> And if you want portable pre-processing or code generation, use
> something that generates the code rather than inventing tools and
> features that don't exist, nor will ever exist. It is also quite common
> to use scripts in languages like perl or python to generate tables and
> other pre-calculated values for inclusion in C code.
though there are things that i will not disclose, i've never had to invent any
tools for the project i'm working on.... everything is legit. this is the only
time that i've had to. so believe me if i said i've considered all
*conventional* solutions
> Most modern compilers will do a pretty reasonable job of constant
> propagation and calculating expressions using constant values. And most
> will apply "inline" as you would expect, unless you intentionally hamper
> the compiler by not enabling optimisations. Using macros, incidentally,
> does not "FORCE" the compiler to do anything - I know at least one
> compiler that will take common sections of code (from macros or "normal"
> text) and refactor it artificial functions, expending stack space and
> run time speed to reduce code size. And "immediate addressing" is not
> necessarily a good optimisation - beware making generalisations like
> that. Let the compiler do what it is good at doing - generating optimal
> code for the target in question - and don't try to second-guess it. You
> will end up with bigger and slower code.
i'm not one to share techniques/methodologies, 1) but if it's the case for more
than, say 70%, of systems/processors and 2) it takes very little penalty;
then i'd write it that way. if it's not optimized, just let the compiler (if
it's as good as you say it is) re-optimize it. if the compiler ain't good
enough to do that, well it's not a good compiler anyway. but the code will
still work.
> I really don't want to discourage someone from wanting to contribute to
> gcc development, but this is very much a dead-end idea. I applaud your
> enthusiasm, but keep a check on reality - you are an amateur just
> starting C programming. C has been used for the last forty years - with
> gcc coming up for its 25th birthday this spring. If this idea were that
> simple, and that good, it would already be implemented. As you gain
> experience and knowledge with C (and possibly C++), you will quickly
> find that a preprocessor like you describe is neither necessary nor
> desirable.
you know there's no way i can't answer that without invoking the wrath of the
community.
