What is loop unrolling in compiler optimizations?

What is loop unrolling in compiler optimizations?

Loop unrolling is a compiler optimization technique that reduces the overhead of loop control by increasing the number of operations performed within a single iteration.

How does loop unrolling improve performance?

It improves performance by decreasing the number of iterations, which reduces the loop control overhead and can enhance instruction-level parallelism.

Are there any downsides to loop unrolling?

Yes, downsides include increased code size and potential cache performance issues due to larger instruction footprints.

Can you give an example of loop unrolling in code?

Sure! For example, a loop that adds elements of an array can be unrolled to perform multiple additions in a single iteration, reducing the loop count.