/usr/include/boost/compute/algorithm
Edit: /usr/include/boost/compute/algorithm/unique_copy.hpp (6429B)
//---------------------------------------------------------------------------//
// Copyright (c) 2014 Roshan
//
// 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_UNIQUE_COPY_HPP
#define BOOST_COMPUTE_ALGORITHM_UNIQUE_COPY_HPP
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
namespace boost {
namespace compute {
namespace detail {
template
inline OutputIterator serial_unique_copy(InputIterator first,
InputIterator last,
OutputIterator result,
BinaryPredicate op,
command_queue &queue)
{
if(first == last){
return result;
}
typedef typename std::iterator_traits::value_type value_type;
const context &context = queue.get_context();
size_t count = detail::iterator_range_size(first, last);
detail::meta_kernel k("serial_unique_copy");
vector unique_count_vector(1, context);
size_t size_arg = k.add_arg("size");
size_t unique_count_arg = k.add_arg(memory_object::global_memory, "unique_count");
k << k.decl("index") << " = 0;\n"
<< k.decl("current") << " = " << first[k.var("0")] << ";\n"
<< result[k.var("0")] << " = current;\n"
<< "for(uint i = 1; i < size; i++){\n"
<< " " << k.decl("next") << " = " << first[k.var("i")] << ";\n"
<< " if(!" << op(k.var("current"), k.var("next")) << "){\n"
<< " " << result[k.var("++index")] << " = next;\n"
<< " " << "current = next;\n"
<< " }\n"
<< "}\n"
<< "*unique_count = index + 1;\n";
k.set_arg(size_arg, count);
k.set_arg(unique_count_arg, unique_count_vector.get_buffer());
k.exec_1d(queue, 0, 1, 1);
uint_ unique_count;
copy_n(unique_count_vector.begin(), 1, &unique_count, queue);
return result + unique_count;
}
template
inline OutputIterator unique_copy(InputIterator first,
InputIterator last,
OutputIterator result,
BinaryPredicate op,
command_queue &queue)
{
if(first == last){
return result;
}
const context &context = queue.get_context();
size_t count = detail::iterator_range_size(first, last);
// flags marking unique elements
vector flags(count, context);
// find each unique element and mark it with a one
transform(
first, last - 1, first + 1, flags.begin() + 1, not2(op), queue
);
// first element is always unique
fill_n(flags.begin(), 1, 1, queue);
// storage for desination indices
vector indices(count, context);
// copy indices for each unique element
vector::iterator last_index = detail::copy_index_if(
flags.begin(), flags.end(), indices.begin(), lambda::_1 == 1, queue
);
// copy unique values from input to output using the computed indices
gather(indices.begin(), last_index, first, result, queue);
// return an iterator to the end of the unique output range
return result + std::distance(indices.begin(), last_index);
}
} // end detail namespace
/// Makes a copy of the range [first, last) and removes all consecutive
/// duplicate elements (determined by \p op) from the copy. If \p op is not
/// provided, the equality operator is used.
///
/// \param first first element in the input range
/// \param last last element in the input range
/// \param result first element in the result range
/// \param op binary operator used to check for uniqueness
/// \param queue command queue to perform the operation
///
/// \return \c OutputIterator to the end of the result range
///
/// Space complexity: \Omega(4n)
///
/// \see unique()
template
inline OutputIterator unique_copy(InputIterator first,
InputIterator last,
OutputIterator result,
BinaryPredicate op,
command_queue &queue = system::default_queue())
{
BOOST_STATIC_ASSERT(is_device_iterator::value);
BOOST_STATIC_ASSERT(is_device_iterator::value);
size_t count = detail::iterator_range_size(first, last);
if(count < 32){
return detail::serial_unique_copy(first, last, result, op, queue);
}
else {
return detail::unique_copy(first, last, result, op, queue);
}
}
/// \overload
template
inline OutputIterator unique_copy(InputIterator first,
InputIterator last,
OutputIterator result,
command_queue &queue = system::default_queue())
{
BOOST_STATIC_ASSERT(is_device_iterator::value);
BOOST_STATIC_ASSERT(is_device_iterator::value);
typedef typename std::iterator_traits::value_type value_type;
return ::boost::compute::unique_copy(
first, last, result, ::boost::compute::equal_to(), queue
);
}
} // end compute namespace
} // end boost namespace
#endif // BOOST_COMPUTE_ALGORITHM_UNIQUE_COPY_HPP