imatcopy_batch

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

Description

The imatcopy_batch routines perform a series of in-place scaled matrix copies or transpositions. They are batched versions of imatcopy, but the imatcopy_batch routines perform their operations with groups of matrices. Each group contains matrices with the same parameters.

There is a strided API, in which the matrices in a batch are a set distance away from each other in memory and in which all matrices share the same parameters (for example matrix size), and a more flexible group API where each group of matrices has the same parameters but the user may provide multiple groups that have different parameters. The group API argument structure is better suited to USM pointers than to sycl::buffer arguments, so we only specify it for USM inputs. The strided API works with both USM and buffer memory.

	strided API	group API
Buffer memory	supported	not supported
USM pointers	supported	supported

imatcopy_batch supports the following precisions:

T
float
double
std::complex<float>
std::complex<double>

imatcopy_batch (Buffer Version)

Description

The buffer version of imatcopy_batch supports only the strided API.

The operation for the strided API is defined as:

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

where:

op(X) is one of op(X) = X, or op(X) = X^T, or op(X) = X^H,

alpha is a scalar,

C is a matrix to be transformed in place,

and C is m x n.

The matrix_array_in_out buffer contains all the input matrices. The stride between matrices is given by the stride parameter. The total number of matrices in matrix_array_in_out is given by the batch_size parameter.

Strided API

Syntax

namespace oneapi::mkl::blas::column_major {
    void imatcopy_batch(sycl::queue &queue,
                        oneapi::mkl::transpose trans,
                        std::int64_t m,
                        std::int64_t n,
                        T alpha,
                        sycl::buffer<T, 1> &matrix_array_in_out,
                        std::int64_t ld_in,
                        std::int64_t ld_out,
                        std::int64_t stride,
                        std::int64_t batch_size);
}

namespace oneapi::mkl::blas::row_major {
    void imatcopy_batch(sycl::queue &queue,
                        oneapi::mkl::transpose trans,
                        std::int64_t m,
                        std::int64_t n,
                        T alpha,
                        sycl::buffer<T, 1> &matrix_array_in_out,
                        std::int64_t ld_in,
                        std::int64_t ld_out,
                        std::int64_t stride,
                        std::int64_t batch_size);
}

Input Parameters

queue

The queue where the routine should be executed.

trans

Specifies op(C), the transposition operation applied to the matrices C. See oneMKL defined datatypes for more details.

m

Number of rows of each matrix C on input. Must be at least zero.

n

Number of columns of each matrix C on input. Must be at least zero.

alpha

Scaling factor for the matrix transpositions or copies.

matrix_array_in_out

Buffer holding the input matrices C with size stride * batch_size.

ld_in

The leading dimension of the matrices C on input. It must be positive, and must be at least m if column major layout is used, and at least n if row-major layout is used.

ld_out

The leading dimension of the matrices C on output. It must be positive.

	C not transposed	C transposed
Column major	ld_out must be at least m.	ld_out must be at least n.
Row major	ld_out must be at least n.	ld_out must be at least m.

stride

Stride between different C matrices.

	C not transposed	C transposed
Column major	stride must be at least max(ld_in*m, ld_out*m).	stride must be at least max(ld_in*m, ld_out*n).
Row major	stride must be at least max(ld_in*n, ld_out*n).	stride must be at least max(ld_in*n, ld_out*m).

batch_size

Specifies the number of matrix transposition or copy operations to perform.

Output Parameters

matrix_array_in_out

Output buffer, overwritten by batch_size matrix copy or transposition operations of the form alpha * op(C).

Throws

This routine shall throw the following exceptions if the associated condition is detected. An implementation may throw additional implementation-specific exception(s) in case of error conditions not covered here.

oneapi::mkl::invalid_argument

oneapi::mkl::unsupported_device

oneapi::mkl::host_bad_alloc

oneapi::mkl::device_bad_alloc

oneapi::mkl::unimplemented

imatcopy_batch (USM Version)

Description

The USM version of imatcopy_batch supports the group API and the strided API.

The operation for the group API is defined as:

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

The operation for the strided API is defined as:

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

where:

op(X) is one of op(X) = X, or op(X) = X^T, or op(X) = X^H,

alpha is a scalar,

C is a matrix to be transformed in place,

and C is m x n.

