cvs commit: src/sys/sys systm.h

[Colin Percival]

cperciva    2007-02-14 05:21:22 UTC

  FreeBSD src repository

  Modified files:
    sys/sys              systm.h 
  Log:
  Optimize bitcount32 by replacing 6 logical operations with 2.  The key
  observation here is that it doesn't matter what garbage accumulates in
  bits which we're going to end up masking away anyway, as long as the
  garbage doesn't overflow into bits which we care about.
  
  This improved version may not be the fastest possible on all systems,
  but it's certainly going to be better than what was here before.
  
  Revision  Changes    Path
  1.249     +3 -3      src/sys/sys/systm.h