Which code style is better in terms of readability and performance?

Question

I am wondering which code style is better for

1. human readability
2. program performance

Let's imagine we have 2 functions:

// first one
void foo(void) {
    if (error)
        exit(1);
    ....
}

// second one
void bar(void) {
    if (!error) {
        ....
    }
    else
        exit(1);
}

Both of them work in the same way in terms of execution, but which code style is preferable?

Answer 1

If I had to choose out of these two only, I'd choose the first one.

Reason:

1. It's simple. (does not use any operator like !)
2. It does not need comments to explain what happens inside. (self-readable code)
3. It avoids extra pair of { } which makes the code more readable
4. Both performs nearly the same, I highly doubt there will be a difference in performance.

Hence, first one is preferable.