dot#

Computes the dot product of two real vectors.

Description#

The dot routines perform a dot product between two vectors. The operation is defined as:

\[\mathrm{result} = \sum_{i=1}^n X_i Y_i\]

dot supports the following precisions:

T

Tres

sycl::half

sycl::half

oneapi::mkl::bfloat16

oneapi::mkl::bfloat16

float

float

double

double

float

double

Note

For mixed precision version (inputs are float while result is double), dot product is computed with double precision.

dot (Buffer Version)#

Syntax#

namespace oneapi::mkl::blas::column_major {
    void dot(sycl::queue &queue,
             std::int64_t n,
             sycl::buffer<T,1> &x,
             std::int64_t incx,
             sycl::buffer<T,1> &y,
             std::int64_t incy,
             sycl::buffer<Tres,1> &result)
}
namespace oneapi::mkl::blas::row_major {
    void dot(sycl::queue &queue,
             std::int64_t n,
             sycl::buffer<T,1> &x,
             std::int64_t incx,
             sycl::buffer<T,1> &y,
             std::int64_t incy,
             sycl::buffer<Tres,1> &result)
}

Input Parameters#

queue

The queue where the routine should be executed.

n

Number of elements in vectors x and y.

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.

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 of vector y.

Output Parameters#

result

Buffer where the result (a scalar) will be stored.

dot (USM Version)#

Syntax#

namespace oneapi::mkl::blas::column_major {
    sycl::event dot(sycl::queue &queue,
                    std::int64_t n,
                    const T *x,
                    std::int64_t incx,
                    const T *y,
                    std::int64_t incy,
                    Tres *result,
                    const std::vector<sycl::event> &dependencies = {})
}
namespace oneapi::mkl::blas::row_major {
    sycl::event dot(sycl::queue &queue,
                    std::int64_t n,
                    const T *x,
                    std::int64_t incx,
                    const T *y,
                    std::int64_t incy,
                    Tres *result,
                    const std::vector<sycl::event> &dependencies = {})
}

Input Parameters#

queue

The queue where the routine should be executed.

n

Number of elements in vectors x and y.

x

Pointer to input vector x. Size of the array holding vector x must be least (1 + (n – 1)*abs(incx)). See Matrix Storage for more details.

incx

Stride of vector x.

y

Pointer to input vector y. Size of the array holding 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#

result

Pointer to where the result (a scalar) will be stored.

Return Values#

Output event to wait on to ensure computation is complete.