RFR: 8345172: x86: Some CPU feature asserts are declared as 32-bit only [v2]

[Damon Fenacci]

On Thu, 28 Nov 2024 11:07:13 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> Noticed this while cleaning up the 32-bit x86 code. We baseline our 64-bit x86 to be at least UseSSE=2. Therefore we still need to check for features UseSSE > 2. I have found a few places where we do NOT_LP64 for these checks. I checked other `VMVersion::supports_*()` uses, and I think these are the only two outliers.
>
> Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Tja

Thanks for cleaning up. I happened to notice that for SSE2 most asserts are `NOT_LP64`
https://github.com/openjdk/jdk/blob/02db63862e5b3a85cee105538ee2c52f9e64d353/src/hotspot/cpu/x86/assembler_x86.cpp#L1538
but not all, e.g.
https://github.com/openjdk/jdk/blob/02db63862e5b3a85cee105538ee2c52f9e64d353/src/hotspot/cpu/x86/assembler_x86.cpp#L4617
Do you know if there is a reason for that difference? (in the end it just results in a superfluous assert for x64 but maybe we should be consistent...)

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PR Comment: https://git.openjdk.org/jdk/pull/22432#issuecomment-2507973623