compute_backward<typename descriptor_type, typename_data_type>¶
Computes the backward FFT. This routine belongs to the oneapi::mkl::dft
namespace.
Description¶
The compute_backward<typename descriptor_type, typename_data_type>
function accepts a descriptor object followed by one or more data parameters. Given a successfully configured and committed descriptor, this function computes the backward FFT, that is, the transform with the minus sign in the exponent, . This function throws an
std::runtime_exception
in the case that it fails.
The FFT descriptor must be properly configured prior to the function call. Function calls needed to configure an FFT descriptor for a particular call to an FFT computation function are summarized in Configuring and Computing an FFT in C/C++.
The number of the data parameters that the function requires may vary depending on the configuration of the descriptor. This variation is accommodated by variable parameters.
API¶
Syntax¶
Using SYCL buffers
namespace oneapi::mkl::dft{
void compute_backward<descriptor_type,
data_type>(descriptor_type &desc, cl::sycl::buffer<data_type,
1> &inout);
void compute_backward<descriptor_type, input_type,
output_type>(descriptor_type &desc,
cl::sycl::buffer<input_type, 1> &in,
cl::sycl::buffer<output_type, 1> &out);
}
Using USM pointers
namespace oneapi::mkl::dft{
cl::sycl::event compute_backward<descriptor_type,
data_type>(descriptor_type &desc, data_type* inout, const
cl::sycl::vector_class<cl::sycl::event> &dependencies = {});
cl::sycl::event compute_backward<descriptor_type, input_type,
output_type>(descriptor_type &desc, input_type* in,
output_type* out, const
cl::sycl::vector_class<cl::sycl::event> &dependencies = {});
}
Include Files¶
oneapi/mkl/dfti.hpp
Input Parameters¶
Name |
Type |
Description |
---|---|---|
inout, in |
|
SYCL buffer or USM pointer containing an array of length no less than specified at during construction of the handle. |
The suffix in parameter names corresponds to the value of the configuration parameter mkl::dft::ConfigParam::PLACEMENT
as follows:
inout to INPLACE
in to NOT_INPLACE
Output Parameters¶
Name |
Type |
Description |
---|---|---|
inout, out |
|
SYCL buffer or USM pointer containing an array of length no less than specified during construction of the handle. |
The suffix in parameter names corresponds to the value of the
configuration parameter mkl::dft::config_param::PLACEMENT
as follows:
inout to INPLACE
out to NOT_INPLACE