Re: 64-bit integers in Ada

[Robert A Duff <bobduff@shell01.TheWorld.com>]

Richard Riehle <richard@adaworks.com> writes:

> Robert A Duff wrote:
> 
> > Note that the RM does not require support for 64-bit integers
> > (unfortunately, IMHO), and there are compilers that do not support
> > 64-bit integers.
> 
> Robert,
> 
> We still have quite a few embedded platforms for which 64 bit
> integers are not supported.   We would like to be able to use
> Ada 95 for them, so a requirement for a language feature that
> is not supported would be meaningless.

All processors can easily support 64-bit arithmetic, or 640-bit
arithmetic.  It's not meaningless -- it just means that the
implementation has to provide software support.

I think I know how to design such a feature in accordance with the
"Bauer Principle", which Robert Dewar recently told us the name of.  So
if you have an 8-bit processor, maybe you don't want 64-bit integers, or
maybe you don't want 32- or even 16-bit integers, but I still think the
compiler should be required to provide them.  And more.

>...   Also, there has been
> some discussion, in the past, about support for eight-bit
> microcontrollers such as the I-8051 family.   I am sure some
> compiler developer would find it very entertaining to design
> an Ada compiler with 8051 64 bit integers, but also  quite
> useless.

Why?  What is the largest integer that a programmer might want, given
that the programmer has chosen an 8-bit processor?

Where do you draw the line?

To me 8-bit processor implies limited address space, but I don't see why
that *necessarily* implies small integers.

> Richard Riehle

- Bob