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Creating New Datatypes

Travis Koehring edited this page Aug 12, 2021 · 16 revisions

Overview

This document describes the APIs provided by Yaksa to create datatypes. Similarly to MPI datatypes, Yaksa defines native (or builtin) datatypes as well as derived datatypes. Native datatypes are basic building blocks that Yaksa can use to construct arbitrarily complex data layout representations using Yaksa derived datatypes.

The document presents the datatype creation APIs and showcases examples for each of them. Pack and Unpack shows how the layouts presented in the examples can be used with pack and unpack routines.

API

yaksa_type_create_contig()

int yaksa_type_create_contig(intptr_t       count,
                             yaksa_type_t   oldtype,
                             yaksa_info_t   info,
                             yaksa_type_t * newtype)
  • Creates a contig layout.
  • Parameters
    • [in] count: Number of elements of the old type
    • [in] oldtype: Base datatype forming each element in the contig
    • [in] info: Info hint to apply
    • [out] newtype: Final generated type
  • Return values
    • On success, YAKSA_SUCCESS is returned.
    • On error, a non-zero error code is returned.

The following example showcases the use yaksa_type_create_contig API to create a new contig layout.

#include <yaksa.h>

int main()
{
    int rc;
    int input_matrix[64] = {
        0,  1,  2,  3,  4,  5,  6,  7,
        8,  9, 10, 11, 12, 13, 14, 15,
       16, 17, 18, 19, 20, 21, 22, 23,
       24, 25, 26, 27, 28, 29, 30, 31,
       32, 33, 34, 35, 36, 37, 38, 39,
       40, 41, 42, 43, 44, 45, 46, 47,
       48, 49, 50, 51, 52, 53, 54, 55,
       56, 57, 58, 59, 60, 61, 62, 63};
    yaksa_type_t contig;

    yaksa_init(YAKSA_INIT_ATTR__DEFAULT); /* before any yaksa API is called the
                                             library must be initialized */

    rc = yaksa_type_create_contig(64, YAKSA_TYPE__INT, NULL, &contig);
    assert(rc == YAKSA_SUCCESS);

    yaksa_type_free(contig);

    yaksa_finalize();
    return 0;
}

The code snippet creates a new contig layout containing 64 signed integer elements, thus the contig layout covers all the elements in the input_matrix.


yaksa_type_create_dup()

int yaksa_type_create_dup(yaksa_type_t   oldtype,
                          yaksa_info_t   info,
                          yaksa_type_t * newtype)
  • Create a copy of the old datatype
  • Parameters
    • [in] oldtype: Base datatype being dup'ed
    • [in] info: Info hint to apply
    • [out] newtype: Final generated type
  • Return values
    • On success, YAKSA_SUCCESS is returned.
    • On error, a non-zero error code is returned.

yaksa_type_create_vector()

int yaksa_type_create_vector(int            count,
                             int            blocklength,
                             int            stride,
                             yaksa_type_t   oldtype,
                             yaksa_info_t   info,
                             yaksa_type_t * newtype)
  • Create a vector layout
  • Parameters
    • [in] count: Number of blocks in the vector
    • [in] blocklength: Length of each block
    • [in] stride: Increment from the start of one block to another (represented in terms of the count of oldtype)
    • [in] oldtype: Base datatype forming each element in new type
    • [in] info: Info hint to apply
    • [out] newtype: Final generated type
  • Return values
    • On success, YAKSA_SUCCESS is returned.
    • On error, a non-zero error code is returned.

The following example showcases the use yaksa_type_create_vector API to create a new vector layout.

