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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),

C \leftarrow alpha*A*B + beta*C

If (left_right = side::right),

C \leftarrow alpha*B*A + beta*C

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)
}

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)
}

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.

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 (Buffer 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,
                     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,
                     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.

dependencies

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

gemm her2k