featherkit_simplex_tests.cpp

#include <chrono>
#include <iostream>
#include <fea/util/noise.hpp>

int main()
{
	fea::Noise noise;

	uint64_t min(-1), max(0), avg(0);
	int steps = 10;

	for(int n=0; n < steps; ++n)
	{
		auto start = std::chrono::high_resolution_clock::now();

		for(unsigned int i=0; i < 100000000; ++i)
		{
			noise.simplexOctave3D(i*0.1f, i*2.f, i*3.f);
		}

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

		uint64_t current = std::chrono::duration_cast<std::chrono::microseconds>(end-start).count();

		std::cout<<"Step: "<<current<<"us"<<std::endl;

		min = std::min(current, min);
		max = std::max(current, max);
		avg += current;
	}

	avg /= steps;

	std::cout<<"Times (min, max, avg): "<<min<<"us, "<<max<<"us, "<<avg<<"us"<<std::endl;
}

/*

Built on ArchLinux x86_64 with GCC 4.9.1
Featherkit-util linked as static library
CPU: Intel Core i7 4770 @ 3.4 GHz
Tests were performed with TurboBoost on, and the clock speed was 3.75GHz

Featherkit with `-O3`:
	- C++ Noise:
		- With std::pow():
			- Times (min, max, avg): 18500990us, 19314295us, 18761359us
		- With expanded exponent:
			- Times (min, max, avg): 13590441us, 13778924us, 13641680us
		- With expanded exponent and fast_floor:
			- Times (min, max, avg): 12741825us, 12785273us, 12761292us
	- ASM Noise:
			- Times (min, max, avg): 17619293us, 18048159us, 17756850us

Featherkit with `-O3 -march=native -mfpmath=sse`:
	- C++ Noise:
		- With std::pow():
			- Times (min, max, avg): 16363849us, 16540378us, 16425663us
		- With expanded exponent:
			- Times (min, max, avg): 12010800us, 12160890us, 12042282us
		- With expanded exponent and fast_floor:
			- Times (min, max, avg): 11155214us, 11217809us, 11175114us
	- ASM Noise:
			- Times (min, max, avg): 17765922us, 17830874us, 17787408us

	
	If I compile the example with `-O3 -march=native -mfpmath=sse`, I get:
	- C++ Noise:
		- With expanded exponent:
			- Times (min, max, avg): 11598168us, 11839490us, 11654674us
		- With expanded exponent and fast_floor:
			- Times (min, max, avg): 10935452us, 10988102us, 10964837us

*/