/*******************************************************

* Copyright (c) 2014, ArrayFire

* All rights reserved.

*

* This file is distributed under 3-clause BSD license.

* The complete license agreement can be obtained at:

* http://arrayfire.com/licenses/BSD-3-Clause

********************************************************/

#pragma once

#include <cmath>

#define divup(a, b) (((a) + (b)-1) / (b))

unsigned nextpow2(unsigned x);

// isPrime & greatestPrimeFactor are tailored after

// itk::Math::{IsPrimt, GreatestPrimeFactor}

template<typename T>

inline bool isPrime(T n) {

if (n <= 1) return false;

const T last = (T)std::sqrt((double)n);

for (T x = 2; x <= last; ++x) {

if (n % x == 0) return false;

}

return true;

}

template<typename T>

inline T greatestPrimeFactor(T n) {

T v = 2;

while (v <= n) {

if (n % v == 0 && isPrime(v))

n /= v;

else

v += 1;

}

return v;

}