module __float64__is_nan(
  input wire [63:0] f,
  output wire out
);
  wire [10:0] f_bexp;
  wire [51:0] f_fraction;
  assign f_bexp = f[62:52];
  assign f_fraction = f[51:0];
  assign out = f_bexp == 11'h7ff & f_fraction != 52'h0_0000_0000_0000;
endmodule