[Bug tree-optimization/59124] [4.9/5/6 Regression] Wrong warnings "array subscript is above array bounds"

[pangbw at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59124

--- Comment #32 from baoshan <pangbw at gmail dot com> ---
(In reply to Manuel López-Ibáñez from comment #30)
> (In reply to baoshan from comment #29)
> > > However, it is clear that _14 = baz[_9] is executed only 5 times (not 5
> > > times + 1). Why is this estimate wrong?
> > 
> > The max value of n is 6, so the max value of i is 5 as "i < n", then the max
> > value of j is 4 as "j = i - 1" which means the max iterate times is 4.
> 
> True! Well, that reinforces my point that something is very wrong in the
> estimation. What is it?

And I think it is not wrong, it's just inaccurate, and it is not making any
wrong result in running time.

Can you point me how to proceed?