EA runs a first time, finds a non escaping allocation, splits unique types, creates extra phi nodes, then `LoadFlat` nodes for that allocation are expanded. EA runs a second time. At a `Region`, it finds 2 `Phi` for alias 19:
1866 Phi === 1206 1867 1858 [[ 1948 1304 1855 1317 1250 1936 1263 ]] #memory Memory: @aryptr:flat:atomic:instptr:compiler/valhalla/inlinetypes/TestFlatArrayMemoryPhi$MyValue:BotPTR:exact *,iid=bot[int:2] (java/lang/Cloneable,java/io/Serializable):NotNull:exact:flat():atomic+any,iid=44, name=b1, idx=19; !orig=[1208],[1938],[1553],[1239] !jvms: TestFlatArrayMemoryPhi::test @ bci:34 (line 58) 2073 Phi === 1206 1149 1858 [[ 1948 2061 ]] #memory Memory: @aryptr:flat:atomic:instptr:compiler/valhalla/inlinetypes/TestFlatArrayMemoryPhi$MyValue:BotPTR:exact *,iid=bot[int:2] (java/lang/Cloneable,java/io/Serializable):NotNull:exact:flat():atomic+any,iid=44, name=b1, idx=19; !orig=2060,[1208],[1938],[1553],[1239] !jvms: TestFlatArrayMemoryPhi::test @ bci:34 (line 58) The first one was created by EA on its first run. The second was created after the first round of EA: it's the result of the transformation of `(Phi (MergeMem ))` into `(MergeMem (Phi ..) (Phi ..)`. The second `Phi` references another bottom memory `Phi` (1149) and that confuses the logic of EA. The reason, that second `Phi` is created after EA is that initially the bottom `Phi` has a `LoadFlat` as input but it gets removed because it's from the non escaping allocation and the `Phi`'s input becomes a `MergeMem`. To fix that, I propose that the logic that finds the memory state for a particular alias during EA skips over `LoadFloat` nodes: either a `LoadFloat` is for the current non escaping allocation and it's going away anyway or it's from some other allocation and it's unrelated. --------- - [x] I confirm that I make this contribution in accordance with the [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). ------------- Commit messages: - un-problem list - shenandoah build fix - test & fix Changes: https://git.openjdk.org/valhalla/pull/2459/files Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=2459&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8374742 Stats: 73 lines in 4 files changed: 67 ins; 5 del; 1 mod Patch: https://git.openjdk.org/valhalla/pull/2459.diff Fetch: git fetch https://git.openjdk.org/valhalla.git pull/2459/head:pull/2459 PR: https://git.openjdk.org/valhalla/pull/2459
