[Bug middle-end/59448] Code generation doesn't respect C11 address-dependency

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59448

--- Comment #19 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
On Tue, 28 Oct 2014, torvald at gcc dot gnu.org wrote:

> Alternatively, we could try to be conservative and add an acquire barrier
> before the function body if any parameter of the function has
> carries_dependency; and, likewise, add an acquire barrier after every call to a
> function which has carries_dependency.
> 
> I don't have more input from the ISO C side, but I would guess that the
> situation there is similar.

As previously noted:

* ISO C does not have carries_dependency (or attributes at all).

* carries_dependency is about increasing optimization, not decreasing it.  
If it affects when barriers are added, it does so by allowing some 
barriers to be omitted that would otherwise be required.