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

Manuel Hässig duke at openjdk.org
Fri Mar 28 10:28:20 UTC 2025


# 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

-------------

Commit messages:
 - Add regression test
 - ir-framework: Add OrI, and OrL nodes
 - OrI/OrLNode: fold x | -1

Changes: https://git.openjdk.org/jdk/pull/24289/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24289&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8352893
  Stats: 108 lines in 3 files changed: 108 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/24289.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24289/head:pull/24289

PR: https://git.openjdk.org/jdk/pull/24289


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