Contents

# 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:
dot
supports the following precisions:
T
T_res
sycl::half
sycl::half
oneapi::mkl::bfloat16
oneapi::mkl::bfloat16
float
float
double
double
float
double
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<T_res,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<T_res,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,
T_res *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,
T_res *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.

#### Product and Performance Information

1

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