#include <yaksa.h>

int main()
{
    int rc;
    int input_matrix[64] = {
        0,  1,  2,  3,  4,  5,  6,  7,
        8,  9, 10, 11, 12, 13, 14, 15,
       16, 17, 18, 19, 20, 21, 22, 23,
       24, 25, 26, 27, 28, 29, 30, 31,
       32, 33, 34, 35, 36, 37, 38, 39,
       40, 41, 42, 43, 44, 45, 46, 47,
       48, 49, 50, 51, 52, 53, 54, 55,
       56, 57, 58, 59, 60, 61, 62, 63};
    yaksa_type_t vector;

    yaksa_init(YAKSA_INIT_ATTR__DEFAULT); /* before any yaksa API is called the
                                             library must be initialized */

    rc = yaksa_type_create_vector(8, 1, 8, YAKSA_TYPE__INT, NULL, &vector);
    assert(rc == YAKSA_SUCCESS);

    yaksa_type_free(vector);

    yaksa_finalize();
    return 0;
}

The created vector layout contains 8 blocks, each made of 1 signed integer and with a distance between the first elements of two consecutive blocks of 8 signed integers. The same layout can also be obtained using yaksa_create_hvector by replacing the number of bytes in the stride with its number of bytes (i.e. 32). The vector layout covers all the elements of any of the columns in input_matrix. The following example shows the layout when it is applied to the beginning of input_matrix (the second column could be selected by applying the layout to input_matrix + 1):

/* input_matrix layout */      /* input_matrix + 1 layout */
  0  x  x  x  x  x  x  x             1  x  x  x  x  x  x
  8  x  x  x  x  x  x  x          x  9  x  x  x  x  x  x
 16  x  x  x  x  x  x  x          x 17  x  x  x  x  x  x
 24  x  x  x  x  x  x  x          x 25  x  x  x  x  x  x
 32  x  x  x  x  x  x  x          x 33  x  x  x  x  x  x
 40  x  x  x  x  x  x  x          x 41  x  x  x  x  x  x
 48  x  x  x  x  x  x  x          x 49  x  x  x  x  x  x
 56  x  x  x  x  x  x  x          x 57  x  x  x  x  x  x

yaksa_type_create_hvector()

int yaksa_type_create_hvector(int            count,
                              int            blocklength,
                              intptr_t       stride, 
                              yaksa_type_t   oldtype,
                              yaksa_info_t   info,
                              yaksa_type_t * newtype)
  • Create a hvector layout
  • Parameters
    • [in] count: Number of blocks in the vector
    • [in] blocklength: Length of each block
    • [in] stride: Increment from the start of one block to another (represented in bytes)
    • [in] oldtype: Base datatype forming each element in new type
    • [in] info: Info hint to apply
    • [out] newtype: Final generated type
  • Return values
    • On success, YAKSA_SUCCESS is returned.
    • On error, a non-zero error code is returned.

The "h" in hvector stands for heterogeneous and refers to the fact that the stride does not have to be a multiple of the vector's base type length but can be any number of bytes. The following example showcases the use yaksa_type_create_hvector API to create a new hvector layout.

#include <yaksa.h>

int main()
{
    int rc;
    int input_matrix[64] = {
        0,  1,  2,  3,  4,  5,  6,  7,
        8,  9, 10, 11, 12, 13, 14, 15,
       16, 17, 18, 19, 20, 21, 22, 23,
       24, 25, 26, 27, 28, 29, 30, 31,
       32, 33, 34, 35, 36, 37, 38, 39,
       40, 41, 42, 43, 44, 45, 46, 47,
       48, 49, 50, 51, 52, 53, 54, 55,
       56, 57, 58, 59, 60, 61, 62, 63};
    yaksa_type_t hvector;

    yaksa_init(YAKSA_INIT_ATTR__DEFAULT); /* before any yaksa API is called the
                                             library must be initialized */

    rc = yaksa_type_create_hvector(8, 1, 8 * sizeof(int), YAKSA_TYPE__INT,
                                   NULL, &hvector);
    assert(rc == YAKSA_SUCCESS);

    yaksa_type_free(hvector);

    yaksa_finalize();
    return 0;
}

The following example shows the layout when the hvector datatype is applied to the input_matrix:

/* input_matrix layout */
  0  x  x  x  x  x  x  x
  8  x  x  x  x  x  x  x
 16  x  x  x  x  x  x  x
 24  x  x  x  x  x  x  x
 32  x  x  x  x  x  x  x
 40  x  x  x  x  x  x  x
 48  x  x  x  x  x  x  x
 56  x  x  x  x  x  x  x

