ParallelPrefixAdder constructor

Implementation

ParallelPrefixAdder(super.a, super.b,
    {super.carryIn,
    ParallelPrefix Function(List<Logic>, Logic Function(Logic, Logic)) ppGen =
        KoggeStone.new,
    super.name = 'parallel_prefix_adder'}) {
  final l = List<Logic>.generate(a.width - 1,
      (i) => [a[i + 1] & b[i + 1], a[i + 1] | b[i + 1]].swizzle());
  final cin = carryIn ?? Const(0);
  // ignore: cascade_invocations
  l.insert(
      0,
      [(a[0] & b[0]) | (a[0] & cin) | (b[0] & cin), a[0] | b[0] | cin]
          .swizzle());
  final u = ppGen(
      l, (lhs, rhs) => [rhs[1] | rhs[0] & lhs[1], rhs[0] & lhs[0]].swizzle());
  sum <=
      [
        u.val[a.width - 1][1],
        List<Logic>.generate(
            a.width,
            (i) => (i == 0)
                ? a[i] ^ b[i] ^ cin
                : a[i] ^ b[i] ^ u.val[i - 1][1]).rswizzle()
      ].swizzle();
}