On Tue, Oct 06, 2020 at 03:48:38PM +0200, Martin Liška wrote:
> On 10/6/20 9:47 AM, Richard Biener wrote:
> > But is it really extensible with the current implementation? I doubt so.
>
> I must agree with the statement. So let's make the pass properly.
> I would need a help with the algorithm where I'm planning to do the following
> steps:
>
> 1) for each BB ending with a gcond, parse index variable and it's VR;
> I'll support:
> a) index == 123 ([123, 123])
> b) 1 <= index && index <= 9 ([1, 9])
> c) index == 123 || index == 12345 ([123, 123] [12345, 12345])
> d) index != 1 ([1, 1])
> e) index != 1 && index != 5 ([1, 1] [5, 5])
The fold_range_test created cases are essential to support, so
f) index - 123U < 456U ([123, 456+123])
g) (unsigned) index - 123U < 456U (ditto)
but the discovery should actually recurse on all of those forms, so it will
handle
(unsigned) index - 123U < 456U || (unsigned) index - 16384U <= 32711U
etc.
You can see what reassoc init_range_entry does and do something similar?
Jakub
