On Sat, Sep 24, 2011 at 11:24 AM, Richard Guenther <richard.guent...@gmail.com> wrote: > On Thu, Sep 15, 2011 at 6:26 PM, Paolo Bonzini <bonz...@gnu.org> wrote: >> On 09/15/2011 06:19 PM, Richard Henderson wrote: >>> >>> I wouldn't go that far. They *used* to be compiler barriers, >>> but clearly something broke at some point without anyone noticing. >>> We don't know how many versions are affected until we debug it. >>> For all we know it broke in 4.5 and 4.4 is fine. >> >> 4.4 is not necessarily fine, it may also be that an unrelated 4.5 change >> exposed a latent bug. >> >> But indeed Richard Sandiford mentioned offlist that perhaps >> ALIAS_SET_MEMORY_BARRIER machinery broke. Fixing the bug in 4.5/4.6/4.7 >> will definitely shed more light. > > ALIAS_SET_MEMORY_BARRIER?! Eh, well - that will make TBAA consider > something a memory barrier (I suppose the value of the macro is just zero), > but clearly non-TBAA alias analysis will happily disambiguate things.
Nope, it's implemented/tested in a way that should work (on RTL, that is). Richard.
