Re: Ada Compilers

["Marin David Condic" <dont.bother.mcondic.auntie.spam@[acm.org>]

Well, from a purely *practical* standpoint (realizing that we are talking
about existing implementations rather than either the language or any
particular compiler) we might say this: Most popular Ada implementations are
generating code that is pretty efficient in comparison to most other
compiled languages. You won't discover that your basic workstation/PC
application programmed in Ada is somehow bog-slow in comparison to the same
thing in some other language typically used for the same application.

Now a few caveats: If you truly have a time-critical application, you'd best
conduct a timing study with algorithms typical of the application at hand.
Compilers (even for the same language) can have a good deal of variance in
terms of the code they generate for different operations. Be sure that when
timing any Ada code, that you either *really* know what you're doing or that
you are working with the vendor to get the best possible optimization. (Its
easy to compile with all runtime checking in place and/or by using
constructs unwisely and discovering you have pretty slow code. Quite often
throwing a few compiler switches, or including a few pragmas or otherwise
tweaking things a bit, you get really nice code. But you need to know...)

There are some Ada implementations for some targets that are extremely
highly optimizing and will do a wonderful job of producing highly efficient
code. Remember that Ada was originally invented for embedded, real time
apps, so it is possible to find very efficient compilers. However, that
isn't saying there are highly efficient compilers for all platforms and
targets. It also isn't saying that they will be efficient for the algorithms
you intend to use. Compiler timing studies are *very* complex to get right.
(I've been through a couple of serious ones) But its the only way to get any
truly useful information.

MDC
--
Marin David Condic
Senior Software Engineer
Pace Micro Technology Americas    www.pacemicro.com
Enabling the digital revolution
e-Mail:    marin.condic@pacemicro.com


"David Rasmussen" <david.rasmussen@gmx.spam.egg.sausage.and.spam.net> wrote
in message news:3CE58053.2020809@gmx.spam.egg.sausage.and.spam.net...
>
> I know that, of course. My question was of a more pragmatic nature. Most
> languages (ML, Lisp, Java etc.) could have compilers that created as
> good code on a given platform (say x86), as the best C compilers for the
> same platform. But in real life, this is not at all the case. So my
> question was if, in practice, most Ada compilers generate code that is
> comparable to, say, C++ compilers. The question makes a lot of pragmatic
> sense.
>