[Bug target/100998] [12 Regression] bug in experimental GCC12 with optimization '-O1', disappears with optimization '-O0'

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100998

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Peter Bergner from comment #3)
> (In reply to Andrew Pinski from comment #2)
> > If this is powerpc and on power10, then it is most likely caused by r12-1020.
> 
> Not arguing with you, but how did you pinpoint this commit?

It is just a guess based on understanding what the RTL would look like and what
changes were going on in the powerpc backend and the reporter is from IBM and
you work on the powerpc backend.  Also the code looks correct on both aarch64
and x86_64 so I figured it is most likely a target issue.