sycl::buffer - Posted on July 21, 2024 - See https://sycl.tech - Logs Home - d0032

sycl::buffer

cpp/c++ sycl::buffer - The sycl::buffer class defines a shared array of one, two or three dimensions that can be used by the SYCL kernel and has to be accessed using accessor classes. Buffers are templated on both the type of their data, and the number of dimensions that the data is stored and accessed through.

cpp examples

cpp/c++ examples: sycl::buffer

#include <sycl/sycl.hpp>
#include <numbers>
#include <iostream>
#include <numeric>

namespace gpu
{

class copy_kernel
{
private:
	sycl::accessor<float, 1, sycl::access_mode::read> __in_accessor;
	sycl::accessor<float, 1, sycl::access_mode::write> __out_accessor;
public:
	copy_kernel() = delete;
	copy_kernel(
		sycl::accessor<float, 1, sycl::access_mode::read> in_accessor__,
		sycl::accessor<float, 1, sycl::access_mode::write> out_accessor__,
		sycl::handler & handler__
	):
		__in_accessor{in_accessor__},
		__out_accessor{out_accessor__}
	{
	}
public:
	void operator()(sycl::nd_item<1> item) const
	{
		sycl::id<1> id = item.get_global_id();
		this->__out_accessor[id] = this->__in_accessor[id];
	}
};

}	// namespace gpu

int main()
{
	std::vector<float> input(16);
	std::iota(input.begin(), input.end(), 1.4f);

	// sycl::buffer
	auto in_buffer = new sycl::buffer<float, 1>{input.data(), sycl::range<1>{input.size()}};
	// sycl::buffer
	auto out_buffer = new sycl::buffer<float, 1>{sycl::range<1>{input.size()}};

	sycl::queue queue{sycl::gpu_selector_v};

	queue.submit(
		[&] (sycl::handler & handler)
		{

			auto in_accessor = sycl::accessor<float, 1, sycl::access_mode::read>{* in_buffer, handler, sycl::read_only};
			// template params are auto-deduced
			auto out_accessor = sycl::accessor{* out_buffer, handler, sycl::write_only};

			auto copy_kernel = gpu::copy_kernel{in_accessor, out_accessor, handler};
			handler.parallel_for<class ken1>(
				sycl::nd_range<1>{
					sycl::range<1>{input.size()},	// global range
					sycl::range<1>{input.size()/4}	// local range: work group size
				},
				copy_kernel
			);
		}
	);
	auto result_accessor = out_buffer->get_host_access();
	std::copy(result_accessor.begin(), result_accessor.end(), std::ostream_iterator<float>{std::cout, " "});
	std::cout << std::endl;

	delete in_buffer;
	delete out_buffer;
}

acpp prog.cpp -std=c++23 -o prog

dpcpp prog.cpp -std=c++23 -o prog

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See Also

acpp

dpcpp