Processors who's stack grows up

In comp.arch.embedded Everett M. Greene <mojaveg@mojaveg.iwvisp.com> wrote:

> Fortran not supporting recursion is an industry myth probably a
> side-effect of early implementation techniques.  There is nothing in
> the ANSI Fortran standard which precludes a stack-oriented
> implementation thus allowing recursion.

You're missing the point, I think.  The fact that the Fortran standard
doesn't preclude a stack-based implementation allowing allow
recursion, by no means implies that Fortran "supports recursion".  To
back up a claim that Fortran (as such, rather than a particular
implementation) supported recursion, the language standard would have
to *enforce* that it's possible.  I'm quite sure it doesn't

-- 
Hans-Bernhard Broeker (broeker@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain.

On Wed, 19 Jan 2005 09:27:34 PST, mojaveg@mojaveg.iwvisp.com (Everett
M. Greene) wrote:

>Fortran not supporting recursion is an industry myth
>probably a side-effect of early implementation techniques.
>There is nothing in the ANSI Fortran standard 

That may be the case with Fortran 77 and later versions, but I was
referring to Fortran II and Fortran IV.

>which
>precludes a stack-oriented implementation thus allowing
>recursion.

If you put the local variables into a stack, it would break quite a
lot old Fortran programs (including some widely used library code)
that assume that the local variable values are maintained between
calls.

Paul
 

Paul Keinanen <keinanen@sci.fi> writes:
>mojaveg@mojaveg.iwvisp.com (Everett M. Greene) wrote:
> 
> >Fortran not supporting recursion is an industry myth
> >probably a side-effect of early implementation techniques.
> >There is nothing in the ANSI Fortran standard 
> 
> That may be the case with Fortran 77 and later versions, but I was
> referring to Fortran II and Fortran IV.
> 
> >which
> >precludes a stack-oriented implementation thus allowing
> >recursion.
> 
> If you put the local variables into a stack, it would break quite a
> lot old Fortran programs (including some widely used library code)
> that assume that the local variable values are maintained between
> calls.

I just said the standard doesn't preclude reentrancy.

Since the standard doesn't define the behavior, different
programs written for different implementations may rely on
the behavior of a particular implementation.