On Tue, Jan 17, 2023 at 11:59:53AM +0100, Aldy Hernandez wrote:
>
>
> On 1/17/23 10:47, Jakub Jelinek wrote:
>
> > Aldy/Andrew, is the ranger query ok or should I use something different
> > when check_range_stmt is non-NULL and I know on which statement to ask?
>
> <snip>
>
> > + int_range_max r;
> > + if (!get_global_range_query ()->range_of_expr (r, rotcnt,
> > + check_range_stmt))
> > + return false;
>
> range_of_expr will work with and without a statement. If no statement is
> provided, it will return the global range. So you can use the same
> range_of_expr call with a statement or without one if you don't know it.
>
> Note that get_global_range_query () will always return a global query object
> (think SSA_NAME_RANGE_INFO). It will never use an existing ranger (for
> example, if called within VRP or another pass that has an active ranger
> enabled). If simplify_rotate() may be used from some of these passes you
> *may* want to use get_range_query() which will pick up the active ranger, or
> a global query object if no ranger is active.
This is always in the forwprop pass.
I think it doesn't have any active ranger instance, but I could be wrong.
A question would be if it would be worth to activate it in this spot lazily
if it isn't active yet (and destruct at the end of the pass).
> For that matter, since get_global_range_query() uses a global query, it
> really doesn't matter if you pass a statement or not, since our global range
> store has no context (SSA_NAME_RANGE_INFO). Although, I personally always
> pass the statement if known, because it's good form, and if things ever
> change to an active ranger, everything will just work.
Jakub
