[Info-vax] VMS internals design, was: Re: BASIC and AST routines

[Simon Clubley]

On 2021-11-29, Arne Vajhøj <arne at vajhoej.dk> wrote:
> On 11/29/2021 1:57 PM, Simon Clubley wrote:
>> On 2021-11-26, Arne Vajhøj <arne at vajhoej.dk> wrote:
>>> On 11/26/2021 2:26 PM, Simon Clubley wrote:
>>>> And the reason I thought it _must_ be Macro-32 related was because the
>>>> real reason was so crazy it never even occurred to me. :-)
>>>
>>> So anything you don't know why is by default a Macro-32 problems??
>>>
>> 
>> No. Read my detailed reply to Dan.
>> 
>> In my eyes, there must have been a reason for those registers being
>> present and only Macro-32 code could have made any use of them if
>> they were going to be used by the AST routine itself.
>
> So do something only possible in Macro-32 and not possible in C?
>
> And that is still relevant for "application programming"?
>

That was the thinking yes, before I found out the real reason.

Before that, I _was_ thinking something along the lines of maybe
being able to disturb program state directly in a way that a HLL
would not because the code generated by the HLL compiler would be
guaranteed to save and restore program state for you.

The problem was that I couldn't see what and I now know the reason why. :-)

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.