oneapi::mkl::sparse::gemv#
Computes a sparse matrix-dense vector product.
Description#
Note
Refer to Sparse BLAS Supported Data and Integer Types for a list of supported <DATA_TYPE>
and <INT_TYPE>
data
and integer types and refer to Error Handling for a detailed description of
the possible exceptions thrown.
The oneapi::mkl::sparse::gemv
routine computes a sparse matrix-dense vector product defined as
where \(\alpha\) and \(\beta\) are scalars, \(A\) is a general sparse matrix of
dimensions num_rows
rows and num_cols
columns and \(op()\) is a matrix modifier:
The dense vectors \(x\) and \(y\) are appropriately sized based on matrix product dimensions of \(\text{op}(A)\).
API#
Syntax#
Using SYCL buffers:
namespace oneapi::mkl::sparse {
void gemv (
sycl::queue &queue,
oneapi::mkl::transpose opA,
const DATA_TYPE alpha,
oneapi::mkl::sparse::matrix_handle_t A,
sycl::buffer<DATA_TYPE, 1> &x,
const DATA_TYPE beta,
sycl::buffer<DATA_TYPE, 1> &y)
}
Using USM pointers:
namespace oneapi::mkl::sparse {
sycl::event gemv (
sycl::queue &queue,
oneapi::mkl::transpose opA,
const DATA_TYPE alpha,
oneapi::mkl::sparse::matrix_handle_t A,
const DATA_TYPE *x,
DATA_TYPE beta,
DATA_TYPE *y,
const std::vector<sycl::event> &dependencies= {})
}
Include Files#
oneapi/mkl/spblas.hpp
Input Parameters#
- queue
Specifies the SYCL command queue which will be used for SYCL kernels execution.
- opA
Specifies operation
op()
on input matrix.oneapi::mkl::transpose::nontrans
Non-transpose, \(\text{op}(A) = A\).
oneapi::mkl::transpose::trans
Transpose, \(\text{op}(A) = A^{T}\).
oneapi::mkl::transpose::conjtrans
Conjugate transpose, \(\text{op}(A) = A^{H}\).
- alpha
Specifies the scalar, \(\alpha\).
- A
Handle to object containing sparse matrix and other internal data. Created using one of the
oneapi::mkl::sparse::set_<sparse_matrix_type>_data
routines.Note
The supported cases for
<sparse_matrix_type>
arecsr
andcoo
on both CPU and GPU devices.- x
SYCL buffer or device-accessible USM pointer of size at least equal to the number of columns of input matrix if
opA
=oneapi::mkl::transpose::nontrans
and at least the number of rows of input matrix otherwise.- beta
Specifies the scalar, \(\beta\).
- y
SYCL buffer or device-accessible USM pointer of size at least equal to the number of rows of the input matrix if
opA
=oneapi::mkl::transpose::nontrans
and at least the number of columns of the input matrix otherwise.- dependencies
A vector of type
std::vector<sycl::event>
containing the list of events that theoneapi::mkl::sparse::gemv
routine depends on.
Output Parameters#
- y
Overwritten by the updated vector \(y\).
Return Values (USM Only)#
- sycl::event
SYCL event which can be waited upon or added as a dependency for the completion of the
gemv
routine.
Examples#
An example of how to use oneapi::mkl::sparse::gemv
with SYCL buffers
or USM pointers can be found in the oneMKL installation directory,
under:
share/doc/mkl/examples/sycl/sparse_blas/source/coo_gemv.cpp
share/doc/mkl/examples/sycl/sparse_blas/source/csr_gemv_usm.cpp