A more useful example of hvector use case is shown at the end of this document to perform a matrix transposition.


yaksa_type_create_indexed_block()

int yaksa_type_create_indexed_block(int            count,
                                    int            blocklength, 
                                    const int    * array_of_displacements,
                                    yaksa_type_t   oldtype,
                                    yaksa_info_t   info,
                                    yaksa_type_t * newtype)
  • Create a block-indexed layout
  • Parameters
    • [in] count: Number of blocks in the new type
    • [in] blocklength: Length of each block
    • [in] array_of_displacements: Starting offset to each block (represented in terms of the count of oldtype)
    • [in] oldtype: Base datatype forming each element in the new type
    • [in] info: Info hint to apply
    • [out] newtype: Final generated type
  • Return values
    • On success, YAKSA_SUCCESS is returned.
    • On error, a non-zero error code is returned.

The following example showcases the use yaksa_type_create_indexed_block API to create a new indexed block layout.

#include <yaksa.h>

int main()
{
    int rc;
    int input_matrix[64] = {
        0,  1,  2,  3,  4,  5,  6,  7,
        8,  9, 10, 11, 12, 13, 14, 15,
       16, 17, 18, 19, 20, 21, 22, 23,
       24, 25, 26, 27, 28, 29, 30, 31,
       32, 33, 34, 35, 36, 37, 38, 39,
       40, 41, 42, 43, 44, 45, 46, 47,
       48, 49, 50, 51, 52, 53, 54, 55,
       56, 57, 58, 59, 60, 61, 62, 63};
    yaksa_type_t indx_block;
    intptr_t array_of_displacements[8] = {
        4 , 12, 20, 28,
        32, 40, 48, 56};

    yaksa_init(YAKSA_INIT_ATTR__DEFAULT); /* before any yaksa API is called the
                                             library must be initialized */

    rc = yaksa_type_create_indexed_block(8, 4, array_of_displacements,
                                         YAKSA_TYPE__INT, NULL, &indx_block);
    assert(rc == YAKSA_SUCCESS);

    yaksa_type_free(indx_block);

    yaksa_finalize();
    return 0;
}

The indx_block layout covers the following elements in input_matrix:

/* input_matrix layout */
  x  x  x  x  4  5  6  7
  x  x  x  x 12 13 14 15
  x  x  x  x 20 21 22 23
  x  x  x  x 28 29 30 31
 32 33 34 35  x  x  x  x
 40 41 42 43  x  x  x  x
 48 49 50 51  x  x  x  x
 56 57 58 59  x  x  x  x

yaksa_type_create_hindexed_block()

int yaksa_type_create_hindexed_block(int              count,
                                     int              blocklength, 
                                     const intptr_t * array_of_displacements, 
                                     yaksa_type_t     oldtype,
                                     yaksa_info_t     info,
                                     yaksa_type_t   * newtype)
  • Create a block-hindexed layout
  • Parameters
    • [in] count: Number of blocks in the new type
    • [in] blocklength: Length of each block
    • [in] array_of_displacements: Starting offset to each block (represented in bytes)
    • [in] oldtype: Base datatype forming each element in the new type
    • [in] info: Info hint to apply
    • [out] newtype: Final generated type
  • Return values
    • On success, YAKSA_SUCCESS is returned.
    • On error, a non-zero error code is returned.

Similarly to the previously described hvector datatype, the hindexed block datatype can be used to access heterogeneous data using byte displacements (rather than units of the base type) as shown in the following example:

#include <yaksa.h>

int main()
{
    int rc;
    int input_matrix[64] = {
        0,  1,  2,  3,  4,  5,  6,  7,
        8,  9, 10, 11, 12, 13, 14, 15,
       16, 17, 18, 19, 20, 21, 22, 23,
       24, 25, 26, 27, 28, 29, 30, 31,
       32, 33, 34, 35, 36, 37, 38, 39,
       40, 41, 42, 43, 44, 45, 46, 47,
       48, 49, 50, 51, 52, 53, 54, 55,
       56, 57, 58, 59, 60, 61, 62, 63};
    yaksa_type_t hindx_block;
    intptr_t array_of_displacements[8] = {
        4  * sizeof(int), 12 * sizeof(int), 20 * sizeof(int), 28 * sizeof(int),
        32 * sizeof(int), 40 * sizeof(int), 48 * sizeof(int), 56 * sizeof(int)};

