[Bug tree-optimization/30911] VRP fails to eliminate range checks in Ada code

[Arnaud Charlet]

> > Is there anyway for the optimizers to get at this range information still?
> > Or was range information removed because it is essentially impossible to use
> > it correctly (if so this bug report should be closed as unfixable)?
> 
> It was removed because it was impossible to use it correctly.  The "fix"
> is to derive range information from existing range checks, possibly
> inter-procedurally.

Right, as soon as you have one range check, the compiler can make more
precise assumptions/conclusions about the actual range.

Arno