This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: [tree-ssa] Write to global memory not hoisted out of loop
On Fri, 30 Apr 2004, Steven Bosscher wrote:
> On Apr 30, 2004 01:14 PM, Richard Guenther <rguenth@tat.physik.uni-tuebingen.de> wrote:
>
> > Writes to global memory are not hoisted out of a computation loop.
>
> Try this with the LNO branch, iirc it can do this.
Not as of gcc (GCC) 3.5-tree-ssa-lno 20040430 (merged 20040425) (-O2
-ftree-loop-optimize -ffast-math), neither with static nor without.
> > Is there already a PR about this pessimization? (Couldn't find one)
>
> Why is this a pessimization, does gcc 3.4.0 do what you want? Looks
> like just a missed opportunity. I am more surprised that making tmp
> static doesn't help...
Yes, I assumed tree-ssa can do this with some part of DOM - but
appearantly not. No version of gcc can do this, but I think of
pessimization as of "worse than best possible", not as of a regression
towards an older release.
Richard.
--
Richard Guenther <richard dot guenther at uni-tuebingen dot de>
WWW: http://www.tat.physik.uni-tuebingen.de/~rguenth/