RFR: 8373999: C2: apply KnownBits and unsigned bounds to Add / Sub operations [v5]

Wed Jan 14 13:36:11 UTC 2026

> Hi,
> 
> This PR improves the implementation of `AddNode/SubNode::Value` by taking advantage of the additional information in `TypeInt`. The implementation has some pretty non-trivial logic. Fortunately, the test infrastructure is already there.
> 
> Please take a look and leave your reviews, thanks a lot.

Quan Anh Mai has updated the pull request incrementally with one additional commit since the last revision:

  Improve comments

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Changes:
  - all: https://git.openjdk.org/jdk/pull/28897/files
  - new: https://git.openjdk.org/jdk/pull/28897/files/fe534505..ae17b24e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=28897&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28897&range=03-04

  Stats: 15 lines in 1 file changed: 0 ins; 0 del; 15 mod
  Patch: https://git.openjdk.org/jdk/pull/28897.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28897/head:pull/28897

PR: https://git.openjdk.org/jdk/pull/28897