On Mon, 8 Dec 2025 09:57:12 GMT, Christian Hagedorn <[email protected]> wrote:
>> This patch turns the boolean flag `_flat_in_array` into a new `FlatInArray` >> enum to properly define a (Boolean) lattice. This mainly allows us to >> cleanly represent "maybe flat in array" and "not flat in array". The >> dedicated top element is the dual of "maybe flat in array". >> >> To simplify the review and to better understand what the changes are, I >> added code comments directly in the PR. >> >> Here is a high-level overview of the changes: >> - `FlatInArray` enum to define a lattice for `flat_in_array`: >> https://github.com/openjdk/valhalla/blob/6b1930c7b9a359223a998d0086a1326a9d7905e7/src/hotspot/share/opto/type.hpp#L1182-L1199 >> - Updated `meet` operations accordingly. Needed to be careful when doing the >> meet above the centerline. >> - Added single `compute_flat_in_array()` method to properly compute the >> `flat_in_array` property from the information we have when we need to set >> flat in array newly (this was no properly done before). >> - In `flatten_alias_type()`, we flatten to "maybe flat in array". >> >> #### Testing: >> - t1-4 + valhalla-comp-stress >> >> Thanks for your feedback, >> Christian > > Christian Hagedorn has updated the pull request incrementally with one > additional commit since the last revision: > > review Tobias Thanks. Looks good! ------------- Marked as reviewed by thartmann (Committer). PR Review: https://git.openjdk.org/valhalla/pull/1774#pullrequestreview-3551251029
