Re: Ada for C30

[jfj (John Fountain, Jr.)]

kilgallen@eisner.decus.org (Larry Kilgallen, LJK Software) wrote:
>In article <3io711$hs5@bighorn.accessnv.com>, jfj (John Fountain, Jr.) writes:
>
>> writing phase at all.  This should prove to be interesting.
>> Overall, my intuition tells me if I could do it in C I can
>> do it in Tartan Ada with a little careful construction.
This is a refernce to CODE GENERATION AND OPTIMIZATION.
>> Probably the biggest hurdle is that C's memory allocation
>> are very easy to predict, while in Ada we are not always
>> sure of what the compiler will construct and where things
>> will be allocated from.
THIS IS A REFERENCE TO STACK USAGE.
>
>There have always been problems with people writing a Fortran
>program in some other language, such that no matter what language
>they use it comes out looking like Fortran.
Pretty rude.  Where is the reference to FORTRAN?  I like it.  Used it
for years.  Beats Pabst Blue Ribbon.
>
>If you need to know how C or Ada is going to allocate the memory,
>and depend on undocumented (and therefore non-guaranteed) compiler
>behavior, you may be in for a rude awakening with the next version
>of any language compiler from any vendor.
YES. I NEED TO KNOW.  I ALWAYS WANT TO KNOW.
I am new to Ada. I do not know if the LRM states that static objects
(static is a C'ism for never moves) in the declarative section of a
package, will be allocated off the stack when the package is
elaborated at run time.

This is what Tartan does.  Being caught off guard by this, I was just
stating that I needed to be CAREFUL as to where I assume objects
will be allocated from...
>
>If you require a particular memory layout, you should depend on
>documented features of the language.  In Ada the Representation
>Clauses are the major mechanism for accomplishing this. In some
>cases Address Clauses may also be relevant.
I am well aware of the FOR USE AT clause.  This is very useful for
those objects like UARTS, but I think it would be un-Ada to use
this to overcome stack allocations.
>
>Whatever your language, you should rely on documented (and therefore
>guaranteed) compiler features to produce particular memory usage.
I always strive to use every undocumented feature of every OS and
language I come by, as evidenced by my posting.  In fact, I have
written a letter to Mr. Bill Gates stating that I would be the premier
Windows programmer since I am so good at doing this. (Novell
has made an offer but they don't do it like Windoze does.)
>
>Larry Kilgallen
>whose representation clauses
>"just worked" when DEC released Alpha AXP :-)

Nice machine.  Try it on a DSP with local/global/cache that change
size from board to board and change wait state just to aggravate you.

pleasently insulted,

John Fountain, Jr.
jfj@accessnv.com

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