🚧 Python Compiler

[erick-xanadu]

Context:

Description of the Change: Initial design:

1. Use the same interface as plugins to denote adding a pass. E.g.,

# also pipeline
@apply_pass("catalyst_xdsl_plugin.pass-name")
@qml.qnode(device)
def func(): ...

will denote that we are running pass-name to the func qnode and the pass comes from xDSL.

2. With the xDSL plugin being used during compilation, it will trigger a different path. The idea here is that xDSL will be in charge of running the apply-transform-sequence pass that we currently use in MLIR. This pass is the one that uses the transform dialect and applies already named passes.
3. We will look at each pass-name and if it exists in MLIR, run it on MLIR. If it doesn't exist in MLIR, look for it registered in xDSL and apply it.
4. After finishing running the apply-transform-sequence pass in xDSL, we will change the run command sent to Catalyst to omit it and continue the lowering process as usual.

Benefits:

Possible Drawbacks:

Related GitHub Issues:

[mudit2812]

I made the implementation a bit better by replacing recursion with a while loop. cancel_ops is not needed anymore:

    @pattern_rewriter.op_type_rewrite_pattern
    def match_and_rewrite(self, funcOp: func.FuncOp, rewriter: pattern_rewriter.PatternRewriter):
        """Deep Cancel for Self Inverses"""
        for op in funcOp.body.walk():

            while isinstance(op, CustomOp) and op.gate_name.data in self_inverses:

                next_user = None
                for use in op.results[0].uses:
                    user = use.operation
                    if isinstance(user, CustomOp) and user.gate_name.data == op.gate_name.data:
                        next_user = user
                        break

                if next_user is None:
                    break

                rewriter._replace_all_uses_with(next_user.results[0], op.in_qubits[0])
                rewriter.erase_op(next_user)
                rewriter.erase_op(op)

                op = op.in_qubits[0].owner

[erick-xanadu]

d3dac88

[github-actions]

Hello. You may have forgotten to update the changelog!
Please edit doc/releases/changelog-dev.md on your branch with:

• A one-to-two sentence description of the change. You may include a small working example for new features.
• A link back to this PR.
• Your name (or GitHub username) in the contributors section.

[mudit2812]

Just a note that if capture is disabled before executing, the tracing will happen without the plxpr pipeline. I'll share more details on Slack.

[erick-xanadu]

Dropped in favour of #1715 and PennyLaneAI/pennylane#7367