RFR: 8360192: C2: Make the type of count leading/trailing zero nodes more precise [v5]

[Qizheng Xing]

On Mon, 4 Aug 2025 16:50:09 GMT, Jasmine Karthikeyan <jkarthikeyan at openjdk.org> wrote:

>> Qizheng Xing has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains six additional commits since the last revision:
>> 
>>  - Merge branch 'master' into enhance-clz-type
>>  - Move `TestCountBitsRange` to `compiler.c2.gvn`
>>  - Fix null checks
>>  - Narrow type bound
>>  - Use `BitsPerX` constant instead of `sizeof`
>>  - Make the type of count leading/trailing zero nodes more precise
>
> test/hotspot/jtreg/compiler/c2/gvn/TestCountBitsRange.java line 43:
> 
>> 41:     static int i = RunInfo.getRandom().nextInt();
>> 42:     static long l = RunInfo.getRandom().nextLong();
>> 43: 
> 
> It would be nice to also check the return values of the functions with a non-compiled version, so that we can make sure that the constant folding results are correct as well.

Updated, thanks!

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PR Review Comment: https://git.openjdk.org/jdk/pull/25928#discussion_r2255958271