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

[Andrew Dinn]

On Mon, 14 Jul 2025 15:36:41 GMT, Vladimir Kozlov <kvn at openjdk.org> wrote:

> On x86 byte_map_base is handled in GC code:

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?

If that is the case then I don't think we need the immAOTRuntimeConstantsAddress and loadAOTRCAddress rules in x86_64.ad either. Likewise we can drop the equivalents from aarch64.ad.

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PR Comment: https://git.openjdk.org/jdk/pull/26249#issuecomment-3070146912