Re: -warmup

[Werner LEMBERG]

>> To summarize: Benchmark comparisons only work if there is a sound
>> mathematical foundation to reduce the noise.
> 
> I am probably not qualified, but I am following the discussion for
> some time.  And I think there is a problem with the benchmarking
> itself.  If I understand correctly the nice tables show the same
> code on the same machine so 40% difference or so is not ok.
> 
> I had a quick look at ftbench.c and I have the impression that the
> timer ist using by clock_gettime for every single iteration twice.
> I had expected to do N iterations with a single clock_gettime before
> and after N iterations.  If the benchmarked code is short this will
> accumulate errors that cannot be removed afterwards.  But I may be
> wrong...

Alexei?


    Werner