-OoDEADSTORE takes on too much, chapter Ⅲ.

This code compiled with -O4 -OoDEADSTORE dares to drop fr := 0.

function FileSizeFractionalPart(sz: uint64): uint32;
var
	fr: uint32;
begin
	fr := 0;
	while sz > 1000 do
	begin
		fr := sz mod 1024;
		sz := sz div 1024;
	end;
	result := fr;
end;

begin
	writeln(FileSizeFractionalPart(12));
end.

Possible output:

22353340