UOpToParallel doesn't work with scf.

[weinbe58]

from bloqade import qasm2
from bloqade.qasm2.passes import UOpToParallel


@qasm2.extended
def main():
    q = qasm2.qreg(n_qubits=4)
    c = qasm2.creg(4)
    qasm2.h(q[0])
       
    qasm2.measure(q, c)

    if c[0] == 0:
        qasm2.x(q[0])
        qasm2.x(q[1])
    else:
        qasm2.x(q[2])
        qasm2.x(q[3])
        
    return q

UOpToParallel(main.dialects,rewrite_to_native_first=True)(main)
main.print()

This ideally would parallelize the if-blocks but currently it does not:

func.func main() -> !py.IList[!py.Qubit, !Any] {
  ^0(%main_self):
  │ %0 = py.constant.constant 4 : !py.int
  │ %q = qasm2.core.qreg.new(n_qubits=%0) : !py.IList[!py.Qubit, !Any]
  │ %c = qasm2.core.creg.new(n_bits=%0) : !py.CReg
  │ %1 = py.constant.constant 0 : !py.int
  │ %2 = qasm2.core.qreg.get(reg=%q, idx=%1) : !py.Qubit
  │ %3 = py.constant.constant 1.5707963267949 : !py.float
  │ %4 = py.constant.constant 0.0 : !py.float
  │ %5 = py.constant.constant 3.14159265358979 : !py.float
  │      qasm2.uop.U(qarg=%2, theta=%3, phi=%4, lam=%5)
  │      qasm2.core.measure(qarg=%q, carg=%c)
  │ %6 = qasm2.core.creg.get(reg=%c, idx=%1) : !py.Bit
  │ %7 = py.cmp.eq(lhs=%6, rhs=%1) : !py.bool
  │      scf.if %7 {
  │      │ ^1(%14):
  │      │ │  %8 = py.constant.constant 0 : !py.int
  │      │ │  %9 = qasm2.core.qreg.get(reg=%q, idx=%8) : !py.Qubit
  │      │ │ %10 = py.constant.constant 3.14159265358979 : !py.float
  │      │ │ %11 = py.constant.constant 0.0 : !py.float
  │      │ │       qasm2.uop.U(qarg=%9, theta=%10, phi=%11, lam=%10)
  │      │ │ %12 = py.constant.constant 1 : !py.int
  │      │ │ %13 = qasm2.core.qreg.get(reg=%q, idx=%12) : !py.Qubit
  │      │ │       qasm2.uop.U(qarg=%13, theta=%10, phi=%11, lam=%10)
  │      │ │       scf.yield 
  │      } else {
  │      │ ^2(%21):
  │      │ │ %15 = py.constant.constant 2 : !py.int
  │      │ │ %16 = qasm2.core.qreg.get(reg=%q, idx=%15) : !py.Qubit
  │      │ │ %17 = py.constant.constant 3.14159265358979 : !py.float
  │      │ │ %18 = py.constant.constant 0.0 : !py.float
  │      │ │       qasm2.uop.U(qarg=%16, theta=%17, phi=%18, lam=%17)
  │      │ │ %19 = py.constant.constant 3 : !py.int
  │      │ │ %20 = qasm2.core.qreg.get(reg=%q, idx=%19) : !py.Qubit
  │      │ │       qasm2.uop.U(qarg=%20, theta=%17, phi=%18, lam=%17)
  │      │ │       scf.yield 
  │      } -> purity=False
  │      func.return %q
} // func.func main