[tmva][sofie] Add ONNX InstanceNormalization operator

[gluonparticle]

InstanceNormalization Operator for SOFIE Inference Engine

Why

InstanceNormalization is widely used in modern computer vision models (e.g., Style Transfer, GANs).
Supporting this operator in the SOFIE ONNX parser expands the range of physics-adjacent ML models that can be converted to high-performance C++.

---

What

• ROperator_InstanceNormalization.hxx
  New template implementing the $N, C, H, W$ normalization logic.

• RModelParser_ONNX.cxx
  Registered the operator and added epsilon attribute parsing.

• test_InstanceNormalization.cxx
  Added a unit test to verify the correctness of emitted C++ code.

---

Testing

• Local build verified with -Ddev=ON using GCC 15.2.1.
• Unit test test_instancenorm passed with [SUCCESS].

[github-actions]

Test Results

    21 files      21 suites   2d 23h 9m 46s ⏱️
 3 835 tests  3 833 ✅  1 💤  1 ❌
72 227 runs  72 194 ✅ 18 💤 15 ❌

For more details on these failures, see this check.

Results for commit 94047f9.

♻️ This comment has been updated with latest results.

[gluonparticle]

@lmoneta I've re run the clang-format with correct flags I'd missed before.

Regarding the other CI pipeline failures (specifically on mac-beta ARM64 and ubuntu2604), looking at the logs, these appear to be existing infrastructure regressions in the PyROOT/cppyy bindings and the DistRDF Spark backends.

Please let me know if you need anything else from my end, Thanks! ;

[gluonparticle]

@lmoneta @bellenot @sanjibansg Sorry to bother you again.

Please let me know if you need anything else from my side to re-run the checks and/or anything from my side on this PR.

The other failed checks (specifically on mac-beta ARM64 and ubuntu2604) appear to be existing infrastructure regressions in the PyROOT/cppyy bindings and the DistRDF Spark backends.

Thanks! ;

[sanjibansg]

Hi @gluonparticle,
Thanks for your PR on adding the implementation for the InstanceNormalization operator. I have a question regarding the test you propose to add.

[gluonparticle]

Hi @gluonparticle, Thanks for your PR on adding the implementation for the InstanceNormalization operator. I have a question regarding the test you propose to add.

Please let me know if you need anything else from my side. Thanks! ;

[sanjibansg]

Hi @gluonparticle, Thanks for your PR on adding the implementation for the InstanceNormalization operator. I have a question regarding the test you propose to add.

Please let me know if you need anything else from my side. Thanks! ;

Hi @gluonparticle,
Could you look into the merge conflicts and try resolving them?

Thanks,
Sanjiban

[gluonparticle]

Hi @gluonparticle, Thanks for your PR on adding the implementation for the InstanceNormalization operator. I have a question regarding the test you propose to add.

Please let me know if you need anything else from my side. Thanks! ;

Hi @gluonparticle, Could you look into the merge conflicts and try resolving them?

Thanks, Sanjiban

Hi @sanjibansg

We definitely just crossed paths like a merge conflict. I was in the middle of fixing that last remaining conflict when you commented. Everything is now fully resolved and synced with master.

I've also ran the git-clang-format wrt origin/master and clang format on the files.

Thank you for your cooperation ;

[gluonparticle]

Hi @sanjibansg Could you please re-run the workflow trigger for the CI/CD checks.

Thanks for your cooperation ;

[gluonparticle]

Hi @lmoneta @bellenot, Please let me know if the latest changes are ready to go for the CI run.

I've migrated the test as required and resolved all merge conflicts.

Please let me know if there's anything else I should polish from my end. Thanks! ;

[sanjibansg]

I see there are still some conflicts in tmva/sofie_parsers/src/RModelParser_ONNX.cxx, could you try rebasing with the master?

[gluonparticle]

I see there are still some conflicts in tmva/sofie_parsers/src/RModelParser_ONNX.cxx, could you try rebasing with the master?

Hi @sanjibansg , I've rebased and manually resolved the new conflicts along with local rebuild for the changes. Thanks! ;

[sanjibansg]

Hi @gluonparticle,
Thanks for this implementation, could of comments.

[sanjibansg]

I do not think this is where it should be included

[sanjibansg]

Could you follow the convention in this subdirectory on adding the parsing methods like we do in https://github.com/gluonparticle/root/blob/94047f9f573478b77d53cecd27de46481e7da7e2/tmva/sofie_parsers/src/ParseBatchNormalization.cxx