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

[rguenth at gcc dot gnu.org]

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

--- Comment #18 from Richard Biener <rguenth at gcc dot gnu.org> ---
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?