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Re: PRE (sometimes) confuses ivopts/scev?
- From: Richard Guenther <rguenth at tat dot physik dot uni-tuebingen dot de>
- To: Daniel Berlin <dberlin at dberlin dot org>
- Cc: Ulrich Weigand <uweigand at de dot ibm dot com>, <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 27 Jan 2005 11:45:12 +0100 (CET)
- Subject: Re: PRE (sometimes) confuses ivopts/scev?
On Wed, 26 Jan 2005, Daniel Berlin wrote:
>
>
> On Wed, 26 Jan 2005, Richard Guenther wrote:
>
> > On Wed, 26 Jan 2005, Richard Guenther wrote:
> >
> >> and the code produced is even better than before with -fno-tree-pre!
> >>
> >> For a runtime test of the tramp3d testcase we gain about 2% in
> >> runtime compared to -fno-tree-pre and about 5% compared to -ftree-pre
> >> without your patch.
> >
> > Btw., we take a compile-time hit of ~0.5% for the tramp3d testcase,
> > but this could well be noise.
>
> Can you give this patch a try and let me know if it still has the same
> effect?
> It's like the last patch, only it will remove dead code that is not
> inserted.
> (It's currently in stage2 of bootstrap, but my last version of itpassed
> all regressions test, and all i did was update the comments and remove the
> processed sbitmap :P)
It basically does the same, the only difference is
alwazn:tests> diff pr19624.cpp.t50.pre.after pr19624.cpp.t50.pre
562a563
> Removing unnecessary insertion:pretmp.102_1654 = i_719 + 1;
3172d3172
< pretmp.102D.5437_1654 = iD.2790_719 + 1;
though that may be because there are a few day of updates between
the runs.
Richard.
--
Richard Guenther <richard dot guenther at uni-tuebingen dot de>
WWW: http://www.tat.physik.uni-tuebingen.de/~rguenth/