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syr2
Computes a rank-2 update of a symmetric matrix.
Description
The syr2 routines compute two scalar-vector-vector products, add them and add the result to a matrix, with a symmetric matrix. The operation is defined as:
where:
alpha is a scalar
A is n x n symmetric matrix
x and y are vectors of length n
syr2 supports the following precisions:
T |
|---|
float |
double |
std::complex<float> |
std::complex<double> |
syr2 (Buffer Version)
Syntax
namespace oneapi::mkl::blas::column_major {
void syr2(sycl::queue &queue,
oneapi::mkl::uplo upper_lower,
std::int64_t n,
T alpha,
sycl::buffer<T,1> &x,
std::int64_t incx,
sycl::buffer<T,1> &y,
std::int64_t incy,
sycl::buffer<T,1> &a,
std::int64_t lda)
}
namespace oneapi::mkl::blas::row_major {
void syr2(sycl::queue &queue,
oneapi::mkl::uplo upper_lower,
std::int64_t n,
T alpha,
sycl::buffer<T,1> &x,
std::int64_t incx,
sycl::buffer<T,1> &y,
std::int64_t incy,
sycl::buffer<T,1> &a,
std::int64_t lda)
}
Input Parameters
- queue
-
The queue where the routine should be executed.
- upper_lower
-
Specifies whether matrix A is upper or lower triangular. See Data Types for more details.
- n
-
Number of columns of matrix A. Must be at least zero.
- alpha
-
Scaling factor for the matrix-vector product.
- x
-
Buffer holding input vector x. Size of the buffer must be at least (1 + (n - 1)*abs(incx)). See Matrix Storage for more details.
- incx
-
Stride of vector x. Must not be zero.
- y
-
Buffer holding input/output vector y. Size of the buffer must be at least (1 + (n - 1)*abs(incy)). See Matrix Storage for more details.
- incy
-
Stride of vector y. Must not be zero.
- a
-
Buffer holding input matrix A. Size of the buffer must be at least lda * n. See Matrix Storage for more details.
- lda
-
Leading dimension of matrix A. Must be at least n and positive.
Output Parameters
- a
-
Buffer holding updated upper triangular part of the symmetric matrix A if upper_lower=upper, or updated lower triangular part of the symmetric matrix A if upper_lower=lower.
syr2 (USM Version)
Syntax
namespace oneapi::mkl::blas::column_major {
sycl::event syr2(sycl::queue &queue,
oneapi::mkl::uplo upper_lower,
std::int64_t n,
T alpha,
const T *x,
std::int64_t incx,
const T *y,
std::int64_t incy,
T *a,
std::int64_t lda,
const std::vector<sycl::event> &dependencies = {})
}
namespace oneapi::mkl::blas::row_major {
sycl::event syr2(sycl::queue &queue,
oneapi::mkl::uplo upper_lower,
std::int64_t n,
T alpha,
const T *x,
std::int64_t incx,
const T *y,
std::int64_t incy,
T *a,
std::int64_t lda,
const std::vector<sycl::event> &dependencies = {})
}
Input Parameters
- queue
-
The queue where the routine should be executed.
- upper_lower
-
Specifies whether matrix A is upper or lower triangular. See Data Types for more details.
- n
-
Number of columns of matrix A. Must be at least zero.
- alpha
-
Scaling factor for the matrix-vector product.
- x
-
Pointer to input vector x. Size of the array holding input vector x must be at least (1 + (n - 1)*abs(incx)). See Matrix Storage for more details.
- incx
-
Stride of vector x. Must not be zero.
- y
-
Pointer to input/output vector y. Size of the array holding input/output vector y must be at least (1 + (n - 1)*abs(incy)). See Matrix Storage for more details.
- incy
-
Stride of vector y. Must not be zero.
- a
-
Pointer to input matrix A. Size of the array holding input matrix A must be at least lda * n. See Matrix Storage for more details.
- lda
-
Leading dimension of matrix A. Must be at least n and positive.
- dependencies
-
List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies.
Output Parameters
- a
-
Pointer to updated upper triangular part of the symmetric matrix A if upper_lower=upper, or updated lower triangular part of the symmetric matrix A if upper_lower=lower.
Return Values
Output event to wait on to ensure computation is complete.