RFR: 8352893: C2: OrL/INode::add_ring optimize (x | -1) to -1 [v3]

[Tobias Hartmann]

On Mon, 31 Mar 2025 14:31:43 GMT, Manuel Hässig <duke at openjdk.org> wrote:

>> # Issue Summary
>> 
>> The `add_ring()` implementations of `OrINode` and `OrLNode` are missing the optimization that an or with a value where all bits are ones (since we have signed integers in this case `~0 == -1`) will always yield all zeroes.
>> 
>> # Changes
>> 
>> This PR makes the following straight forward changes:
>>  - `Or(I|L)Node::add_ring()` returns `-1` if one of the two inputs is `-1`.
>>  - Add `Or(I|L)` nodes to the IR framework.
>>  - Add a regression IR test for the implemented optimization.
>> 
>> # Testing
>> 
>> - [Github Actions](https://github.com/mhaessig/jdk/actions/runs/14110978686)
>> - Ran tier1 through tier3 and Oracle internal testing
>
> Manuel Hässig has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Remove loop in test and instead use random values

Looks good to me too.

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Marked as reviewed by thartmann (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/24289#pullrequestreview-2732401043