gbmv#
Computes a matrix-vector product with a general band matrix.
Description
The gbmv
routines compute a scalar-matrix-vector product and add
the result to a scalar-vector product, with a general band matrix.
The operation is defined as
where:
op(A
) is one of op(A
) = A
, or op(A
) =
A
T, or op(A
) = A
H,
alpha
and beta
are scalars,
A
is an m
-by-n
matrix with kl
sub-diagonals and
ku
super-diagonals,
x
and y
are vectors.
gbmv
supports the following precisions.
T
float
double
std::complex<float>
std::complex<double>
gbmv (Buffer Version)#
Syntax
namespace oneapi::mkl::blas::column_major {
void gbmv(sycl::queue &queue,
onemkl::transpose trans,
std::int64_t m,
std::int64_t n,
std::int64_t kl,
std::int64_t ku,
T alpha,
sycl::buffer<T,1> &a,
std::int64_t lda,
sycl::buffer<T,1> &x,
std::int64_t incx,
T beta,
sycl::buffer<T,1> &y,
std::int64_t incy)
}
namespace oneapi::mkl::blas::row_major {
void gbmv(sycl::queue &queue,
onemkl::transpose trans,
std::int64_t m,
std::int64_t n,
std::int64_t kl,
std::int64_t ku,
T alpha,
sycl::buffer<T,1> &a,
std::int64_t lda,
sycl::buffer<T,1> &x,
std::int64_t incx,
T beta,
sycl::buffer<T,1> &y,
std::int64_t incy)
}
Input Parameters
- queue
The queue where the routine should be executed.
- trans
Specifies op(
A
), the transposition operation applied toA
. See oneMKL Defined Datatypes for more details.- m
Number of rows of
A
. Must be at least zero.- n
Number of columns of
A
. Must be at least zero.- kl
Number of sub-diagonals of the matrix
A
. Must be at least zero.- ku
Number of super-diagonals of the matrix
A
. Must be at least zero.- alpha
Scaling factor for the matrix-vector product.
- a
Buffer holding input matrix
A
. Must have size at leastlda
*n
if column major layout is used or at leastlda
*m
if row major layout is used. See Matrix Storage for more details.- lda
Leading dimension of matrix
A
. Must be at least (kl
+ku
+ 1), and positive.- x
Buffer holding input vector
x
. The lengthlen
of vectorx
isn
ifA
is not transposed, andm
ifA
is transposed. The buffer must be of size at least (1 + (len
- 1)*abs(incx
)). See Matrix Storage for more details.- incx
Stride of vector
x
.- beta
Scaling factor for vector
y
.- y
Buffer holding input/output vector
y
. The lengthlen
of vectory
ism
, ifA
is not transposed, andn
ifA
is transposed. The buffer must be of size at least (1 + (len
- 1)*abs(incy
)) wherelen
is this length. See Matrix Storage for more details.- incy
Stride of vector
y
.
Output Parameters
- y
Buffer holding the updated vector
y
.
gbmv (USM Version)#
Syntax
namespace oneapi::mkl::blas::column_major {
sycl::event gbmv(sycl::queue &queue,
onemkl::transpose trans,
std::int64_t m,
std::int64_t n,
std::int64_t kl,
std::int64_t ku,
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 gbmv(sycl::queue &queue,
onemkl::transpose trans,
std::int64_t m,
std::int64_t n,
std::int64_t kl,
std::int64_t ku,
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 = {})
}
Input Parameters
- queue
The queue where the routine should be executed.
- trans
Specifies op(
A
), the transposition operation applied toA
. See oneMKL Defined Datatypes for more details.- m
Number of rows of
A
. Must be at least zero.- n
Number of columns of
A
. Must be at least zero.- kl
Number of sub-diagonals of the matrix
A
. Must be at least zero.- ku
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
if column major layout is used or at leastlda
*m
if row major layout is used. See Matrix Storage for more details.- lda
Leading dimension of matrix
A
. Must be at least (kl
+ku
+ 1), and positive.- x
Pointer to input vector
x
. The lengthlen
of vectorx
isn
ifA
is not transposed, andm
ifA
is transposed. The array holding input vectorx
must be of size at least (1 + (len
- 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 lengthlen
of vectory
ism
, ifA
is not transposed, andn
ifA
is transposed. The array holding input/output vectory
must be of size at least (1 + (len
- 1)*abs(incy
)) wherelen
is this length. 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.
Parent topic: BLAS Level 2 Routines