https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101145
--- Comment #6 from Jiu Fu Guo <guojiufu at gcc dot gnu.org> ---
> As tests, for below loop, adjust_cond_for_loop_until_wrap return false:
>
> foo (int *__restrict__ a, int *__restrict__ b, unsigned i)
> {
> while (++i > 100)
> *a++ = *b++ + 1;
> }
For the above code, niter still may be zero: e.g. "i < 100" at the start.
For the below code, niter can be determined as constant at compiling time.
>
> For below code, adjust_cond_for_loop_until_wrap returns true:
> i = UINT_MAX - 200;
> while (++i > 100)
> *a++ = *b++ + 1;
For below code, niter is also may be zero: e.g. "UINT_MAX - 100 < n" .
i = UINT_MAX - 200
while (++i > n)
*a++ = *b++ + 1;
