You are to write an ARM assembly program that uses the Sieve of Eratosthenes (er-uh-tos-thuh-neez) algorithm to calculate all prime numbers less than or equal to N, where N is a named constant. A good description of the algorithm can be found at http://www.geeksforgeeks.org/sieve-of-eratosthenes/.
The program below is a C++ version of the solution. The first N+1 bytes of memory beginning at address 0x40000000 will correspond to the bool prime[N+1] array. Each entry in this array will be of type DCB.
The first available full-word boundary address after the end of the prime array will corresponds to the start of the vector<unsigned int primes data store. Each entry in this data store will be of type DCD. Obviously your program will be unable to actually display the prime numbers as does the C++ version.
Submit your .s file through Canvas.
// C++ program to calculate all primes less than or equal to
// N using Sieve of Eratosthenes. The primes are stored in a vector
#include <vector
#include <iostream
using namespace std;
int main() {
// Create a boolean array "prime[0..N]" and initialize
// all entries it as true. A value in prime[i] will
// finally be false if i is Not a prime, else true.
const unsigned int N = 100;
bool prime[N+1];
for(unsigned int i=0; i<N+1; i++)
prime[i] = true;
for (unsigned int p=2; p*p<=N; p++) {
// If prime[p] is not changed, then it is a prime
if (prime[p] == true) {
// Update all multiples of p
for (unsigned int i=p*2; i<=N; i += p)
prime[i] = false;
}
}
vector<unsigned int primes;
// Save all primes in a vector
for (unsigned int p=2; p<=N; p++) {
if (prime[p] == true)
primes.push_back(p);
}
// Display the contents of the vector
for (unsigned int prime : primes)
cout << prime << endl;
return 0;
}
