RFR: 8350896: Integer/Long.compress gets wrong type from CompressBitsNode::Value [v9]

[Emanuel Peter]

On Tue, 3 Jun 2025 09:20:57 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Fix aarch64 failure
>
> src/hotspot/share/opto/intrinsicnode.cpp line 288:
> 
>> 286:     //     For constant mask strictly less than zero, maximum result value will be
>> 287:     //     same as mask value with its sign bit flipped, assuming all but last read
>> 288:     //     source bits are set to 1.
> 
> Suggestion:
> 
>     //     For constant mask strictly less than zero, the maximum result value will be
>     //     the same as the mask value with its sign bit flipped, assuming all source bits but the last
>     //     are set to 1.

Honestly, I don't understand the sign flip... hmm

> src/hotspot/share/opto/intrinsicnode.cpp line 298:
> 
>> 296:     //    result.hi = 0xEFFFFFFF ^ 0x80000000 = 0x6FFFFFFF
>> 297:     //    result.lo = 0x80000000
>> 298:     //
> 
> Same here: why not do a proper `if-else`, and add the comments to each scope directly?

`Result.Hi` -> `result.hi` etc for consistency.

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PR Review Comment: https://git.openjdk.org/jdk/pull/23947#discussion_r2123251808
PR Review Comment: https://git.openjdk.org/jdk/pull/23947#discussion_r2123233772