https://gcc.gnu.org/bugzilla/show_bug.cgi?id=76774
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |RESOLVED
Resolution|--- |INVALID
--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Peter Sewell from comment #4)
> (In reply to Andrew Pinski from comment #3)
> > What code were you expecting anyways?
>
> I hadn't noticed how recent the other-size LL/SC were. But then I would
> have expected a 4-byte representation for _Atomic(_Bool) on the older
> machines, to minimise the amount of code between the lwarx and stwcx; would
> that have some other disadvantage?
Yes that would break Abis. In that power7 compiled code would be incompatible
with power9 one.
>
> I don't think the code you've got is functionally wrong on normal h/w. We
> noticed this running in a semantics-based emulator that's very picky about
> reading from uninitialised memory, but on normal h/w the extra memory will
> AFAICS always be mapped and be within the same reservation granule.
Sorry but there is nothing that can be done here. This is a similar issue on
mips too.
