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. The operation is defined as:
where:
- xandyare vectors ofnelements
- alphais 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 vectorx.
- alpha
- Specifies scalaralpha.
- x
- Buffer holding input vectorx. Size of the buffer must be at least (1 + (n– 1)*abs(incx)). See Matrix Storage for more details.
- incx
- Stride of vectorx.
- y
- Buffer holding input vectory. Size of the buffer must be at least (1 + (n– 1)*abs(incy)). See Matrix Storage for more details.
- incy
- Stride of vectory.
Output Parameters
- y
- Buffer holding updated vectory.
Examples
An example of how to use
axpy
can be found in the oneMKL
installation directory, under:examples/dpcpp/blas/source/axpy.cpp
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 vectorx.
- alpha
- Specifies scalaralpha.
- x
- Pointer to input vectorx. Size of the array holding vectorxmust be at least (1 + (n– 1)*abs(incx)). See Matrix Storage for more details.
- incx
- Stride of vectorx.
- y
- Pointer to input vectory. Size of the array holding vectorymust be at least (1 + (n– 1)*abs(incy)). See Matrix Storage for more details.
- incy
- Stride of vectory.
- dependencies
- List of events to wait for before starting computation, if any. If omitted, defaults to no dependencies.
Output Parameters
- y
- Pointer to updated vectory.
Return Values
Output event to wait on to ensure computation is complete.