analysis: reference analysis for squin qubits and jeff wires

[nathanieltornow]

This PR adds a forward analysis that states which allocation or parameter each value refers to.

Design

The analysis is generic and lives in bloqade/analysis/reference/, like the address analysis. A subclass implements: kind(type) says whether a type is one tracked item (Whole), a register of items (Register) or untracked, and register_length(root, call) gives the static length of a register. QubitReferenceAnalysis in bloqade/squin/analysis/reference.py tracks squin qubits, and WireReferenceAnalysis in bloqade/jeff/analysis/wire.py tracks jeff wires.

Example

@squin.kernel
def flip(q: Qubit) -> Qubit:
    squin.x(q)
    return q

@squin.kernel
def fresh() -> Qubit:
    return squin.qubit.new()

@squin.kernel
def main(data: ilist.IList[Qubit, Any], n: int, i: int):
    fixed = squin.qalloc(3)
    dynamic = squin.qalloc(n)
    a = fresh()
    b = fresh()
    c = flip(a)
    squin.cx(fixed[-1], dynamic[i])
    squin.cx(data[0], b)
    squin.h(c)

analysis = QubitReferenceAnalysis(main.dialects)
frame, _ = analysis.run(main)
main.print(analysis=frame.entries)

%data    --> Register(%data)
%fixed   = qalloc(%0)            # ---> Register(%fixed = qalloc()[0])
%dynamic = qalloc(%n)            # ---> Register(%dynamic = qalloc()[0])
%a       = fresh()               # ---> Whole(%a = fresh()[0])
%b       = fresh()               # ---> Whole(%b = fresh()[0])
%c       = flip(%a)              # ---> Whole(%a = fresh()[0])
%2       = getitem(%fixed, -1)   # ---> Slot(%fixed = qalloc()[0], 2)
%3       = getitem(%dynamic, %i) # ---> Slot(%dynamic = qalloc()[0], %i)
%6       = getitem(%data, 0)     # ---> Slot(%data, 0)

Limits

The result of a recursive call, a slice of a register, an index into a list at a runtime index, and a root that a callee allocates without returning it are Unknown.

Also in this PR

• bloqade/constants.py::constant_int reads an integer out of any statement with kirin's ConstantLike trait. It replaces bloqade/jeff/constants.py::const_int.
• jeff Call declares a StaticCall trait.

[codecov]

Codecov Report

❌ Patch coverage is 95.74944% with 19 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/bloqade/jeff/analysis/wire.py	93.69%	7 Missing ⚠️
src/bloqade/analysis/reference/analysis.py	95.41%	6 Missing ⚠️
src/bloqade/analysis/reference/impls.py	94.11%	4 Missing ⚠️
src/bloqade/analysis/reference/lattice.py	98.78%	1 Missing ⚠️
src/bloqade/squin/analysis/reference.py	96.29%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!

[david-pl]

Neat PR, just some small issues with Bottom types and I'm not sure what happens when you nest return values. Otherwise looks good, so I'm approving to unblock merging, but it might make sense to address some things first.

[david-pl]

Is there some walking logic in kirin that can already do this?

[nathanieltornow]

yes, replaced

[david-pl]

What's the reason behind this lower default? InterpreterABC has default=800.

[nathanieltornow]

it was because of the issue of the C-stack overflowing (QuEraComputing/kirin#743)

now, i removed the line and skip the tests that have recursive structure.

[david-pl]

What happens if there is a nested return, e.g. return ((q, q), 1)?

[nathanieltornow]

We now explicitly reject nested nodes as returns

[david-pl]

Doesn't play nice when type_ is Bottom.

[nathanieltornow]

fixed

[david-pl]

Another if where Bottom would lead to the wrong behavior.

[nathanieltornow]

fixed