[Bug tree-optimization/49093] [4.6/4.7 Regression] ICE in vect_enhance_data_refs_alignment() with volatile inside peeled loop

[rguenther at suse dot de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49093

--- Comment #6 from rguenther at suse dot de <rguenther at suse dot de> 2011-05-31 08:43:39 UTC ---
On Tue, 31 May 2011, irar at il dot ibm.com wrote:

> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49093
> 
> --- Comment #5 from Ira Rosen <irar at il dot ibm.com> 2011-05-31 08:30:49 UTC ---
> (In reply to comment #4)
> 
> > I think that's reasonable for 4.6.  But we don't need to make
> > data-ref analysis fail just because of volatile references - we for
> > example can easily unroll a loop with volatile loads/stores.
> > 
> > Of course this case seems to be special - how do we deal with
> > stmts with no uses during vectorization?  Or do we assume
> > they don't happen because usually DCE gets rid of them?
> 
> We ignore them. But this is under the assumption that they don't have memory
> accesses.

Ah, I see.  Yes, I guess not vectorizing for volatiles is the way
to go then.

Richard.