On Mon, 18 Nov 2024 14:34:13 GMT, Quan Anh Mai <qa...@openjdk.org> wrote:
>> @rkennke >>> BTW, this problem is not specific to UseCompactObjectHeaders - I think the >>> same problem would happen with -UseCompressedClassPointers. With >>> uncompressed class-pointers, byte[] would start at offset 20, while long[] >>> start at offset 24. But nobody cares about -UCCP I think. >> >> Sure. But I guess some people will want to run both `AlignVector` and >> `UseCompactObjectHeaders` in the future. Some machines simply do require >> strict alignment. So they will have to live with that tradeoff. > > @eme64 Tbh I don't see how `AlignVector` can mitigate the issue if strict > alignment is required unless the object base is guaranteed to be aligned at > least as much as the vector length. @merykitty the object base is always at least `8-byte` aligned, see `ObjectAlignmentInBytes` - this also holds for all arrays. But the issue is the offset from the object base to the array payload. @rkennke yes, working on fixing the tests :) ------------- PR Comment: https://git.openjdk.org/jdk/pull/20677#issuecomment-2483236250
