RFR: 8335444: Generalize implementation of AndNode mul_ring [v3]

[Emanuel Peter]

On Wed, 7 Aug 2024 01:20:09 GMT, Jasmine Karthikeyan <jkarthikeyan at openjdk.org> wrote:

>> Hi all,
>> I've written this patch which improves type calculation for bitwise-and functions. Previously, the only cases that were considered were if one of the inputs to the node were a positive constant. I've generalized this behavior, as well as added a case to better estimate the result for arbitrary ranges. Since these are very common patterns to see, this can help propagate more precise types throughout the ideal graph for a large number of methods, making other optimizations and analyses stronger. I was interested in where this patch improves types, so I ran CTW for `java_base` and `java_base_2` and printed out the differences in this gist [here](https://gist.github.com/jaskarth/b45260d81ab621656f4a55cc51cf5292). While I don't think it's particularly complicated I've also added some discussion of the mathematics below, mostly because I thought it was interesting to work through :)
>> 
>> This patch passes tier1-3 testing on my linux x64 machine. Thoughts and reviews would be very appreciated!
>
> Jasmine Karthikeyan has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Check IR before macro expansion

I think there are still quite a few unaddressed review comments above, so I'll hold off with reviewing myself. Feel free to ping me if you need another review.

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PR Comment: https://git.openjdk.org/jdk/pull/20066#issuecomment-2326704510