axpby#

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

Description

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

\[y \leftarrow beta * y + alpha * x\]

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

axpby supports the following precisions.

T

float

double

std::complex<float>

std::complex<double>

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

axpby (Buffer Version)#

Syntax

namespace oneapi::math::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::math::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 vector x and y.
alpha: Specifies the scalar alpha.
x: Buffer holding input vector x. The buffer must be of size at least (1 + (n – 1)*abs(incx)). See Matrix Storage for more details.
incx: Stride between two consecutive elements of the x vector.
beta: Specifies the scalar beta.
y: Buffer holding input vector y. The buffer must be of size at least (1 + (n – 1)*abs(incy)). See Matrix Storage for more details.
incy: Stride between two consecutive elements of the y vector.

Output Parameters

y: Buffer holding the updated vector y.

Throws

This routine shall throw the following exceptions if the associated condition is detected. An implementation may throw additional implementation-specific exception(s) in case of error conditions not covered here.

oneapi::math::invalid_argument

oneapi::math::unsupported_device

oneapi::math::host_bad_alloc

oneapi::math::device_bad_alloc

oneapi::math::unimplemented

axpby (USM Version)#

Syntax

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

namespace oneapi::math::blas::row_major {
    sycl::event axpby(sycl::queue &queue,
                     std::int64_t n,
                     value_or_pointer<T> alpha,
                     const T *x, std::int64_t incx,
                     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.
n: Number of elements in vector x and y.
alpha: Specifies the scalar alpha. See Scalar Arguments in BLAS for more details.
beta: Specifies the scalar beta. See Scalar Arguments in BLAS for more details.
x: Pointer to the input vector x. The allocated memory must be of size at least (1 + (n – 1)*abs(incx)). See Matrix Storage for more details.
incx: Stride between consecutive elements of the x vector.
y: Pointer to the input vector y. The allocated memory must be of size at least (1 + (n – 1)*abs(incy)). See Matrix Storage for more details.
incy: Stride between consecutive elements of the y vector.
dependencies: List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies.