Return all prime numbers smaller than M

Question

Given an integer M. return all prime numbers smaller than M.

Give a algorithm as good as you can. Need to consider time and space complexity.

Answer 1

The usual answer is to implement the Sieve of Eratosthenes, but this is really only a solution for finding the list of all prime numbers smaller than N. If you want primality tests for specific numbers, there are better choices for large numbers.