    yaksa_init(YAKSA_INIT_ATTR__DEFAULT); /* before any yaksa API is called the
                                             library must be initialized */

    rc = yaksa_type_create_hindexed_block(8, 4, array_of_displacements,
                                          YAKSA_TYPE__INT, NULL, &hindx_block);
    assert(rc == YAKSA_SUCCESS);

    yaksa_type_free(hindx_block);

    yaksa_finalize();
    return 0;
}

The following example shows the layout when it is applied to the beginning of input_matrix:

/* input_matrix layout */
  x  x  x  x  4  5  6  7
  x  x  x  x 12 13 14 15
  x  x  x  x 20 21 22 23
  x  x  x  x 28 29 30 31
 32 33 34 35  x  x  x  x
 40 41 42 43  x  x  x  x
 48 49 50 51  x  x  x  x
 56 57 58 59  x  x  x  x

yaksa_type_create_indexed()

int yaksa_type_create_indexed(int            count,
                              const int      array_of_blocklengths, 
                              const int    * array_of_displacements,
                              yaksa_type_t   oldtype,
                              yaksa_info_t   info,
                              yaksa_type_t * newtype)
  • Create an indexed layout
  • Parameters
    • [in] count: Number of blocks in the new type
    • [in] array_of_blocklengths: Array of lengths of each block
    • [in] array_of_displacements: Starting offset to each block (represented in terms of the count of oldtype)
    • [in] oldtype: Base datatype forming each element in the new type
    • [in] info: Info hint to apply
    • [out] newtype: Final generated type
  • Return values
    • On success, YAKSA_SUCCESS is returned.
    • On error, a non-zero error code is returned.

The following example showcases the use yaksa_type_create_indexed API to create a new indexed layout.

#include <yaksa.h>

int main()
{
    int rc;
    int input_matrix[64] = {
        0,  1,  2,  3,  4,  5,  6,  7,
        8,  9, 10, 11, 12, 13, 14, 15,
       16, 17, 18, 19, 20, 21, 22, 23,
       24, 25, 26, 27, 28, 29, 30, 31,
       32, 33, 34, 35, 36, 37, 38, 39,
       40, 41, 42, 43, 44, 45, 46, 47,
       48, 49, 50, 51, 52, 53, 54, 55,
       56, 57, 58, 59, 60, 61, 62, 63};
    yaksa_type_t indexed;
    int array_of_blocklengths[7] = {
        1,
        2, 2, 
        4, 4, 4, 4};
    intptr_t array_of_displacements[7] = {
        9 ,
        18, 26,
        36, 44, 52, 60};

    yaksa_init(YAKSA_INIT_ATTR__DEFAULT); /* before any yaksa API is called the
                                             library must be initialized */

    rc = yaksa_type_create_indexed(7, array_of_blocklengths, array_of_displacements, 
                                   YAKSA_TYPE__INT, NULL, &indexed);
    assert(rc == YAKSA_SUCCESS);

    yaksa_type_free(indexed);

    yaksa_finalize();
    return 0;
}

The indexed layout covers the following elements in input matrix:

/* input_matrix layout */
  x  x  x  x  x  x  x  x
  x  9  x  x  x  x  x  x
  x  x 18 19  x  x  x  x
  x  x 26 27  x  x  x  x
  x  x  x  x 36 37 38 39
  x  x  x  x 44 45 46 47
  x  x  x  x 52 53 54 55
  x  x  x  x 60 61 62 63

The same layout can also be obtained using yaksa_type_create_hindexed() by expressing the displacement array in bytes instead of base element units.


yaksa_type_create_hindexed()

int yaksa_type_create_hindexed(int              count,
                               const int        array_of_blocklengths, 
                               const intptr_t * array_of_displacements, 
                               yaksa_type_t     oldtype,
                               yaksa_info_t     info,
                               yaksa_type_t   * newtype)
  • Create an hindexed layout
  • Parameters
    • [in] count: Number of blocks in the new type
    • [in] array_of_blocklengths: Array of lengths of each block
    • [in] array_of_displacements: Starting offset to each block (represented in bytes)
    • [in] oldtype: Base datatype forming each element in the new type
    • [in] info: Info hint to apply
    • [out] newtype: Final generated type
  • Return values
    • On success, YAKSA_SUCCESS is returned.
    • On error, a non-zero error code is returned.

