$bitstream = "\x18\xf0\xff\x0f\x10\xaa\x55\x20\xde\xad\xbe\xef";;

( $f1, $f2, $f3 ) = map unpack( 'L', pack( 'b32', $_ )), unpack 'C/b C/b C/b', $bitstream;;

print for $f1, $f2, $f3;;
1048560
21930
4022250974