List defined inside a kernel passed into subkernel throws an error
Open
Nobody has claimed this yet.
bug
python bridge
stale-notified
- Dominant language
- C++
- Stars
- 1.1k
- Forks
- 456
- Avg merge
- 1d 22h
- Merged PRs (30d)
- 165
Description
Required prerequisites
- Consult the security policy. If reporting a security vulnerability, do not report the bug using this form. Use the process described in the policy to report the issue.
- Make sure you've read the documentation. Your issue may be addressed there.
- Search the issue tracker to verify that this hasn't already been reported. +1 or comment there if it has.
- If possible, make a PR with a failing test to give us a starting point to work on!
Describe the bug
from typing import List
import cudaq
# Define a quantum kernel that applies X gates to supplied indices
@cudaq.kernel
def padX(qubits: cudaq.qvector, indices: List[int]):
for i in indices:
x(qubits[i])
@cudaq.kernel
def main_kernel(num_qubits: int, some_list: List[int]):
q = cudaq.qvector(num_qubits)
x(q)
padX(q, some_list) #list passed in works
padX(q, [0, 1]) #list passed in as argument works
xyz = [0, 1] #list can be defined inside a kernel - no errors here
padX(q, xyz) #list defined inside kernel then passed in DOES NOT WORK
some_list = [0, 1]
num_qubits = 3
print(cudaq.draw(main_kernel, num_qubits, some_list))
print(cudaq.sample(main_kernel, num_qubits, some_list))
RuntimeError: could not compile code for 'main_kernel'.
error: 'func.call' op operand type mismatch: expected operand type '!cc.stdvec<i64>', but provided '!cc.ptr<!cc.stdvec<i64>>' for operand number 1
Steps to reproduce the bug
NA
Expected behavior
NA
Is this a regression? If it is, put the last known working version (or commit) here.
Not a regression
Environment
- CUDA Quantum version:
- Python version:
- C++ compiler:
- Operating system:
Suggestions
NA
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the supplied Python reproducer and the reported func.call operand type mismatch. Trace compilation of the xyz list defined inside main_kernel when it is passed to padX, comparing it with the working external and inline list cases. Done means the reproducer compiles successfully and both cudaq.draw and cudaq.sample work for the kernel-defined list.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- cpp, python
- Domain
- compilers, quantum-computing
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100