RadixSortMsdBenchmark.cpp

#include <stddef.h>
#include <stdio.h>
#include <iostream>
#include <algorithm>
#include <chrono>
#include <random>
#include <ratio>
#include <vector>
#include <execution>

#include "RadixSortMSD.h"
#include "RadixSortMsdParallel.h"

using std::chrono::duration;
using std::chrono::duration_cast;
using std::chrono::high_resolution_clock;
using std::milli;
using std::random_device;
using std::sort;
using std::vector;

const int iterationCount = 5; 

static void print_results(const char* const tag, const vector<unsigned>& sorted, size_t sortedLength,
	high_resolution_clock::time_point startTime,
	high_resolution_clock::time_point endTime) {
	printf("%s: Lowest: %u Highest: %u Time: %fms\n", tag,
		sorted[0], sorted[sortedLength - 1],
		duration_cast<duration<double, milli>>(endTime - startTime).count());
}


int RadixSortMsdBenchmark(vector<unsigned>& uints)
{
	vector<unsigned> uintsCopy(  uints);
	vector<unsigned> tmp_working(uints);
	//vector<unsigned> sorted(uints);

	printf("\n");
	// time how long it takes to sort them:
	for (int i = 0; i < iterationCount; ++i)
	{
		for (size_t j = 0; j < uints.size(); j++) {	// copy the original random array into the source array each time, since ParallelMergeSort modifies the source array while sorting
			//uints[j] = j + 2;							// for pre-sorted array testing
			uintsCopy[j] = uints[j];
			//sorted[j] = (unsigned)j;									// page in the destination array into system memory
		}
		// Eliminate compiler ability to optimize paging-in of the input and output arrays
		// Paging-in source and destination arrays leads to a 50% speed-up on Linux, and 15% on Windows

		vector<unsigned> sorted_reference(uints);
		sort(std::execution::par_unseq, sorted_reference.begin(), sorted_reference.end());

		//printf("uintsCopy address = %p   sorted address = %p   value at a random location = %lu %lu\n", uintsCopy, sorted, sorted[static_cast<unsigned>(rd()) % uints.size()], uintsCopy[static_cast<unsigned>(rd()) % uints.size()]);
		const auto startTime = high_resolution_clock::now();
		//RadixSortLSDPowerOf2RadixScalar_unsigned_TwoPhase(  uintsCopy.data(), sorted.data(), (unsigned long)uints.size());
		//RadixSortLSDPowerOf2RadixParallel_unsigned_TwoPhase(uintsCopy.data(), sorted.data(), (unsigned long)uints.size());
		//hybrid_inplace_msd_radix_sort(uintsCopy.data(), (unsigned long)uints.size());
		//ParallelAlgorithms::parallel_hybrid_inplace_msd_radix_sort(uintsCopy.data(), (unsigned long)uints.size());
		RadixSortMSDStablePowerOf2Radix_unsigned(uintsCopy.data(), tmp_working.data(), uints.size());
		const auto endTime = high_resolution_clock::now();
		print_results("Radix Sort MSD", uintsCopy, uints.size(), startTime, endTime);

		if (!std::equal(sorted_reference.begin(), sorted_reference.end(), uintsCopy.begin()))
		{
			printf("Arrays are not equal\n");
			exit(1);
		}
	}

	return 0;
}