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-rw-r--r--src/boost/libs/compute/perf/perf_tbb_merge.cpp95
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diff --git a/src/boost/libs/compute/perf/perf_tbb_merge.cpp b/src/boost/libs/compute/perf/perf_tbb_merge.cpp
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+//---------------------------------------------------------------------------//
+// Copyright (c) 2014 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.
+//---------------------------------------------------------------------------//
+
+#include <algorithm>
+#include <iostream>
+#include <vector>
+
+#include <tbb/parallel_for.h>
+
+#include "perf.hpp"
+
+// example from: http://www.threadingbuildingblocks.org/docs/help/reference/algorithms/parallel_for_func.htm
+using namespace tbb;
+
+template<typename Iterator>
+struct ParallelMergeRange {
+ static size_t grainsize;
+ Iterator begin1, end1; // [begin1,end1) is 1st sequence to be merged
+ Iterator begin2, end2; // [begin2,end2) is 2nd sequence to be merged
+ Iterator out; // where to put merged sequence
+ bool empty() const {return (end1-begin1)+(end2-begin2)==0;}
+ bool is_divisible() const {
+ return (std::min)( end1-begin1, end2-begin2 ) > grainsize;
+ }
+ ParallelMergeRange( ParallelMergeRange& r, split ) {
+ if( r.end1-r.begin1 < r.end2-r.begin2 ) {
+ std::swap(r.begin1,r.begin2);
+ std::swap(r.end1,r.end2);
+ }
+ Iterator m1 = r.begin1 + (r.end1-r.begin1)/2;
+ Iterator m2 = std::lower_bound( r.begin2, r.end2, *m1 );
+ begin1 = m1;
+ begin2 = m2;
+ end1 = r.end1;
+ end2 = r.end2;
+ out = r.out + (m1-r.begin1) + (m2-r.begin2);
+ r.end1 = m1;
+ r.end2 = m2;
+ }
+ ParallelMergeRange( Iterator begin1_, Iterator end1_,
+ Iterator begin2_, Iterator end2_,
+ Iterator out_ ) :
+ begin1(begin1_), end1(end1_),
+ begin2(begin2_), end2(end2_), out(out_)
+ {}
+};
+
+template<typename Iterator>
+size_t ParallelMergeRange<Iterator>::grainsize = 1000;
+
+template<typename Iterator>
+struct ParallelMergeBody {
+ void operator()( ParallelMergeRange<Iterator>& r ) const {
+ std::merge( r.begin1, r.end1, r.begin2, r.end2, r.out );
+ }
+};
+
+template<typename Iterator>
+void ParallelMerge( Iterator begin1, Iterator end1, Iterator begin2, Iterator end2, Iterator out ) {
+ parallel_for(
+ ParallelMergeRange<Iterator>(begin1,end1,begin2,end2,out),
+ ParallelMergeBody<Iterator>(),
+ simple_partitioner()
+ );
+}
+
+int main(int argc, char *argv[])
+{
+ perf_parse_args(argc, argv);
+
+ std::cout << "size: " << PERF_N << std::endl;
+ std::vector<int> v1 = generate_random_vector<int>(PERF_N / 2);
+ std::vector<int> v2 = generate_random_vector<int>(PERF_N / 2);
+ std::vector<int> v3(PERF_N);
+
+ std::sort(v1.begin(), v1.end());
+ std::sort(v2.begin(), v2.end());
+
+ perf_timer t;
+ for(size_t trial = 0; trial < PERF_TRIALS; trial++){
+ t.start();
+ ParallelMerge(v1.begin(), v1.end(), v2.begin(), v2.end(), v3.begin());
+ t.stop();
+ }
+ std::cout << "time: " << t.min_time() / 1e6 << " ms" << std::endl;
+
+ return 0;
+}