RFR: 8315066: Add unsigned bounds and known bits to TypeInt/Long [v7]

[Quan Anh Mai]

On Tue, 3 Sep 2024 14:27:22 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Quan Anh Mai has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 11 commits:
>> 
>>  - fix compile errors
>>  - Merge branch 'master' into unsignedbounds
>>  - add comments
>>  - Merge branch 'master' into unsignedbounds
>>  - fix release build
>>  - add comments, group arguments to reduce C-style reference passing arguments
>>  - fix tests, add verify
>>  - add unit tests
>>  - fix template parameter
>>  - refactor
>>  - ... and 1 more: https://git.openjdk.org/jdk/compare/d8e4d3f2...d5ad9f1a
>
> What are your thoughts on how we are going to debug-print the new int-type? We probably do not always want to print the KnownBits, in general that is way too verbose. But in some alignment example, it would be nice to know that it is the `int/long` range, but the lowest 3 bits are always zero, hence 8 byte aligned.

@eme64 Thanks for your patience, I believe the sole reason I can navigate this algorithm is that I am the author, so all the logic seems so natural to me =D Please let me know if there is any place you are still confused.

@vnkozlov Rethinking about the format, since I decided to drop the bit information in normal dumping, it seems natural to make the dumper more aware of different bound values. Regarding JMH benchmark, this patch is likely to not provide any benefit directly, as no node has taken advantage of additional information. The main benefit comes from arithmetic nodes taking advantage of additional information to enhance their analysis as well as simplify current ones. I do not have concrete results regarding compilation time, I have only run a few simple comparisons with `-XX:+CITime -Xcomp` and it seems that the compilation time does not change significantly.

Thanks very much.

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PR Comment: https://git.openjdk.org/jdk/pull/17508#issuecomment-2329841995