RFR: 8322589: Add Ideal transformation: (~a) & (~b) => ~(a | b) [v5]

[Tobias Hartmann]

On Fri, 5 Jan 2024 21:43:39 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#L1616C28-L1616C28); 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 incrementally with one additional commit since the last revision:
> 
>   update the copyright dates.

src/hotspot/share/opto/addnode.hpp line 84:

> 82:   // Utility function to check if the given node is a NOT operation,
> 83:   // i.e., n == m ^ (-1).
> 84:   static bool is_not(PhaseGVN* phase, Node* n, BasicType bt);

Could these be made non-static?

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PR Review Comment: https://git.openjdk.org/jdk/pull/16333#discussion_r1444226697