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//---------------------------------------------------------------------------//
// Copyright (c) 2013 Kyle Lutz <kyle.r.lutz@gmail.com>
//
// Distributed under the Boost Software License, Version 1.0
// See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt
//
// See http://boostorg.github.com/compute for more information.
//---------------------------------------------------------------------------//
#include <iostream>
#include <boost/compute/core.hpp>
namespace compute = boost::compute;
// this example demonstrates how to use the Boost.Compute classes to
// setup and run a simple vector addition kernel on the GPU
int main()
{
// get the default device
compute::device device = compute::system::default_device();
// create a context for the device
compute::context context(device);
// setup input arrays
float a[] = { 1, 2, 3, 4 };
float b[] = { 5, 6, 7, 8 };
// make space for the output
float c[] = { 0, 0, 0, 0 };
// create memory buffers for the input and output
compute::buffer buffer_a(context, 4 * sizeof(float));
compute::buffer buffer_b(context, 4 * sizeof(float));
compute::buffer buffer_c(context, 4 * sizeof(float));
// source code for the add kernel
const char source[] =
"__kernel void add(__global const float *a,"
" __global const float *b,"
" __global float *c)"
"{"
" const uint i = get_global_id(0);"
" c[i] = a[i] + b[i];"
"}";
// create the program with the source
compute::program program =
compute::program::create_with_source(source, context);
// compile the program
program.build();
// create the kernel
compute::kernel kernel(program, "add");
// set the kernel arguments
kernel.set_arg(0, buffer_a);
kernel.set_arg(1, buffer_b);
kernel.set_arg(2, buffer_c);
// create a command queue
compute::command_queue queue(context, device);
// write the data from 'a' and 'b' to the device
queue.enqueue_write_buffer(buffer_a, 0, 4 * sizeof(float), a);
queue.enqueue_write_buffer(buffer_b, 0, 4 * sizeof(float), b);
// run the add kernel
queue.enqueue_1d_range_kernel(kernel, 0, 4, 0);
// transfer results back to the host array 'c'
queue.enqueue_read_buffer(buffer_c, 0, 4 * sizeof(float), c);
// print out results in 'c'
std::cout << "c: [" << c[0] << ", "
<< c[1] << ", "
<< c[2] << ", "
<< c[3] << "]" << std::endl;
return 0;
}
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