[Bug ipa/80728] IPA-reference suppresses compiler memory barrier

["rguenther at suse dot de" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80728

--- Comment #5 from rguenther at suse dot de <rguenther at suse dot de> ---
On Mon, 15 May 2017, amonakov at gcc dot gnu.org wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80728
> 
> --- Comment #4 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
> ipa-reference.c has:
> 
> /* Set of all interesting module statics.  A bit is set for every module
>    static we are considering.  This is added to the local info when asm
>    code is found that clobbers all memory.  */
> static bitmap all_module_statics;
> 
> 
> but I don't see where the code implementing the last statement in the comment
> is.
> I only see how indirect calls are handled (and I think barriers due to atomics
> and asms can be handled in a similar fashion).

Yeah, the comment refers to the old implementation (which likely was 
fine).  The new implementation simply uses the ipa_ref lists instead
of walking stmts.