RFR: 8322077: Add Ideal transformation: (~a) | (~b) => ~(a & b)

Thu Dec 14 17:38:05 UTC 2023

On Tue, 24 Oct 2023 05:02:56 GMT, Zhiqiang Zang <duke at openjdk.org> wrote:

> Hello,
> 
> (~a) | (~b) => ~(a & b) is a widely seen pattern, for example it is implemented for LLVM [here](https://github.com/llvm/llvm-project/blob/397f1ce9efb4eea1ee10fe4833f733b8c7abd878/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp#L1617C28-L1617C28); however it is missing in current implementation of hotspot. This pull request adds this transformation and associated tests.
> 
> Thanks.

A JBS issue has been created for this: [JDK-8322077](https://bugs.openjdk.org/browse/JDK-8322077). Please update the PR accordingly.

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PR Comment: https://git.openjdk.org/jdk/pull/16334#issuecomment-1855407243