Efficiency of boolean comparisons? In C

Question

I'm writing a loop in C, and I am just wondering on how to optimize it a bit. It's not crucial here as I'm just practicing, but for further knowledge, I'd like to know:

In a loop, for example the following snippet:

int i = 0;
while (i < 10) {
    printf("%d\n", i);
    i++;
}

Does the processor check both (i < 10) and (i == 10) for every iteration? Or does it just check (i < 10) and, if it's true, continue?

If it checks both, wouldn't:

int i = 0;
while (i != 10) {
    printf("%d\n", i);
    i++;
}

be more efficient?

Thanks!

Answer 1

Both will be translated in a single assembly instruction. Most CPUs have comparison instructions for LESS THAN, for LESS THAN OR EQUAL, for EQUAL and for NOT EQUAL.