RFR: 8331341: secondary_super_cache does not scale well: C1 and interpreter [v23]

[Dean Long]

On Mon, 14 Oct 2024 10:08:57 GMT, Andrew Haley <aph at openjdk.org> wrote:

>> src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp line 1863:
>> 
>>> 1861: 
>>> 1862:   // Is there another entry to check? Consult the bitmap.
>>> 1863:   eor(slot, slot, (u1)(Klass::SECONDARY_SUPERS_TABLE_SIZE - 1));
>> 
>> Can we remove this XOR if we don't destroy the original value at line 1820?
>
> I don't think we have a spare register,

What if you changed lines 1820-1821 like so:

eor(temp2, slot, (u1)(Klass::SECONDARY_SUPERS_TABLE_SIZE - 1));
lslv(temp2, r_bitmap, temp2);

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PR Review Comment: https://git.openjdk.org/jdk/pull/19989#discussion_r1799974941