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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:
LaTex Math image.
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.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.