Re: [PATCH] Loop unswitching: support gswitch statements.

[Andrew MacLeod <amacleod@redhat.com>]

On 1/5/22 07:34, Richard Biener wrote:
> On Thu, Dec 9, 2021 at 2:02 PM Martin Liška <mliska@suse.cz> wrote:
>> On 11/30/21 12:17, Richard Biener wrote:
>>
> +                 unswitch_predicate *predicate
> +                   = new unswitch_predicate (expr, idx, edge_index);
> +                 ranger->gori ().outgoing_edge_range_p
> (predicate->true_range, e,
> +                                                        idx,
> *get_global_range_query ());
> +                 /* Huge switches are not supported by Ranger.  */
> +                 if (predicate->true_range.undefined_p ())
>
> I hope ranger will set the range to varying_p () in that case, not
> undefined?  But even
> then, is that a reason for punting?  I guess we fail to prune cases in
> that case but
> the cost modeling should then account for those and thus we are at
> least consistent?

huge switches not supported?  I don't know what you mean, either that or 
I forget :-)  If there are more edges than multi-ranges support, then 
things will start getting merged because they cant be represented.. and 
the default case may then also contain some values that also have 
cases..  but all inconsistencies will move towards varying.. not undefined.

Andrew