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) =AT, or op(A) =AHalphaandbetaare scalarsAismxnmatrix withklsub-diagonals andkusuper-diagonalsxandyare vectors
gbmv supports the following precisions:
T |
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gbmv (Buffer Version)#
Syntax#
namespace oneapi::mkl::blas::column_major {
void gbmv(queue &queue,
oneapi::mkl::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(queue &queue,
oneapi::mkl::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 to matrixA. See Data Types for more details.- m
Number of rows of matrix
A. Must be at least zero.- n
Number of columns of matrix
A. Must be at least zero.- kl
Number of sub-diagonals of matrix
A. Must be at least zero.- ku
Number of super-diagonals of matrix
A. Must be at least zero.- alpha
Scaling factor for the matrix-vector product.
- a
Buffer holding input matrix
A. Size of the buffer must be at leastlda*nif column major layout is used, or at leastlda*mif 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 length(len) of vectorxisnifAis not transposed, andmifAis transposed. Size of the buffer must be at least (1 + (len- 1)*abs(incx)). See Matrix Storage for more details.- incx
Stride of vector
x. Must not be zero.- beta
Scaling factor for vector
y. Ifbeta= 0, vectorydoes not need to be initialized before callinggbmv.- y
Buffer holding input/output vector
y. The length(len) of vectoryism, ifAis not transposed, andnifAis transposed. Size of the buffer must be at least (1 + (len- 1)*abs(incy)). See Matrix Storage for more details.- incy
Stride of vector
y.
Output Parameters#
- y
Buffer holding updated vector
y.
gbmv (USM Version)#
Syntax#
namespace oneapi::mkl::blas::column_major {
sycl::event gbmv(queue &queue,
oneapi::mkl::transpose trans,
std::int64_t m,
std::int64_t n,
std::int64_t kl,
std::int64_t ku,
oneapi::mkl::value_or_pointer<T> alpha,
const T *a,
std::int64_t lda,
const T *x,
std::int64_t incx,
oneapi::mkl::value_or_pointer<T> beta,
T *y,
std::int64_t incy,
const std::vector<sycl::event> &dependencies = {})
}
namespace oneapi::mkl::blas::row_major {
sycl::event gbmv(queue &queue,
oneapi::mkl::transpose trans,
std::int64_t m,
std::int64_t n,
std::int64_t kl,
std::int64_t ku,
oneapi::mkl::value_or_pointer<T> alpha,
const T *a,
std::int64_t lda,
const T *x,
std::int64_t incx,
oneapi::mkl::value_or_pointer<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 to matrixA. See Data Types for more details.- m
Number of rows of matrix
A. Must be at least zero.- n
Number of columns of matrix
A. Must be at least zero.- kl
Number of sub-diagonals of matrix
A. Must be at least zero.- ku
Number of super-diagonals of matrix
A. Must be at least zero.- alpha
Scaling factor for the matrix-vector product. See Scalar Arguments for more information on the
value_or_pointerdata type.- a
Pointer to input matrix
A. Size of the array must be at leastlda*nif column major layout is used, or at leastlda*mif 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 lengthlenof vectorxisnifAis not transposed, andmifAis transposed. Size of the array holding input vectorxmust be at least (1 + (len- 1)*abs(incx)). See Matrix Storage for more details.- incx
Stride of vector
x. Must not be zero.- beta
Scaling factor for vector
y. Ifbeta= 0, vectorydoes not need to be initialized before callinggbmv. See Scalar Arguments for more information on thevalue_or_pointerdata type.- y
Pointer to input/output vector
y. The lengthlenof vectoryism, ifAis not transposed, andnifAis transposed. Size of the array holding input/output vectorymust be at least (1 + (len- 1)*abs(incy)) wherelenis 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 updated vector
y.
Return Values#
Output event to wait on to ensure computation is complete.