sbmv (USM Version)¶
Computes a matrix-vector product with a symmetric band matrix.
Description¶
The sbmv
routines compute a scalar-matrix-vector product and add the result to a scalar-vector product, with a symmetric band matrix. The operation is defined as
where:
alpha
andbeta
are scalars,A
is ann
-by-n
symmetric matrix withk
super-diagonals,x
andy
are vectors of lengthn
.
API¶
Syntax¶
namespace oneapi::mkl::blas::column_major {
sycl::event sbmv(sycl::queue &queue,
onemkl::uplo upper_lower,
std::int64_t n,
std::int64_t k,
T alpha,
const T *a,
std::int64_t lda,
const T *x,
std::int64_t incx,
T beta,
T *y,
std::int64_t incy,
const std::vector<sycl::event> &dependencies = {})
}
namespace oneapi::mkl::blas::row_major {
sycl::event sbmv(sycl::queue &queue,
onemkl::uplo upper_lower,
std::int64_t n,
std::int64_t k,
T alpha,
const T *a,
std::int64_t lda,
const T *x,
std::int64_t incx,
T beta,
T *y,
std::int64_t incy,
const std::vector<sycl::event> &dependencies = {})
}
The USM version of sbmv
supports the following precisions and devices.
T |
Devices Supported |
---|---|
|
Host, CPU, and GPU |
|
Host, CPU, and GPU |
Input Parameters¶
- exec_queue
The queue where the routine should be executed.
- upper_lower
Specifies whether
A
is upper or lower triangular. See Data Types for more details.- n
Number of rows and columns of
A
. Must be at least zero.- k
Number of super-diagonals of the matrix
A
. Must be at least zero.- alpha
Scaling factor for the matrix-vector product.
- a
Pointer to input matrix
A
. The array holding input matrixA
must have size at leastlda
*n
. See ref:matrix-storage for more details.- lda
Leading dimension of matrix
A
. Must be at least (k
+ 1), and positive.- x
Pointer to input vector
x
. The array holding input vectorx
must be of size at least (1 + (n
- 1)*abs(incx
)). See ref:matrix-storage for more details.- incx
Stride of vector
x
.- beta
Scaling factor for vector
y
.- 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 ref:matrix-storage for more details.- incy
Stride of vector
y
.- dependencies
List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies.
Output Parameters¶
- y
Pointer to the updated vector
y
.
Return Values¶
Output event to wait on to ensure computation is complete.