spr2#
Computes a rank-2 update of a symmetric packed matrix.
Description
The spr2
routines compute two scalar-vector-vector products and add
them to a symmetric packed matrix. The operation is defined as:
where:
alpha
is scalar,
A
is an n
-by-n
symmetric matrix, supplied in packed form,
x
and y
are vectors of length n
.
spr
supports the following precisions.
T
float
double
spr2 (Buffer Version)#
Syntax
namespace oneapi::mkl::blas::column_major {
void spr2(sycl::queue &queue,
onemkl::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)
}
namespace oneapi::mkl::blas::row_major {
void spr2(sycl::queue &queue,
onemkl::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)
}
Input Parameters
- queue
The queue where the routine should be executed.
- upper_lower
Specifies whether
A
is upper or lower triangular. See oneMKL defined datatypes for more details.- n
Number of rows and columns of
A
. Must be at least zero.- alpha
Scaling factor for the matrix-vector product.
- x
Buffer holding input vector
x
. The buffer must be of size at least (1 + (n
- 1)*abs(incx
)). See Matrix Storage for more details.- incx
Stride of vector
x
.- y
Buffer holding input/output vector
y
. The buffer must be of size at least (1 + (n
- 1)*abs(incy
)). See Matrix Storage for more details.- incy
Stride of vector
y
.- a
Buffer holding input matrix
A
. Must have size at least (n
*(n
-1))/2. See Matrix Storage for more details.
Output Parameters
- a
Buffer holding the updated upper triangular part of the symmetric matrix
A
ifupper_lower
=upper
or the updated lower triangular part of the symmetric matrixA
ifupper_lower
=lower
.
Throws
This routine shall throw the following exceptions if the associated condition is detected. An implementation may throw additional implementation-specific exception(s) in case of error conditions not covered here.
spr2 (USM Version)#
Syntax
namespace oneapi::mkl::blas::column_major {
sycl::event spr2(sycl::queue &queue,
onemkl::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,
const std::vector<sycl::event> &dependencies = {})
}
namespace oneapi::mkl::blas::row_major {
sycl::event spr2(sycl::queue &queue,
onemkl::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,
const std::vector<sycl::event> &dependencies = {})
}
Input Parameters
- queue
The queue where the routine should be executed.
- upper_lower
Specifies whether
A
is upper or lower triangular. See oneMKL defined datatypes for more details.- n
Number of rows and columns of
A
. Must be at least zero.- alpha
Scaling factor for the matrix-vector product.
- x
Pointer to input vector
x
. The array holding input vectorx
must be of size at least (1 + (n
- 1)*abs(incx
)). See Matrix Storage for more details.- incx
Stride of vector
x
.- y
Pointer to input/output vector
y
. The array holding input/output vectory
must be of size at least (1 + (n
- 1)*abs(incy
)). See Matrix Storage for more details.- incy
Stride of vector
y
.- a
Pointer to input matrix
A
. The array holding input matrixA
must have size at least (n
*(n
-1))/2. See Matrix Storage for more details.- dependencies
List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies.
Output Parameters
- a
Pointer to the updated upper triangular part of the symmetric matrix
A
ifupper_lower
=upper
or the updated lower triangular part of the symmetric matrixA
ifupper_lower
=lower
.
Return Values
Output event to wait on to ensure computation is complete.
Throws
This routine shall throw the following exceptions if the associated condition is detected. An implementation may throw additional implementation-specific exception(s) in case of error conditions not covered here.
oneapi::mkl::unsupported_device
Parent topic: BLAS Level 2 Routines