[Bug tree-optimization/104356] [12 Regression] divide by zero trap incorrectly optimized away

[amacleod at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104356

--- Comment #45 from Andrew Macleod <amacleod at redhat dot com> ---

> 
> That said, range-ops, from say
> 
>   [0,1] = [0,2] / y;
> 
> may _not_ reason that 'y' is not 0 when non-call EH.  That is, you need to be
> careful on the reverse ops but I think not on the forward ops.

We do not currently try to figure anything via reverse ops for general divide
operations.

For exact_divide we try if Y is a non-zero singleton, but that's about it.