hbmv (USM Version)¶
Computes a matrix-vector product using a Hermitian band matrix.
Syntax
event hbmv(queue &exec_queue, 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 vector_class<event> &dependencies = {})
The USM version of hbmv
supports the following precisions and devices.
T
Devices Supported
std::complex<float>
Host, CPU, and GPU
std::complex<double>
Host, CPU, and GPU
Description
The hbmv routines compute a scalar-matrix-vector product and add the result to a scalar-vector product, with a Hermitian band matrix. The operation is defined as
y <- alpha*A*x + beta*y
where:
alpha
andbeta
are scalars,
A
is ann
-by-n
Hermitian band matrix, withk
super-diagonals,
x
andy
are vectors of lengthn
.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 the input matrix
A
. The array holding input matrixA
must have size at leastlda
*n
. See 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 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 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.