# Pastebin nCgRhWBm
always @(mb_sig)
    begin
       mb_shift_sig = mb_sig << 18;
    end
 
    always @ (op_sig_gen_new or ma_sig_m or r_sig or c_sig_gen_new or a_sig)
    begin
       case (op_sig_gen_new[1:0])
          2'b00 : a_mux = {r_sig};    // [53:0]
          2'b01 : a_mux = ma_sig_m;
          2'b10 : a_mux = {(signedr_sig & c_sig_gen_new[17]), c_sig_gen_new[17:0], a_sig};
          2'b11 : a_mux = 0;
       endcase
    end

    always @ (op_sig_gen_new or mb_sig_m or c_sig_gen_new or b_sig or mb_shift_sig)
    begin
       case (op_sig_gen_new[3:2])
          2'b00 : b_mux = mb_shift_sig;
          2'b01 : b_mux = mb_sig_m;
          2'b10 : b_mux = {(signedr_sig & c_sig_gen_new[44]), c_sig_gen_new[44:27], b_sig};
          2'b11 : b_mux = 0;
       endcase 
    end

    always @(cin_sig or signedcin_sig)
    begin
      if (signedcin_sig == 1'b1)
        begin
           cin_shift_sig[35:0] = cin_sig[53:18];
           cin_shift_sig[54:36] = { cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53],
                            cin_sig[53]};
        end
      else
        begin
           cin_shift_sig[35:0] =  cin_sig[53:18];
           cin_shift_sig[54:36] = 0;
        end
    end
 
    always @ (*)
    begin
       case (op_sig_gen_new[6:4])
          3'b000 : c_mux = 0;
          3'b001 : c_mux = cin_shift_sig;
          3'b010 : c_mux = {signedcin_sig, cin_sig};
          3'b011 : c_mux = {(c_sig_gen_new[53] & signedr_sig), c_sig_gen_new};     
          3'b100 : c_mux = {(c_sig_gen_new[17] & signedr_sig), c_sig_gen_new[17:0], a_sig};
//          3'b101 : c_mux = {r_sig[51], r_sig[51], r_sig[51:0]};
          3'b101 : c_mux = {r_sig};     // [53:0]
          3'b110 : c_mux = {1'b0, rnd_pattern};
          3'b111 : c_mux = {1'b0, rnd_pattern_m1};
       endcase
    end