On Mon, 28 Oct 2024 04:55:37 GMT, Quan Anh Mai <qa...@openjdk.org> wrote:
>> Ah, I see what you mean now. I think this makes extending IGVN more >> appealing because we could continue to do Ideal on lowered nodes, as you >> mentioned. We could override `PhaseGVN::apply_ideal` to return `nullptr` >> when processing regular nodes, but run the other `Ideal` type when >> encountering lowered nodes. Do you think it would be better to add another >> method to `Node` or should we re-use the existing Ideal call, but lowering >> specific nodes are guarded with a new node flag? > > I think having a new method in `Node` would be more manageable, I can imagine > it allows us to reuse pre-lowered nodes for lowering. The example I gave > above we reuse `ExtractI` since the semantics is still the same, the only > difference is that from here `ExtractI` can only appear with the index > parameter being smaller than 4. I think in general we'll want different nodes to reduce sources of ambiguity, but I've made this change in the latest patch. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/21599#discussion_r1821863386
