compute/perf/perf_tbb_accumulate.cpp
2015-05-17 20:32:09 -07:00

76 lines
2.0 KiB
C++

//---------------------------------------------------------------------------//
// Copyright (c) 2013-2014 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 <numeric>
#include <vector>
#include <tbb/blocked_range.h>
#include <tbb/parallel_reduce.h>
#include "perf.hpp"
int rand_int()
{
return static_cast<int>((rand() / double(RAND_MAX)) * 25.0);
}
template<class T>
struct Sum {
T value;
Sum() : value(0) {}
Sum( Sum& s, tbb::split ) {value = 0;}
void operator()( const tbb::blocked_range<T*>& r ) {
T temp = value;
for( T* a=r.begin(); a!=r.end(); ++a ) {
temp += *a;
}
value = temp;
}
void join( Sum& rhs ) {value += rhs.value;}
};
template<class T>
T ParallelSum( T array[], size_t n ) {
Sum<T> total;
tbb::parallel_reduce( tbb::blocked_range<T*>( array, array+n ),
total );
return total.value;
}
int main(int argc, char *argv[])
{
perf_parse_args(argc, argv);
std::cout << "size: " << PERF_N << std::endl;
// create vector of random numbers on the host
std::vector<int> host_vector(PERF_N);
std::generate(host_vector.begin(), host_vector.end(), rand_int);
int sum = 0;
perf_timer t;
for(size_t trial = 0; trial < PERF_TRIALS; trial++){
t.start();
sum = ParallelSum<int>(&host_vector[0], host_vector.size());
t.stop();
}
std::cout << "time: " << t.min_time() / 1e6 << " ms" << std::endl;
std::cout << "sum: " << sum << std::endl;
int host_sum = std::accumulate(host_vector.begin(), host_vector.end(), int(0));
if(sum != host_sum){
std::cerr << "ERROR: sum (" << sum << ") != (" << host_sum << ")" << std::endl;
return -1;
}
return 0;
}