https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106187
--- Comment #30 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Earnshaw from comment #29)
> Thanks for having a look, yes, I was at a loss to understand how that change
> (which is before the problematic hunk would be the cause of the problem. It
> looks like we can rule that change out as a real fix.
>
> > The code at RTL expansion time looks reasonable (also from an aliasing POV),
> > if -fno-strict-aliasing fixes it, does -fno-schedule-insn{,2} also?
>
> Yes, disabling scheduling also solves the issue.
There are several sched* debug counters, so maybe bisecting to the wrong
schedule via -fdbg-cnt=sched_insn might work. I think the above strongly
hints at either RTL/target messing up alias info somewhere or scheduling not
properly computing dependences.
