RFR: 8322077: Add Ideal transformation: (~a) | (~b) => ~(a & b) [v11]

[Tobias Hartmann]

On Tue, 9 Jan 2024 06:06:51 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.
>
> Zhiqiang Zang 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 14 additional commits since the last revision:
> 
>  - adapt to new changes from the dependant pr.
>  - Merge branch 'andnode-PNewDeMorganLawAndToOr' into ornode-PNewDeMorganLawOrToAnd
>  - adapt changes from the dependent pr.
>  - Merge branch 'andnode-PNewDeMorganLawAndToOr' into ornode-PNewDeMorganLawOrToAnd
>  - Update test/hotspot/jtreg/compiler/c2/irTests/DeMorganLawLongTests.java
>    
>    Co-authored-by: Tobias Hartmann <tobias.hartmann at oracle.com>
>  - Update test/hotspot/jtreg/compiler/c2/irTests/DeMorganLawIntTests.java
>    
>    Co-authored-by: Tobias Hartmann <tobias.hartmann at oracle.com>
>  - Add tests for using De Morgan's Law for both optimizations.
>  - remove unused code from tests.
>  - update the copyright dates.
>  - address comments.
>  - ... and 4 more: https://git.openjdk.org/jdk/compare/2acdb5e1...b21e242b

Marked as reviewed by thartmann (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/16334#pullrequestreview-1810664512