[Info-vax] 64-bit (was Re: New CEO of VMS Software)

[Arne Vajhøj]

On 1/9/2024 4:06 PM, John Dallman wrote:
> In article <unk7ka$24i3c$1 at dont-email.me>, seaohveh at hoffmanlabs.invalid
> (Stephen Hoffman) wrote:
> 
>> On 2024-01-06 15:30:00 +0000, John Dallman said:
>>> First, complete the 64-bit API, after all these years. It's a
>>> fairly well-defined task, but I don't know how big it is.
>> There's no way to do that without breaking source-level
>> compatibility, and probably not without also doing a migration to a
>> parallel set of 64-bit APIs.
>>
>> Basically, the image activator examines the image and decides which
>> implementation to activate within; the existing 32- and 64-bit
>> implementation, or 64-bit new.
> 
> I was presuming that the 64-bit VMS APIs would have 64-bit specific names,
> as the 64-bit versions that already do, as best I know. That would means
> there were a full set of APIs, both 32-bit and 64-bit, at OS level, in
> the same implementation.

I think that is the only safe option.

> Cross-compiled MACRO-32 code could then gradually transition between them,
> by source adaptation. Higher-level languages could offer compiler options
> for selecting APIs.
> 
> Or does this not make sense?

I suspect that all direct calls to LIB$ and SYS$ no matter if it is
Macro-32 or Fortran or C would have to be manually edited to use
new 64 bit capable version, but that the various language RTL
could switch to 64 bit capable versions transparently.

Arne