Add option to control unwind lowering

[1tnguyen]

• Added configurable AOT unwind-mode: cfg (default), dataflow, or none.

• Wired the option through target YAML, C++ nvq++, and Python compilation pipelines.

• Updated aggressive inlining pipeline which also runs unwind lowering

• Initialized the dataflow pass’s dfJump state (None) to prevent undefined value.

• Added C++/Python fake-target and focused MLIR regression coverage.

[github-actions]

CI Summary (push) — ✅ passed

Run #33042656789 · ✅ 7 · ⏩ 7 · ❌ 0 · ⛔ 0

Top-level jobs (14)

Job	Result
binaries	⏩ skipped
build_and_test	✅ success
changes	✅ success
config_devdeps	✅ success
config_source_build	⏩ skipped
config_wheeldeps	✅ success
devdeps	✅ success
docker_image	⏩ skipped
gen_code_coverage	⏩ skipped
metadata	✅ success
python_metapackages	⏩ skipped
python_wheels	⏩ skipped
source_build	⏩ skipped
wheeldeps	✅ success

⏩ Skipped jobs (7) — intentionally skipped on PR builds; run on merge_group / workflow_dispatch

Job
binaries
config_source_build
docker_image
gen_code_coverage
python_metapackages
python_wheels
source_build

All sub-jobs (43) — every matrix leg, with links

Job	Status	Link
Build and test (amd64, gcc12, openmpi) / Dev environment (Debug)	✅ success	view
Build and test (amd64, gcc12, openmpi) / Dev environment (Python)	✅ success	view
Build and test (amd64, llvm, openmpi) / Dev environment (Debug)	✅ success	view
Build and test (amd64, llvm, openmpi) / Dev environment (Python)	✅ success	view
Build and test (arm64, llvm, openmpi) / Dev environment (Debug)	✅ success	view
Build and test (arm64, llvm, openmpi) / Dev environment (Python)	✅ success	view
CI Summary	❔ in_progress	view
Check for stable CUDA-Q changes	✅ success	view
Configure build (devdeps)	✅ success	view
Configure build (source_build)	⏩ skipped	view
Configure build (wheeldeps)	✅ success	view
Create CUDA Quantum installer	⏩ skipped	view
Create Docker images	⏩ skipped	view
Create Python metapackages	⏩ skipped	view
Create Python wheels	⏩ skipped	view
Gen code coverage	⏩ skipped	view
Load dependencies (amd64, gcc12) / Caching	✅ success	view
Load dependencies (amd64, gcc12) / Finalize	✅ success	view
Load dependencies (amd64, gcc12) / Metadata	✅ success	view
Load dependencies (amd64, llvm) / Caching	✅ success	view
Load dependencies (amd64, llvm) / Finalize	✅ success	view
Load dependencies (amd64, llvm) / Metadata	✅ success	view
Load dependencies (arm64, gcc12) / Caching	✅ success	view
Load dependencies (arm64, gcc12) / Finalize	✅ success	view
Load dependencies (arm64, gcc12) / Metadata	✅ success	view
Load dependencies (arm64, llvm) / Caching	✅ success	view
Load dependencies (arm64, llvm) / Finalize	✅ success	view
Load dependencies (arm64, llvm) / Metadata	✅ success	view
Load source build cache	⏩ skipped	view
Load wheel dependencies (amd64, 12.6) / Caching	✅ success	view
Load wheel dependencies (amd64, 12.6) / Finalize	✅ success	view
Load wheel dependencies (amd64, 12.6) / Metadata	✅ success	view
Load wheel dependencies (amd64, 13.0) / Caching	✅ success	view
Load wheel dependencies (amd64, 13.0) / Finalize	✅ success	view
Load wheel dependencies (amd64, 13.0) / Metadata	✅ success	view
Load wheel dependencies (arm64, 12.6) / Caching	✅ success	view
Load wheel dependencies (arm64, 12.6) / Finalize	✅ success	view
Load wheel dependencies (arm64, 12.6) / Metadata	✅ success	view
Load wheel dependencies (arm64, 13.0) / Caching	✅ success	view
Load wheel dependencies (arm64, 13.0) / Finalize	✅ success	view
Load wheel dependencies (arm64, 13.0) / Metadata	✅ success	view
Prepare cache clean-up	❔ in_progress	view
Retrieve PR info	✅ success	view

✅ Required checks (6/6) — declared in .github/required-checks.yml for push

Required check	Status	Link
Build and test (amd64, llvm, openmpi) / Dev environment (Debug)	✅ success	view
Build and test (amd64, llvm, openmpi) / Dev environment (Python)	✅ success	view
Build and test (arm64, llvm, openmpi) / Dev environment (Debug)	✅ success	view
Build and test (arm64, llvm, openmpi) / Dev environment (Python)	✅ success	view
Build and test (amd64, gcc12, openmpi) / Dev environment (Debug)	✅ success	view
Build and test (amd64, gcc12, openmpi) / Dev environment (Python)	✅ success	view

[schweitzpgi]

Looking good. I think we should disentangle unwinding and inlining. I don't know why they are conflated in the pipeline today. Weirdness.

[schweitzpgi]

These are separate passes that ought to have no relationship to each other. I'm not sure why unwinding was buried in the inlining pipeline. It should be pulled out and stand on its own feet at this point.

[schweitzpgi]

Yeah, this is truly weird. Unwinding ought to happen very early. Once done, it should never be thought about again. It's a pass for lowering very high-level syntactic goop from the front-end to a correct and selectable lower-level IR. That selectability is precisely what we want now.

[sacpis]

Overall LGTM. Thanks @1tnguyen. Left few comments.

[sacpis]

Tried running the following code

import cudaq

cudaq.set_target("quake_fake")

@cudaq.kernel
def test(n: int) -> int:
    total = 0
    for i in range(3):
        if i == n:
            break
        total += 1
    return total

cudaq.run(test, 1, shots_count=1)

it fails with an error as

error: operand #0 does not dominate this use
Traceback (most recent call last):
  File "/usr/local/cudaq/cudaq/kernel/ast_bridge.py", line 6273, in compile_to_mlir
    cudaq_runtime.runPassManager(pm, bridge.module)
RuntimeError: pass pipeline failed

Seems like when a cc.loop has a step region, the pass moves the step region's body into a new guard cc.if but leaves the region's terminator behind. %4 is now defined inside the if, so the IR fails the dominance verifier. The while-region case right below handles exactly this by yielding the value out of the guard. The step region case does not.

[sacpis]

Let's add for loop variants with break, continue and early return as well?

for i in range(3):
    if i == n:
        break

[1tnguyen]

Yeah, this is an edge case that we're investigating. I'll add the test case when it is fixed.