boost/compute
2
0
Fork 0
mirror of https://github.com/boostorg/compute.git synced 2026-01-27 06:42:19 +00:00
Code Issues Projects Releases Wiki Activity

Fix issues with gather() algorithm

Browse Source 
This fixes some issues with the gather algorithm and also
adds another test for it.
This commit is contained in:
Kyle Lutz
2013-12-21 15:34:29 -08:00
parent 55783258e7
commit 0d9be38326
2 changed files with 47 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
include/boost/compute/algorithm/gather.hpp
View File

@@ -48,15 +48,15 @@ struct gather_kernel
} // end detail namespace
/// Copies the elements from the range [\p first, \p last) to the range
/// beginning at \p result using the input indices from the range beginning
/// at \p map.
/// Copies the elements using the indices from the range [\p first, \p last)
/// to the range beginning at \p result using the input values from the range
/// beginning at \p input.
///
/// \see scatter()
template<class InputIterator, class MapIterator, class OutputIterator>
inline void gather(InputIterator first,
InputIterator last,
MapIterator map,
inline void gather(MapIterator first,
MapIterator last,
InputIterator input,
OutputIterator result,
command_queue &queue = system::default_queue())
{
@@ -71,8 +71,8 @@ inline void gather(InputIterator first,
output_value_type>::source();
kernel kernel = kernel::create_with_source(source, "gather", context);
kernel.set_arg(0, first.get_buffer());
kernel.set_arg(1, map.get_buffer());
kernel.set_arg(0, input.get_buffer());
kernel.set_arg(1, first.get_buffer());
kernel.set_arg(2, result.get_buffer());
size_t offset = first.get_index();

45
test/test_gather.cpp
View File

@@ -12,25 +12,58 @@
#include <boost/test/unit_test.hpp>
#include <boost/compute/system.hpp>
#include <boost/compute/algorithm/copy_if.hpp>
#include <boost/compute/algorithm/gather.hpp>
#include <boost/compute/container/vector.hpp>
#include "check_macros.hpp"
#include "context_setup.hpp"
namespace bc = boost::compute;
namespace compute = boost::compute;
BOOST_AUTO_TEST_CASE(gather_int)
{
int input_data[] = { 1, 2, 3, 4, 5 };
bc::vector<int> input(input_data, input_data + 5, context);
compute::vector<int> input(5, context);
compute::copy_n(input_data, 5, input.begin(), queue);
int map_data[] = { 0, 4, 1, 3, 2 };
bc::vector<int> map(map_data, map_data + 5, context);
int indices_data[] = { 0, 4, 1, 3, 2 };
compute::vector<int> indices(5, context);
compute::copy_n(indices_data, 5, indices.begin(), queue);
bc::vector<int> output(5, context);
bc::gather(input.begin(), input.end(), map.begin(), output.begin());
compute::vector<int> output(5, context);
compute::gather(
indices.begin(), indices.end(), input.begin(), output.begin(), queue
);
CHECK_RANGE_EQUAL(int, 5, output, (1, 5, 2, 4, 3));
}
BOOST_AUTO_TEST_CASE(copy_index_then_gather)
{
// input data
int data[] = { 1, 4, 3, 2, 5, 9, 8, 7 };
compute::vector<int> input(8, context);
compute::copy_n(data, 8, input.begin(), queue);
// function returning true if the input is odd
BOOST_COMPUTE_FUNCTION(bool, is_odd, (int),
{
return _1 % 2 != 0;
});
// copy indices of all odd values
compute::vector<int> odds(5, context);
compute::detail::copy_index_if(
input.begin(), input.end(), odds.begin(), is_odd, queue
);
CHECK_RANGE_EQUAL(int, 5, odds, (0, 2, 4, 5, 7));
// gather all odd values
compute::vector<int> odd_values(5, context);
compute::gather(
odds.begin(), odds.end(), input.begin(), odd_values.begin(), queue
);
CHECK_RANGE_EQUAL(int, 5, odd_values, (1, 3, 5, 9, 7));
}
BOOST_AUTO_TEST_SUITE_END()