cvs commit: src/sys/libkern mcount.c

[Bruce Evans]

bde         2007-06-13 06:17:48 UTC

  FreeBSD src repository

  Modified files:
    sys/libkern          mcount.c 
  Log:
  Unbreak high resolution profiling a little: use dummy asms to prevent
  timing loops being optimized away.
  
  Once apon a time, gcc promised not to optimize away timing loops, but
  gcc started optimizing away the call to a null function in the timing
  loop here some time between gcc-3.3.3 and gcc-3.4.6, and it started
  optimizing away the timing loop itself some time between gcc-3.4.6
  and gcc-4.2.
  
  Revision  Changes    Path
  1.24      +6 -1      src/sys/libkern/mcount.c