#include "reduce_sum.hpp"

#include <tbb/parallel_reduce.h>

#include <tbb/blocked_range.h>

#include <tbb/global_control.h>

// reduce_sum_tbb

void reduce_sum_tbb(unsigned num_threads) {

tbb::global_control c(

tbb::global_control::max_allowed_parallelism, num_threads

);

tbb::parallel_reduce(

tbb::blocked_range<double*>(vec.data(), vec.data() + vec.size()),

0.0,

[](const tbb::blocked_range<double*>& r, double value) {

return std::accumulate(r.begin(), r.end(), value);

},

[](double l, double r) -> double {

return l + r;

}

);

//std::cout << reduce_sum() << std::endl;

}

std::chrono::microseconds measure_time_tbb(unsigned num_threads) {

auto beg = std::chrono::high_resolution_clock::now();

reduce_sum_tbb(num_threads);

auto end = std::chrono::high_resolution_clock::now();

return std::chrono::duration_cast<std::chrono::microseconds>(end - beg);

}