RFR: 8343214: Fix encoding errors in APX New Data Destination Instructions Support [v5]

[Sandhya Viswanathan]

On Mon, 4 Nov 2024 18:10:47 GMT, Srinivas Vamsi Parasa <sparasa at openjdk.org> wrote:

>> The goal of this PR is to fix instruction encoding errors for some of the instructions which support the APX New Data Destination (NDD) and No Flags (NF) features (added in [JDK-8329035](https://bugs.openjdk.org/browse/JDK-8329035))
>> 
>> The correctness of the encoding is verified by comparing to the reference encoding by GCC using an automated tool (https://github.com/openjdk/jdk/pull/21795)
>
> Srinivas Vamsi Parasa has updated the pull request incrementally with one additional commit since the last revision:
> 
>   remove map4 enum; replace with comment

src/hotspot/cpu/x86/assembler_x86.cpp line 2637:

> 2635:   attributes.set_address_attributes(/* tuple_type */ EVEX_NOSCALE, /* input_size_in_bits */ EVEX_32bit);
> 2636:   // NDD shares its encoding bits with NDS bits for regular EVEX instruction.
> 2637:   // Therefore, DST is passed as the second argument to minimize changes in the leaf level routine.

dst is not the second argument here so the comment can be removed.

src/hotspot/cpu/x86/assembler_x86.cpp line 14858:

> 14856:   InstructionAttr attributes(AVX_128bit, /* vex_w */ true, /* legacy_mode */ false, /* no_mask_reg */ true, /* uses_vl */ false);
> 14857:   // NDD shares its encoding bits with NDS bits for regular EVEX instruction.
> 14858:   // Therefore, DST is passed as the second argument to minimize changes in the leaf level routine.

dst is not the second argument here so the comment can be removed.

src/hotspot/cpu/x86/assembler_x86.cpp line 14880:

> 14878:   attributes.set_address_attributes(/* tuple_type */ EVEX_NOSCALE, /* input_size_in_bits */ EVEX_64bit);
> 14879:   // NDD shares its encoding bits with NDS bits for regular EVEX instruction.
> 14880:   // Therefore, DST is passed as the second argument to minimize changes in the leaf level routine.

dst is not the second argument here so the comment can be removed.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21770#discussion_r1828415495
PR Review Comment: https://git.openjdk.org/jdk/pull/21770#discussion_r1828414929
PR Review Comment: https://git.openjdk.org/jdk/pull/21770#discussion_r1828414685