[fpc-other] Re: [fpc-pascal] Speed

[Vinzent Höfler]

L wrote:

> I assumed that airplanes did not use GNU and that they used some other Ada
> compiler designed for performance and reliability.

Well, AdaCore's compiler is not exactly GNU, although basically they 
maintain the code base for a couple of years now. ;)

> I assume that airplanes
> require more performance over a desktop computer since airplanes are an embedded
> system. I could be wrong.

You are wrong indeed. As in every real-time system the main concern is 
not "lightning fast most of the time", but rather "fast enough all of 
the time".

Lockheed-Martin even uses virtual machines for the C130J flight control 
system, because that saves them from needing to recertify each runtime 
again and again. IIRC they talked about deadlines of about 25 ms which 
are proven to be easily met by the code.

> This is why I have always been interested in getting more non-GUI units out
> there for FPC so that more people would use FPC for different things like server
> programming, embedded programming. I assume something designed for an embedded
> systems such as ada would be more geared toward performance, since more people
> would be reporting compiler problems and bugs for embedded systems.. not GUI
> programs.

Well, Ada compiled code (even for the GNU one) usually performs "good 
enough". Subtract (means: turn off) all the runtime checks you get 
performance equally to that of a state of the art C compiler. If you 
want to get beyond that, you have to use handcrafted assembler code. ;)



Vinzent.