RFR: 8328998: Encoding support for Intel APX extended general-purpose registers [v23]

[Emanuel Peter]

On Tue, 21 May 2024 16:53:38 GMT, Steve Dohrmann <duke at openjdk.org> wrote:

>> src/hotspot/cpu/x86/assembler_x86.cpp line 1668:
>> 
>>> 1666: void Assembler::andnl(Register dst, Register src1, Register src2) {
>>> 1667:   assert(VM_Version::supports_bmi1(), "bit manipulation instructions not supported");
>>> 1668:   assert(!needs_eevex(dst, src1, src2) || UseAPX, "extended gpr use requires UseAPX and UseAVX > 2");
>> 
>> Technical detail: `UseAPX and UseAVX > 2` sounds wrong. Did you mean to say "or"? Because UseAPX is only enabled when `UseAVX >= 3`.
>
> Thanks, see comment below.

I think the confusion comes from the "or" in the code, and the "and" in the assert description.

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PR Review Comment: https://git.openjdk.org/jdk/pull/18476#discussion_r1608681525