Re: fold strlen (s) eq/ne 0 to *s eq/ne 0 on GIMPLE

[Andrew Pinski <pinskia@gmail.com>]

On Mon, Aug 1, 2016 at 12:15 AM, Prathamesh Kulkarni
<prathamesh.kulkarni@linaro.org> wrote:
> Hi Richard,
> The attached patch tries to fold strlen (s) eq/ne 0 to *s eq/ne 0 on GIMPLE.
> I am not sure where was the ideal place to put this transform in and ended up
> adding it to strlen_optimize_stmt().
> Does that look OK ?

I suspect it might be better in match.pd.

>
> I needed to add TODO_update_ssa to strlen pass, otherwise we hit the
> following assert in execute_todo():
> if (flag_checking
>       && cfun
>       && need_ssa_update_p (cfun))
>     gcc_assert (flags & TODO_update_ssa_any);

Also you only need to update the virtual SSAs rather than a full SSA update.

Thanks,
Andrew

>
> Bootstrap+test in progress on x86_64-unknown-linux-gnu.
>
> Thanks,
> Prathamesh