Similarly to the previously described hindexed block datatype, the hindexed datatype can be used to access heterogeneous data using byte displacements (rather than units of the base type) as shown in the following example:

#include <yaksa.h>

int main()
{
    int rc;
    int input_matrix[64] = {
        0,  1,  2,  3,  4,  5,  6,  7,
        8,  9, 10, 11, 12, 13, 14, 15,
       16, 17, 18, 19, 20, 21, 22, 23,
       24, 25, 26, 27, 28, 29, 30, 31,
       32, 33, 34, 35, 36, 37, 38, 39,
       40, 41, 42, 43, 44, 45, 46, 47,
       48, 49, 50, 51, 52, 53, 54, 55,
       56, 57, 58, 59, 60, 61, 62, 63};
    yaksa_type_t hindexed;
    int array_of_blocklengths[7] = {
        1,
        2, 2, 
        4, 4, 4, 4};
    intptr_t array_of_displacements[7] = {
        9  * sizeof(int),
        18 * sizeof(int), 26 * sizeof(int),
        36 * sizeof(int), 44 * sizeof(int), 52 * sizeof(int), 60 * sizeof(int)};

    yaksa_init(YAKSA_INIT_ATTR__DEFAULT); /* before any yaksa API is called the
                                             library must be initialized */

    rc = yaksa_type_create_indexed(7, array_of_blocklengths, array_of_displacements, 
                                   YAKSA_TYPE__INT, NULL, &hindexed);
    assert(rc == YAKSA_SUCCESS);

    yaksa_type_free(hindexed);

    yaksa_finalize();
    return 0;
}

The following example shows the layout when it is applied to the beginning of input_matrix:

/* input_matrix layout */
  x  x  x  x  x  x  x  x
  x  9  x  x  x  x  x  x
  x  x 18 19  x  x  x  x
  x  x 26 27  x  x  x  x
  x  x  x  x 36 37 38 39
  x  x  x  x 44 45 46 47
  x  x  x  x 52 53 54 55
  x  x  x  x 60 61 62 63

yaksa_type_create_struct()

int yaksa_type_create_struct(int                  count,
                             const int          * array_of_blocklengths, 
                             const intptr_t     * array_of_displacements, 
                             const yaksa_type_t * array_of_types,
                             yaksa_info_t         info,
                             yaksa_type_t       * newtype)
  • Create a struct layout
  • Parameters
    • [in] count: Number of blocks in the new type
    • [in] array_of_blocklengths: Array of lengths of each block
    • [in] array_of_displacements: Starting offset to each block
    • [in] array_of_types: Array of base datatypes forming each element in the new type
    • [in] info: Info hint to apply
    • [out] newtype: Final generated type
  • Return values
    • On success, YAKSA_SUCCESS is returned.
    • On error, a non-zero error code is returned.

The following example showcases the use yaksa_type_create_struct API to create a new struct layout.

#include <yaksa.h>

int main()
{
    int rc;
    yaksa_type_t str;
    yaksa_type_t array_of_types[4] = {
        YAKSA_TYPE__CHAR, 
        YAKSA_TYPE__INT, 
        YAKSA_TYPE__LONG, 
        YAKSA_TYPE__LONG_DOUBLE};
    int array_of_blocklengths[4] = {
        6, 3, 2, 1};
    intptr_t array_of_displacements[4] = {
        0,
        (sizeof(char) * 6),
        (sizeof(char) * 6) + (sizeof(int) * 3),
        (sizeof(char) * 6) + (sizeof(int) * 3) + (sizeof(long) * 2)};

