[PATCH] Remove -Wunsafe-loop-optimizations option (PR middle-end/86095)

[Richard Biener]

On Mon, 25 Jun 2018, NightStrike wrote:

> On Fri, Jun 15, 2018 at 3:08 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> > Hi!
> >
> > As mentioned in the PR, all traces of this warning option except these
> > were removed earlier, so the warning option does nothing.
> 
> This is unfortunate.  As noted here:
> 
> https://gcc.gnu.org/ml/gcc-patches/2016-07/msg01057.html
> 
> The warning is (or, it used to be) good at finding code areas to
> rewrite, and it's MUCH easier to use than the giant walls of text from
> -fopt-info.  Is it possible to recreate this functionality in some
> other way (or has that already been done, and I missed it)?

I guess it would be straight forward to queue an optinfo record
about ->assumptions being present on loops.  It's just that
passes tend to not use the more "complex" number_of_iterations_exit ()
interface but rather the overly simplistic interface giving up
in more complex situations.

-fopt-info-missed has the issue that existing passes were converted
to the opt-info dumping machinery without much thought on what
exactly is worth reporting under "missed"...

Richard.