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

[ramana at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173

--- Comment #19 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> ---
(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?

Not sure if this is related to comment #c2 where the reference is to a 15%
regression in bzip2 compress at O3. Sebastian could probably confirm.

I don't think we can ignore the regression though, can we ?

regards
Ramana