    yaksa_init(YAKSA_INIT_ATTR__DEFAULT); /* before any yaksa API is called the
                                             library must be initialized */

    rc = yaksa_type_create_struct(4, array_of_blocklengths, array_of_displacements, 
                                  array_of_types, NULL, &str);
    assert(rc == YAKSA_SUCCESS);

    yaksa_type_free(str);

    yaksa_finalize();
    return 0;
}

The created struct layout describes to the following C structure

struct {
    char        a[6];
    int         b[3];
    long        c[2];
    long double d;
}

yaksa_type_create_subarray()

int yaksa_type_create_subarray(int                     ndims,
                               const int             * array_of_sizes, 
                               const int             * array_of_subsizes, 
                               const int             * array_of_starts,
                               yaksa_subarray_order_e  order, 
                               yaksa_type_t            oldtype,
                               yaksa_info_t            info,
                               yaksa_type_t          * newtype)
  • Create a subarray layout
  • Parameters
    • [in] ndims: Number of dimensions in the array
    • [in] array_of_sizes: Dimension sizes of the entire array
    • [in] array_of_subsizes: Dimension sizes of the subarray
    • [in] array_of_starts: Start location ("corner representing the start") of the subarray
    • [in] order: Data layout order (C or Fortran)
    • [in] oldtype: Base datatype forming each element of the new type
    • [in] info: Info hint to apply
    • [out] newtype: Final generated type
  • Return values
    • On success, YAKSA_SUCCESS is returned.
    • On error, a non-zero error code is returned.

The following example showcases the use yaksa_type_create_subarray API to create a new subarray layout.

#include <yaksa.h>

int main()
{
    int rc;
    int input_matrix[64] = {
        0,  1,  2,  3,  4,  5,  6,  7,
        8,  9, 10, 11, 12, 13, 14, 15,
       16, 17, 18, 19, 20, 21, 22, 23,
       24, 25, 26, 27, 28, 29, 30, 31,
       32, 33, 34, 35, 36, 37, 38, 39,
       40, 41, 42, 43, 44, 45, 46, 47,
       48, 49, 50, 51, 52, 53, 54, 55,
       56, 57, 58, 59, 60, 61, 62, 63};
    yaksa_type_t subarray;
    int ndims = 2;
    int array_of_sizes[2] = {8, 8};
    int array_of_subsizes[2] = {4, 4};
    int array_of_starts[2] = {4, 4};
    yaksa_subarray_order_e order = YAKSA_SUBARRAY_ORDER__C;

    yaksa_init(YAKSA_INIT_ATTR__DEFAULT); /* before any yaksa API is called the
                                             library must be initialized */

    rc = yaksa_type_create_subarray(ndims, array_of_sizes, array_of_subsizes, 
                                    array_of_starts, order, YAKSA_TYPE__INT, 
                                    NULL, &subarray);
    assert(rc == YAKSA_SUCCESS);

    yaksa_type_free(subarray);

    yaksa_finalize();
    return 0;
}

The subarray layout covers the following elements in input_matrix:

/* input_matrix layout */
  x  x  x  x  x  x  x  x
  x  x  x  x  x  x  x  x
  x  x  x  x  x  x  x  x
  x  x  x  x  x  x  x  x
  x  x  x  x 36 37 38 39
  x  x  x  x 44 45 46 47
  x  x  x  x 52 53 54 55
  x  x  x  x 60 61 62 63

The layout show above can also be obtained using yaksa_type_create_hindexed_block or yaksa_type_create_hindexed.


yaksa_type_create_resized()

int yaksa_type_create_resized(yaksa_type_t   oldtype,
                              intptr_t       lb,
                              uintptr_t      extent,
                              yaksa_info_t   info,
                              yaksa_type_t * newtype)
  • Create a resized layout with updated lower bound and extent
  • Parameters
    • [in] oldtype: Base datatype forming each element in new type
    • [in] lb: New lower bound to use
    • [in] extent: New extent to use
    • [in] info: Info hint to apply
    • [out] newtype: Final generated type
  • Return values
    • On success, YAKSA_SUCCESS is returned.
    • On error, a non-zero error code is returned.

