118 lines
4.4 KiB
Plaintext
118 lines
4.4 KiB
Plaintext
|
//---------------------------------------------------------------------------//
|
||
|
|
// Copyright (c) 2013-2015 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.
|
||
|
|
//---------------------------------------------------------------------------//
|
||
|
|
|
||
|
|
#ifndef BOOST_COMPUTE_ALGORITHM_TRANSFORM_IF_HPP
|
||
|
|
#define BOOST_COMPUTE_ALGORITHM_TRANSFORM_IF_HPP
|
||
|
|
|
||
|
|
#include <boost/compute/cl.hpp>
|
||
|
|
#include <boost/compute/system.hpp>
|
||
|
|
#include <boost/compute/command_queue.hpp>
|
||
|
|
#include <boost/compute/algorithm/count.hpp>
|
||
|
|
#include <boost/compute/algorithm/count_if.hpp>
|
||
|
|
#include <boost/compute/algorithm/exclusive_scan.hpp>
|
||
|
|
#include <boost/compute/container/vector.hpp>
|
||
|
|
#include <boost/compute/detail/meta_kernel.hpp>
|
||
|
|
#include <boost/compute/detail/iterator_range_size.hpp>
|
||
|
|
#include <boost/compute/iterator/discard_iterator.hpp>
|
||
|
|
|
||
|
|
namespace boost {
|
||
|
|
namespace compute {
|
||
|
|
namespace detail {
|
||
|
|
|
||
|
|
template<class InputIterator, class OutputIterator, class UnaryFunction, class Predicate>
|
||
|
|
inline OutputIterator transform_if_impl(InputIterator first,
|
||
|
|
InputIterator last,
|
||
|
|
OutputIterator result,
|
||
|
|
UnaryFunction function,
|
||
|
|
Predicate predicate,
|
||
|
|
bool copyIndex,
|
||
|
|
command_queue &queue)
|
||
|
|
{
|
||
|
|
typedef typename std::iterator_traits<OutputIterator>::difference_type difference_type;
|
||
|
|
|
||
|
|
size_t count = detail::iterator_range_size(first, last);
|
||
|
|
if(count == 0){
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
|
||
|
|
const context &context = queue.get_context();
|
||
|
|
|
||
|
|
// storage for destination indices
|
||
|
|
::boost::compute::vector<cl_uint> indices(count, context);
|
||
|
|
|
||
|
|
// write counts
|
||
|
|
::boost::compute::detail::meta_kernel k1("transform_if_write_counts");
|
||
|
|
k1 << indices.begin()[k1.get_global_id(0)] << " = "
|
||
|
|
<< predicate(first[k1.get_global_id(0)]) << " ? 1 : 0;\n";
|
||
|
|
k1.exec_1d(queue, 0, count);
|
||
|
|
|
||
|
|
// count number of elements to be copied
|
||
|
|
size_t copied_element_count =
|
||
|
|
::boost::compute::count(indices.begin(), indices.end(), 1, queue);
|
||
|
|
|
||
|
|
// scan indices
|
||
|
|
::boost::compute::exclusive_scan(
|
||
|
|
indices.begin(), indices.end(), indices.begin(), queue
|
||
|
|
);
|
||
|
|
|
||
|
|
// copy values
|
||
|
|
::boost::compute::detail::meta_kernel k2("transform_if_do_copy");
|
||
|
|
k2 << "if(" << predicate(first[k2.get_global_id(0)]) << ")" <<
|
||
|
|
" " << result[indices.begin()[k2.get_global_id(0)]] << "=";
|
||
|
|
|
||
|
|
if(copyIndex){
|
||
|
|
k2 << k2.get_global_id(0) << ";\n";
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
k2 << function(first[k2.get_global_id(0)]) << ";\n";
|
||
|
|
}
|
||
|
|
|
||
|
|
k2.exec_1d(queue, 0, count);
|
||
|
|
|
||
|
|
return result + static_cast<difference_type>(copied_element_count);
|
||
|
|
}
|
||
|
|
|
||
|
|
template<class InputIterator, class UnaryFunction, class Predicate>
|
||
|
|
inline discard_iterator transform_if_impl(InputIterator first,
|
||
|
|
InputIterator last,
|
||
|
|
discard_iterator result,
|
||
|
|
UnaryFunction function,
|
||
|
|
Predicate predicate,
|
||
|
|
bool copyIndex,
|
||
|
|
command_queue &queue)
|
||
|
|
{
|
||
|
|
(void) function;
|
||
|
|
(void) copyIndex;
|
||
|
|
|
||
|
|
return result + count_if(first, last, predicate, queue);
|
||
|
|
}
|
||
|
|
|
||
|
|
} // end detail namespace
|
||
|
|
|
||
|
|
/// Copies each element in the range [\p first, \p last) for which
|
||
|
|
/// \p predicate returns \c true to the range beginning at \p result.
|
||
|
|
template<class InputIterator, class OutputIterator, class UnaryFunction, class Predicate>
|
||
|
|
inline OutputIterator transform_if(InputIterator first,
|
||
|
|
InputIterator last,
|
||
|
|
OutputIterator result,
|
||
|
|
UnaryFunction function,
|
||
|
|
Predicate predicate,
|
||
|
|
command_queue &queue = system::default_queue())
|
||
|
|
{
|
||
|
|
return detail::transform_if_impl(
|
||
|
|
first, last, result, function, predicate, false, queue
|
||
|
|
);
|
||
|
|
}
|
||
|
|
|
||
|
|
} // end compute namespace
|
||
|
|
} // end boost namespace
|
||
|
|
|
||
|
|
#endif // BOOST_COMPUTE_ALGORITHM_TRANSFORM_IF_HPP
|