[fpc-devel] Re: Comparison FPC 2.6.2 - Kylix 3

[Graeme Geldenhuys]

On 2013-03-03 23:21, Marcos Douglas wrote:
> 
> Sad. Instead of "fight", why not walking together?

I'm not joining any "fight", simply wanted to know what the 'm' stood for.


> I do not know nothing about compilers, but I know the Florian Klämpfl
> will do nothing about you're saying because do you do not have
> proposed improvements!

You said it yourself... most of us know nothing about compiler coding.
So how are we supposed to propose improvements! All we can do is file
bug reports on things we can duplicate, or highlight issues. This is
what Martin is doing here.

4.4 seconds (Kylix under Linux) vs 89 seconds (FPC under Linux)... That
is just too a huge performance difference to justify. Yes, we all know
the argument about more platforms, maintainable code etc, but that
couldn't possible be the only reason for such a huge speed difference.
Somewhere there is a serious bottleneck(s), or the FPC team simply
disregard optimization completely. From why I have heard them say, the
latter is more likely [unfortunately].

But let me repeat what you said earlier. Some of use know nothing about
compilers coding, so not much we can do about it. The task falls
squarely on the select few, but they have no interest in that.
Optimization is boring work, compared to implementing the latest CPU
target or language feature. I understand that fully. A great pity.


> You are only showing the Delphi/Kylix speed is
> extremely superior

And Martin is just showing half the problem. The Delphi & Kylix
compilers also produce executables that run 10+ times faster than what
FPC 2.6.0 can produce. Even on the more optimized 32-bit compiler. And
don't even think of mentioning that faster hardware will mask the
problem - it doesn't. I have a i7-2660K running at 3.6Ghz with high
performance RAM and 450MB read speed SSD. I noticed a > 10+ times
difference in running executables on my hardware.

And comments from Florian like "expect FPC to get even slower by the
next release" doesn't help much.

Nobody expects FPC to beat Delphi or Kylix performance, but FPC
degrading its speed (compile time and executable run time) year-on-year
is not a good sign for the long run.


Anyway, this is nothing new. I mentioned this long ago, and made my
peace with it. I have to cherish the fact that FPC is luckily still
faster that C/C++ compilers.

Regards,
  - Graeme -

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