On Wed, Jan 31, 2024 at 12:16:59PM -0800, Andi Kleen wrote:
> > This results in "error: cannot tail-call: cannot tail-call: other reasons".
> > So the second argument should be "other reasons" only.
>
> Yes will fix those. Thanks.
>
> >
> > I notice that if I don't use -O2 I also get "other reasons". But it should
> > be
> > easy-ish to say "cannot tail-call: optimizations not enabled" or so.
>
> It's unfortunately not easy to distinguish. It's not just -O2, but
> various missing transformations make tree-tailcall not do it its job,
> and they could depend on other flags. But there might be also other
> reasons not related to the optimization that makes the tail call fall.
> I would be uncomfortable reporting the problem is -O2 when it might
> be something else.
>
> The right fix would be to make tree-tailcall not fail with optimization,
> and for the remaining cases add errors there. But that would
> make the patch a lot bigger and it's not clear it would improve usability
> that much. So I opted to just mention the problem in the documentation.
Ah, we don't want that. I meant to check the simplest case:
if (optimize < 2)
...
but if it's more complicated than that then let's let it be.
Thanks,
Marek
