  fn_exit:
    MPIR_CHKLMEM_FREEALL();
    MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPI_TYPE_CREATE_SUBARRAY);
    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, __func__, __LINE__, MPI_ERR_OTHER,
                                 "**mpi_type_create_subarray",
                                 "**mpi_type_create_subarray %d %p %p %p %d %D %p", ndims,
                                 array_of_sizes, array_of_subsizes, array_of_starts, order, oldtype,
                                 newtype);
    }
#endif
    mpi_errno = MPIR_Err_return_comm(NULL, __func__, mpi_errno);
    goto fn_exit;
    /* --END ERROR HANDLING-- */
}
