perl -e '@ins=( 518819.748032, 64852.468504*8 );  # less "precise" return value * 8!
for(0,1){ push @outs,unpack("b*",pack("d",$ins[$_])) }
$_ = ($outs[0] ^ $outs[1])|"0"x64; print join("\n","",@outs,$_,"")'

1000001110011000001111111011111101110001010101011111100010000010
1000001110011000001111111011111101110001010101011111100010000010
0000000000000000000000000000000000000000000000000000000000000000