On Tue, 7 Jul 2026 23:45:45 GMT, Dean Long <[email protected]> wrote:
>> David Simms has updated the pull request with a new target base due to a >> merge or a rebase. The pull request now contains 2900 commits: >> >> - Merge branch '8317277' into jep401_sub_review_8317278 >> - Merge remote-tracking branch 'valhalla/lworld' into 8317277 >> - Merge >> >> Merge jdk-28+5 >> - 8386602: [lworld] C2: assert(n != top() || r->in(pnum) == top()) failed: >> live value must not be garbage >> >> Reviewed-by: thartmann >> - 8386499: [lworld] java/util/Arrays/ArraysEqCmpTest.java fails with >> unexpected layoutKind 5 >> >> Reviewed-by: chagedorn >> - 8387629: [lworld] Don't use apiNote for some recent JDI spec updates >> >> Reviewed-by: sspitsyn >> - 8387682: [lworld] Mention preview API in description of >> can_support_value_objects capability >> >> Reviewed-by: cjplummer >> - 8387657: [lworld] Object Tags section of JVMTI spec should make it clear >> that ObjectFree event is not sent for value objects >> >> Reviewed-by: sspitsyn, cjplummer >> - 8382226: [lworld] C2: Fix _copyOf/_copyOfRange intrinsic for flat >> abstract value class arrays >> >> Reviewed-by: qamai, thartmann >> - 8387612: [lworld] C2: assert(array_type->is_flat() || >> ideal.ctrl()->in(0)->as_If()->is_flat_array_check(&_gvn)) failed: Should be >> found >> >> Co-authored-by: Marc Chevalier <[email protected]> >> Reviewed-by: thartmann >> - ... and 2890 more: https://git.openjdk.org/jdk/compare/db987b1e...f1f6d35d > > src/hotspot/share/ci/ciObjArrayKlass.cpp line 203: > >> 201: ciKlass* ciObjArrayKlass::exact_klass() { >> 202: // This cannot be an exact klass because the refined types subtype it >> 203: return nullptr; > > This seems overly conservative. Shouldn't we at least allow the old code > when Valhalla --enable-preview features are turned off? Even when Valhalla > features are turned on, I suspect that there are situations where we can do > better than always returning nullptr. That's indeed conservative. For the non-Valhalla/non-preview case, we could return ciObjArrayKlass::make(element_klass(), true /* refined_type */); where we returned `this` in the old code (we cannot return `this` since we also use the new metadata hierarchy without `--enable-preview`). For the Valhalla/enable-preview case, we could probably also do better. I filed [JDK-8388014](https://bugs.openjdk.org/browse/JDK-8388014) to address that separately. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/31122#discussion_r3551283662
