RFR: 8326135: Enhance adlc to report unused operands [v4]

[kuaiwei]

On Thu, 22 Feb 2024 04:14:47 GMT, Vladimir Ivanov <vlivanov at openjdk.org> wrote:

>> kuaiwei has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   fix copyright header and comment
>
> src/hotspot/share/adlc/archDesc.cpp line 27:
> 
>> 25: 
>> 26: // archDesc.cpp - Internal format for architecture definition
>> 27: #include <unordered_set>
> 
> Even though it's not hotspot code per se (but a tool used during build), it'll be the first usage of C++ STL in the hotspot code base.
> 
> HotSpot Coding Style [1] clearly states "Avoid using the C++ Standard Library." 
> 
> @kimbarrett what are your thoughts on it?
> 
> [1] https://github.com/openjdk/jdk/blob/master/doc/hotspot-style.md

I think adlc is almost a stand alone tool, it only depends on src/hotspot/share/opto/opcodes.cpp . Could we move it to src/utils?

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PR Review Comment: https://git.openjdk.org/jdk/pull/17910#discussion_r1498710467