[Info-vax] VAX VMS going forward

[Arne Vajhøj]

On 7/28/2020 8:51 AM, Simon Clubley wrote:
> On 2020-07-28, Arne Vajhøj <arne at vajhoej.dk> wrote:
>> On 7/28/2020 8:31 AM, Simon Clubley wrote:
>>>
>>> Only on VMS. This is (mostly) not a significant problem on other
>>> operating systems because the vast majority of the work is done for
>>> you by the compiler and linker in those environments after you tell
>>> the compiler whether you want your code to run with 32-bit or 64-bit
>>> addresses and other features.
>>
>> ????
>>
>> On what other platform is it common to pass 64 bit addresses
>> as 32 bit bit values with implicit values for the remaining bits?
> 
> As you should well know, you simply don't have to worry about this
> in those environments. My answer above should have been enough for
> you to understand the point I was making.
> 
> You tell the compiler whether you want a 32-bit or 64-bit executable
> and it, the linker, and OS support libraries takes care of most of
> the work for you (if not all the work).
> 
> I wish it was that simple on VMS.

Other environments are not doing this at all.

Many other environments has 32 bit mode and 64 bit mode. Different
instruction sets and address size in the CPU. Two sets of
libraries. Etc..

But that is completely different from what VMS has.

VMS Alpha/Itanium only has 64 bit mode and 64 bit addresses in the
CPU, single instruction set and one set of libraries. That single set
of libraries just have a lot of API's only passing lower half of
addresses and a few passing full addresses.

Totally apples and oranges.

Arne