axpby

oneMKL - Data Parallel C++ Developer Reference

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ID 772045

Date 3/31/2021

Version

Public

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axpby

Computes a vector-scalar product added to a scaled-vector.

Description

The axpby routines compute two scalar-vector products and add them:

where:

x and y are vectors of n elements
alpha and beta are scalars

axpby supports the following precisions:

T
`float`
`double`
`std::complex<float>`
`std::complex<double>`

axpby (Buffer Version)

Syntax

namespace oneapi::mkl::blas::column_major {
  void axpby(sycl::queue &queue,
             std::int64_t n,
             T alpha,
             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 axpby(sycl::queue &queue,
             std::int64_t n,
             T alpha,
             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.
n: Number of elements in vectors x and y.
alpha: Specifies the scalar alpha.
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 between two consecutive elements of vector x.
beta: Specifies the scalar beta.
y: Buffer holding input vector y. Size of the buffer must be at least 1 + (n - 1)*abs(incy)). See Matrix Storage for more details.
incy: Stride between two consecutive elements of vector y.

Output Parameters

y: Buffer holding updated vector y.

axpby (USM Version)

Syntax

namespace oneapi::mkl::blas::column_major {
  sycl::event axpby(sycl::queue &queue,
                    std::int64_t n,
                    T alpha,
                    const T *x,
                    std::int64_t incx,
                    T beta,
                    T *y,
                    std::int64_t incy,
                    const std::vector<event> &dependencies = {});
  }

namespace oneapi::mkl::blas::row_major {
  sycl::event axpby(sycl::queue &queue,
                    std::int64_t n,
                    T alpha,
                    const T *x,
                    std::int64_t incx,
                    T beta,
                    T *y,
                    std::int64_t incy,
                    const std::vector<event> &dependencies = {});
  }

Input Parameters

queue: The queue where the routine should be executed.
n: Number of elements in vectors x and y.
alpha: Specifies the scalar alpha.
x: Pointer to the input vector x. Size of the array must be at least 1 + (n - 1)*abs(incx)). See Matrix Storage for more details.
incx: Stride between two consecutive elements of vector x.
beta: Specifies the scalar beta.
y: Pointer to the input vector y. Size of the array must be at least 1 + (n - 1)*abs(incy)). See Matrix Storage for more details.
incy: Stride between two consecutive elements of vector y.
dependencies: List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies.

Output Parameters

y: Array holding updated vector y.

Return Values

Output event to wait on to ensure computation is complete.

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oneMKL - Data Parallel C++ Developer Reference

axpby

Description

axpby (Buffer Version)

axpby (USM Version)