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[Bug tree-optimization/62173] [5.0 regression] 64bit Arch can't ivopt while 32bit Arch can
- From: "LpSolit at netscape dot net" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Tue, 27 Jan 2015 10:24:29 +0000
- Subject: [Bug tree-optimization/62173] [5.0 regression] 64bit Arch can't ivopt while 32bit Arch can
- Auto-submitted: auto-generated
- References: <bug-62173-4 at http dot gcc dot gnu dot org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173
--- Comment #29 from Jiong Wang <jiwang at gcc dot gnu.org> ---
(In reply to amker from comment #20)
> (In reply to Richard Biener from comment #18)
> > It's probably not correct to simply transfer range info from *idx to
> > iv->base.
> > Instead SCEV analysis needs to track the range of CHREC_LEFT when it analyzes
> > the SSA use-def chain. That's of course a much bigger change :/
> >
> > The patch may still help in some cases - I suppose the original testcase is
> > reduced from sth else?
>
> Of course, take range information into consideration is always an
> improvement.
The RANGE info is a good idea, Bin, it's worth a quick exploration.