Инвертировать порядок байт

type
  TMyByte = array of byte;
 
var
  dump: TMyByte;
 
 
procedure TForm1.Button1Click(Sender: TObject);
Var
  FS: TFileStream;
begin
  if not OpenDialog1.Execute then exit;
 
  FS := TFileStream.Create(OpenDialog1.FileName, fmOpenRead or fmShareDenyNone);
  SetLength(dump, FS.Size);
  FS.Read(PChar(dump)^, Length(dump));
  FS.Free();
end;

function BSwap16(W: Word): Word; 
asm
  XCHG    AL,AH
end;

var
  dump: array of byte;
 
implementation
 
{$R *.dfm}
 
procedure ReverseWords();
begin
  for var idx:= 0 to (length(dump) div 2) - 1 do
    begin
      dump[2 * idx]:=     dump[2 * idx] xor dump[2 * idx + 1];
      dump[2 * idx + 1]:= dump[2 * idx + 1] xor dump[2 * idx];
      dump[2 * idx]:=     dump[2 * idx] xor dump[2 * idx + 1];
    end;
end;
 
procedure TForm1.Button1Click(Sender: TObject);
Var
  FS: TFileStream;
begin
  if not OpenDialog1.Execute 
    then exit;
 
  FS := TFileStream.Create(OpenDialog1.FileName, fmOpenRead or fmShareDenyNone);
    try
      SetLength(dump, FS.Size);
      FS.Read(dump[0], Length(dump));
    finally
    FS.Free();
    end;
  
  ReverseWords; 
end;

procedure ReverseWords(var dump: TBytes);

procedure ReverseWords(var dump: TBytes);