[MLX] Add aten.bitwise_or op handler

[devin-lai]

Summary:

• Add an MLX schema node and op handler for aten.bitwise_or Tensor and Scalar overloads.
• Execute the node through MLX bitwise_or in the runtime interpreter.
• Add bool, integer, and scalar op test coverage.

Fixes #18926.

Testing:

• cmake --build cmake-out-mlx --target op_test_runner -j2
• PATH="$PWD/.venv-mlx/bin:$PATH" .venv-mlx/bin/python -m executorch.backends.mlx.test.run_all_tests bitwise_or_bool bitwise_or_int bitwise_or_scalar --timeout 180
• cmake --build cmake-out-mlx --target strict_compile_test -j2
• git diff --check
• py_compile on changed Python files
• lintrunner --take FLAKE8,CLANGFORMAT,NEWLINE,ETCAPITAL,LICENSELINT on touched files

cc @metascroy

[pytorch-bot]

🔗 Helpful Links

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❌ 1 Unclassified Failure

As of commit af4d4bf with merge base 40b0a35 ():

UNCLASSIFIED FAILURE - DrCI could not classify the following job because the workflow did not run on the merge base. The failure may be pre-existing on trunk or introduced by this PR:

• MLX / backend-tester (models) / test-mlx-backend-models (gh) (this job did not run on the merge base, so DrCI cannot tell whether the failure is pre-existing)
  RuntimeError: Command bash /Users/runner/work/_temp/exec_script failed with exit code 1

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[devin-lai]

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@pytorchbot label "release notes: apple"

[nil-is-all]

@claude review

[claude]

Claude finished @nil-is-all's task in 2m 43s —— View job

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Code Review: [MLX] Add aten.bitwise_or op handler

• Read changed files and gather context
• Review backends/mlx/ops.py changes
• Review backends/mlx/runtime/MLXInterpreter.h changes
• Review backends/mlx/serialization/schema.fbs changes
• Review backends/mlx/test/test_ops.py changes
• Post review feedback

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Verdict: Looks good. This is a clean, well-structured addition that follows the exact same pattern as the existing bitwise_and op. No issues found.

Details

Schema (schema.fbs):

• BitwiseOrNode table correctly mirrors the BitwiseAndNode structure with a, b, and out fields
• Appended to the OpNode union at the end (respecting backward compatibility rules)

Runtime (MLXInterpreter.h):

• exec_bitwise_or follows the identical pattern as exec_bitwise_and — delegates directly to MLX's bitwise_or
• Dispatch case OpCode::BITWISE_OR correctly wired up in the switch statement

Python ops (ops.py):

• Registers both Tensor and Scalar overloads via the _BINARY_OPS table with has_scalar=True
• Correctly imports BitwiseOrNode from the generated schema

Tests (test_ops.py):

• bitwise_or_bool and bitwise_or_int cover Tensor-Tensor via the _BINARY_OP_TESTS table
• BitwiseOrScalarTest covers the Scalar overload with bool, int32, and int64 dtypes
• Test structure is identical to the existing BitwiseAndScalarTest

No correctness, performance, or compatibility concerns. The implementation correctly leverages MLX's native bitwise_or which handles broadcasting, and the scalar variant is handled by the framework's existing _BINARY_OPS infrastructure that wraps scalars into tensors before calling the op.

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[metascroy]

LGTM...let's see what CI says

[pytorch-bot]

Workflows were awaiting approval. CI has now been triggered for the ciflow labels on this PR.

[metascroy]

@devin-lai it looks like [MLX / backend-tester (models) / test-mlx-backend-models (push)] is failing. Can you have a look at why?