hemm

Intel® oneAPI Math Kernel Library (oneMKL) - Data Parallel C++ Developer Reference

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ID 772045

Date 12/16/2022

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hemm

Computes a matrix-matrix product where one input matrix is hermitian and one is general.

Description

The hemm routines compute a scalar-matrix-matrix product and add the result to a scalar-matrix product, where one of the matrices in the multiplication is hermitian. The argument left_right determines if the hermitian matrix, A, is on the left of the multiplication (left_right = side::left) or on the right (left_right = side::right). The operation is defined as:

If (left_right = side::left),

If (left_right = side::right),

where:

alpha and beta are scalars
A is either m x m or n x n hermitian matrix
B and C are m x n matrices

hemm supports the following precisions:

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

hemm (Buffer Version)

Syntax

namespace oneapi::mkl::blas::column_major {
    void hemm(sycl::queue &queue,
              oneapi::mkl::side left_right,
              oneapi::mkl::uplo upper_lower,
              std::int64_t m,
              std::int64_t n,
              T alpha,
              sycl::buffer<T,1> &a,
              std::int64_t lda,
              sycl::buffer<T,1> &b,
              std::int64_t ldb,
              T beta,
              sycl::buffer<T,1> &c,
              std::int64_t ldc,
              compute_mode mode = compute_mode::unset)
}

namespace oneapi::mkl::blas::row_major {
    void hemm(sycl::queue &queue,
              oneapi::mkl::side left_right,
              oneapi::mkl::uplo upper_lower,
              std::int64_t m,
              std::int64_t n,
              T alpha,
              sycl::buffer<T,1> &a,
              std::int64_t lda,
              sycl::buffer<T,1> &b,
              std::int64_t ldb,
              T beta,
              sycl::buffer<T,1> &c,
              std::int64_t ldc,
              compute_mode mode = compute_mode::unset)
}

Input Parameters

queue: The queue where the routine should be executed.
left_right: Specifies whether matrix A is on the left side or right side of the multiplication. See Data Types for more details.
upper_lower: Specifies whether matrix A is upper or lower triangular. See Data Types for more details.
m: Number of rows of matrix B and matrix C. Must be at least zero.
n: Number of columns of matrix B and matrix C. Must be at least zero.
alpha: Scaling factor for matrix-matrix product.
a: Buffer holding input matrix A. Size of the buffer must be at least lda * m if left_right = side::left or lda * n if left_right = side::right. See Matrix Storage for more details.
lda: Leading dimension of matrix A. Must be at least m if left_right = side::left or at least n if left_right = side::right. Must be positive.
b: Buffer holding input matrix B. Size of the buffer must be at least ldb * n if column major layout or at least ldb * m if row major layout is used. See Matrix Storage for more details.
ldb: Leading dimension of matrix B. Must be at least m if column major layout or at least n if row major layout is used. Must be positive.
beta: Scaling factor for matrix C.
c: Buffer holding input/output matrix C. Size of the buffer must be at least ldc * n if column major layout or at least ldc * m if row major layout is used. See Matrix Storage for more details.
ldc: Leading dimension of matrix C. Must be at least m if column major layout or at least n if row major layout is used. Must be positive.
mode: Optional. Compute mode settings. See Compute Modes for more details.

Output Parameters

c: Output buffer overwritten by alpha * A * B + beta * C if left_right = side::left or alpha * B * A + beta * C if left_right = side::right.

NOTE:

If beta = 0, matrix C does not need to be initialized before calling hemm.

hemm (USM Version)

Syntax

namespace oneapi::mkl::blas::column_major {
    sycl::event hemm(sycl::queue &queue,
                     oneapi::mkl::side left_right,
                     oneapi::mkl::uplo upper_lower,
                     std::int64_t m,
                     std::int64_t n,
                     T alpha,
                     const T *a,
                     std::int64_t lda,
                     const T *b,
                     std::int64_t ldb,
                     T beta,
                     T *c,
                     std::int64_t ldc,
                     compute_mode mode = compute_mode::unset,
                     const std::vector<sycl::event> &dependencies = {})
}

namespace oneapi::mkl::blas::row_major {
    sycl::event hemm(sycl::queue &queue,
                     oneapi::mkl::side left_right,
                     oneapi::mkl::uplo upper_lower,
                     std::int64_t m,
                     std::int64_t n,
                     T alpha,
                     const T *a,
                     std::int64_t lda,
                     const T *b,
                     std::int64_t ldb,
                     T beta,
                     T *c,
                     std::int64_t ldc,
                     compute_mode mode = compute_mode::unset,
                     const std::vector<sycl::event> &dependencies = {})
}

Input Parameters

queue

The queue where the routine should be executed.

left_right

Specifies whether matrix A is on the left side or right side of the multiplication. See Data Types for more details.

upper_lower

Specifies whether matrix A is upper or lower triangular. See Data Types for more details.

m

Number of rows of matrix B and matrix C. Must be at least zero.

n

Number of columns of matrix B and matrix C. Must be at least zero.

alpha

Scaling factor for matrix-matrix product.

a

Pointer to input matrix A. Size of the array must be at least lda * m if left_right = side::left or lda * n if left_right = side::right. See Matrix Storage for more details.

lda

Leading dimension of matrix A. Must be at least m if left_right = side::left or at least n if left_right = side::right. Must be positive.

b

Pointer to input matrix B. Size of the array must be at least ldb * n if column major layout or at least ldb * m if row major layout is used. See Matrix Storage for more details.

ldb

Leading dimension of matrix B. Must be at least m if column major layout or at least n if row major layout is used. Must be positive.

beta

Scaling factor for matrix C.

c

Pointer to input/output matrix C. Size of the array must be at least ldc * n if column major layout or at least ldc * m if row major layout is used. See Matrix Storage for more details.

ldc

Leading dimension of matrix C. Must be at least m if column major layout or at least n if row major layout is used. Must be positive.

mode

Optional. Compute mode settings. See Compute Modes for more details.

dependencies

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

mode and dependencies may be omitted independently; it is not necessary to specify mode in order to provide dependencies.

Output Parameters

c: Pointer to output matrix overwritten by alpha * A * B + beta * C if left_right = side::left or alpha * B * A + beta * C if left_right = side::right.

NOTE:

If beta = 0, matrix C does not need to be initialized before calling hemm.

Return Values

Output event to wait on to ensure computation is complete.

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Intel® oneAPI Math Kernel Library (oneMKL) - Data Parallel C++ Developer Reference

hemm

Description

hemm (Buffer Version)

hemm (USM Version)