[Bug rtl-optimization/101995] [9/10/11/12 Regression] regression built-in memset missed-optimization arm -Os since r9-3594

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101995

--- Comment #7 from Segher Boessenkool <segher at gcc dot gnu.org> ---
I don't see any problem with aarch64 fwiw.

If RA decides it does not want to tie the new pseudo to the argument
register, it may have a reason for it?  Or suboptimal heuristics.

What is this REG_RETURNED thing?