LiftContext::lift_op responsible for ~25% of the generated llvm ir

[bjorn3]

$ cargo llvm-lines -p rspirv
  Lines          Copies       Function name
  -----          ------       -------------
  434621 (100%)  6861 (100%)  (TOTAL)
  113962 (26.2%)    1 (0.0%)  rspirv::lift::LiftContext::lift_op

I wonder if it would be possible to have all operand matches of all instructions with the same "function signature" be grouped together. Something like:

145u32 | 146u32 => {
    let id1 = (match operands.next() {
        Some(&dr::Operand::IdRef(ref value)) => Some(*value),
        Some(_) => return Err(OperandError::WrongType.into()),
        None => None,
    }).ok_or(OperandError::Missing)?;
    let id2 = (match operands.next() {
        Some(&dr::Operand::IdRef(ref value)) => Some(*value),
        Some(_) => return Err(OperandError::WrongType.into()),
        None => None,
    })
    .ok_or(OperandError::Missing)?;
    match raw.class.opcode as u32 {
        145u32 => ops::Op::MatrixTimesVector { matrix: id1, vector: id2 },
        146u32 => ops::Op::MatrixTimesMatrix { left_matrix: id1, right_matrix: id2 },
        _ => unreachable!(),
    }
}

instead of

145u32 => Ok(ops::Op::MatrixTimesVector {
    matrix: (match operands.next() {
        Some(&dr::Operand::IdRef(ref value)) => Some(*value),
        Some(_) => return Err(OperandError::WrongType.into()),
        None => None,
    })
    .ok_or(OperandError::Missing)?,
    vector: (match operands.next() {
        Some(&dr::Operand::IdRef(ref value)) => Some(*value),
        Some(_) => return Err(OperandError::WrongType.into()),
        None => None,
    })
    .ok_or(OperandError::Missing)?,
}),
146u32 => Ok(ops::Op::MatrixTimesMatrix {
    left_matrix: (match operands.next() {
        Some(&dr::Operand::IdRef(ref value)) => Some(*value),
        Some(_) => return Err(OperandError::WrongType.into()),
        None => None,
    })
    .ok_or(OperandError::Missing)?,
        right_matrix: (match operands.next() {
        Some(&dr::Operand::IdRef(ref value)) => Some(*value),
        Some(_) => return Err(OperandError::WrongType.into()),
        None => None,
    })
    .ok_or(OperandError::Missing)?,
}),