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imatcopy_batch

Computes a group of in-place scaled matrix transpose or copy operations using general matrices.

Description

The imatcopy_batch routines perform a series of in-place scaled matrix copies or transpositions. They are similar to the imatcopy routines, but the imatcopy_batch routines perform their operations with groups of matrices. The groups contain matrices with the same parameters.

The operation for the strided API is defined as:

for i = 0 … batch_size – 1
    AB is a matrix at offset i * stride in ab_array
    AB = alpha * op(AB)
end for

The operation for the group API is defined as:

idx = 0
for i = 0 … group_count – 1
    m,n, alpha, lda, ldb and group_size at position i in their respective arrays
    for j = 0 … group_size – 1
        AB is a matrix at position idx in AB_array
        AB = alpha * op(AB)
        idx := idx + 1
    end for
end for

where:

  • op(X) is one of op(X) = X, op(X) = X', or op(X) = conjg(X')

  • alpha is a scalar

  • AB is a matrix to be transformed in place

The strided API is available with USM pointers or buffer arguments for the input and output arrays, while the group API is available only with USM pointers.

For the strided API, the single buffer or array AB contains all the matrices to be transformed in place. The locations of the individual matrices within the buffer or array are given by stride lengths, while the number of matrices is given by the batch_size parameter.

For the group API, the matrices are given by arrays of pointers. AB represents a matrix stored at the address pointed to by ab_array. The number of entries in ab_array is total_batch_count = the sum of all the group_size entries.

API

Syntax

Strided API

USM arrays:

event imatcopy_batch(queue &queue,
   transpose trans,
   std::int64_t m,
   std::int64_t n,
   T alpha,
   const T *ab,
   std::int64_t lda,
   std::int64_t ldb,
   std::int64_t stride,
   std::int64_t batch_size,
   const vector_class<event> &dependencies = {});

Buffer arrays:

void imatcopy_batch(queue &queue, transpose trans,
   std::int64_t m, std::int64_t n, T alpha,
   cl::sycl::buffer<T, 1> &ab, std::int64_t lda,
   std::int64_t ldb, std::int64_t stride,
   std::int64_t batch_size);

Group API

event imatcopy_batch(queue &queue, const transpose *trans_array,
                     const std::int64_t *m_array,
                     const std::int64_t *n_array,
                     const T *alpha_array, T **ab_array,
                     const std::int64_t *lda_array,
                     const std::int64_t *ldb_array,
                     std::int64_t group_count,
                     const std::int64_t *groupsize,
                     const vector_class<event> &dependencies = {});

imatcopy_batch supports the following precisions and devices:

T

Devices Supported

float

Host, CPU, and GPU

double

Host, CPU, and GPU

std::complex<float>

Host, CPU, and GPU

std::complex<double>

Host, CPU, and GPU

Input Parameters

Strided API

trans

Specifies op(AB), the transposition operation applied to the matrices AB.

m

Number of rows for each matrix AB on input. Must be at least 0.

n

Number of columns for each matrix AB on input. Must be at least 0.

alpha

Scaling factor for the matrix transpose or copy operation.

ab

Buffer holding the matrices AB. Must have size at least stride*batch_size.

lda

Leading dimension of the AB matrices on input. If matrices are stored using column major layout, lda must be at least m. If matrices are stored using row major layout, lda must be at least n. Must be positive.

ldb

Leading dimension of the AB matrices on output. If matrices are stored using column major layout, ldb must be at least m if AB is not transposed or n if AB is transposed. If matrices are stored using row major layout, ldb must be at least n if AB is not transposed or at least m if AB is transposed. Must be positive.

stride

Stride between the different AB matrices. It must be at least max(ldb,lda)*max(ka, kb), where:

  • ka is m if column major layout is used or n if row major

    layout is used

  • kb is n if column major layout is used and AB is not

    transposed, or m otherwise

batch_size

Specifies the number of matrices to transpose or copy.

dependencies

List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies.

Group API

trans_array

Array of size group_count. Each element i in the array specifies op(AB) the transposition operation applied to the matrices AB.

m_array

Array of size group_count of number of rows of AB on input. Each must be at least 0.

n_array

Array of size group_count of number of columns of AB on input. Each must be at least 0.

alpha_array

Array of size group_count containing scaling factors for the matrix transpositions or copies.

ab_array

Array of size total_batch_count, holding pointers to arrays used to store AB matrices.

lda_array

Array of size group_count. The leading dimension of the matrix input AB. If matrices are stored using column major layout, lda_array[i] must be at least m_array[i]. If matrices are stored using row major layout, lda_array[i] must be at least n_array[i]. Must be positive.

ldb_array

Array of size group_count. The leading dimension of the output matrix AB. Each entry ldb_array[i] must be positive and at least:

  • m_array[i] if column major layout is used and AB is not transposed

  • m_array[i] if row major layout is used and AB is transposed (AB’)

  • n_array[i] otherwise

group_count

Number of groups. Must be at least 0.

group_size

Array of size group_count. The element group_size[i] is the number of matrices in the group i. Each element in group_size must be at least 0.

dependencies

List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies.

Output Parameters

Strided API

ab

Output buffer, overwritten by batch_size matrix multiply operations of the form alpha*op(AB).

Group API

ab_array

Output array of pointers to AB matrices, overwritten by total_batch_count matrix transpose or copy operations of the form alpha*op(AB).

omatcopy_batch omatadd_batch