syr2k

oneMKL - Data Parallel C++ Developer Reference

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ID 772045

Date 10/31/2024

Version

Public

Visible to Intel only — GUID: GUID-526EB25D-02CE-4C0A-B1A4-93F54F2EB6F2

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syr2k

Performs a symmetric rank-2k update.

Description

The syr2k routines perform a rank-2k update of an n x n symmetric matrix C by general matrices A and B. The operation is defined as:

If trans = transpose::nontrans,

where A and B are n x k matrices.

If trans = transpose::trans,

where A and B are k x n matrices.

In both cases:

alpha and beta are scalars
C is symmetric matrix, A and B are general matrices
The inner dimension of both matrix multiplications is k

syr2k supports the following precisions:

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

syr2k (Buffer Version)

Syntax

namespace oneapi::mkl::blas::column_major {
    void syr2k(sycl::queue &queue,
               oneapi::mkl::uplo upper_lower,
               oneapi::mkl::transpose trans,
               std::int64_t n,
               std::int64_t k,
               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 syr2k(sycl::queue &queue,
               oneapi::mkl::uplo upper_lower,
               oneapi::mkl::transpose trans,
               std::int64_t n,
               std::int64_t k,
               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.

upper_lower

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

trans

Specifies the transposition operation applied as described above. Conjugation is never performed even if trans = transpose::conjtrans.

n

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

k

Inner dimension of matrix multiplications. Must be at least zero.

alpha

Complex scaling factor for the rank-2k update.

a

Buffer holding input matrix A. See Matrix Storage for more details.

	`trans` = `transpose::nontrans`	`trans` = `transpose::trans` or `trans` = `transpose::conjtrans`
Column major	`A` is `n` x `k` matrix. Size of array `a` must be at least `lda` * `k`	`A` is `k` x `n` matrix. Size of array `a` must be at least `lda` * `n`
Row major	`A` is `n` x `k` matrix. Size of array `a` must be at least `lda` * `n`	`A` is `k` x `n` matrix. Size of array `a` must be at least `lda` * `k`

lda

Leading dimension of matrix A. Must be positive.

	`trans` = `transpose::nontrans`	`trans` = `transpose::trans` or `trans` = `transpose::conjtrans`
Column major	Must be at least `n`	Must be at least `k`
Row major	Must be at least `k`	Must be at least `n`

b

Buffer holding input matrix B. See Matrix Storage for more details.

	`trans` = `transpose::nontrans`	`trans` = `transpose::trans` or `trans` = `transpose::conjtrans`
Column major	`B` is `n` x `k` matrix. Size of array `b` must be at least `ldb` * `k`	`B` is `k` x `n` matrix. Size of array `b` must be at least `ldb` * `n`
Row major	`B` is `n` x `k` matrix. Size of array `b` must be at least `ldb` * `n`	`B` is `k` x `n` matrix. Size of array `b` must be at least `ldb` * `k`

ldb

Leading dimension of matrix B. Must be positive.

	`trans` = `transpose::nontrans`	`trans` = `transpose::trans` or `trans` = `transpose::conjtrans`
Column major	Must be at least `n`	Must be at least `k`
Row major	Must be at least `k`	Must be at least `n`

beta

Real scaling factor for matrix C.

c

Buffer holding input/output matrix C. Size of the buffer must be at least ldc * n. See Matrix Storage for more details.

ldc

Leading dimension of matrix C. Must be positive and at least n.

mode

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

Output Parameters

c: Output buffer overwritten by updated C matrix.

syr2k (USM Version)

Syntax

namespace oneapi::mkl::blas::column_major {
    sycl::event syr2k(sycl::queue &queue,
                      oneapi::mkl::uplo upper_lower,
                      oneapi::mkl::transpose trans,
                      std::int64_t n,
                      std::int64_t k,
                      oneapi::mkl::value_or_pointer<T> alpha,
                      const T *a,
                      std::int64_t lda,
                      const T *b,
                      std::int64_t ldb,
                      oneapi::mkl::value_or_pointer<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 syr2k(sycl::queue &queue,
                      oneapi::mkl::uplo upper_lower,
                      oneapi::mkl::transpose trans,
                      std::int64_t n,
                      std::int64_t k,
                      oneapi::mkl::value_or_pointer<T> alpha,
                      const T *a,
                      std::int64_t lda,
                      const T *b,
                      std::int64_t ldb,
                      oneapi::mkl::value_or_pointer<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.

upper_lower

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

trans

Specifies the transposition operation applied as described above. Conjugation is never performed even if trans = transpose::conjtrans.

n

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

k

Inner dimension of matrix multiplications. Must be at least zero.

alpha

Complex scaling factor for the rank-2k update. See Scalar Arguments for more information on the value_or_pointer data type.

a

Pointer to input matrix A. See Matrix Storage for more details.

	`trans` = `transpose::nontrans`	`trans` = `transpose::trans` or `trans` = `transpose::conjtrans`
Column major	`A` is `n` x `k` matrix. Size of array `a` must be at least `lda` * `k`	`A` is `k` x `n` matrix. Size of array `a` must be at least `lda` * `n`
Row major	`A` is `n` x `k` matrix. Size of array `a` must be at least `lda` * `n`	`A` is `k` x `n` matrix. Size of array `a` must be at least `lda` * `k`

lda

Leading dimension of matrix A. Must be positive.

	`trans` = `transpose::nontrans`	`trans` = `transpose::trans` or `trans` = `transpose::conjtrans`
Column major	Must be at least `n`	Must be at least `k`
Row major	Must be at least `k`	Must be at least `n`

b

Pointer to input matrix B. See Matrix Storage for more details.

	`trans` = `transpose::nontrans`	`trans` = `transpose::trans` or `trans` = `transpose::conjtrans`
Column major	`B` is `n` x `k` matrix. Size of array `b` must be at least `ldb` * `k`	`B` is `k` x `n` matrix. Size of array `b` must be at least `ldb` * `n`
Row major	`B` is `n` x `k` matrix. Size of array `b` must be at least `ldb` * `n`	`B` is `k` x `n` matrix. Size of array `b` must be at least `ldb` * `k`

ldb

Leading dimension of matrix B. Must be positive.

	`trans` = `transpose::nontrans`	`trans` = `transpose::trans` or `trans` = `transpose::conjtrans`
Column major	Must be at least `n`	Must be at least `k`
Row major	Must be at least `k`	Must be at least `n`

beta

Real scaling factor for matrix C. See Scalar Arguments for more information on the value_or_pointer data type.

c

Pointer to input/output matrix C. Size of the array must be at least ldc * n. See Matrix Storage for more details.

ldc

Leading dimension of matrix C. Must be positive and at least n.

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 updated C matrix.

Return Values

Output event to wait on to ensure computation is complete.

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oneMKL - Data Parallel C++ Developer Reference

syr2k

Description

syr2k (Buffer Version)

syr2k (USM Version)