RFR: 8351994: Enable Extended EVEX to REX2/REX demotion when src and dst are the same [v23]

[Srinivas Vamsi Parasa]

On Thu, 22 May 2025 20:44:59 GMT, Srinivas Vamsi Parasa <sparasa at openjdk.org> wrote:

>>> > Hi @vamsi-parasa , I don't see demotion tests being generated with full mode gtest, i.e. python3 x86-asmtest.py --full
>>> 
>>> Please see the updated `x86-asmtest.py` refactored to work with full set (`--full`). Please let me know if anything is missing.
>> 
>> Hi @vamsi-parasa ,
>> I am seeing some failures with --full mode when ENABLE_DEMOTION=False
>> /home/jatinbha/sandboxes/apx-release/jdk/test/hotspot/gtest/x86/test_assembler_x86.cpp:61: Failure
>> Failed
>> __ ecmovq (Assembler::Condition::greater, r31, r31, Address(rcx, rdx, (Address::ScaleFactor)0, +0x3c8d1915));
>> OpenJDK:       cc cc cc cc cc cc cc cc cc cc cc
>> GNU Assembler: 62 64 84 10 4f bc 11 15 19 8d 3c
>> [  FAILED  ] AssemblerX86.validate_vm (13562 ms)
>> [----------] 1 test from AssemblerX86 (13708 ms total)
>
> Hi Jatin (@jatin-bhateja),
> 
> Incorporated the changes suggested for cpu_family and is_P6_or_later() and other minor changes. Please let me know if everything looks good.
> 
> Thanks,
> Vamsi

> @vamsi-parasa Testing launched, ping me again in 24h :)

Thanks Emanuel (@eme64)! Please let me know if there're are any issues with the tests.

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PR Comment: https://git.openjdk.org/jdk/pull/24431#issuecomment-2904838851