[vectorIntrinsics] RFR: 8285281: [x86] Add C2 mid-end and back-end implementation for COMPRESS_BITS and EXPAND_BITS operations [v2]

[Xiaohong Gong]

On Sun, 24 Apr 2022 04:15:43 GMT, Xiaohong Gong <xgong at openjdk.org> wrote:

>> Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   8285281: Removing CompressExpand.java since fallback implementation directly calls new [Integer/Long].[compress/expand] Java SE APIs
>
> src/hotspot/share/opto/intrinsicnode.cpp line 171:
> 
>> 169:     // compress(x, -1) == x
>> 170:     if(phase->type(n->in(2))->higher_equal( TypeLong::MINUS_1)) return n->in(1);
>> 171:   }
> 
> The codes are almost the same for int and long type except for the "ZERO and MINUS_1" node. Could you please remove the duplicate codes by just defining different `ZERO` and `MUNUS_1` nodes for int and long?

One more style issue: `higher_equal( TypeLong::MINUS_1)  -> higher_equal(TypeLong::MINUS_1)`

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PR: https://git.openjdk.java.net/panama-vector/pull/195