------- Comment #4 from rakdver at kam dot mff dot cuni dot cz 2010-08-27
16:33 -------
Subject: Re: New: Number of iteration
analysis bogus
> when looking at the exit 6->7 number_of_iterations_ne is present with
> iv->base (cxb3014__test_block__char_pointers__element * {ref-all}) ref_4(D)
> and final 0B, the step is 1. We then do
>
> else
> {
> s = fold_convert (niter_type, iv->step);
> c = fold_build2 (MINUS_EXPR, niter_type,
> fold_convert (niter_type, final),
> fold_convert (niter_type, iv->base));
> }
>
> which creates -(UNSIGNED_64) ref_4(D) for c, with no_overflow set as we
> do for pointers (but note we now have unsigned_type_for, a non-pointer!)
This looks correct to me, as far as I can tell. The original induction
variable
has pointer type, and thus it cannot overflow without causing undefined
behavior.
I do not understand the problem; what would you expect the result of the
analysis to be?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45427
