Computes a matrix-vector product using a general matrix.
event gemv(queue &exec_queue, transpose trans, std::int64_t m, std::int64_t n, 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 gemv supports the following precisions and devices.
T | Devices Supported |
---|---|
float | Host, CPU, and GPU |
double | Host, CPU, and GPU |
std::complex<float> | Host, CPU, and GPU |
std::complex<double> | Host, CPU, and GPU |
The gemv routines compute a scalar-matrix-vector product and add the result to a scalar-vector product, with a general matrix. The operation is defined as
y <- alpha*op(A)*x + beta*y
where:
op(A) is one of op(A) = A, or op(A) = AT, or op(A) = AH,
alpha and beta are scalars,
A is an m-by-n matrix, and x, y are vectors.
The queue where the routine should be executed.
Specifies op(A), the transposition operation applied to A. See Data Types for more details.
Specifies the number of rows of the matrix A. The value of m must be at least zero.
Specifies the number of columns of the matrix A. The value of n must be at least zero.
Scaling factor for the matrix-vector product.
The array holding input matrix A must have size at least lda*n if column major layout is used, or at least lda*m if row major layout is used.
The leading dimension of matrix A. It must be positive and at least m if column major layout is used or at least n if row major layout is used.
Pointer to the input vector x. The length len of vector x is n if A is not transposed, and m if A is transposed. The array holding vector x must be of size at least (1 + (len - 1)*abs(incx)). See Matrix and Vector Storage for more details.
The stride of vector x.
The scaling factor for vector y.
Pointer to input/output vector y. The length len of vector y is m, if A is not transposed, and n if A is transposed. The array holding input/output vector y must be of size at least (1 + (len - 1)*abs(incy)) where len is this length. See Matrix and Vector Storage for more details.
The stride of vector y.
List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies.
The pointer to updated vector y.
An example of how to use gemvcan be found in the Intel® oneMKL installation directory, under:
examples/sycl/blas/gemv.cpp
Output event to wait on to ensure computation is complete.