[Bug tree-optimization/62173] [5.0 regression] 64bit Arch can't ivopt while 32bit Arch can

[LpSolit at netscape dot net]

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.