Re: Timing things.

[tmoran@bix.com (Tom Moran)]

>Windows98 PC using Gnat 3.11p
>...
>I am getting either end_time and start_time are the same or
>num_micros is 110_000
  Sounds like it's using the standard PC clock that tickes every 55
milliseconds.  You can get a different compiler, or a different OS or
machine, or make a direct OS call to QueryPerformanceCounter (sp?)
or
> start_time := ada.real_time.clock;
    for trial in 1 .. 100 loop
>do operations ( e.g. build 10_000 element heap in at least 23_000
>               comparisons)
   end loop;
>end_time := ada.real_time.clock;
>num_micros := ada.real_time."/"(ada.real_time."-"(end_time,start_time),

ada.real_time.microseconds(1))/100; ie, run the test long enough to
get multiple clock ticks, then divide the elapsed time by the number
of trials you used.