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Re: [PATCH][LTO] Stream zeroness of alias-sets
On Thu, 6 Aug 2009, Diego Novillo wrote:
> On Thu, Aug 6, 2009 at 17:34, Richard Henderson<rth@redhat.com> wrote:
> > On 08/06/2009 01:57 PM, Diego Novillo wrote:
> >>
> >> I don't think there's a good reason why we should distinguish
> >> TYPE_REF_CAN_ALIAS_ALL from alias_set == 0. ÂIs there?
> >
> > TYPE_REF_CAN_ALIAS_ALL is on the pointer type, whereas
> > alias_set 0 (or the may_alias attr) is on the base type?
>
> But may_alias *sets* TYPE_REF_CAN_ALIAS_ALL. Ah, but it does it to
> the pointed-to type. Wonky, but OK.
Indeed. Note that the may_alias attribute does map to the same concept
(only accesses through pointers to types marked so are affected). We
don't have a user-visible feature that would allow the storage itself
to get alias-set zero which is what the C++ FE needs for the
TYPE_PTRMEMFUNC_P case.
I have installed the patch for now.
Thanks,
Richard.