spmv

Intel® oneAPI Math Kernel Library (oneMKL) - Data Parallel C++ Developer Reference

Download PDF

ID 772045

Date 12/16/2022

Version

Public

A newer version of this document is available. Customers should click here to go to the newest version.

Visible to Intel only — GUID: GUID-B5EE215C-A6FB-4F99-997B-E0E42FFBFE56

View Details

spmv

Computes a matrix-vector product with a symmetric packed matrix.

Description

The spmv routines compute a scalar-matrix-vector product and add the result to a scalar-vector product, with a symmetric packed matrix. The operation is defined as:

where:

alpha and beta are scalars
A is n x n symmetric matrix, supplied in packed form
x and y are vectors of length n

spmv supports the following precisions:

T
`float`
`double`

spmv (Buffer Version)

Syntax

namespace oneapi::mkl::blas::column_major {
    void spmv(sycl::queue &queue,
              oneapi::mkl::uplo upper_lower,
              std::int64_t n,
              T alpha,
              sycl::buffer<T,1> &a,
              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 spmv(sycl::queue &queue,
              oneapi::mkl::uplo upper_lower,
              std::int64_t n,
              T alpha,
              sycl::buffer<T,1> &a,
              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.
upper_lower: Specifies whether matrix A is upper or lower triangular. See Data Types for more details.
n: Number of rows and columns 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 least (n*(n+1))/2. See Matrix Storage for more details.
x: Buffer holding input vector x. Size of the buffer must be 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: Buffer holding input/output vector y. Size of the buffer must be at least (1 + (n - 1)*abs(incy)). See Matrix Storage for more details.
incy: Stride of vector y.

Output Parameters

y: Buffer holding updated vector y.

spmv (USM Version)

Syntax

namespace oneapi::mkl::blas::column_major {
    sycl::event spmv(sycl::queue &queue,
                     oneapi::mkl::uplo upper_lower,
                     std::int64_t n,
                     T alpha,
                     const T *a,
                     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 spmv(sycl::queue &queue,
                     oneapi::mkl::uplo upper_lower,
                     std::int64_t n,
                     T alpha,
                     const T *a,
                     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.
upper_lower: Specifies whether matrix A is upper or lower triangular. See Data Types for more details.
n: Number of rows and columns of matrix A. Must be at least zero.
alpha: Scaling factor for the matrix-vector product.
a: Pointer to input matrix A. Size of the array holding input matrix A must be at least (n*(n+1))/2. See Matrix Storage for more details.
x: Pointer to input vector x. Size of the array holding input vector x must be 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. Size of the array holding input/output vector y must be 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 updated vector y.

Return Values

Output event to wait on to ensure computation is complete.

Select Your Language

Using Intel.com Search

Quick Links

Recent Searches

Advanced Search

Only search in

Intel® oneAPI Math Kernel Library (oneMKL) - Data Parallel C++ Developer Reference

spmv

Description

spmv (Buffer Version)

spmv (USM Version)