In this recipe, we will learn to print the sum of a sequence of numbers from 1 to a limit entered by the user using the loop unrolling technique. Loop unrolling means reducing or removing the loops from the program to reduce overheads applied while running the loops. Basically, for running a loop, the operating system has to manage two overheads – the first overhead is to maintain the count of the loop and the second overhead is to do conditional branching. Loop unrolling helps in avoiding these two overheads. Let's see how.