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diff --git a/boost/compute/algorithm/detail/count_if_with_ballot.hpp b/boost/compute/algorithm/detail/count_if_with_ballot.hpp
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+++ b/boost/compute/algorithm/detail/count_if_with_ballot.hpp
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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_COUNT_IF_WITH_BALLOT_HPP
+#define BOOST_COMPUTE_ALGORITHM_DETAIL_COUNT_IF_WITH_BALLOT_HPP
+
+#include <boost/compute/context.hpp>
+#include <boost/compute/command_queue.hpp>
+#include <boost/compute/container/vector.hpp>
+#include <boost/compute/algorithm/reduce.hpp>
+#include <boost/compute/functional/detail/nvidia_ballot.hpp>
+#include <boost/compute/functional/detail/nvidia_popcount.hpp>
+#include <boost/compute/detail/meta_kernel.hpp>
+
+namespace boost {
+namespace compute {
+namespace detail {
+
+template<class InputIterator, class Predicate>
+inline size_t count_if_with_ballot(InputIterator first,
+                                   InputIterator last,
+                                   Predicate predicate,
+                                   command_queue &queue)
+{
+    size_t count = iterator_range_size(first, last);
+    size_t block_size = 32;
+    size_t block_count = count / block_size;
+    if(block_count * block_size != count){
+        block_count++;
+    }
+
+    const ::boost::compute::context &context = queue.get_context();
+
+    ::boost::compute::vector<uint_> counts(block_count, context);
+
+    ::boost::compute::detail::nvidia_popcount<uint_> popc;
+    ::boost::compute::detail::nvidia_ballot<uint_> ballot;
+
+    meta_kernel k("count_if_with_ballot");
+    k <<
+        "const uint gid = get_global_id(0);\n" <<
+
+        "bool value = false;\n" <<
+        "if(gid < count)\n" <<
+        "    value = " << predicate(first[k.var<const uint_>("gid")]) << ";\n" <<
+
+        "uint bits = " << ballot(k.var<const uint_>("value")) << ";\n" <<
+
+        "if(get_local_id(0) == 0)\n" <<
+            counts.begin()[k.var<uint_>("get_group_id(0)") ]
+                << " = " << popc(k.var<uint_>("bits")) << ";\n";
+
+    k.add_set_arg<const uint_>("count", count);
+
+    k.exec_1d(queue, 0, block_size * block_count, block_size);
+
+    uint_ result;
+    ::boost::compute::reduce(
+        counts.begin(),
+        counts.end(),
+        &result,
+        queue
+    );
+    return result;
+}
+
+} // end detail namespace
+} // end compute namespace
+} // end boost namespace
+
+#endif // BOOST_COMPUTE_ALGORITHM_DETAIL_COUNT_IF_WITH_BALLOT_HPP