[Bug rtl-optimization/109592] Failure to recognize shifts as sign/zero extension

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109592

--- Comment #10 from Jeffrey A. Law <law at gcc dot gnu.org> ---
Created attachment 55218
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55218&action=edit
(Incomplete) Patch