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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.
+//---------------------------------------------------------------------------//
+
+#ifndef BOOST_COMPUTE_ALGORITHM_DETAIL_SCAN_ON_CPU_HPP
+#define BOOST_COMPUTE_ALGORITHM_DETAIL_SCAN_ON_CPU_HPP
+
+#include <iterator>
+
+#include <boost/compute/device.hpp>
+#include <boost/compute/kernel.hpp>
+#include <boost/compute/command_queue.hpp>
+#include <boost/compute/detail/meta_kernel.hpp>
+#include <boost/compute/detail/iterator_range_size.hpp>
+
+namespace boost {
+namespace compute {
+namespace detail {
+
+template<class InputIterator, class OutputIterator, class T, class BinaryOperator>
+inline OutputIterator scan_on_cpu(InputIterator first,
+ InputIterator last,
+ OutputIterator result,
+ bool exclusive,
+ T init,
+ BinaryOperator op,
+ command_queue &queue)
+{
+ if(first == last){
+ return result;
+ }
+
+ typedef typename
+ std::iterator_traits<InputIterator>::value_type input_type;
+ typedef typename
+ std::iterator_traits<OutputIterator>::value_type output_type;
+
+ const context &context = queue.get_context();
+
+ // create scan kernel
+ meta_kernel k("scan_on_cpu");
+
+ // Arguments
+ size_t n_arg = k.add_arg<ulong_>("n");
+ size_t init_arg = k.add_arg<output_type>("initial_value");
+
+ if(!exclusive){
+ k <<
+ k.decl<const ulong_>("start_idx") << " = 1;\n" <<
+ k.decl<output_type>("sum") << " = " << first[0] << ";\n" <<
+ result[0] << " = sum;\n";
+ }
+ else {
+ k <<
+ k.decl<const ulong_>("start_idx") << " = 0;\n" <<
+ k.decl<output_type>("sum") << " = initial_value;\n";
+ }
+
+ k <<
+ "for(ulong i = start_idx; i < n; i++){\n" <<
+ k.decl<const input_type>("x") << " = "
+ << first[k.var<ulong_>("i")] << ";\n";
+
+ if(exclusive){
+ k << result[k.var<ulong_>("i")] << " = sum;\n";
+ }
+
+ k << " sum = "
+ << op(k.var<output_type>("sum"), k.var<output_type>("x"))
+ << ";\n";
+
+ if(!exclusive){
+ k << result[k.var<ulong_>("i")] << " = sum;\n";
+ }
+
+ k << "}\n";
+
+ // compile scan kernel
+ kernel scan_kernel = k.compile(context);
+
+ // setup kernel arguments
+ size_t n = detail::iterator_range_size(first, last);
+ scan_kernel.set_arg<ulong_>(n_arg, n);
+ scan_kernel.set_arg<output_type>(init_arg, static_cast<output_type>(init));
+
+ // execute the kernel
+ queue.enqueue_1d_range_kernel(scan_kernel, 0, 1, 1);
+
+ // return iterator pointing to the end of the result range
+ return result + n;
+}
+
+} // end detail namespace
+} // end compute namespace
+} // end boost namespace
+
+#endif // BOOST_COMPUTE_ALGORITHM_DETAIL_SCAN_ON_CPU_HPP