Re: Concertlina II: Full Circle

On Tue, 18 Jun 2024 19:40:48 -0000 (UTC), Thomas Koenig
<tkoenig@netcologne.de> wrote:

John Savard <quadibloc@servername.invalid> schrieb:

On Tue, 18 Jun 2024 16:17:33 -0000 (UTC), Thomas Koenig
<tkoenig@netcologne.de> wrote:

John Savard <quadibloc@servername.invalid> schrieb:

>

Also, this looping instruction is strictly a way to directly encode
the FORTRAN DO loop. It does not attempt any vectorization.

>

Which one, the FORTRAN 66 one or the one since FORTRAN 77?

>

FORTRAN IV (or 66) indeed.

>
It was actually not defined in the standard, in practice it
was usually implemented by a test at the bottom of the loop,
and programs depended on that.
>
FORTRAN 77 fixed that, so now
>
DO 100 I=1,0
>
...
 100   CONTINUE
>
is executed zero times.

Ah. I can't include that fix now, as I've changed things so that one
of the parameters is at the end of the loop, so the instruction that
heads the loop doesn't know if the "step" parameter is negative or
not.

The change has not yet been posted.

I thought you were asking about whether I included stuff like DO
WHILE. That would have to be done using old-fashioned conditional
branch instructions.

John Savard