axpy#
Computes a vector-scalar product and adds the result to a vector.
Description
The axpy
routines compute a scalar-vector product and add the result
to a vector:
where:
x
and y
are vectors of n
elements,
alpha
is a scalar.
axpy
supports the following precisions.
T
float
double
std::complex<float>
std::complex<double>
axpy (Buffer Version)#
Syntax
namespace oneapi::mkl::blas::column_major {
void axpy(sycl::queue &queue,
std::int64_t n,
T alpha,
sycl::buffer<T,1> &x,
std::int64_t incx,
sycl::buffer<T,1> &y,
std::int64_t incy)
}
namespace oneapi::mkl::blas::row_major {
void axpy(sycl::queue &queue,
std::int64_t n,
T alpha,
sycl::buffer<T,1> &x,
std::int64_t incx,
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
.- 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 of vector
x
.- 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 of vector
y
.
Output Parameters
- y
Buffer holding the updated vector
y
.
axpy (USM Version)#
Syntax
namespace oneapi::mkl::blas::column_major {
sycl::event axpy(sycl::queue &queue,
std::int64_t n,
T alpha,
const T *x,
std::int64_t incx,
T *y,
std::int64_t incy,
const std::vector<sycl::event> &dependencies = {})
}
namespace oneapi::mkl::blas::row_major {
sycl::event axpy(sycl::queue &queue,
std::int64_t n,
T alpha,
const T *x,
std::int64_t incx,
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
.- alpha
Specifies the scalar alpha.
- x
Pointer to the input vector
x
. The array holding the vectorx
must be of size at least (1 + (n
– 1)*abs(incx
)). See Matrix Storage for more details.- incx
Stride of vector
x
.- y
Pointer to the input vector
y
. The array holding the vectory
must be of size 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
- y
Pointer to the updated vector
y
.
Return Values
Output event to wait on to ensure computation is complete.
Parent topic: BLAS Level 1 Routines