Cudaq Frontend

[ACE07-Sev]

Description

Added initial commit for tackling #2200 .

License

• I license this contribution under the terms of the GNU GPL, version 3 and grant Unitary Foundation the right to provide additional permissions as described in section 7 of the GNU GPL, version 3.

Before opening the PR, please ensure you have completed the following where appropriate.

• I added unit tests for new code.
• I used type hints in function signatures.
• I used Google-style docstrings for functions.
• I updated the documentation where relevant.
• Added myself / the copyright holder to the AUTHORS file

[ACE07-Sev]

@natestemen Greetings,

Hope you're doing well. Kindly have a look to see if it's good to go on the conversions.py side. Do lmk if you want additional or modified behavior.

Quick question, I couldn't add tests since I wasn't sure how you exactly determine what unit tests to be added for each frontend. I frankly couldn't really see a pattern/template based on the other frontends to add for cudaq, so please let me know what you'd like me to add testers for.

[natestemen]

Thanks for getting this started! The first thing to do would be to add CUDAQ to the supported frontends:

mitiq/mitiq/typing.py

Line 76 in 899e07a

class SUPPORTED_PROGRAM_TYPES(EnhancedEnum):

Once it's in there, it will be automatically tested via lots of the other tests. A few small, individual tests would also be good to see though. Just small circuit conversions.

[natestemen]

It specifically only works with u3 and cx?

[ACE07-Sev]

If you mean qbraid's conversion, no, only single qubit gates and single controlled single qubit gates. Issue is that cudaq doesn't have ccx or mcx. They just do cx([0, 1, 2], [3]) for instance for mcx(replace indices there with qr[i] of course for correct syntax).

So, I thought it'd be better to just use u3 and cx when converting to cudaq side. It keeps maintenance easier, and would work for all custom gates.

[ACE07-Sev]

Thanks for getting this started! The first thing to do would be to add CUDAQ to the supported frontends:

Copy that.

Once it's in there, it will be automatically tested via lots of the other tests. A few small, individual tests would also be good to see though. Just small circuit conversions.

Sure thing, I'll see if the tests pass for it.

[ACE07-Sev]

Do I need to add the cudaq install to anywhere else besides pyproject.toml?

[ACE07-Sev]

Sorry by the way for pushing this without making sure all tests pass. I'm having some trouble getting the test CI to run fully (keeps getting stuck at the end). I'm gonna test module by module for now.

[natestemen]

Not a problem for continuing to test things out using GitHub actions here!

Since cudaq doesn't distribute wheels for non-linux OS's (NVIDIA/cuda-quantum#2065 (comment)), it might be worth considering how to run the tests only on linux builds. This is certainly possible, but we'll want to consider the tradeoff of complexity if we have to add lots of hacks to make it work. Typically for an isolated feature I might just say throw the tests in a new file and run those on the linux builds, but since this feature modifies QPROGRAM and many tests inspect that object to determine which tests to run, I don't see a clear path there. Maybe you have an idea?

[ACE07-Sev]

it might be worth considering how to run the tests only on linux builds.

Sure, I'll update the workflow minimally to enable this with cudaq.

[ACE07-Sev]

My ongoing notes on remaining tests that are failing. I fixed most, but these remain at the moment.

# These *seem* to be failing due to the floating point error introduced by cudaq which affects `has_stabilizer_effect` of cirq
FAILED mitiq/cdr/tests/test_cdr.py::test_execute_with_cdr[2-kwargs1-linear_fit_function-cudaq] - assert 0.0363123477534954 <= 0.005075633525848389
FAILED mitiq/cdr/tests/test_cdr.py::test_decorator_execute_with_cdr[2-kwargs1-linear_fit_function-cudaq] - assert 0.0363123477534954 <= 0.005075633525848389
FAILED mitiq/cdr/tests/test_cdr.py::test_mitigated_execute_with_cdr[2-kwargs1-linear_fit_function-cudaq] - assert 0.0363123477534954 <= 0.005075633525848389
FAILED mitiq/cdr/tests/test_clifford_utils.py::test_count_non_cliffords[cudaq] - assert 4 == 2

FAILED mitiq/cdr/tests/test_clifford_training_data.py::test_generate_training_circuits_any_qprogram[cudaq] - assert False

FAILED mitiq/pec/tests/test_pec.py::test_execute_with_pec_mitigates_noise[cudaq-serial_executor-circuit0] - assert 0.026311278343200684 < 0.026311278343200684
FAILED mitiq/pec/tests/test_pec.py::test_execute_with_pec_mitigates_noise[cudaq-serial_executor-circuit1] - assert 0.12331032752990723 < 0.12331032752990723
FAILED mitiq/pec/tests/test_pec.py::test_execute_with_pec_mitigates_noise[cudaq-batched_executor-circuit0] - assert 0.026311278343200684 < 0.026311278343200684
FAILED mitiq/pec/tests/test_pec.py::test_execute_with_pec_mitigates_noise[cudaq-batched_executor-circuit1] - assert 0.12331032752990723 < 0.12331032752990723

[ACE07-Sev]

It's not installing cudaq again hehe. I'll try to fix it.

[ACE07-Sev]

I'll circle back to this soon.