On Thu, 26 Sep 2024 11:39:02 GMT, Roman Kennke <rken...@openjdk.org> wrote:
>> src/hotspot/cpu/x86/stubGenerator_x86_64.cpp line 4008:
>>
>>> 4006: #ifdef COMPILER2
>>> 4007: if ((UseAVX == 2) && EnableX86ECoreOpts &&
>>> !UseCompactObjectHeaders) {
>>> 4008: generate_string_indexof(StubRoutines::_string_indexof_array);
>>
>> This stub routine should be re-enabled if `UseCompactObjectHeaders` is to
>> become non-experimental and enabled by default in the future. Is there a RFE
>> for this task?
>
> This comes from an assert in `LibraryCallKit::inline_string_indexOfI` and I
> believe we can perhaps remove that assert and the !UCOH clause. I checked a
> couple of tests that tripped that assert, and they seem to work fine, and I
> also checked the code in `LibraryCallKit::inline_string_indexOfI` and
> `generate_string_indexof_stubs()` and could not find anything obvious that
> requires the base offset to be >=16. I am not sure why that assert is there.
> I am now running tier1-4 with that change:
> https://github.com/rkennke/jdk/commit/7001783e8c11718226506f42b7c1f1fda1af3ad0
>
> If you know (or find) any reason why we need that assert, please let me know.
> Otherwise I'd remove it, if you don't have objections.
I am not familiar with the `indexOf` implementation, but here is a relevant
comment that motivates the assertion:
https://github.com/openjdk/jdk/pull/16753#discussion_r1592774634.
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PR Review Comment: https://git.openjdk.org/jdk/pull/20677#discussion_r1777033220
