module opt_compact_prefix_pack64 (
  input  logic [63:0] sig,
  output logic [63:0] sig2
);
  always_comb begin
    sig2 = '0;
    for (int I = 0, indx = 0; I < 64; I++) begin
      if (sig[I]) begin
        sig2[indx] = sig[I];
        indx += 1;
      end
    end
  end
endmodule

module opt_compact_prefix_pack128 (
  input  logic [127:0] sig,
  output logic [127:0] sig2
);
  always_comb begin
    sig2 = '0;
    for (int I = 0, indx = 0; I < 128; I++) begin
      if (sig[I]) begin
        sig2[indx] = sig[I];
        indx += 1;
      end
    end
  end
endmodule