Recently, I've stumbled upon an interview question where you need to write a code that's optimized for ARM, especially for iphone:
Write a function which takes an array of char (ASCII symbols) and find the most frequent character.
char mostFrequentCharacter(char* str, int size)The function should be optimized to run on dual-core ARM-based processors, and an infinity amount of memory.
http://stackoverflow.com/questions/32706934/optimize-c-code-for-arm-based-devices