memset_pattern4 test

main.cpp

#include <iostream>
#include <chrono>
#include <string.h>

namespace laziness {
	struct SimpleStopWatch {
		void start() {
			_start = std::chrono::high_resolution_clock::now();
		}
		
		template <typename T = std::chrono::nanoseconds>
		typename T::rep rap() {
			_end = std::chrono::high_resolution_clock::now();
			return std::chrono::duration_cast<T>(_end - _start).count();
		}
		
		template <typename T = std::chrono::nanoseconds>
		typename T::rep getLastRap() const {
			return std::chrono::duration_cast<T>(_end - _start).count();
		}
		
		auto getLastRapMilliseconds() const 
		-> decltype(getLastRap<std::chrono::milliseconds>()) {
			return getLastRap<std::chrono::milliseconds>();
		}
		
		auto getLastRapMicroseconds() const 
		-> decltype(getLastRap<std::chrono::microseconds>()) {
			return getLastRap<std::chrono::microseconds>();
		}
		
		auto getLastRapNanoseconds() const
		-> decltype(getLastRap<std::chrono::nanoseconds>()) {
			return getLastRap<std::chrono::nanoseconds>();
		}
		
		decltype(std::chrono::high_resolution_clock::now()) _start, _end;
	};
};

using namespace std;
#define w 800
#define h 600
int main(int argc, char *argv[]) {
	const int loop = 1000;
	{
		unsigned char buf[4 * w * h];
		unsigned char c[4] = {255, 255, 0, 255};
		laziness::SimpleStopWatch timer;
		timer.start();
		for(int i = 0; i < loop; i++) {
			memset_pattern4(buf, c, w * h);
		}
		timer.rap();
		auto t = timer.getLastRapNanoseconds();
		std::cout << t << std::endl;
	}
	
	{
		unsigned char buf[4 * w * h];
		unsigned char c[4] = {255, 255, 0, 255};
		laziness::SimpleStopWatch timer;
		timer.start();
		size_t size = w * h;
		for(int i = 0; i < loop; i++) {
			for(int j = 0; j < size; j++) memcpy(buf + 4 * j, c, 4);
		}
		timer.rap();
		auto t = timer.getLastRapNanoseconds();
		std::cout << t << std::endl;
	}
	
	{
		unsigned char buf[4 * w * h];
		unsigned char c[4] = {255, 255, 0, 255};
		laziness::SimpleStopWatch timer;
		timer.start();
		size_t size = w * h * 4;
		for(int i = 0; i < loop; i++) {
			for(int j = 0; j < size; j += 4) memcpy(buf + j, c, 4);
		}
		timer.rap();
		auto t = timer.getLastRapNanoseconds();
		std::cout << t << std::endl;
	}
	
	{
		unsigned char buf[4 * w * h];
		unsigned char c[4] = {255, 255, 0, 255};
		laziness::SimpleStopWatch timer;
		timer.start();
		size_t size = w * h * 4;
		for(int i = 0; i < loop; i++) {
			for(int j = 0; j < size; j += 4) {
				buf[j] = c[0];
				buf[j + 1] = c[1];
				buf[j + 2] = c[2];
				buf[j + 3] = c[3];
			}
		}
		timer.rap();
		auto t = timer.getLastRapNanoseconds();
		std::cout << t << std::endl;
	}
}