But this is slower than with multiplication, as Linus explains:

  the simple shift+add version is all totally serialized
  and nothing can be done before the previous operation
  ends: as a result the three adds and three shifts will
  inevitably take 6 cycles (the original P4 had that 
  double-pumped ALU, but not for shifts). That's already
  slower than almost any multiply.

Edit: oops, I forgot your '(without multiplication)' qualifier. Yes, your way is likely the quickest without multiplication.