On Mon, Nov 11, 2013 at 12:29:29PM +0100, Richard Biener wrote:
> On Fri, Nov 8, 2013 at 6:51 PM, Hendrik Greving
> <hendrik.greving.in...@gmail.com> wrote:
> > That didn't do it. What was the rationale w.r.t. to the relation
> > between the vectorized sequenced and/or the alignment (I think these
> > things are actually 2 separate things..) and the common block?!
>
> We cannot adjust the alignment of a common block as we don't know
> which common block the linker will pick in the end. We can (and do)
> adjust the alignment of global variables though. And C++ defaults
> to -fno-common.
>
> In general when asking optimization questions it helps to provide
> a testcase that can be compiled - otherwise you just provoke
> random guesses (like mine) ;)
Well, we had the discussion about turning -fno-common by default for C as
well, I think it wouldn't hurt and let people use -fcommon if they need it.
Jakub