This example shows how to use a resized vector datatype to perform a matrix transposition. A matrix transposition layout can be created using the following code.

#include <yaksa.h>

int main()
{
    int rc;
    int input_matrix[64] = {
        0,  1,  2,  3,  4,  5,  6,  7,
        8,  9, 10, 11, 12, 13, 14, 15,
       16, 17, 18, 19, 20, 21, 22, 23,
       24, 25, 26, 27, 28, 29, 30, 31,
       32, 33, 34, 35, 36, 37, 38, 39,
       40, 41, 42, 43, 44, 45, 46, 47,
       48, 49, 50, 51, 52, 53, 54, 55,
       56, 57, 58, 59, 60, 61, 62, 63};
    yaksa_type_t vector;
    yaksa_type_t vector_resized;
    yaksa_type_t transpose;

    yaksa_init(YAKSA_INIT_ATTR__DEFAULT);

    /* create a vector datatype for the elements in the matrix. The 
     * layout has 8 blocks (as the # of elements in a column), 1
     * element per block and a stride between blocks of 8 elements
     * (the # of elements in a row) */   
    rc = yaksa_type_create_vector(8, 1, 8, YAKSA_TYPE__INT, NULL, &vector);
    assert(rc == YAKSA_SUCCESS);

    /* change the extent of the datatype from 228 to 4 bytes so that the 
     * first element of a column starts after the first element in the 
     * previous instead of the last */
    rc = yaksa_type_create_resized(vector, 0, sizeof(int), NULL, &vector_resized);
    assert(rc == YAKSA_SUCCESS);

    /* create a transpose layout by lining up a number of resized
     * column layouts equal to the number of columns (i.e. 8) */
    rc = yaksa_type_create_contig(8, vector_resized, NULL, &transpose);
    assert(rc == YAKSA_SUCCESS);

    yaksa_type_free(vector);
    yaksa_type_free(vector_resized);
    yaksa_type_free(transpose);

    yaksa_finalize();
    return 0;
}

The previous code creates a vector type representing columns in input_matrix. After, it resizes the extent of the vector type using yaksa_type_create_resized. The extent marks the end of a datatype element and the beginning of the next, thus resizing the extent from the original 228 bytes to 4 can make columns interleave with each other in the final transpose layout, the resulting layout for input matrix follows.

/* input_matrix layout */
 0  8 16 24 32 40 48 56
 1  9 17 25 33 41 49 57
 2 10 18 26 34 42 50 58
 3 11 19 27 35 43 51 59
 4 12 20 28 36 44 52 60
 5 13 21 29 37 45 53 61
 6 14 22 30 38 46 54 62
 7 15 23 31 39 47 55 63

Note that without the resizing of the extent the second row of the matrix would start with the element 57 instead of 1 and memory outside the matrix would be erroneously referenced after it.

Please also note that the same result, as for previous code, can be achieved by creating a hvector of the column vector as following shown.

#include <yaksa.h>

int main()
{
    int rc;
    int input_matrix[64];
    yaksa_type_t vector;
    yaksa_type_t hvector;

    yaksa_init(YAKSA_INIT_ATTR__DEFAULT);

    rc = yaksa_type_create_vector(8, 1, 8, YAKSA_TYPE__INT, NULL, &vector);
    assert(rc == YAKSA_SUCCESS);

    rc = yaksa_type_create_hvector(8, 1, sizeof(int), vector, NULL, &hvector);
    assert(rc == YAKSA_SUCCESS);

    yaksa_type_free(vector);
    yaksa_type_free(hvector);

    yaksa_finalize();
    return 0;
}

In this example the extent of the hvector type is set to sizeof(int). Thus, every vector element in hvector starts after the first integer in the previous vector element (4 bytes), effectively achieving the same interleaving as for the resized example.


yaksa_type_free()

int yaksa_type_free(yaksa_type_t type)
  • Free datatype
  • Parameters
    • [in] type: the datatype being freed
  • Return values
    • On success, YAKSA_SUCCESS is returned.
    • On error, a non-zero error code is returned.