RFR: 8345169: Implement JEP XXX: Remove the 32-bit x86 Port

[Coleen Phillimore]

On Fri, 10 Jan 2025 13:54:32 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> src/hotspot/cpu/x86/templateTable_x86.cpp line 330:
>> 
>>> 328: void TemplateTable::dconst(int value) {
>>> 329:   transition(vtos, dtos);
>>> 330:   if (UseSSE >= 2) {
>> 
>> I admit that I don't know what UseSSE is but now this is unconditional?  Is there a further cleanup necessary for this option?
>
> Yes, now it is unconditional. x86_64 [requires](https://github.com/openjdk/jdk/blob/ec7393e9190c1b93ca08e1107f734c869f400b89/src/hotspot/cpu/x86/vm_version_x86.cpp#L896-L903) UseSSE >= 2. Only x86_32 cared about UseSSE < 2, so now we can eliminate these checks. I think I got the majority, if not all of the cases where these checks are now redundant: there are more in various assemblers and compiler code.

Maybe this should change from range (2,4) then.
  product(int, UseSSE, 4,                                                   \
          "Highest supported SSE instructions set on x86/x64")              \
          range(0, 4)                                                       \

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PR Review Comment: https://git.openjdk.org/jdk/pull/22567#discussion_r1910614336