Iterating over all unsigned integers in a for loop

Question

Let\'s say I want to iterate over all integers in a for loop. For the sake of discussion, assume I am calling some unknown function f(unsigned x) f

Answer 1

You can do it with a do-while loop, but you lose all the niceties of the for syntax.

It is still doable with do-while loop by using an anonymous block scope:

{
    unsigned i = 0;
    do { f(i); } while (++i != 0);
}

While this construct may not be most idiomatic, it is an obvious candidate for clear assembly code. For example, gcc -O compiles it as:

.L2:
        mov     edi, ebx   ; ebx starts with zero
        call    f
        add     rbx, 1
        cmp     rbx, rbp   ; rbp is set with 4294967296
        jne     .L2