#include "reduce_sum.hpp"

#include <taskflow/taskflow.hpp>

#include <taskflow/algorithm/reduce.hpp>

void reduce_sum_taskflow(unsigned num_threads) {

static tf::Executor executor(num_threads);

tf::Taskflow taskflow;

double result = 0.0;

taskflow.reduce_by_index(

tf::IndexRange<size_t>(0, vec.size(), 1),

result,

[&](tf::IndexRange<size_t> range, std::optional<double> running_total) {

double partial_sum = running_total ? *running_total : 0.0;

for(size_t i=range.begin(); i<range.end(); i+=range.step_size()) {

partial_sum += vec[i];

}

return partial_sum;

},

std::plus<double>()

);

executor.run(taskflow).get();

}

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

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

reduce_sum_taskflow(num_threads);

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

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

}