Re: 64-bit integers in Ada

[dewar@gnat.com (Robert Dewar)]

Richard Riehle <richard@adaworks.com> wrote in message news:<3D46DC69.7C291297@adaworks.com>...
> Robert,
> 
> We still have quite a few embedded platforms for which 64 bit
> integers are not supported. 

There is no reason for hardware support here, even the ia32
does not have hardware support, but 64-bit integers are
very useful and must be supported, just as floating-point
MUST be supported even on processors with no floating-point.

>  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.

gcc supports 64-bit integers on virtually all processors
including 8-bit microprocessors.

> 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,

Not so much entertaining, but rather quite straightforward.

> but also  quite useless.

Not at all! If your application requires 64-bit integers,
e.g. long durations measured in nanoseconds, then you have
to have this facility, and it is far better that it be
provided by the compiler, rather than having to cook up some half
baked software multiple precision support which
is likely to be FAR less efficient, and certainly far less
convenient.

Once again, in a language which requires all implementations to
provide floating-point, it seems a trivial additional effort to
provide 64-bit integer support.

Note that if anyone bothers to port GNAT to an 8-bit microprocessor
currently supported by GCC, then the 64-bit integer support will come
for free.

> Richard Riehle