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

Developer Reference

Contents

syr

Computes a rank-1 update of a symmetric matrix.

Description

The
syr
 routines compute a scalar-vector-vector product and add the result to a matrix, with a symmetric matrix. The operation is defined as:
LaTex Math image.
where:
  • alpha
     is scalar
  • A
     is
    n
     x
    n
     symmetric matrix
  • x
     is a vector of length
    n
syr
 supports the following precisions:
T
float
double

syr (Buffer Version)

Syntax
namespace oneapi::mkl::blas::column_major {
    void syr(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> &a,
             std::int64_t lda)
}
namespace oneapi::mkl::blas::row_major {
    void syr(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> &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
.
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
.

syr (USM Version)

Syntax
namespace oneapi::mkl::blas::column_major {
    sycl::event syr(sycl::queue &queue,
                    oneapi::mkl::uplo upper_lower,
                    std::int64_t n,
                    T alpha,
                    const T *x,
                    std::int64_t incx,
                    T *a,
                    std::int64_t lda,
                    const std::vector<sycl::event> &dependencies = {})
}
namespace oneapi::mkl::blas::row_major {
    sycl::event syr(sycl::queue &queue,
                    oneapi::mkl::uplo upper_lower,
                    std::int64_t n,
                    T alpha,
                    const T *x,
                    std::int64_t incx,
                    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
.
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.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.