[Bug target/65697] __atomic memory barriers not strong enough for __sync builtins

[mwahab at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65697

--- Comment #44 from mwahab at gcc dot gnu.org ---
(In reply to James Greenhalgh from comment #43)
> (In reply to torvald from comment #37)
> 
> > > I'm not worried about __sync_lock_release, I think the documentation is
> > > strong enough and unambiguous.
> > 
> > Are you aware that the GCC's __sync disallow store-store reordering across
> > __sync_lock_release, whereas the psABI docs don't?
> 
> No I was not, and even looking exactly for the text you were referring to,
> it took
> me three attempts to spot it. Yes, I understand now why you are concerned
> about
> the GCC wording. Perhaps this is just an artefact of a mistake transcribing
> the psABI?
> 
> AArch64 is certainly not providing that guarantee just now.

I wasn't able to find the text, could you copy it in a reply. 
In the GCC manual, the only description of __sync_lock_release behaviour is in
the last paragraph. That descriptions seems consistent with the function being
a release barrier and with the current Aarch64 code generated for it.