RFR: 8361892: AArch64: Incorrect matching rule leading to improper oop instruction encoding [v2]

[Vladimir Kozlov]

On Mon, 14 Jul 2025 17:18:10 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

> > Ok, but those two methods cover cases where mov/lea instructions are directly generated into the code stream. Why is there no need for a C2 rule for immByteMapBaee and loadByteMapBase in x86_64.ad. Is it because nothing inserts the card table base into a C2 graph as a ConP node now that we have late barrier generation?
> 
> Correct.

Correction. It is true for G1, Z, Shenandoah. For others we still have constant in C2 IR: 
https://github.com/openjdk/leyden/blob/premain/src/hotspot/share/gc/shared/c2/cardTableBarrierSetC2.cpp#L38

I think we never fully tested AOT with them.

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PR Comment: https://git.openjdk.org/jdk/pull/26249#issuecomment-3070382780