boost/compute/algorithm/replace.hpp
//---------------------------------------------------------------------------//
// 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.
//---------------------------------------------------------------------------//
#ifndef BOOST_COMPUTE_ALGORITHM_REPLACE_HPP
#define BOOST_COMPUTE_ALGORITHM_REPLACE_HPP
#include <boost/static_assert.hpp>
#include <boost/compute/system.hpp>
#include <boost/compute/command_queue.hpp>
#include <boost/compute/detail/meta_kernel.hpp>
#include <boost/compute/detail/iterator_range_size.hpp>
#include <boost/compute/type_traits/is_device_iterator.hpp>
namespace boost {
namespace compute {
namespace detail {
template<class Iterator, class T>
class replace_kernel : public meta_kernel
{
public:
replace_kernel()
: meta_kernel("replace")
{
m_count = 0;
}
void set_range(Iterator first, Iterator last)
{
m_count = detail::iterator_range_size(first, last);
*this <<
"const uint i = get_global_id(0);\n" <<
"if(" << first[var<cl_uint>("i")] << " == " << var<T>("old_value") << ")\n" <<
" " << first[var<cl_uint>("i")] << '=' << var<T>("new_value") << ";\n";
}
void set_old_value(const T &old_value)
{
add_set_arg<T>("old_value", old_value);
}
void set_new_value(const T &new_value)
{
add_set_arg<T>("new_value", new_value);
}
void exec(command_queue &queue)
{
if(m_count == 0){
// nothing to do
return;
}
exec_1d(queue, 0, m_count);
}
private:
size_t m_count;
};
} // end detail namespace
/// Replaces each instance of \p old_value in the range [\p first,
/// \p last) with \p new_value.
///
/// Space complexity: \Omega(1)
template<class Iterator, class T>
inline void replace(Iterator first,
Iterator last,
const T &old_value,
const T &new_value,
command_queue &queue = system::default_queue())
{
BOOST_STATIC_ASSERT(is_device_iterator<Iterator>::value);
detail::replace_kernel<Iterator, T> kernel;
kernel.set_range(first, last);
kernel.set_old_value(old_value);
kernel.set_new_value(new_value);
kernel.exec(queue);
}
} // end compute namespace
} // end boost namespace
#endif // BOOST_COMPUTE_ALGORITHM_REPLACE_HPP