For the group API, the matrices are given by arrays of pointers. C represents a matrix stored at the address pointed to by matrix_array_in_out. The number of entries in matrix_array_in_out is given by:

\[total\_batch\_count = \sum_{i=0}^{group\_count-1}group\_size[i]\]

For the strided API, the single array C 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.

Group API

Syntax

namespace oneapi::mkl::blas::column_major {
    event imatcopy_batch(sycl::queue &queue,
                         const oneapi::mkl::transpose *trans_array,
                         const std::int64_t *m_array,
                         const std::int64_t *n_array,
                         const T *alpha_array,
                         T **matrix_array_in_out,
                         const std::int64_t *ld_in_array,
                         const std::int64_t *ld_out_array,
                         std::int64_t group_count,
                         const std::int64_t *groupsize,
                         const std::vector<sycl::event> &dependencies = {});
}

namespace oneapi::mkl::blas::row_major {
    event imatcopy_batch(sycl::queue &queue,
                         const oneapi::mkl::transpose *trans_array,
                         const std::int64_t *m_array,
                         const std::int64_t *n_array,
                         const T *alpha_array,
                         T **matrix_array_in_out,
                         const std::int64_t *ld_in_array,
                         const std::int64_t *ld_out_array,
                         std::int64_t group_count,
                         const std::int64_t *groupsize,
                         const std::vector<sycl::event> &dependencies = {});
}

Input Parameters

queue

The queue where the routine should be executed.

trans_array

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

m_array

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

n_array

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

alpha_array

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

matrix_array_in_out

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

ld_in_array

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

ld_out_array

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

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

• m_array[i] if row major layout is used and C is transposed

• 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

matrix_array_in_out

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

Return Values

Output event to wait on to ensure computation is complete.

Strided API

Syntax

namespace oneapi::mkl::blas::column_major {
    sycl::event imatcopy_batch(sycl::queue &queue,
                               oneapi::mkl::transpose trans,
                               std::int64_t m,
                               std::int64_t n,
                               value_or_pointer<T> alpha,
                               const T *matrix_array_in_out,
                               std::int64_t ld_in,
                               std::int64_t ld_out,
                               std::int64_t stride,
                               std::int64_t batch_size,
                               const std::vector<sycl::event> &dependencies = {});

namespace oneapi::mkl::blas::row_major {
    sycl::event imatcopy_batch(sycl::queue &queue,
                               oneapi::mkl::transpose trans,
                               std::int64_t m,
                               std::int64_t n,
                               value_or_pointer<T> alpha,
                               const T *matrix_array_in_out,
                               std::int64_t ld_in,
                               std::int64_t ld_out,
                               std::int64_t stride,
                               std::int64_t batch_size,
                               const std::vector<sycl::event> &dependencies = {});

Input Parameters

queue

The queue where the routine should be executed.

trans

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

m

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

n

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

alpha

Scaling factor for the matrix transpose or copy operation. See Scalar Arguments in BLAS for more details.

matrix_array_in_out

Array holding the matrices C. Must have size at least stride*batch_size.

ld_in

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

ld_out

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

stride

Stride between different C matrices within matrix_array_in_out.

	C not transposed	C transposed
Column major	stride must be at least max(ld_in*m, ld_out*m).	stride must be at least max(ld_in*m, ld_out*n).
Row major	stride must be at least max(ld_in*n, ld_out*n).	stride must be at least max(ld_in*n, ld_out*m).

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.

Output Parameters

matrix_array_in_out

Output array, overwritten by batch_size matrix transposition or copy operations of the form alpha*op(C).

Return Values

Output event to wait on to ensure computation is complete.

Throws

This routine shall throw the following exceptions if the associated condition is detected. An implementation may throw additional implementation-specific exception(s) in case of error conditions not covered here.

oneapi::mkl::invalid_argument

oneapi::mkl::unsupported_device

oneapi::mkl::host_bad_alloc

oneapi::mkl::device_bad_alloc

oneapi::mkl::unimplemented

Parent topic: BLAS-like Extensions