[Bug rtl-optimization/128119] [17 Regression] volatile and atomic loads removed at -O2 on x86_64 since r17-4656

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128119

--- Comment #3 from Drea Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Drea Pinski from comment #2)
> (In reply to Sam James from comment #1)
> > It bisects to r17-4656-gd382f953805cb0, but I did it with a grep on the
> > assembly rather than a dump, so may not be robust enough.
> 
> No that seems reasonible, There must be a missing side_effects_p  check
> somewhere.

It might not be in the patch itself but rather ASHIFTRT simplify_rtx code.